U.S. patent application number 16/749241 was filed with the patent office on 2020-07-30 for pcv2 orf2 carrier platform.
The applicant listed for this patent is Boehringer Ingelheim Animal Health USA Inc.. Invention is credited to Luis Alejandro HERNANDEZ, Eric Martin VAUGHN.
Application Number | 20200237894 16/749241 |
Document ID | 20200237894 / US20200237894 |
Family ID | 1000004765399 |
Filed Date | 2020-07-30 |
Patent Application | download [pdf] |
![](/patent/app/20200237894/US20200237894A1-20200730-D00000.png)
![](/patent/app/20200237894/US20200237894A1-20200730-D00001.png)
![](/patent/app/20200237894/US20200237894A1-20200730-D00002.png)
![](/patent/app/20200237894/US20200237894A1-20200730-D00003.png)
![](/patent/app/20200237894/US20200237894A1-20200730-D00004.png)
United States Patent
Application |
20200237894 |
Kind Code |
A1 |
HERNANDEZ; Luis Alejandro ;
et al. |
July 30, 2020 |
PCV2 ORF2 CARRIER PLATFORM
Abstract
The present invention relates to an immunogen-carrier, wherein
the immunogen-carrier is preferably a virus-like particle (VLP)
composed of a plurality of a modified PCV2 ORF2 protein. In
particular, the present invention belongs to the field of
compliance markers and marker vaccines which allow for the
differentiation between infected and vaccinated individuals. In
particular, it relates to a compliance marker for vaccines
including a subunit antigen, and a DIVA (Differentiating Infected
from Vaccinated Animals) system which makes it possible to
differentiate between animals infected with a pathogen and animals
treated with a subunit antigen derived from said pathogen.
Inventors: |
HERNANDEZ; Luis Alejandro;
(Story City, IA) ; VAUGHN; Eric Martin; (Ames,
IA) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Boehringer Ingelheim Animal Health USA Inc. |
Duluth |
GA |
US |
|
|
Family ID: |
1000004765399 |
Appl. No.: |
16/749241 |
Filed: |
January 22, 2020 |
Related U.S. Patent Documents
|
|
|
|
|
|
Application
Number |
Filing Date |
Patent Number |
|
|
15562167 |
Sep 27, 2017 |
10555994 |
|
|
PCT/US2016/024631 |
Mar 29, 2016 |
|
|
|
16749241 |
|
|
|
|
62140284 |
Mar 30, 2015 |
|
|
|
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
C12N 2770/10034
20130101; C12N 2799/026 20130101; A61K 2039/5258 20130101; C12N
2750/10022 20130101; C07K 1/14 20130101; C07K 14/005 20130101; C07K
2319/40 20130101; C12N 2750/10034 20130101; G01N 33/5308 20130101;
A61P 31/20 20180101; A61K 2039/552 20130101; C12N 15/62 20130101;
A61K 2039/6075 20130101; C12N 2770/10022 20130101; G01N 33/566
20130101; C12N 2750/10023 20130101; A61K 39/12 20130101 |
International
Class: |
A61K 39/12 20060101
A61K039/12; C07K 14/005 20060101 C07K014/005; A61P 31/20 20060101
A61P031/20; C07K 1/14 20060101 C07K001/14; C12N 15/62 20060101
C12N015/62; G01N 33/53 20060101 G01N033/53; G01N 33/566 20060101
G01N033/566 |
Claims
1. A polypeptide selected from the group consisting of the
following (a), (b), and (c): a. a PCV2 ORF2 protein characterized
in that at least one amino acid residue in the BC loop is replaced
by an amino acid sequence of interest; b. a PCV2 ORF2 protein
characterized in that an amino acid sequence of interest is
inserted into the BC loop; c. a combination of (a) and (b).
2. The polypeptide of claim 1, wherein the BC loop is the region of
the amino acid positions 58 to 66, and wherein the numbering of the
amino acid positions refers to the amino acid sequence of wild type
PCV2 ORF2 protein.
3. The polypeptide of claim 1, wherein the amino acid sequence of
interest is an amino acid sequence comprising or consisting of at
least two amino acid residues or preferably of at least eight amino
acid residues.
4. The polypeptide of claim 1, wherein the amino acid sequence of
interest comprises or consists of a heterologous amino acid
sequence.
5. The polypeptide of claim 1, wherein the amino acid sequence of
interest is selected from the group consisting of an epitope of
interest, a biological response modulator, a growth factor, a
recognition sequence, a fusion protein, and wherein the epitope of
interest is preferably an epitope of interest from an antigen or a
veterinary pathogen or toxin and wherein the epitope of interest is
a peptide encoded by the orf5 gene of PRRS virus and wherein the
peptide encoded by the orf5 gene of PRRS virus preferably comprises
or consists of the amino acid sequence of SEQ ID NO:6 or preferably
comprises or consists of at least 8 consecutive amino acid residues
of the sequence set forth in SEQ ID NO: 6.
6. The polypeptide of claim 1, wherein the amino acid sequence of
interest comprises or consists of an epitope of interest, and
wherein the epitope of interest is preferably an amino acid
sequence comprising or consisting of 8 to 25 amino acid
residues.
7. The polypeptide of claim 1, wherein in (a) at least one amino
acid residue in the region of the amino acid positions 58 to 64 is
replaced by an amino acid sequence of interest, and wherein the
numbering of the amino acid positions refers to the amino acid
sequence of wild type PCV2 ORF2 protein.
8. The polypeptide of claim 1, wherein in (a) at least two amino
acid residues in the BC loop are replaced by an amino acid sequence
of interest.
9. The polypeptide of claim 1, wherein in (a) two, three, four,
five, six, or seven amino acid residues in the BC loop are replaced
by an amino acid sequence of interest.
10. The polypeptide of claim 1, wherein in (a) the six amino acid
residues of the amino acid positions 58 to 63 are replaced by an
amino acid sequence of interest, wherein the numbering of the amino
acid positions refers to the amino acid sequence of wild type PCV2
ORF2 protein; and/or the amino acid sequence of interest comprises
or consists of an amino acid sequence consisting of 11 amino acid
residues, and/or the amino acid sequence of interest comprises or
consists of the sequence of SEQ ID NO:5 or SEQ ID NO:7.
11. The polypeptide of claim 1, wherein said polypeptide is a
recombinant protein, preferably a recombinant baculovirus expressed
protein.
12. The polypeptide of claim 1, wherein said PCV2 ORF2 protein is a
PCV2 subtype b (PCV2b) ORF2 protein or a PCV2 subtype a (PCV2a)
ORF2 protein and/or wherein said PCV2 ORF2 protein comprises or
consists of an amino acid sequence having at least 90% sequence
identity with the amino acid sequence of SEQ ID NO:2 or SEQ ID
NO:3.
13. The polypeptide of claim 1, wherein said polypeptide comprises
or consists of an amino acid sequence having at least 90% sequence
identity with the amino acid sequence of SEQ ID NO: 1.
14. The polypeptide claim 2, wherein said wild type PCV2 ORF2
protein is the protein set forth in SEQ ID NO:2 or SEQ ID NO:3.
15. An immunogenic composition containing the polypeptide of claim
1.
16. A polynucleotide comprising a sequence which encodes the
polypeptide of claim 1.
17. A plasmid, preferably an expression vector, which comprises a
polynucleotide comprising a sequence which encodes the polypeptide
of claim 1.
18. A cell comprising a plasmid, preferably an expression vector,
which comprises a polynucleotide comprising a sequence which
encodes the polypeptide of claim 1.
19. A virus like particle composed of a plurality of the
polypeptide of claim 1.
20. A baculovirus containing a polynucleotide comprising a sequence
which encodes the polypeptide of any one of claims 1 to 14.
21. A cell, preferably an insect cell, comprising a baculovirus
which contains a polynucleotide comprising a sequence which encodes
the polypeptide of any one of claims 1 to 14.
22. Use of: the polypeptide of any one of claims 1 to 14, the
immunogenic composition of claim 15, the polynucleotide of claim
16, the virus like particle of claim 19, the baculovirus of claim
20, the plasmid of claim 17, and/or the cell of claim 18 or 21 for
the preparation of a medicament, preferably of a vaccine.
23. The polypeptide of any one of claims 1 to 14 or immunogenic
composition of claim 15 for use in a method for the treatment or
prevention of an infection with PCV2, the reduction, prevention or
treatment of clinical signs caused by an infection with PCV2, or
the prevention or treatment of a disease caused by an infection
with PCV2.
24. The polypeptide of any one of claims 1 to 14 or immunogenic
composition of claim 15 for use according to claim 23, wherein the
infection with PCV2 is an infection with PCV2 subtype b (PCV2b)
and/or with PCV2 of a subtype other than subtype 2b.
25. The polypeptide of any one of claims 1 to 20 or immunogenic
composition of claim 15 for use according to claim 23 or 24,
wherein the infection with PCV2 is an infection with PCV2 of a
subtype other than subtype 2b.
26. The polypeptide of any one of claims 1 to 14 or immunogenic
composition of claim 15 for use according to claim 24, wherein the
infection with PCV2 is a concurrent infection with (i) PCV2b and
(ii) PCV2 of a subtype other than subtype 2b.
27. The polypeptide of any one of claims 1 to 14 or immunogenic
composition of claim 15 for use according to any one of claims 24
to 26, wherein the infection with PCV2 of a subtype other than
subtype 2b is an infection with PCV2 subtype a (PCV2a) and/or PCV2
subtype c (PCV2c).
28. The polypeptide of any one of claims 1 to 14 or immunogenic
composition of claim 15 for use according to any one of claims 24
to 27, wherein the infection with PCV2 of a subtype other than
subtype 2b is an infection with PCV2a.
29. The polypeptide of any one of claims 1 to 14 or immunogenic
composition of claim 15 for use according to any one of claims 23
to 28, wherein the infection with PCV2 is a concurrent infection
with (i) PCV2b and (ii) PCV2a.
30. The polypeptide of any one of claims 1 to 14 or immunogenic
composition of claim 15 for use according to any one of claims 23
to 29, wherein said infection with PCV2b is an infection with a
PCV2 comprising a polypeptide that is at least 94% or preferably at
least 95% identical to the sequence of SEQ ID NO:2 or comprising a
polynucleotide which comprises a sequence encoding a polypeptide
that is at least 94% or preferably at least 95% identical to the
sequence of SEQ ID NO:2.
31. The polypeptide of any one of claims 1 to 14 or immunogenic
composition of claim 15 for use according to any one of claims 23
to 30, wherein said infection with PCV2a is an infection with a
PCV2 comprising a polypeptide that is at least 94% or preferably at
least 95% identical to the sequence of SEQ ID NO:3 or comprising a
polynucleotide which comprises a sequence encoding a polypeptide
that is at least 94% or preferably at least 95% identical to the
sequence of SEQ ID NO:3.
32. The polypeptide of any one of claims 1 to 14 or immunogenic
composition of claim 15 for use according to any one of claims 23
to 31, wherein the treatment or prevention of an infection with
PCV2 is based on or comprises or consists of the induction of an
immune response against said PCV2, said clinical signs are selected
from the group consisting of lymphoid depletion, lymphoid
inflammation, positive IHC for PCV2 antigen of lymphoid tissue,
viremia, nasal shedding, pyrexia, reduced average daily weight
gain, lung inflammation, positive IHC for PCV2 antigen of lung
tissue, or said disease is PMWS.
33. The polypeptide of any one of claims 1 to 14 or immunogenic
composition of claim 15 for use according to 24 to 32, wherein the
treatment or prevention of an infection with PCV2 of a subtype
other than 2b is based on or comprises or consists of the induction
of an immune response against said PCV2 of a subtype other than 2b
or the concurrent induction of an immune response against said PCV2
of a subtype other than 2b and PCV2b.
34. A method for the treatment or prevention of an infection with
PCV2, the reduction, prevention or treatment of clinical signs
caused by an infection with PCV2, or the prevention or treatment of
a disease caused by an infection with PCV2, comprising
administering the polypeptide of any one of claims 1 to 14 or the
immunogenic composition of claim 15 to an animal, wherein said
infection with PCV2 is preferably the infection with PCV2 according
to any one of claims 24 to 32.
35. Use of the polypeptide of any one of claims 1 to 14 or the
immunogenic composition of claim 15 for the preparation of a
medicament for the treatment or prevention of an infection with
PCV2, the reduction, prevention or treatment of clinical signs
caused by an infection with PCV2 or for the treatment or prevention
of a disease caused by an infection with PCV2, wherein said
infection with PCV2 is preferably the infection with PCV2 according
to any one of claims 24 to 32.
36. The method of claim 34 or the use of claim 35, wherein the
treatment or prevention of an infection with PCV2 is based on or
comprises or consists of the induction of an immune response
against said PCV2, or wherein the prevention, reduction or
treatment of an infection with PCV2 of a subtype other than subtype
2a is based on or comprises or consists of the induction of an
immune response against said PCV2 of a subtype other than subtype
2a or the concurrent induction of an immune response against said
PCV2 of a subtype other than subtype a and PCV2a, said clinical
signs are selected from the group consisting of lymphoid depletion,
lymphoid inflammation, positive IHC for PCV2 antigen of lymphoid
tissue, viremia, nasal shedding, pyrexia, reduced average daily
weight gain, lung inflammation positive IHC for PCV2 antigen of
lung tissue, or said disease is PMWS.
37. The polypeptide of any one of claims 1 to 14 or immunogenic
composition of claim 15 for use according to any one of claims 23
to 33, or the method of claim 34 or 36, or the use according to
claim 35 or 36, wherein said polypeptide or said immunogenic
composition is administered only once.
38. A method of producing the polypeptide of any one of claims 1 to
14, comprising transfecting a cell with the plasmid of claim
27.
39. A method of producing the polypeptide of any one of claims 1 to
14, comprising infecting a cell, preferably an insect cell, with
the baculovirus of claim 20.
40. A method of determining whether an individual has received an
immunogenic composition containing the polypeptide of any one
claims 1 to 14, wherein said method comprises determining in a
biological sample obtained from said individual the presence or
absence of one or more markers showing that the individual has
received said amino acid sequence of interest, and wherein the
presence of said one or more markers in said biological sample
indicates that said individual has received said immunogenic
composition.
41. The method of claim 40, wherein said one or more markers
showing that the individual has received the amino acid sequence of
interest are antibodies specific for said amino acid sequence of
interest.
42. The method of claim 40 or 41, comprising the steps of:
contacting the biological sample with a capture reagent immobilized
to a solid support, wherein the immobilized capture reagent is
capable of binding said one or more markers, and determining the
presence or absence of said one or more markers bound to the
capture reagent, wherein the presence of said one or more markers
bound to the capture reagent is indicative for the presence of said
one or more markers in said biological sample.
43. The method of any one of claims 40 to 42, wherein said method
comprises determining in said biological sample the presence or
absence of said one or more markers, wherein said markers are
antibodies specific for said amino acid sequence of interest, and
wherein said method comprises the steps of: a. contacting the
biological sample with a capture reagent immobilized to a solid
support, wherein the capture reagent is selected from the group
consisting of: i. a protein comprising the amino acid sequence of
interest, ii. a peptide comprising or consisting of the amino acid
sequence of interest; b. separating the biological sample from the
immobilized capture reagent; c. contacting the immobilized capture
reagent-antibody complex with a detectable agent that binds to the
antibody of the reagent-antibody complex; and d. measuring the
level of antibody bound to the capture reagent using a detection
means for the detectable agent.
44. The method of claim 43, wherein the measuring step (D) further
comprises a comparison with a standard curve to determine the level
of antibody bound to the capture reagent
45. The method of claim 43 or 44, wherein said detectable agent
that binds to the antibody of the reagent-antibody complex is a
detectable antibody, preferably a labelled secondary antibody
46. The method of any one of claims 40 to 45 further comprising the
step of determining in said biological sample the presence of one
or more analytes selected from the group consisting of antibodies
specific for a polypeptide comprising or consisting of an amino
acid sequence having at least 90% sequence identity with the amino
acid sequence of SEQ ID NO:2 or SEQ ID NO:3.
47. The method of any one of claims 40 to 46, wherein the
individual is a pig or a rabbit.
48. The method of any one of claims 40 to 47, wherein the
biological sample has been isolated from a pig.
49. The method of any one of claims 40 to 48, wherein the
biological sample is selected from the group consisting of whole
blood, blood plasma, serum, urine, and oral fluids.
50. The method of any one of claims 40 to 49, wherein the
immobilized capture reagent is coated on a microtiter plate.
51. A kit for determining whether an individual has received an
immunogenic composition containing the polypeptide of claim 1,
wherein said kit contains one or more capture reagents immobilized
to a solid support, wherein the one or more immobilized capture
reagents are capable of binding antibodies specific for said amino
acid sequence of interest.
52. The kit of claim 51, wherein the capture reagent is selected
from the group consisting of: i. a protein comprising the amino
acid sequence of interest; and ii. a peptide comprising or
consisting of the amino acid sequence of interest.
Description
SEQUENCE LISTING
[0001] This application contains a sequence listing in accordance
with 37 C.F.R. 1.821-1.825. The sequence listing accompanying this
application is hereby incorporated by reference in its
entirety.
BACKGROUND OF THE INVENTION
Technical Field
[0002] The present invention relates to an immunogen-carrier,
wherein the immunogen-carrier is preferably a virus-like particle
(VLP) composed of a plurality of a modified PCV2 ORF2 protein. In
particular, the present invention belongs to the field of
compliance markers and marker vaccines which allow for the
differentiation between infected and vaccinated individuals. In
particular, it relates to a compliance marker for vaccines
including a subunit antigen, and a DIVA (Differentiating Infected
from Vaccinated Animals) system which makes it possible to
differentiate between animals infected with a pathogen and animals
treated with a subunit antigen derived from said pathogen.
Background Information
[0003] Porcine circovirus type 2 (PCV2) is a small (17-22 nm in
diameter), icosahedral, non-enveloped DNA virus, which contains a
single-stranded circular genome. PCV2 shares approximately 80%
sequence identity with porcine circovirus type 1 (PCV-1). However,
in contrast with PCV1, which is generally non-virulent, swine
infected with PCV2 exhibit a syndrome commonly referred to as
Post-weaning Multisystemic Wasting Syndrome (PMWS). PMWS is
clinically characterized by wasting, paleness of the skin,
unthriftiness, respiratory distress, diarrhea, icterus, and
jaundice. In some affected swine, a combination of all signs will
be apparent while other swine will only have one or two of these
clinical signs. During necropsy, microscopic and macroscopic
lesions also appear on multiple tissues and organs, with lymphoid
organs being the most common site for lesions. A strong correlation
has been observed between the amount of PCV2 nucleic acid or
antigen and the severity of microscopic lymphoid lesions. Mortality
rates for swine infected with PCV2 can approach 80%. In addition to
PMWS, PCV2 has been associated with several other infections
including pseudorabies, porcine reproductive and respiratory
syndrome (PRRS), Glasser's disease, streptococcal meningitis,
salmonellosis, postweaning colibacillosis, dietetic hepatosis, and
suppurative bronchopneumonia.
[0004] Currently, there are three subtypes of PCV2 known (PCV2a,
PCV2b and PCV2c), which are classified according to a unified
nomenclature for PCV2 genotypes (Segales, J. et al., 2008, PCV-2
genotype definition and nomenclature, Vet Rec 162:867-8). Two
further subtypes (PCV2d and PCV2e) have been proposed (Wang et al.,
Virus Res. 2009 145(1):151-6) but, however, it was demonstrated
later that they belong to the PCV2a and PCV2b clusters (Cortey et
al., Vet Microbiol. 2011 149(3-4):522-32011). According to this
unified nomenclature for PCV2 genotypes the orf2 gene is used to
perform genotyping for pcv-2, wherein the genotyping is based on
the proportion of nucleotide sites at which two sequences being
compared are different (p distance). This value is obtained by
dividing the number of nucleotide differences by the total number
of nucleotides compared (Kumar et al, 2001 Bioinformatics 17,
1244-1245) and subsequently, the construction of a p
distance/frequency histogram enables to determine potential cut-off
values to distinguish different genotypes (Rogers and Harpending,
1992 Molecular Biology and Evolution 9, 552-569; Biagini et al.,
1999 Journal of General Virology 80, 419-424). Using this
methodology, ORF2 PCV-2 sequences are assigned to different
genotypes when the genetic distance between them is 0035.
[0005] WO2011116094 A2 discloses a chimeric porcine circovirus
infectious DNA clone and live attenuated chimeric virus with the
PCV2 of subtype PCV2b, and a capsid gene of subtype PCV2b
integrated into a non-pathogenic PCV1 virus genome, wherein the
attenuated chimeric virus can be used as a live vaccine, as well as
an inactivated (killed) vaccine.
[0006] Vaccination is an essential tool to manage herd health, in
particular in high density confinement settings where many food
animals are raised. When disease outbreaks occur in animals that
were supposedly vaccinated, questions arise as to whether the
vaccine failed to protect the animals or whether the vaccine was
delivered properly, wherein the latter possibility regarding proper
delivery of the vaccine is referred to as vaccine compliance.
[0007] The use of compliance markers for determining if an animal
has been properly vaccinated is thus highly desired by producers.
WO 2009/058835 A1 describes e.g. the use of purified xylanase which
was added as a compliance marker to a swine influenza vaccine.
[0008] Vaccines used in programs for controlling viral outbreaks
and infections must have an effective system to monitor for
continued presence of viral infection within the population.
However, vaccination complicates large scale surveillance for the
spread of the infection by e.g. serological means, as both
vaccinated and exposed individuals produce antibody specific for
the virus. The antigenic similarity between the infecting virulent
field strain of the virus and the viral vaccine frequently hampers
the discrimination between infected and vaccinated subjects as
vaccination results in the occurrence and persistence of antibodies
that are indistinguishable between infected and vaccinated
individuals.
[0009] There is increasing worldwide interest in DIVA
(differentiating infected and vaccinated animals) vaccination
strategies. For example, the joint WHO/FAO/OIE meetings on avian
influenza strain H5N1 HPAI have recommended that all vaccination is
practiced using a DIVA, so spread of infection can be monitored.
However, current DIVA methods are difficult to scale-up and often
have problems with the differentiation of vaccination from
infection with other circulating viral strains.
[0010] Current methods of monitoring include physical tagging of
vaccinated animals, the use of sentinel animals, and virological
testing. However, these current methods have a number of
limitations due to logistical and economic reasons.
[0011] The physical tagging of vaccinated animals involves the time
consuming individual identification of vaccinated individuals by
physical means such as ear tags, leg bands or wing tags. Also, the
use of unvaccinated sentinel animals is logistically and
economically difficult and there is also a risk that if sentinels
become infected with the virus, e.g. poultry infected with H5N1
virus, there is increased risk of spread to humans. Virological
testing of individuals via screening and detection of live virus or
RT-PCR surveillance testing is a very expensive and infrastructure
heavy process, which is not applicable for subunit vaccines, and
only provides information relating to the current status of an
individual, and does not allow analysis of the infection and/or
vaccination history of that individual.
[0012] In view of said limitations, the use of marker vaccines
allowing a serological discrimination of vaccinated and infected
animals is highly preferable, wherein such marker vaccines can be
prepared either as negative or positive marker vaccine.
[0013] A negative marker vaccine is prepared by using an antigenic
portion of the pathogen or by the removal of an antigen from the
pathogen, which provokes specific antibodies in infected animals.
Negative marker vaccines are usually either subunit vaccines or
attenuated live vaccines containing a genetically engineered strain
lacking an immunogenic antigen. An example for a negative marker
vaccine is e.g., the use of baculovirus-expressed classical swine
fever virus (CSFV) E2 protein as a subunit antigen for vaccinating
against classical swine fever, wherein a detection of antibodies
specific for other antigens of CSFV, e.g., E.sup.RNs protein or NS3
protein, in sera of vaccinated pigs shows a CSFV infection.
[0014] A positive marker vaccine contains an additional antigen
which induces specific antibodies in vaccinated individuals but not
in infected ones. An example for a positive marker vaccine approach
is described in WO 2007/053899 A1, where inactivated H6N2 Avian
Influenza (Al) virus and tetanus toxin, both of which separately
produced, were combined in one injection for vaccinating birds, and
subsequently antibodies specific for tetanus toxin were detected in
sera obtained from said birds as markers showing that the birds
were vaccinated.
[0015] However, the separate production of both the vaccine antigen
and the marker antigen is relatively expensive.
[0016] In view of the above, a simple carrier system is needed
useful as platform for inexpensively producing positive marker
vaccines and effective compliance markers and, additionally,
allowing a strong immunization of animals against PCV2 and, as the
case may be, at least one further pathogen.
BRIEF DESCRIPTION OF THE DRAWINGS
[0017] The following drawings form part of the present
specification and are included to further demonstrate certain
aspects of the present invention. The invention may be better
understood by reference to one or more of these drawings in
combination with the detailed description of specific embodiments
presented herein
[0018] FIG. 1. PCV2b ORF2-c-myc bands were detected in stained
protein gels by size comparison to PCV2b ORF2. Lane 1, Baculo/PCV2b
ORF2 c-myc pellet; Lane 2: Purified PCV2b ORF2 VLPS; Lane 3:
Baculo/pVL1393 No Insert Control. A. Comassie blue stained western
blot; B. anti-PCV2B Swine poly-clonal antibody stained western
blot; C. anti-c-myc monoclonal antibody 9E10 stained western blot,
D. anti-c-myc monoclonal antibody 9E101 stained western blot; E.
anti-c-myc polyclonal rabbit antibody stained western blot; PCV2b
ORF2-c-myc was detected by both anti-PCV2b antibody and anti-c-myc
antibody while PCV2b ORF2 antigen was detected only by PCV2b
antibody.
[0019] FIG. 2. Harvests of BaculoG/PCV2b ORF2 c-myc were
centrifuged at 100,000 g for two hours at 4.degree. C. to pellet
the VLPs. Resuspended pellets were separated on a 10%-60%
discontinuous sucrose gradient by centrifugation at 100,000 g for
two hours at 4.degree. C. to partially purify the PCV2b ORF2-cmyc
proteins for quantitation and VLP confirmation by electron
microscopy (EM). The sucrose gradient was fractionated into 9
fractions and separated by SDS-PAGE where the majority of the PCV2b
ORF2-c-myc was detected in the fractions expected for PCV2b ORF2
VLPs.
[0020] FIG. 3. The PCV2b ORF2-c-myc-containing fractions (boxed
from FIG. 2) were pooled and a sample of the sucrose
gradient-purified material concentrated and submitted for VLP
confirmation by EM using phosphotungstic acid as a negative
stain.
[0021] FIG. 4. ELISA plates were coated with PCV2b ORF2-c-myc VLPs,
PCV2b ORF2 VLPs or Baculovirus control antigen and probed with
serial dilutions of antibodies A. swine anti-PCV2b antibody or B.
mouse anti-c-myc mAb 9E10. Anti-PCV2b antibody recognized both
PCV2b ORF2 VLPs and PCV2b ORF2-c-myc VLPs while anti-c-myc antibody
only recognized PCV2b ORF2-c-myc VLPs.
[0022] FIG. 5. Rabbits were vaccinated with purified PCV2b
ORF2-c-myc VLPs formulated with Freund's adjuvant. The resulting
serum samples were evaluated for an IgG response to c-myc peptide
and PCV2b ORF2 VLPs by ELISA. A. IgG Response to c-myc and PCV2b
ORF2 after 3 vaccinations. All rabbits generated an IgG response to
c-myc peptide and PCV2b ORF2 VLPs after 3 vaccinations. B. IgG
Response to c-myc and PCV2b ORF2 after a single vaccination. Five
out of six rabbits generated an IgG response to c-myc peptide after
a single dose of vaccine while all six rabbits generated an IgG
response to PCV2b ORF2 VLPs after the single dose.
DESCRIPTION OF THE INVENTION
[0023] The solution to the above technical problems is achieved by
the description and the embodiments characterized in the
claims.
[0024] Thus, the invention in its different aspects is implemented
according to the claims.
[0025] The invention is based on the surprising finding that
replacing amino acid residues in the BC loop of PCV2 ORF2 protein
by an epitope of interest allows for the production of VLPs
presenting the epitope of interest and thereby triggering an immune
response against said epitope, while retaining their antigenic
properties in terms of providing active acquired immunity against
PCV2.
[0026] In a first aspect the invention thus relates to a
polypeptide, being is also termed "the polypeptide of the present
invention" hereinafter, which is selected from the group consisting
of the following (a), (b), and (c): [0027] a. a PCV2 ORF2 protein
characterized in that at least one amino acid residue in the BC
loop is replaced by an amino acid sequence of interest; [0028] b. a
PCV2 ORF2 protein characterized in that an amino acid sequence of
interest is inserted into the BC loop; [0029] c. a combination of
(a) and (b).
[0030] The BC loop, as described herein, is in particular
understood to be the region of the amino acid positions 58 to 66,
wherein the numbering of the amino acid positions refers to the
amino acid sequence of wild type PCV2 ORF2 protein.
[0031] It is further understood that the term "replacing amino acid
residues of the BC loop" is in particular equivalent to the term
"replacing amino acid residues in the BC loop".
[0032] As described herein, the numbering of amino acid positions
refers to the amino acid sequence of full length wild type PCV2
ORF2 protein (SEQ ID NO:2 or SEQ ID NO:3). Hence, the numbering of
the amino positions as mentioned herein is with reference to a wild
type PCV2 ORF2 protein sequence having 234 or 233 amino acid
residues, including a methionine residue at the (N-terminal) amino
acid position 1.
[0033] Preferably, the amino acid sequence of interest is an amino
acid sequence comprising or consisting of at least two or three
amino acid residues or preferably of at least eight amino acid
residues.
[0034] The amino acid sequence of interest preferably comprises or
consists of a heterologous amino acid sequence. As used herein the
term "heterologous amino acid sequence" refers to any amino acid
sequence other than a PCV2 ORF2 sequence. More particularly, the
term "heterologous amino acid sequence" refers to an amino acid
sequence not found in that virus, e.g., the proteins of PCV2.
[0035] Preferably, the amino acid sequence of interest is selected
from the group consisting of an epitope of interest, a biological
response modulator, a growth factor, a recognition sequence, a
fusion protein.
[0036] Preferably, the amino acid sequence of interest comprises or
consists of an epitope of interest, and wherein the epitope of
interest is preferably an amino acid sequence comprising or
consisting of 8 to 25 amino acid residues.
[0037] The epitope of interest is preferably an epitope of interest
from an antigen or a veterinary pathogen or toxin, and wherein the
epitope of interest is more preferably a peptide comprising the
c-myc tag peptide or a peptide encoded by the orf5 gene of PRRS
virus.
[0038] The peptide encoded by the orf5 gene of PRRS virus
preferably comprises or consists of the amino acid sequence of SEQ
ID NO:6 or preferably comprises or consists of at least 8
consecutive amino acid residues of the sequence set forth in SEQ ID
NO: 6.
[0039] Preferably, the polypeptide of the invention according to
aspect (a) is a PCV2 ORF2 protein characterized in that at least
one amino acid residue in the region of the amino acid positions 58
to 64 is replaced by an amino acid sequence of interest, and
wherein the numbering of the amino acid positions refers to the
amino acid sequence of wild type PCV2 ORF2 protein.
[0040] The polypeptide of the invention according to aspect (a) is
preferably a PCV2 ORF2 protein characterized in that at least two
or three amino acid residues in the BC loop are replaced by an
amino acid sequence of interest, and wherein preferably two, three,
four, five, six, or seven amino acid residues in the BC loop are
replaced by an amino acid sequence of interest.
[0041] Preferably, the polypeptide according to aspect (a) is a
polypeptide of the invention, wherein: [0042] the six amino acid
residues of the amino acid positions 58 to 63 are replaced by an
amino acid sequence of interest, wherein the numbering of the amino
acid positions refers to the amino acid sequence of wild type PCV2
ORF2 protein; and/or [0043] the amino acid of interest comprises or
consists of an amino acid sequence consisting of 11 amino acid
residues, and/or [0044] the amino acid of interest comprises or
consists of the sequence of SEQ ID NO:5 or SEQ ID NO:7.
[0045] The polypeptide of the present invention is preferably a
recombinant protein, more preferably a recombinant baculovirus
expressed protein.
[0046] The term "recombinant protein", as used herein, in
particular refers to a protein molecule which is expressed from a
recombinant DNA molecule, such as a polypeptide which is produced
by recombinant DNA techniques. An example of such techniques
includes the case when DNA encoding the expressed protein is
inserted into a suitable expression vector, preferably a
baculovirus expression vector, which is in turn used to transfect,
or in case of a baculovirus expression vector to infect, a host
cell to produce the protein or polypeptide encoded by the DNA. The
term "recombinant protein", as used herein, thus in particular
refers to a protein molecule which is expressed from a recombinant
DNA molecule.
[0047] According to a particular example, the recombinant protein
is produced by a method with the following steps: The gene for
polypeptide of the present invention is cloned into a baculovirus
transfer vector; the transfer vector is used to prepare recombinant
baculovirus containing said gene by homologous recombination in
insect cells; and the protein is then expressed in insect cells
during infection with the recombinant baculovirus.
[0048] According to an alternative example, the recombinant protein
is expressed in insect cells from a recombinant expression plasmid.
In the case of this alternative example baculovirus is not
needed.
[0049] It is further understood that the term "recombinant protein
comprising or consisting of a sequence" in particular also concerns
any cotranslational and/or posttranslational modification or
modifications of the sequence affected by the cell in which the
polypeptide is expressed. Thus, the term "recombinant protein
comprising or consisting of a sequence", as described herein, is
also directed to the sequence having one or more modifications
effected by the cell in which the polypeptide is expressed, in
particular modifications of amino acid residues effected in the
protein biosynthesis and/or protein processing, preferably selected
from the group consisting of glycosylations, phosphorylations, and
acetylations.
[0050] Preferably, the recombinant protein according to the
invention is produced or obtainable by a baculovirus expression
system, in particular in cultured insect cells.
[0051] Preferably, the polypeptide of the present invention is
[0052] a. a PCV2 ORF2 protein characterized in that at least one
amino acid residue in the BC loop is replaced by an amino acid
sequence of interest; [0053] b. a PCV2 ORF2 protein characterized
in that an amino acid sequence of interest is inserted into the BC
loop; [0054] c. a combination of (a) and (b), wherein said PCV2
ORF2 protein is a PCV2 subtype b (PCV2b) ORF2 protein or a PCV2
subtype a (PCV2a) ORF2 protein and/or wherein said PCV2 ORF2
protein comprises or consists of an amino acid sequence having at
least 90% sequence identity with the amino acid sequence of SEQ ID
NO:2 or SEQ ID NO:3.
[0055] The polypeptide of the present invention preferably
comprises or consists of an amino acid sequence having at least
90%, preferably at least 92%, more preferably at least 94%, even
more preferably at least 96%, still more preferably at least 98%,
or in particular 100% sequence identity with the amino acid
sequence of SEQ ID NO:1.
[0056] In still another preferred aspect of the present invention,
the wild type PCV2 ORF2 protein, as described herein, is the
protein set forth in SEQ ID NO:2 or SEQ ID NO:3.
[0057] According to another aspect, the invention further provides
an immunogenic composition containing the polypeptide of the
present invention.
[0058] According to another preferred aspect, the invention further
provides an immunogenic composition containing the polypeptide of
the present invention, and a PCV2a ORF2 polypeptide, wherein said
PCV2a ORF2 polypeptide is preferably a polypeptide that is at least
94% or preferably at least 95% identical to the sequence of SEQ ID
NO: 3.
[0059] According to a further aspect, the invention also provides a
polynucleotide comprising a sequence which encodes the polypeptide
of the present invention, wherein said polynucleotide according to
the invention is preferably an isolated polynucleotide.
[0060] For explanatory purposes and in a non-limiting example, the
polynucleotide according to the invention is a polynucleotide
comprising the sequence set forth in SEQ ID NO: 4.
[0061] Production of the polynucleotides described herein is within
the skill in the art and can be carried out according to
recombinant techniques described, among other places, in Sambrook
et al., 2001, Molecular Cloning, A Laboratory Manual, Cold Spring
Harbor Laboratory Press, Cold Spring Harbor, N.Y.; Amusable, et
al., 2003, Current Protocols In Molecular Biology, Greene
Publishing Associates & Wiley Interscience, NY; Innis et al.
(eds), 1995, PCR Strategies, Academic Press, Inc., San Diego; and
Erlich (ed), 1994, PCR Technology, Oxford University Press, New
York, all of which are incorporated herein by reference.
[0062] Also, the invention in particular provides a baculovirus
which contains a polynucleotide comprising a sequence which encodes
the polypeptide of the present invention, wherein said baculovirus
according to the invention is preferably an isolated
baculovirus.
[0063] Further, the invention also provides a plasmid, preferably
an expression vector, which comprises a polynucleotide comprising a
sequence which encodes the polypeptide of the present invention,
wherein said plasmid according to the invention is in particular an
isolated plasmid.
[0064] The invention also provides a cell comprising a baculovirus
which contains a polynucleotide comprising a sequence which encodes
the polypeptide of the present invention, or a plasmid, preferably
an expression vector, which comprises a polynucleotide comprising a
sequence which encodes the polypeptide of the present invention,
wherein said cell according to the invention is preferably an
isolated cell.
[0065] In still another aspect, the invention also relates to the
use of the polypeptide of the present invention; the baculovirus
according to the invention; the immunogenic composition according
to the invention; the polynucleotide according to the invention;
the plasmid according to the invention; and/or the cell according
to the invention for the preparation of a medicament, preferably of
a vaccine.
[0066] In this context, the invention also provides a method of
producing the polypeptide of the present invention of, wherein said
method comprises the step of infecting a cell, preferably an insect
cell, with the baculovirus of the invention.
[0067] Further, the invention also provides a method of producing
the polypeptide of the present invention, wherein said method
comprises the step of transfecting a cell with the plasmid
according to the invention.
[0068] The polypeptide of the present invention is preferably
expressed in high amounts sufficient for the stable self-assembly
of virus like particles (VLPs), which may then be used for a single
shot vaccination, in particular if they are contained in an
immunogenic composition, thereby allowing the reduction and
prevention of clinical signs caused by an infection with PCV2, such
as an infection with PCV2b and/or PCV2a.
[0069] The invention is thus in particular further based on the
polypeptide of the present invention or on the immunogenic
composition according to the invention, respectively, wherein said
polypeptide of the present invention or said immunogenic
composition comprising the polypeptide of the present invention may
be used for particular purposes.
[0070] In one aspect, the invention thus relates to the polypeptide
of the present invention or an immunogenic composition comprising
the polypeptide of the present invention for use in a method for
the treatment or prevention of an infection with PCV2, the
reduction, prevention or treatment of clinical signs caused by an
infection with PCV2, or the prevention or treatment of a disease
caused by an infection with PCV2.
[0071] The invention also provides a method for the treatment or
prevention of an infection with PCV2, the reduction, prevention or
treatment of clinical signs caused by an infection with PCV2, or
the prevention or treatment of a disease caused by an infection
with PCV2, comprising administering the polypeptide of the present
invention or an immunogenic composition comprising the polypeptide
of the present invention to an animal, in particular to an animal
in need thereof.
[0072] Also, the invention provides the use of the polypeptide of
the present invention or of an immunogenic composition comprising
the polypeptide of the present invention for the preparation of a
medicament for the treatment or prevention of an infection with
PCV2, the reduction, prevention or treatment of clinical signs
caused by an infection with PCV2, or the treatment or prevention of
a disease caused by an infection with PCV2.
[0073] In a preferred aspect, the infection with PCV2, as described
herein, is an infection with PCV2 subtype b (PCV2b) and/or an
infection with PCV2 of a subtype other than subtype 2b.
[0074] As used herein, the term "infection with PCV2" is equivalent
to the term "PCV2 infection".
[0075] In particular, the infection with PCV2 of a subtype other
than subtype 2b, as mentioned herein, is an infection with PCV2
subtype a (PCV2a) and/or PCV2 subtype c (PCV2c), and is preferably
an infection with PCV2a.
[0076] The term "PCV2 subtype b (PCV2b) ORF2 protein", as described
herein, relates to the protein encoded by the ORF2 gene of a PCV-2b
as defined by the standardized nomenclature for PCV2 genotype
definition (Segales, J. et al., 2008, PCV-2 genotype definition and
nomenclature, Vet Rec 162:867-8) which is incorporated herein by
reference).
[0077] According to another preferred aspect, the infection with
PCV2 of a subtype other than subtype 2b, as described herein, is a
concurrent infection with (i) PCV2 of a subtype other than subtype
2b and (ii) PCV2b, in particular a concurrent infection with PCV2a
and PCV2b.
[0078] The terms "PCV2a", "PCV2b" and "PCV2c", respectively, as
described herein, relate to PCV-2a, PCV-2b and PCV-2c,
respectively, according to the standardized nomenclature for PCV2
genotype definition (Segales, J. et al., 2008, PCV-2 genotype
definition and nomenclature, Vet Rec 162:867-8, which is
incorporated herein by reference).
[0079] In particular, the infection with PCV2b, as mentioned
herein, is an infection with (i) a PCV2 comprising a polypeptide
that is at least 94%, preferably at least 95%, more preferably at
least 96%, still more preferably at least 97%, yet more preferably
at least 98%, and most preferably at least 99% identical to the
sequence of SEQ ID NO: 2, or (ii) a PCV2 comprising a
polynucleotide which comprises a sequence encoding a polypeptide
that is at least 94%, preferably at least 95%, more preferably at
least 96%, still more preferably at least 97%, yet more preferably
at least 98%, and most preferably at least 99% identical to the
sequence of SEQ ID NO:2.
[0080] As used herein, it is in particular understood that the term
"identical to the sequence of SEQ ID NO: X" is equivalent to the
term "identical to the sequence of SEQ ID NO: X over the length of
SEQ ID NO: X" or to the term "identical to the sequence of SEQ ID
NO: X over the whole length of SEQ ID NO: X", respectively.
Likewise, as used herein, it is in particular understood that the
term "sequence identity with the amino acid sequence of SEQ ID NO:
X" is equivalent to the term "sequence identity with the amino acid
sequence of SEQ ID NO:X over the length of SEQ ID NO: X" or to the
term "sequence identity with the amino acid sequence of SEQ ID NO:X
over the whole length of SEQ ID NO: X", respectively.
[0081] In this context, "X" is any integer selected from 1 to 3 so
that "SEQ ID NO: X" represents any of the SEQ ID NOs mentioned
herein in the context of sequence identity.
[0082] Preferably, the infection with PCV2a, as described herein,
is an infection with (i) a PCV2 comprising a polypeptide that is at
least 94%, preferably at least 95%, more preferably at least 96%,
still more preferably at least 97%, yet more preferably at least
98%, and most preferably at least 99% identical to the sequence of
SEQ ID NO:3, or (ii) a PCV2 comprising a polynucleotide which
comprises a sequence encoding a polypeptide that is at least 94%,
preferably at least 95%, more preferably at least 96%, still more
preferably at least 97%, yet more preferably at least 98%, and most
preferably at least 99% identical to the sequence of SEQ ID
NO:3.
[0083] Preferably, in the context of the present invention, the
treatment or prevention of an infection with PCV2 is based on or
comprises or consists of the induction of an immune response
against said PCV2, the clinical signs, as mentioned herein, are
selected from the group consisting of lymphoid depletion, lymphoid
inflammation, positive IHC for PCV2 antigen of lymphoid tissue,
viremia, nasal shedding, pyrexia, reduced average daily weight
gain, lung inflammation, positive IHC for PCV2 antigen of lung
tissue, and/or the disease, as mentioned herein, PMWS.
[0084] In particular, in the context of the present invention, the
treatment or prevention of an infection with PCV2 of a subtype
other than 2b is based on or comprises or consists of the induction
of an immune response against said PCV2 of a subtype other than 2b
or the concurrent induction of an immune response against said PCV2
of a subtype other than 2b and PCV2b.
[0085] The term "prevention" or "reduction" or "preventing" or
"reducing", respectively, as used herein, means, but is not limited
to a process which includes the administration of a PCV2 antigen,
namely of the polypeptide of the present invention, which is
included in the composition of the invention, to an animal, wherein
said PCV2 antigen, when administered to said animal elicits or is
able to elicit an immune response in said animal against PCV2.
Altogether, such treatment results in reduction of the clinical
signs of a disease caused by PCV2 or of clinical signs associated
with PCV2 infection, respectively. More specifically, the term
"prevention" or "preventing", as used herein, means generally a
process of prophylaxis in which an animal is exposed to the
immunogenic composition of the present invention prior to the
induction or onset of the disease process caused by PCV2.
[0086] Herein, "reduction of clinical signs associated with PCV2
infection" means, but is not limited to, reducing the number of
infected subjects in a group, reducing or eliminating the number of
subjects exhibiting clinical signs of infection, or reducing the
severity of any clinical signs that are present in the subjects, in
comparison to wild-type infection. For example, it should refer to
any reduction of pathogen load, pathogen shedding, reduction in
pathogen transmission, or reduction of any clinical sign
symptomatic of PCV2 infection. Preferably these clinical signs are
reduced in subjects receiving the composition of the present
invention by at least 10% in comparison to subjects not receiving
the composition and may become infected. More preferably, clinical
signs are reduced in subjects receiving the composition of the
present invention by at least 20%, preferably by at least 30%, more
preferably by at least 40%, and even more preferably by at least
50%.
[0087] The term "reduction of viremia" means, but is not limited
to, the reduction of PCV2 virus entering the bloodstream of an
animal, wherein the viremia level, i.e., the number of PCV2 RNA
copies per mL of blood serum or the number of plaque forming
colonies per deciliter of blood serum, is reduced in the blood
serum of subjects receiving the composition of the present
invention by at least 50% in comparison to subjects not receiving
the composition and may become infected. More preferably, the
viremia level is reduced in subjects receiving the composition of
the present invention by at least 90%, preferably by at least
99.9%, more preferably by at least 99.99%, and even more preferably
by at least 99.999%.
[0088] As used herein, the term "viremia" is particularly
understood as a condition in which PCV2 particles reproduce and
circulate in the bloodstream of an animal.
[0089] The term "animal" or "individual", as used herein, in
particular relates to a mammal, preferably to swine, more
preferably to a pig, most preferably to a piglet.
[0090] According to a particular preferred aspect of the invention,
the polypeptide of the present invention or the immunogenic
composition according to the invention is administered only
once.
[0091] Preferably, in the context of the present invention, the
polypeptide of the present invention or the immunogenic composition
according to the invention is to be administered or is
administered, respectively, in particular only once, to an animal,
preferably to a swine, more preferably to a pig, in particular
preferably to a piglet.
[0092] The present invention overcomes the problems inherent in the
prior art and provides a distinct advance in the state of the art.
According to another aspect, the present invention also provides a
method for the treatment or prevention of a PCV2 infection or for
reduction of clinical signs caused by or associated with a PCV2
infection in animals, preferably animals having anti-PCV2
antibodies, comprising the step of administering an effective
amount of the polypeptide of the present invention or the
immunogenic composition according to the invention to that animal
in need of such treatment.
[0093] The terms "vaccine" or "immunogenic composition" (both terms
are used synonymously) as used herein refers to any pharmaceutical
composition containing the polypeptide of the present invention,
which composition can be used to prevent or treat a PCV2
infection-associated disease or condition in a subject. A preferred
immunogenic composition can induce, stimulate or enhance the immune
response against PCV2. The term thus encompasses both subunit
immunogenic compositions, as described below, as well as
compositions containing whole killed, or attenuated and/or
inactivated PCV2 mutant.
[0094] It is in particular understood that the term "PCV2 mutant",
as described herein, relates to a PCV2 mutant comprising the
polypeptide of the present invention and/or the polynucleotide
according to the invention.
[0095] According to another aspect, the present invention also
provides a method for the treatment or prevention of a PCV2
infection or for reduction of clinical signs caused by or
associated with a PCV2 infection in animals, preferably animals
having anti-PCV2 antibodies, in particular maternal derived
anti-PCV2 antibodies, comprising the step of administering an
effective amount of the polypeptide of the present invention or an
immunogenic composition comprising the polypeptide of the present
invention to that animal in need of such treatment, wherein the
immunogenic composition is subunit immunogenic composition, a
composition containing whole killed, or attenuated and/or
inactivated PCV2.
[0096] The term "subunit immunogenic composition" as used herein
refers to a composition containing at least one immunogenic
polypeptide or antigen, but not all antigens, derived from or
homologous to an antigen from a PCV2 mutant. Such a composition is
substantially free of intact PCV2 mutant. Thus, a "subunit
immunogenic composition" is prepared from at least partially
purified or fractionated (preferably substantially purified)
immunogenic polypeptides from a PCV2 mutant, or recombinant analogs
thereof. A subunit immunogenic composition can comprise the subunit
antigen or antigens of interest substantially free of other
antigens or polypeptides from a PCV2 mutant, or in fractionated
from. A preferred immunogenic subunit composition comprises the
polypeptide of the present invention as described herein.
[0097] An "immune response" means but is not limited to the
development in a host of a cellular and/or antibody-mediated immune
response to the composition or vaccine of interest. Usually, an
"immune response" includes but is not limited to one or more of the
following effects: the production or activation of antibodies, B
cells, helper T cells, suppressor T cells, and/or cytotoxic T
cells, directed specifically to an antigen or antigens included in
the composition or vaccine of interest. Preferably, the host will
display either a therapeutic or a protective immunological (memory)
response such that resistance to new infection will be enhanced
and/or the clinical severity of the disease reduced. Such
protection will be demonstrated by either a reduction in number or
severity of, or lack of one or more of the signs associated with
PCV2 infections, in particular an infection with PCV2 subtype b
(PCV2b) and/or an infection with PCV2 of a subtype other than
subtype 2b, in delay of onset of viremia, in a reduced viral
persistence, in a reduction of the overall viral load and/or a
reduction of viral excretion.
[0098] The term "antigen" as used herein refers to an amino acid
sequence which elicits an immunological response as described
above.
[0099] According to a further aspect, the immunogenic composition
as used herein most preferably comprises the polypeptide of the
present invention, or a fragment thereof, expressed by the
polypeptide according to the invention. A preferred polypeptide of
the present invention is that of SEQ ID NO: 1. However, it is
understood by those of skill in the art that this sequence could
vary by as much as 1-5% in sequence homology and still retain the
antigenic characteristics that render it useful in immunogenic
compositions according to invention.
[0100] "Sequence identity" as it is known in the art refers to a
relationship between two or more polypeptide sequences or two or
more polynucleotide sequences, namely a reference sequence and a
given sequence to be compared with the reference sequence. Sequence
identity is determined by comparing the given sequence to the
reference sequence after the sequences have been optimally aligned
to produce the highest degree of sequence similarity, as determined
by the match between strings of such sequences. Upon such
alignment, sequence identity is ascertained on a
position-by-position basis, e.g., the sequences are "identical" at
a particular position if at that position, the nucleotides or amino
acid residues are identical. The total number of such position
identities is then divided by the total number of nucleotides or
residues in the reference sequence to give % sequence identity.
Sequence identity can be readily calculated by known methods,
including but not limited to, those described in Computational
Molecular Biology, Lesk, A. N., ed., Oxford University Press, New
York (1988), Biocomputing: Informatics and Genome Projects, Smith,
D. W., ed., Academic Press, New York (1993); Computer Analysis of
Sequence Data, Part I, Griffin, A. M., and Griffin, H. G., eds.,
Humana Press, New Jersey (1994); Sequence Analysis in Molecular
Biology, von Heinge, G., Academic Press (1987); Sequence Analysis
Primer, Gribskov, M. and Devereux, J., eds., M. Stockton Press, New
York (1991); and Carillo, H., and Lipman, D., SIAM J. Applied
Math., 48: 1073 (1988), the teachings of which are incorporated
herein by reference. Preferred methods to determine the sequence
identity are designed to give the largest match between the
sequences tested. Methods to determine sequence identity are
codified in publicly available computer programs which determine
sequence identity between given sequences. Examples of such
programs include, but are not limited to, the GCG program package
(Devereux, J., et al., Nucleic Acids Research, 12(1): 387 (1984)),
BLASTP, BLASTN and FASTA (Altschul, S. F. et al., J. Molec. Biol.,
215:403-410 (1990). The BLASTX program is publicly available from
NCBI and other sources (BLAST Manual, Altschul, S. et al., NCVI NLM
NIH Bethesda, Md. 20894, Altschul, S. F. et al., J. Molec. Biol.,
215:403-410 (1990), the teachings of which are incorporated herein
by reference). These programs optimally align sequences using
default gap weights in order to produce the highest level of
sequence identity between the given and reference sequences. As an
illustration, by a polynucleotide having a nucleotide sequence
having at least, for example, 85%, preferably 90%, even more
preferably 95% "sequence identity" to a reference nucleotide
sequence, it is intended that the nucleotide sequence of the given
polynucleotide is identical to the reference sequence except that
the given polynucleotide sequence may include up to 15, preferably
up to 10, even more preferably up to 5 point mutations per each 100
nucleotides of the reference nucleotide sequence. In other words,
in a polynucleotide having a nucleotide sequence having at least
85%, preferably 90%, even more preferably 95% identity relative to
the reference nucleotide sequence, up to 15%, preferably 10%, even
more preferably 5% of the nucleotides in the reference sequence may
be deleted or substituted with another nucleotide, or a number of
nucleotides up to 15%, preferably 10%, even more preferably 5% of
the total nucleotides in the reference sequence may be inserted
into the reference sequence. These mutations of the reference
sequence may occur at the 5' or 3' terminal positions of the
reference nucleotide sequence or anywhere between those terminal
positions, interspersed either individually among nucleotides in
the reference sequence or in one or more contiguous groups within
the reference sequence. Analogously, by a polypeptide having a
given amino acid sequence having at least, for example, 85%,
preferably 90%, even more preferably 95% sequence identity to a
reference amino acid sequence, it is intended that the given amino
acid sequence of the polypeptide is identical to the reference
sequence except that the given polypeptide sequence may include up
to 15, preferably up to 10, even more preferably up to 5 amino acid
alterations per each 100 amino acids of the reference amino acid
sequence. In other words, to obtain a given polypeptide sequence
having at least 85%, preferably 90%, even more preferably 95%
sequence identity with a reference amino acid sequence, up to 15%,
preferably up to 10%, even more preferably up to 5% of the amino
acid residues in the reference sequence may be deleted or
substituted with another amino acid, or a number of amino acids up
to 15%, preferably up to 10%, even more preferably up to 5% of the
total number of amino acid residues in the reference sequence may
be inserted into the reference sequence. These alterations of the
reference sequence may occur at the amino or the carboxy terminal
positions of the reference amino acid sequence or anywhere between
those terminal positions, interspersed either individually among
residues in the reference sequence or in the one or more contiguous
groups within the reference sequence. Preferably, residue positions
which are not identical differ by conservative amino acid
substitutions. However, conservative substitutions are not included
as a match when determining sequence identity.
[0101] "Sequence homology", as used herein, refers to a method of
determining the relatedness of two sequences. To determine sequence
homology, two or more sequences are optimally aligned, and gaps are
introduced if necessary. However, in contrast to "sequence
identity", conservative amino acid substitutions are counted as a
match when determining sequence homology. In other words, to obtain
a polypeptide or polynucleotide having 95% sequence homology with a
reference sequence, 85%, preferably 90%, even more preferably 95%
of the amino acid residues or nucleotides in the reference sequence
must match or comprise a conservative substitution with another
amino acid or nucleotide, or a number of amino acids or nucleotides
up to 15%, preferably up to 10%, even more preferably up to 5% of
the total amino acid residues or nucleotides, not including
conservative substitutions, in the reference sequence may be
inserted into the reference sequence. Preferably the homolog
sequence comprises at least a stretch of 50, even more preferably
at least 100, even more preferably at least 250, and even more
preferably at least 500 nucleotides.
[0102] A "conservative substitution" refers to the substitution of
an amino acid residue or nucleotide with another amino acid residue
or nucleotide having similar characteristics or properties
including size, hydrophobicity, etc., such that the overall
functionality does not change significantly.
[0103] "Isolated" means altered "by the hand of man" from its
natural state, i.e., if it occurs in nature, it has been changed or
removed from its original environment, or both. For example, a
polynucleotide or polypeptide naturally present in a living
organism is not "isolated," but the same polynucleotide or
polypeptide separated from the coexisting materials of its natural
state is "isolated", as the term is employed herein.
[0104] Thus, according to a further aspect, the present invention
also provides a method for the treatment or prevention of a PCV2
infection or for reduction of clinical signs caused by or
associated with a PCV2 infection in animals, preferably animals
having anti-PCV2 antibodies, in particular maternal derived
anti-PCV2 antibodies, comprising the step of administering an
effective amount of the polypeptide of the present invention or an
immunogenic composition comprising the polypeptide of the present
invention to that animal in need of such treatment, wherein said
the polypeptide of the present invention is anyone of those,
described herein. Preferably, the polypeptide of the present
invention protein is: (i) a polypeptide comprising or consisting of
the sequence of SEQ ID NO: 1; or (ii) any polypeptide that is at
least 95% homologous to the polypeptide of (i).
[0105] According to a further aspect, the polypeptide of the
present invention is provided in the immunogenic composition at a
protein inclusion level effective for inducing the desired immune
response, namely reducing the incidence of, lessening the severity
of, or preventing or reducing one or more clinical signs resulting
from or associated with a PCV2 infection. Preferably, the inclusion
level of the polypeptide of the present invention is at least 0.2
.mu.g protein/ml of the final immunogenic composition (.mu.g/ml),
more preferably from about 0.2 to about 400 .mu.g/ml, still more
preferably from about 0.3 to about 200 .mu.g/ml, even more
preferably from about 0.35 to about 100 .mu.g/ml, still more
preferably from about 0.4 to about 50 .mu.g/ml, still more
preferably from about 0.45 to about 30 .mu.g/ml, still more
preferably from about 0.5 to about 18 .mu.g/ml, even more
preferably from about 0.6 to about 15 .mu.g/ml even more preferably
from about 0.75 to about 8 .mu.g/ml, even more preferably from
about 1.0 to about 6 .mu.g/ml, still more preferably from about 1.3
to about 3.0 .mu.g/ml, even more preferably from about 1.4 to about
2.5 .mu.g/ml, even more preferably from about 1.5 to about 2.0
.mu.g/ml, and most preferably about 1.6 .mu.g/ml.
[0106] According to a further aspect, the protein inclusion level
is at least 0.2 .mu.g/PCV2b ORF-2 protein as described above per
dose of the final immunogenic composition (.mu.g/dose), more
preferably from about 0.2 to about 400 .mu.g/dose, still more
preferably from about 0.3 to about 200 .mu.g/dose, even more
preferably from about 0.35 to about 100 .mu.g/dose, still more
preferably from about 0.4 to about 50 .mu.g/dose, still more
preferably from about 0.45 to about 30 .mu.g/dose, still more
preferably from about 0.5 to about 18 .mu.g/dose, even more
preferably from about 0.6 to about 15 .mu.g/ml, even more
preferably from about 0.75 to about 8 .mu.g/dose, even more
preferably from about 1.0 to about 6 .mu.g/dose, still more
preferably from about 1.3 to about 3.0 .mu.g/dose, even more
preferably from about 1.4 to about 2.5 .mu.g/dose, even more
preferably from about 1.5 to about 2.0 .mu.g/dose, and most
preferably about 1.6 .mu.g/dose. Also, an inclusion level of the
polypeptide of the present invention (antigen content) of less than
20 .mu.g/dose, preferably of about 0.5 to 18 .mu.g/dose is suitable
to confer immunity in young animals and/or in animals which are
positive for PCV2 antibodies, in particular which are positive for
anti-PCV2 maternal derived antibodies. Thus, according to a further
aspect, the present invention also provides a method for the
treatment or prevention of a PCV2 infection or for reduction of
clinical signs caused by or associated with a PCV2 infection in
animals, preferably animals having anti-PCV2 antibodies, in
particular maternal derived anti-PCV2 antibodies, comprising the
step of administering less than 20 .mu.g/dose, preferably of about
0.5 to 18 .mu.g/dose of the polypeptide of the present invention or
an immunogenic composition comprising the polypeptide of the
present invention to that animal in need of such treatment. Said
polypeptide of the present invention is anything described in this
patent application.
[0107] The polypeptide of the present invention used in the
immunogenic composition in accordance with the present invention
can be derived in any fashion including isolation and purification
of the polypeptide of the present invention, standard protein
synthesis, and recombinant methodology. Preferred methods for
obtaining the polypeptide of the present invention are provided in
WO06/072065, the teachings and content of which are hereby
incorporated by reference in its entirety, since surprisingly it
has been found that the methods described therein for obtaining
PCV2a ORF-2 polypeptide can be used accordingly for obtaining the
polypeptide of the present invention. Briefly, susceptible cells
are infected with a recombinant viral vector containing DNA coding
sequences encoding the polypeptide of the present invention, the
polypeptide of the present invention protein is expressed by the
recombinant virus, and the expressed polypeptide of the present
invention is recovered from the supernatant by filtration and
inactivated by any conventional method, preferably using binary
ethylenimine (BEI), which is then neutralized to stop the
inactivation process.
[0108] The immunogenic composition as used herein also refers to a
composition that comprises i) any of the polypeptides of the
present invention described above, preferably in concentrations
described above, and ii) at least a portion of the viral vector
expressing said polypeptide of the present invention, preferably of
a recombinant baculovirus. Moreover, the immunogenic composition
may comprise i) any of the polypeptides of the present invention
described above, preferably in concentrations described above, ii)
at least a portion of the viral vector expressing said polypeptide
of the present invention, preferably of a recombinant baculovirus,
and iii) a portion of the cell culture supernatant.
[0109] Thus, according to a further aspect, the present invention
also provides a method for the treatment or prevention of a PCV2
infection or for reduction of clinical signs caused by or
associated with a PCV2 infection in animals, preferably animals
having anti-PCV2 antibodies, in particular maternal derived
anti-PCV2 antibodies, comprising the step of administering an
effective amount of the polypeptide of the present invention or an
immunogenic composition comprising the polypeptide of the present
invention to that animal in need of such treatment, wherein the
polypeptide of the present invention is a recombinant, preferably a
baculovirus expressed, polypeptide of the present invention.
Preferably those recombinant or baculovirus expressed polypeptides
of the present invention have the sequence as described above.
[0110] The immunogenic composition as used herein also refers to a
composition that comprises i) any of the polypeptides of the
present invention described above, preferably in concentrations
described above, ii) at least a portion of the viral vector
expressing said polypeptide of the present invention, preferably of
a recombinant baculovirus, and iii) a portion of the cell culture;
wherein about 90% of the components have a size smaller than 1
.mu.m.
[0111] The immunogenic composition as used herein also refers to a
composition that comprises i) any of the polypeptides of the
present invention described above, preferably in concentrations
described above, ii) at least a portion of the viral vector
expressing said polypeptide of the present invention, iii) a
portion of the cell culture, iv) and inactivating agent to
inactivate the recombinant viral vector, preferably BEI, wherein
about 90% of the components i) to iii) have a size smaller than 1
.mu.m. Preferably, BEI is present in concentrations effective to
inactivate the baculovirus, preferably in an amount of 2 to about 8
mM BEI, preferably of about 5 mM BEI.
[0112] The immunogenic composition as used herein also refers to a
composition that comprises i) any of the polypeptides of the
present invention described above, preferably in concentrations
described above, ii) at least a portion of the viral vector
expressing said polypeptide of the present invention, iii) a
portion of the cell culture, iv) an inactivating agent to
inactivate the recombinant viral vector, preferably BEI, and v) a
neutralization agent to stop the inactivation mediated by the
inactivating agent, wherein about 90% of the components i) to iii)
have a size smaller than 1 .mu.m. Preferably, if the inactivating
agent is BEI, said composition comprises sodium thiosulfate in
equivalent amounts to BEI.
[0113] The protein is incorporated into a composition that can be
administered to an animal susceptible to PCV2 infection. In
preferred forms, the composition may also include additional
components known to those of skill in the art (see also,
Remington's Pharmaceutical Sciences. (1990). 18th ed. Mack Publ.,
Easton). Additionally, the composition may include one or more
veterinary-acceptable carriers. As used herein, "a
veterinary-acceptable carrier" includes any and all solvents,
dispersion media, coatings, adjuvants, stabilizing agents,
diluents, preservatives, antibacterial and antifungal agents,
isotonic agents, adsorption delaying agents, and the like. In a
preferred embodiment, the immunogenic composition comprises the
polypeptide of the present invention as provided herewith,
preferably in concentrations described above, which is mixed with
an adjuvant, preferably CARBOPOL.RTM. (The Lubrizol Corporation),
and physiological saline.
[0114] Those of skill in the art will understand that the
composition used herein may incorporate known injectable,
physiologically acceptable sterile solutions. For preparing a
ready-to-use solution for parenteral injection or infusion, aqueous
isotonic solutions, such as e.g., saline or corresponding plasma
protein solutions are readily available. In addition, the
immunogenic and vaccine compositions of the present invention can
include diluents, isotonic agents, stabilizers, or adjuvants.
Diluents can include water, saline, dextrose, ethanol, glycerol,
and the like. Isotonic agents can include sodium chloride,
dextrose, mannitol, sorbitol, and lactose, among others.
Stabilizers include albumin and alkali salts of
ethylendiamintetracetic acid, among others.
[0115] "Adjuvants" as used herein, can include aluminum hydroxide
and aluminum phosphate, saponins e.g., Quil A, QS-21 (Cambridge
Biotech Inc., Cambridge Mass.), GPI-0100 (Galenica Pharmaceuticals,
Inc., Birmingham, Ala.), water-in-oil emulsion, oil-in-water
emulsion, water-in-oil-in-water emulsion. The emulsion can be based
in particular on light liquid paraffin oil (European Pharmacopea
type); isoprenoid oil such as squalane or squalene oil resulting
from the oligomerization of alkenes, in particular of isobutene or
decene; esters of acids or of alcohols containing a linear alkyl
group, more particularly plant oils, ethyl oleate, propylene glycol
di-(caprylate/caprate), glyceryl tri-(caprylate/caprate) or
propylene glycol dioleate; esters of branched fatty acids or
alcohols, in particular isostearic acid esters. The oil is used in
combination with emulsifiers to form the emulsion. The emulsifiers
are preferably nonionic surfactants, in particular esters of
sorbitan, of mannide (e.g., anhydromannitol oleate), of glycol, of
polyglycerol, of propylene glycol and of oleic, isostearic,
ricinoleic or hydroxystearic acid, which are optionally
ethoxylated, and polyoxypropylene-polyoxyethylene copolymer blocks,
in particular PLURONIC.RTM. products, especially L121 (BASF Corp.).
See Hunter et al., The Theory and Practical Application of
Adjuvants (Ed. Stewart-Tull, D. E. S.). John Wiley and Sons, NY, pp
51-94 (1995) and Todd et al., Vaccine 15:564-570 (1997).
[0116] For example, it is possible to use the SPT emulsion
described on page 147 of "Vaccine Design, The Subunit and Adjuvant
Approach" edited by M. Powell and M. Newman, Plenum Press, 1995,
and the emulsion MF59 described on page 183 of this same book.
[0117] A further instance of an adjuvant is a compound chosen from
the polymers of acrylic or methacrylic acid and the copolymers of
maleic anhydride and alkenyl derivative. Advantageous adjuvant
compounds are the polymers of acrylic or methacrylic acid which are
cross-linked, especially with polyalkenyl ethers of sugars or
polyalcohols. These compounds are known by the term carbomer
(Pharmeuropa Vol. 8, No. 2, June 1996). Persons skilled in the art
can also refer to U.S. Pat. No. 2,909,462 which describes such
acrylic polymers cross-linked with a polyhydroxylated compound
having at least 3 hydroxyl groups, preferably not more than 8, the
hydrogen atoms of at least three hydroxyls being replaced by
unsaturated aliphatic radicals having at least 2 carbon atoms. The
preferred radicals are those containing from 2 to 4 carbon atoms,
e.g., vinyls, allyls and other ethylenically unsaturated groups.
The unsaturated radicals may themselves contain other substituents,
such as methyl. The products sold under the name CARBOPOL.RTM. (The
Lubrizol Corporation) are particularly appropriate. They are
cross-linked with an allyl sucrose or with allyl pentaerythritol.
Among them, there may be mentioned CARBOPOL.RTM. 974P, 934P and
971P. Most preferred is the use of CARBOPOL.RTM., in particular the
use of CARBOPOL.RTM. 971P, preferably in amounts of about 500 .mu.g
to about 5 mg per dose, even more preferred in an amount of about
750 .mu.g to about 2.5 mg per dose and most preferred in an amount
of about 1 mg per dose.
[0118] Further suitable adjuvants include, but are not limited to,
the RIBI adjuvant system (Ribi Inc.), Block co-polymer (CytRx,
Atlanta Ga.), SAF-M (Chiron, Emeryville Calif.), monophosphoryl
lipid A, Avridine lipid-amine adjuvant, heat-labile enterotoxin
from E. coli (recombinant or otherwise), cholera toxin, IMS 1314,
or muramyl dipeptide among many others.
[0119] Preferably, the adjuvant is added in an amount of about 100
.mu.g to about 10 mg per dose. Even more preferably, the adjuvant
is added in an amount of about 100 .mu.g to about 10 mg per dose.
Even more preferably, the adjuvant is added in an amount of about
500 .mu.g to about 5 mg per dose. Even more preferably, the
adjuvant is added in an amount of about 750 .mu.g to about 2.5 mg
per dose. Most preferably, the adjuvant is added in an amount of
about 1 mg per dose.
[0120] Additionally, the composition can include one or more
pharmaceutical-acceptable carriers. As used herein, "a
pharmaceutical-acceptable carrier" includes any and all solvents,
dispersion media, coatings, stabilizing agents, diluents,
preservatives, antibacterial and antifungal agents, isotonic
agents, adsorption delaying agents, and the like. Most preferably,
the composition provided herewith, contains polypeptide of the
present invention recovered from the supernatant of in vitro
cultured cells, wherein said cells were infected with a recombinant
viral vector containing DNA encoding the polypeptide of the present
invention and expressing the polypeptide of the present invention,
and wherein said cell culture was treated with about 2 to about 8
mM BEI, preferably with about 5 mM BEI to inactivate the viral
vector, and an equivalent concentration of a neutralization agent,
preferably sodium thiosulfate solution to a final concentration of
about 2 to about 8 mM, preferably of about 5 mM.
[0121] The present invention also relates to an immunogenic
composition that comprises i) any of the polypeptides of the
present invention described above, preferably in concentrations
described above, ii) at least a portion of the viral vector
expressing said polypeptide of the present invention, iii) a
portion of the cell culture, iv) an inactivating agent to
inactivate the recombinant viral vector preferably BEI, and v) an
neutralization agent to stop the inactivation mediated by the
inactivating agent, preferably sodium thiosulfate in equivalent
amounts to BEI; and vi) a suitable adjuvant, preferably
CARBOPOL.RTM. 971 in amounts described above; wherein about 90% of
the components i) to iii) have a size smaller than 1 .mu.m.
According to a further aspect, this immunogenic composition further
comprises a pharmaceutical acceptable salt, preferably a phosphate
salt in physiologically acceptable concentrations. Preferably, the
pH of said immunogenic composition is adjusted to a physiological
pH, meaning between about 6.5 and 7.5.
[0122] The immunogenic composition as used herein also refers to a
composition that comprises per one ml (i) at least 1.6 .mu.g of the
polypeptide of the present invention described above, preferably
less than 20 .mu.g (ii) at least a portion of baculovirus
expressing said polypeptide of the present invention (iii) a
portion of the cell culture, (iv) about 2 to 8 mM BEI, (v) sodium
thiosulfate in equivalent amounts to BEI; and (vi) about 1 mg
CARBOPOL.RTM. 971, and (vii) phosphate salt in a physiologically
acceptable concentration; wherein about 90% of the components (i)
to (iii) have a size smaller than 1 .mu.m and the pH of said
immunogenic composition is adjusted to about 6.5 to 7.5.
[0123] The immunogenic compositions can further include one or more
other immuno-modulatory agents such as, e.g., interleukins,
interferons, or other cytokines. The immunogenic compositions can
also include Gentamicin and Merthiolate. While the amounts and
concentrations of adjuvants and additives useful in the context of
the present invention may readily be determined by the skilled
artisan, the present invention contemplates compositions comprising
from about 50 .mu.g to about 2000 .mu.g of adjuvant and preferably
about 250 .mu.g/ml dose of the vaccine composition. Thus, the
immunogenic composition as used herein also refers to a composition
that comprises from about 1 ug/ml to about 60 .mu.g/ml of
antibiotics, and more preferably less than about 30 .mu.g/ml of
antibiotics.
[0124] The immunogenic composition as used herein also refers to a
composition that comprises (i) any of the polypeptides of the
present invention described above, preferably in concentrations
described above; (ii) at least a portion of the viral vector
expressing said polypeptide of the present invention; (iii) a
portion of the cell culture; (iv) an inactivating agent to
inactivate the recombinant viral vector, preferably BEI; and (v) an
neutralization agent to stop the inactivation mediated by the
inactivating agent, preferably sodium thiosulfate in equivalent
amounts to BEI; (vi) a suitable adjuvant, preferably CARBOPOL.RTM.
971 in amounts described above; (vii) a pharmaceutical acceptable
concentration of a saline buffer, preferably of a phosphate salt;
and (viii) an anti-microbiological active agent; wherein about 90%
of the components (i) to (iii) have a size smaller than 1
.mu.m.
[0125] For investigation of a possible interference of the
polypeptide of the present invention with the maternal antibody a
study may be conducted in which the antibody titers of study
animals are determined at the time of vaccination which are then
grouped into a low, moderate and high antibody class: Geometric
mean titers of <1:100 are considered as low antibody titers,
titers of 1:100 to 1:1000 are considered as moderate antibody
titers and titers of >1:1000 are considered as high antibody
titers. This grouping pattern is comparable to that done in a
Canadian field study where antibody titers of 1:80 were considered
as low, antibody titers of 1:640 as moderate and antibody titers of
>1:1280 as high (Larochelle et al., 2003, Can. J. Vet. Res.; 67:
114-120). In order to analyze the impact of low, medium and high
antibody titers at the time of vaccination on viremia, vaccinated
and placebo-treated animals are compared with regard to the onset,
end, duration of viremia, the number of positive sampling days and
the virus load. The presence of anti-PCV2 antibodies, in particular
of maternal derived antibodies, preferably has no significant
impact of any of those parameters. In other words, the efficacy of
the polypeptide of the present invention in prevention and
treatment of a PCV2 infection or in reduction of clinical signs
caused by or associated with a PCV2 infection in animals is
preferably not affected at the day of vaccination by the presence
of anti-PCV2 antibodies, preferably by anti-PCV2 antibody titers of
up to 1:100, preferably of more than 1:100, even more preferably of
more than 1:250, even more preferably of more than 1:500, even more
preferably of 1:640; even more preferably of more than 1:750, most
preferably of more than 1:1000. This effect may be shown in a one
shot vaccination experiment, which means that the polypeptide of
the present invention is administered only once and without any
subsequent administration of the polypeptide of the present
invention.
[0126] Methods for detection and quantification of anti-PCV2
antibodies are well known in the art. For example detection and
quantification of PCV2 antibodies can be performed by indirect
immunofluorescence as described in Magar et al., 2000, Can. J. Vet
Res.; 64: 184-186 or Magar et al., 2000, J. Comp. Pathol.; 123:
258-269. Further assays for quantification of anti-PCV2 antibodies
are described in Opriessnig et al., 2006, 37th Annual Meeting of
the American Association of Swine Veterinarians. Moreover, an
indirect immunofluorescence assay, that may be used by a person
skilled in the art comprises the steps of: seeding about 20.000 to
60.000 PK15 or VIDO R1 cells per well onto a 96 well plate;
infecting cells with a PCV2 isolate, when monolayers are
approximately 65 to 85% confluent; incubating infected cells for 48
hours; removing medium and washing cells 2 times with PBS;
discarding the wash buffer and treating cells with cold 50/50
methanol/acetone fixative (.about.100 .mu.l/well) for about 15 min
at about -20.degree. C.; discarding the fixative and air drying of
the plates; preparing serial dilutions of porcine serum samples in
PBS and serial dilutions of an anti-PCV2 positive and negative
control sample (Positive Control and Negative Control Samples);
adding the serial dilutions to the plates and incubating to allow
antibodies to bind if present in the serum samples for about 1 hr.
at 36.5.+-.1.degree. C.; washing the plates three times with PBS an
discarding the PBS; staining the plates with a commercial Goat
anti-Swine FITC conjugate diluted 1:100 in PBS and incubated for
about 1 hr. at 36.5.+-.1.degree. C.; removing microplates are
removed from incubator, the conjugate is discarded and the plates
are washed 2 times with PBS; reading the plates using UV microscopy
and reporting individual wells as positive or negative, wherein the
Positive Control and Negative Control samples are used to monitor
the test system; and calculating the serum antibody titers using
the highest dilution showing specific IFA reactivity and the number
of wells positive per dilution, or a 50% endpoint is calculated
using the appropriate Reed-Muench formula.
[0127] Such an assay is described in Example 2 of WO 2008/076915
A2, hereby incorporated by reference.
[0128] In cases of controversial results and in any question of
doubt, anti-PCV2 titers as mentioned herein, refer to those which
are/can be estimated by this assay.
[0129] Thus according to a further aspect, the present invention
provides a method for the treatment or prevention of a PCV2
infection or for reduction of clinical signs caused by or
associated with a PCV2 infection in animals, preferably animals
having anti-PCV2 antibodies, in particular maternal antibodies,
comprising the step of administering an effective amount of a
polypeptide of the present invention to that animal in need of such
treatment, preferably of less than 20 .mu.g/dose wherein said
animal have a detectable anti-PCV2 antibody titer of up to 1:100,
preferably of more than 1:100, even more preferably of more than
1:250, even more preferably of more than 1:500, even more
preferably of 1:640, even more preferably of more than 1:750, most
preferably of more than 1:1000. Preferably, the anti-PCV2 antibody
titer is detectable and quantifiable in a specific anti-PCV2 immune
assay, preferably in the assay as described above, as exemplarily
described in Example 2 of WO 2008/076915 A2. More preferably, those
anti-PCV-2 antibodies are maternal derived antibodies. Most
preferably, the polypeptide of the present invention is only
administered once, preferably with a dose of less than 20
.mu.g/dose.
[0130] Piglets with only low titers (<1:100) or moderate titers
(<1:1000) of maternal derived anti-PCV2 antibodies are not
sufficiently protected against PCV2 infections which occur prior to
week 3 of age. Therefore, vaccination at a very early stage of life
is desirable. Within the context of the invention,
vaccination/treatment of animals at or before 3 weeks of age is
preferred. Moreover, anti-PCV2 antibody titers of more than 1:1000
preferably have no influence on the efficacy of the PCV2 vaccine
regardless of the level of the existing initial antibody titer. For
example, vaccination of high-titer animals (anti-PCV2 antibody
titer >1:1000) preferably result in a shorter duration of
viremia, an earlier end of viremia, less viremic sampling days and
a reduction of the sum of genomic equivalents/ml as compared to
non-vaccinated control animals. Upon comparison of vaccinated
"high", "moderate" and "low titer animals" no significant
differences are preferably observed with regard to the different
parameters of PCV2 viraemia. Also in the presence of high anti-PCV2
antibody titers the polypeptide of the present invention used for
vaccination preferably still significantly reduces viremia in blood
(e.g., end of viremia, duration of viremia, virus load).
Preferably, no differences are found with regard to the live body
weight when comparing low and high titer animals of the vaccinated
group. Furthermore, vaccinated animals with a high anti-PCV2
antibody titer at the time of vaccination/treatment (>1:1000)
also preferably show a significantly higher body weight after the
onset of viremia compared to placebo-treated animals with initial
high antibody titers. Consequently, according to a preferred
aspect, vaccination/treatment of animals of 1 day of age or older
with the polypeptide of the present invention is possible. However,
vaccination should be done within the first 8, preferably within
the first 7 weeks of age. Thus according to a further aspect, the
present invention provides a method for the treatment or prevention
of a PCV2 infection or for reduction of clinical signs caused by or
associated with a PCV2 infection in animals, comprising the step of
administering to that animal in need of such treatment at day 1 of
age or later, preferably but not later than at week 8 of age an
effective amount of the polypeptide of the present invention.
According to a preferred embodiment, less than 20 .mu.g/dose
polypeptide of the present invention are required to confer
immunity in such animal. According to a more preferred embodiment,
the polypeptide of the present invention, preferably less than a 20
.mu.g/dose thereof is only administered once to the animal in need
of such treatment.
[0131] According to a further, more general aspect, the present
invention provides a method for the treatment or prevention of a
PCV2 infection or for reduction of clinical signs caused by or
associated with a PCV2 infection in young animals, comprising the
step of administering an effective amount of the polypeptide of the
present invention to that animal in need of such treatment.
[0132] The term "young animal" as used herein refers to an animal
of 1 to 22 days of age. Preferably, by the term young animal, an
animal of 1 to 20 days of age is meant. More preferably, the term
young animal refers to an animal of 1 to 15 days of age, even more
preferably of 1 day of age to 14 days of age, even more preferably
of 1 to 12 days of age, even more preferably of 1 to 10 days of
age, even more preferably of 1 to 8 days of age, even more
preferably of 1 to 7 days of age, even more preferably of 1 to 6
days of age, even more preferably of 1 to 5 days of age, even more
preferably of 1 to 4 days of age, even more preferably of 1 to 3
days of age, even more preferably of 1 or 2 day(s) of age, most
preferably to an animal of 1 day of age.
[0133] Thus according to a further aspect, the present invention
provides a method for the treatment or prevention of a PCV2
infection or for reduction of clinical signs caused by or
associated with a PCV2 infection in young animals, comprising the
step of administering an effective amount of the polypeptide of the
present invention to an animal of 1 to 22 days of age, preferably
of 1 to 20 days of age, more preferably of 1 to 15 days of age,
even more preferably of 1 to 14 days of age, even more preferably
of 1 to 12 days of age, even more preferably of 1 to 10 days of
age, even more preferably of 1 to 8 days of age, even more
preferably of 1 to 7 days of age, even more preferably of 1 to 6
days of age, even more preferably of 1 to 5 days of age, even more
preferably of 1 to 4 days of age, even more preferably of 1 to 3
days of age, even more preferably of 1 or 2 day(s) of age, most
preferably at 1 day of age in need of such treatment. For example,
the vaccination/treatment on 19 to 22 days of age preferably shows
high efficacy of vaccination. Moreover, vaccination/treatment at 12
to 18, preferably 12 to 14 days of age is preferably very effective
in reduction of clinical signs associated with PCV2 infections,
reduction of overall viral load, reduction of duration of viremia,
delay in onset of viremia, weight gain. Moreover, vaccination at 1
week of age is preferably very effective in reduction of clinical
signs associated with PCV2 infections, reduction of overall viral
load, reduction of duration of viremia, delay in onset of viremia,
weight gain. Preferably less than 20 .mu.g/dose of the polypeptide
of the present invention is required to confer immunity in those
young animals. According to a more preferred embodiment, the
polypeptide of the present invention, preferably less than 20 .mu.g
is only administered once to that young animal in need of such
treatment.
[0134] Due to the ubiquity of PCV2 in the field most of the young
piglets are seropositive in respect to PCV2. Thus according to a
further aspect, the present invention provides a method for the
treatment or prevention of a PCV2 infection or for reduction of
clinical signs caused by or associated with a PCV2 infection in
young animals, preferably animals having anti-PCV2 antibodies at
the day of vaccination, comprising the step of administering an
effective amount of the polypeptide of the present invention to an
animal of 1 to 22 days of age, preferably of 1 to 20 days of age,
more preferably of 1 to 15 days of age, even more preferably of 1
to 14 days of age, even more preferably of 1 to 12 days of age,
even more preferably of 1 to 10 days of age, even more preferably
of 1 to 8 days of age, even more preferably of 1 to 7 days of age,
even more preferably of 1 to 6 days of age, even more preferably of
1 to 5 days of age, even more preferably of 1 to 4 days of age,
even more preferably of 1 to 3 days of age, even more preferably at
1 or 2 day(s) of age, most preferably at 1 day of age in need of
such treatment.
[0135] Preferably, said young animals, at the day of
vaccination/treatment, have a detectable anti-PCV2 antibody titer
of up to 1:100, preferably of more than 1:100, even more preferably
of more than 1:250, even more preferably of more than 1:500, even
more preferably of 1:640, even more preferably of more than 1:750,
most preferably of more than 1:1000 at the day of
vaccination/treatment. Preferably less than 20 .mu.g/dose of the
polypeptide of the present invention are required to confer a
sufficient immunity in those young animals. According to more
preferred embodiment, the polypeptide of the present invention,
preferably less than 20 .mu.g is only administered once to that
young animal in need of such treatment.
[0136] As described above, vaccination/treatment of young animals
with the polypeptide of the present invention preferably results in
shortening of viremic phase as compared to non-vaccinated control
animals. The average shortening time may preferably, for instance,
be 9.5 days as compared to non-vaccinated control animals of the
same species. Therefore, according to a further aspect, the present
invention also provides a method for the treatment or prevention of
a PCV2 infection or for reduction of clinical signs caused by or
associated with a PCV2 infection in young animals, comprising the
step of administering an effective amount of the polypeptide of the
present invention to that animal in need of such treatment, wherein
the treatment or prevention results in shortening of the viremia
phase of 5 or more days, preferably 6 or more days, even more
preferably of 7 or more days, even more preferably of 8 or more
days, even more preferably of 9, even more preferably of 10, even
more preferably of 12, even more preferably of 14, most preferably
of more than 16 days as compared to animals of a non-treated
control group of the same species. In some cases, the viremic phase
is preferably shortening for more than 20 days. In general, the
vaccination of young piglets preferably results in a reduction in
the loss of weight gain, a shorter duration of viremia, an earlier
end to viremia, and a lower virus load. Therefore, according to a
further aspect, the present invention provides a method for the
treatment or prevention of a PCV2 infection or for reduction of
clinical signs caused by or associated with a PCV2 infection in
young animals, comprising the step of administering an effective
amount of the polypeptide of the present invention to that animal
in need of such treatment, wherein said treatment or prevention of
PCV2 infection results in an improvement in comparison to animals
of a non-treated control group of the same species in a vaccine
efficacy parameter selected from the group consisting of a
reduction in the loss of weight gain, a shorter duration of
viremia, an earlier end to viremia, a lower virus load, or
combinations thereof. Preferably less than 20 .mu.g/dose
polypeptide of the present invention are required to cause any of
the improved vaccine efficacy parameter mentioned above. Moreover
such improved vaccine efficacy parameter are achieved by a singly
administration of only one dose.
[0137] The term "an effective amount" as used herein means but is
not limited to an amount of the polypeptide of the present
invention, that elicits or is able to elicit an immune response in
an animal, to which said effective dose of the polypeptide of the
present invention is administered. Preferably, an effective amount
is defined as an amount of the polypeptide of the present invention
that confers at least a 10 weeks duration of immunity (DOI),
preferably at least a12 weeks (DOI), more preferably at least a 15
weeks (DOI), most preferably at least a 20 weeks (DOI).
[0138] The amount that is effective depends on the ingredients of
the vaccine and the schedule of administration. Typically, when an
inactivated virus or a modified live virus preparation is used in
the combination vaccine, an amount of the vaccine containing about
10.sup.2.0 to about 10.sup.9.0 TCID.sub.50 per dose, preferably
about 10.sup.3.0 to about 10.sup.8.0 TCID.sub.50 per dose, more
preferably, about 10.sup.4.0 to about 10.sup.8.0 TCID.sub.50 per
dose. In particular, when modified live PCV2 is used in the
vaccines, the recommended dose to be administered to the
susceptible animal is preferably about 10.sup.3.0 TCID.sub.50
(tissue culture infective dose 50% end point)/dose to about
10.sup.6.0 TCID.sub.50/dose and more preferably about 10.sup.4.0
TCID.sub.50/dose to about 10.sup.5.0 TCID.sub.50/dose. In general,
the quantity of antigen will be between 0.2 and 5000 micrograms,
and between 10.sup.2.0 and 10.sup.9.0 TCID.sub.50, preferably
between 10.sup.3.0 and 10.sup.6.0 TCID.sub.50, more preferably
between 10.sup.4.0 and 10.sup.5.0 TCID.sub.50, when purified
antigen is used.
[0139] Sub-unit vaccines are normally administered with an protein
inclusion level of at least 0.2 .mu.g protein per dose, preferably
with about 0.2 to about 400 .mu.g/dose, still more preferably with
about 0.3 to about 200 .mu.g/dose, even more preferably with about
0.35 to about 100 .mu.g/dose, still more preferably with about 0.4
to about 50 .mu.g/dose, still more preferably with about 0.45 to
about 30 .mu.g/dose, still more preferably with about 0.5 to about
18 .mu.g/dose, still more preferably with about 0.6 to about 16
.mu.g/dose, even more preferably with about 0.75 to about 8
.mu.g/dose, even more preferably with about 1.0 to about 6
.mu.g/dose, still more preferably with about 1.3 to about 3.0
.mu.g/dose.
[0140] Preferably, the prophylactic use of the immunogenic
compositions described supra, is effective for reduction of
clinical signs caused by or associated with PCV2 infections,
preferably in young animals and/or in animals having passive
immunity against PCV2 at the day of treatment. In particular, the
prophylactic use of the immunogenic compositions as described
herein, and specifically of compositions comprising the polypeptide
of the present invention, is preferably effective for reducing
lymphadenopathy, lymphoid depletion and/or multinucleated/giant
histiocytes in animals infected with PCV2 and having maternal
anti-PCV-2 antibodies at the day of treatment/vaccination. For
example it was discovered that the prophylactic use of the
immunogenic compositions as described herein is effective for
reducing lymphoid depletion, lymphoid inflammation, positive IHC
for PCV2 antigen of lymphoid tissue, viremia, nasal shedding,
pyrexia, reduced average daily weight gain, lung inflammation,
positive IHC for PCV2 antigen of lung tissue.
[0141] Furthermore, the prophylactic use of the immunogenic
compositions as described herein is preferably effective for
reducing (1) interstitial pneumonia with interlobular edema, (2)
cutaneous pallor or icterus, (3) mottled atrophic livers, (4)
gastric ulcers, (5) nephritis, (6) reproductive disorders, e.g.,
abortion, stillbirths, mummies, etc., (7) Pia like lesions,
normally known to be associated with Lawsonia intracellularis
infections (Ileitis), (8) lymphadenopathy, (9) lymphoid depletion
and/or (10) multinucleated/giant histiocytes (11) Porcine
Dermatitis and Nephropathy Syndrome (PDNS), (12) PCVAD associated
mortality, (13) PCVAD associated weight loss, (14) reduced growth
variability, (15), reduced frequency of `runts`, (16) reduced
co-infections with Porcine Reproductive and Respiratory Disease
Complex (PRRSV). Such immunogenic composition is also effective in
improving economically important growth parameters such as time to
slaughter, carcass weight, and lean meat ratio. Thus the term
"clinical signs" as used herein, means, but is not limited to (1)
interstitial pneumonia with interlobular edema, (2) cutaneous
pallor or icterus, (3) mottled atrophic livers, (4) gastric ulcers,
(5) nephritis and (6) reproductive disorders, e.g., abortion,
stillbirths, mummies, etc., (7) Pia-like lesions, normally known to
be associated with Lawsonia intracellularis infections (Ileitis),
(8) lymphadenopathy, (9) lymphoid depletion and/or (10)
multinucleated/giant histiocytes (11) Porcine Dermatitis and
Nephropathy Syndrome (PDNS), (12) PCVAD associated mortality, (13)
PCVAD associated weight loss, (14) reduced growth variability (15)
reduced frequency of `runts`, (16) reduced co-infections with
Porcine Reproductive and Respiratory Disease Complex (PRRSV), (17)
lymphoid inflammation, (18) positive IHC for PCV2 antigen of
lymphoid tissue, (19) viremia, (20) nasal shedding, (21) pyrexia,
(22) reduced average daily weight gain, (23) lung inflammation,
(24) positive IHC for PCV2 antigen of lung tissue. Moreover, the
immunogenic composition described herein reduces the overall
circovirus load including a later onset, a shorter duration, an
earlier end of viremia, and a reduced viral load and its
immunosuppressive impact in young animals, in particular in those
having anti-PCV2 antibodies at the day of vaccination, thereby
resulting in a higher level of general disease resistance and a
reduced incidence of PCV2 associated diseases and clinical
signs.
[0142] Thus, according to a further aspect, the present invention
provides a method for the treatment or prevention of a PCV2
infection or for reduction of clinical signs caused by or
associated with a PCV2 infection in young animals and/or in
animals, preferably animals having anti-PCV2 antibodies, comprising
the step of administering an effective amount of the polypeptide of
the present invention or an immunogenic composition comprising the
polypeptide of the present invention to that animal in need of such
treatment, wherein those clinical signs are selected from the group
consisting of: (1) interstitial pneumonia with interlobular edema,
(2) cutaneous pallor or icterus, (3) mottled atrophic livers, (4)
gastric ulcers, (5) nephritis, (6) reproductive disorders, e.g.
abortion, stillbirths, mummies, etc., (7) Pia-like lesions,
normally known to be associated with Lawsonia intracellularis
infections (Ileitis), (8) lymphadenopathy, (9) lymphoid depletion
and/or (10) multinucleated/giant histiocytes, (11), Porcine
Dermatitis and Nephropathy Syndrome (PDNS), (12) PCVAD associated
mortality, (13) PCVAD associated weight loss, (14) reduced growth
variability, (15) reduced frequency of `runts`, (16) reduced
co-infections with Porcine Reproductive and Respiratory Disease
Complex (PRRSV), (17) lymphoid inflammation, (18) positive IHC for
PCV2 antigen of lymphoid tissue, (19) viremia, (20) nasal shedding,
(21) pyrexia, (22) reduced average daily weight gain, (23) lung
inflammation, (24) positive IHC for PCV2 antigen of lung tissue.
According to a further aspect, the present invention provides a
method for the treatment or prevention of a PCV2 infection or for
reduction of clinical signs caused by or associated with a PCV2
infection in young animals, comprising the step of administering an
effective amount of the polypeptide of the present invention to
that animal in need of such treatment, wherein those clinical signs
are selected from the group consisting of: (1) interstitial
pneumonia with interlobular edema, (2) cutaneous pallor or icterus,
(3) mottled atrophic livers, (4) gastric ulcers, (5) nephritis, (6)
reproductive disorders, e.g., abortion, stillbirths, mummies, etc.,
(7) Pia-like lesions, normally known to be associated with Lawsonia
intracellularis infections (Ileitis), (8) lymphadenopathy, (9)
lymphoid depletion and/or (10) multinucleated/giant histiocytes,
(11) Porcine Dermatitis and Nephropathy Syndrome (PDNS), (12) PCVAD
associated mortality, (13) PCVAD associated weight loss, (14)
reduced growth variability, (15) reduced frequency of `runts`, (16)
reduced co-infections with Porcine Reproductive and Respiratory
Disease Complex (PRRSV), (17) lymphoid inflammation, (18) positive
IHC for PCV2 antigen of lymphoid tissue, (19) viremia, (20) nasal
shedding, (21) pyrexia, (22) reduced average daily weight gain,
(23) lung inflammation, (24) positive IHC for PCV2 antigen of lung
tissue.
[0143] The composition according to the invention may be applied,
orally, intradermally, intratracheally, or intravaginally. The
composition preferably may be applied intramuscularly or
intranasally, most preferably intramuscularly. In an animal body,
it can prove advantageous to apply the pharmaceutical compositions
as described above via an intravenous or by direct injection into
target tissues. For systemic application, the intravenous,
intravascular, intramuscular, intranasal, intraarterial,
intraperitoneal, oral, or intrathecal routes are preferred. A more
local application can be effected subcutaneously, intradermally,
intracutaneously, intracardially, intralobally, intramedullarly,
intrapulmonarily or directly in or near the tissue to be treated
(e.g., connective-, bone-, muscle-, nerve-, epithelial tissue).
Depending on the desired duration and effectiveness of the
treatment, the compositions according to the invention may be
administered once or several times, also intermittently, for
instance on a daily basis for several days, weeks or months and in
different dosages.
[0144] Preferably, one dose of the immunogenic composition as
described above is intramuscularly administered to the subject in
need thereof. According to a further aspect, the polypeptide of the
present invention or the immunogenic composition comprising any
such polypeptide of the present invention as described herein is
bottled in and administered at one (1) mL per dose. Thus, according
to a further aspect, the present invention also provides a 1 ml
immunogenic composition, comprising the polypeptide of the present
invention as described herein, for the treatment or prevention of a
PCV2 infection or for reduction of clinical signs caused by or
associated with a PCV2 infection in young animals, comprising the
step of administering an effective amount of the polypeptide of the
present invention protein to that animal in need of such treatment.
According to a further aspect, the present invention also provides
a 1 ml immunogenic composition, comprising the polypeptide of the
present invention as described herein, for the treatment or
prophylaxis of a PCV2 infection or for reduction of clinical signs
caused by or associated with a PCV2 infection in animals,
preferably animals having anti-PCV2 antibodies, comprising the step
of administering an effective amount of the polypeptide of the
present invention or an immunogenic composition comprising the
polypeptide of the present invention to that animal in need of such
treatment.
[0145] According to a further aspect, at least one further
administration of at least one dose of the immunogenic composition
as described above is given to a subject in need thereof, wherein
the second or any further administration is given at least 14 days
beyond the initial or any previous administrations. Preferably, the
immunogenic composition is administered with an immune stimulant.
Preferably, said immune stimulant is given at least twice.
Preferably, at least 3 days, more preferably at least 5 days, even
more preferably at least 7 days are in between the first and the
second or any further administration of the immune stimulant.
Preferably, the immune stimulant is given at least 10 days,
preferably 15 days, even more preferably 20, even more preferably
at least 22 days beyond the initial administration of the
immunogenic composition provided herein. A preferred immune
stimulant is, for example, keyhole limpet hemocyanin (KLH),
preferably emulsified with incomplete Freund's adjuvant (KLH/ICFA).
However, it is herewith understood, that any other immune stimulant
known to a person skilled in the art can also be used. The term
"immune stimulant" as used herein, means any agent or composition
that can trigger the immune response, preferably without initiating
or increasing a specific immune response, for example the immune
response against a specific pathogen. It is further instructed to
administer the immune stimulant in a suitable dose.
[0146] In a further aspect, the invention provides a method of
determining whether an individual has received an immunogenic
composition, in particular a vaccine, containing the polypeptide of
the present invention, wherein said method, comprises the steps of:
[0147] obtaining a biological sample from an individual, and [0148]
determining in said biological sample the presence or absence of
one or more markers showing that the individual has received the
amino acid sequence of interest included in the polypeptide of the
present invention, and wherein the presence of said one or more
markers in said biological sample indicates that said individual
has received said immunogenic composition or wherein the absence of
said one or more markers in said biological sample indicates that
said individual has not received said immunogenic composition.
[0149] According to said first aspect, the present invention hence
provides a method of determining whether an individual has received
an immunogenic composition comprising the polypeptide of the
present invention, said method also being termed "the method of the
present invention" hereinafter, wherein said method in particular
comprises determining in a biological sample obtained from said
individual the presence or absence of one or more markers showing
that the individual has received said amino acid sequence of
interest, and wherein the presence of said one or more markers in
said biological sample indicates that said individual has received
said immunogenic composition.
[0150] Preferably, the immunogenic composition of the present
invention is a marker vaccine, in particular a positive marker
vaccine.
[0151] The term "marker vaccine" as described herein, in particular
specifies a vaccine leading to an immunization in the immunized
organism, which differs from the immunization of the organism
caused by the real pathogen.
[0152] A "positive marker vaccine" particularly relates to a marker
vaccine containing an additional antigen which induces the
production of specific antibodies present in vaccinated individuals
but not in infected ones.
[0153] The term "marker" as used within the context of the present
invention is preferably equivalent to the term "biomarker", and in
particular refers to a measurable substance or compound which
indicates that an individual has been exposed to an immunogenic
composition, preferably to a positive marker vaccine or, more
particular, to the additional antigen of a positive marker vaccine
which induces the production of specific antibodies found in
vaccinated subjects but not in infected ones.
[0154] As used herein, the term "immunogenic composition" in
particular refers to a composition that will elicit an immune
response in an individual that has been exposed to the composition.
An immune response may include induction of antibodies and/or
induction of a T-cell response. Depending on the intended function
of the composition, one or more antigens may be included.
Preferably, the immunogenic composition as described herein is a
vaccine.
[0155] The term "vaccine" as used herein, is in particular defined
in accordance with the pertinent art and relates to a composition
that induces or enhances immunity of an individual to a particular
disease. To this end, the vaccine comprises a compound that is
similar to the pathogen or a compound of said pathogen causing said
disease. Upon contact with this compound, the immune system of the
individual is triggered to recognize the compound as foreign and to
destroy it. The immune system subsequently "remembers" the contact
with this compound, so that at a later contact with the
disease-causing pathogen an easy and efficient recognition and
destruction of the pathogen is ensured. In accordance with the
present invention, the vaccine may be in any formulation for
vaccines known in the art, such as for example vaccines for
intramuscular injection, mucosal vaccines or vaccines for
subcutaneous or intradermal injection as well as vaccines for
inhalation, such as e.g., as aerosols. Such vaccine formulations
are well known in the art and have been described, e.g., in Neutra
M R et al. 2006 Mucosal vaccines: the promise and the challenge
6(2): 148-58 or F. P. Nijkamp, Michael J. Parnham 2011; Principles
of Immunopharmacology ISBN-13: 978-3034601351.
[0156] Preferably, the biological sample is obtained from said
individual 14 to 35 days after the day the individual has been
vaccinated or, respectively, has been supposedly vaccinated.
[0157] The one or more markers showing that the individual has
received the amino acid sequence of interest, which are also termed
"the one or more markers of the present invention" hereinafter, are
antibodies specific for said amino acid sequence of interest.
[0158] Preferably, the antibodies as described herein are
polyclonal antibodies.
[0159] As used herein, the term "antibodies specific for" a defined
antigen in particular refers to antibodies, preferably polyclonal
antibodies, that bind an antigen with an affinity or K.sub.a (i.e.,
an equilibrium association constant of a particular binding
interaction with units of 1/M) of, for example, greater than or
equal to about 10.sup.5M.sup.-1, 10.sup.6M.sup.-1,
10.sup.7M.sup.-1, 10.sup.8M.sup.-1, 10.sup.9M.sup.-1,
10.sup.10M.sup.-1, 10.sup.11M.sup.-1, 10.sup.12M.sup.-1 or
10.sup.13M.sup.-1. Alternatively, binding affinity may be defined
as an equilibrium dissociation constant (K.sub.a) of a particular
binding interaction with units of M (e.g., 10.sup.-5 M to
10.sup.-13M). Binding affinities of antibodies can be readily
determined using techniques well known to those of skill in the art
(see, e.g., Scatchard et al. (1949) Ann. N.Y. Acad. Sci. 51:660;
U.S. Pat. Nos. 5,283,173; 5,468,614; BIACORE.RTM. analysis; or the
equivalent).
[0160] Preferably, the method of the present invention comprises
the steps of: [0161] contacting the biological sample with a
capture reagent immobilized to a solid support, wherein the
immobilized capture reagent is capable of binding said one or more
markers, and [0162] determining the presence or absence of said one
or more markers bound to the capture reagent, wherein the presence
of said one or more markers bound to the capture reagent is
indicative for the presence of said one or more markers in said
biological sample.
[0163] The term "capture reagent", as used herein, in particular
refers to a molecule or a multi-molecular complex that can bind to
a marker. The capture reagent is preferably capable of binding the
marker in a substantially specific manner, preferably with an
affinity or K.sub.a>10.sup.5 or preferably >10.sup.6
M.sup.-1. The capture reagent may optionally be a naturally
occurring, recombinant, or synthetic biomolecule. Proteins and
nucleic acid ligands (aptamers) are highly suitable as capture
agents. A whole virus or a virus fragment or a synthetic peptide
may also serve as preferred capture reagents, since they are
capable of binding antibodies.
[0164] The herein mentioned capture reagent being immobilized to a
solid support and being capable of binding one or more markers of
the present invention, wherein said capture reagent is also termed
"capture reagent according to the present invention" hereinafter,
is preferably (i) a protein comprising the amino acid sequence of
interest or (ii) a peptide, e.g., a synthetic peptide, comprising
or consisting of the amino acid sequence of interest.
[0165] As used herein the term "immobilized" particularly means
that the capture reagent can be attached to a surface (e.g., the
solid support) in any manner or any method; including, e.g.,
reversible or non-reversible binding, covalent or non-covalent
attachment, and the like.
[0166] The term "solid support", as mentioned herein, denotes a
non-fluid substance, and includes chips, vessels, and particles
(including microparticles and beads) made from materials such as
polymer, metal (paramagnetic, ferromagnetic particles), glass, and
ceramic; gel substances such as silica, alumina, and polymer gels;
capillaries, which may be made of polymer, metal, glass, and/or
ceramic; zeolites and other porous substances; electrodes;
microtiter plates; solid strips; and cuvettes, tubes or other
spectrometer sample containers. A solid support component of an
assay is distinguished from inert solid surfaces with which the
assay may be in contact in that a "solid support" contains at least
one moiety on its surface, which is intended to interact with the
capture reagent, either directly or indirectly. A solid support may
be a stationary component, such as a tube, strip, cuvette, or
microtiter plate, or may be non-stationary components, such as
beads and microparticles. Microparticles can also be used as a
solid support for homogeneous assay formats. A variety of
microparticles that allow both non-covalent or covalent attachment
of proteins and other substances may be used. Such particles
include polymer particles such as polystyrene and poly(methyl
methacrylate); gold particles such as gold nanoparticles and gold
colloids; and ceramic particles such as silica, glass, and metal
oxide particles. See for example Martin, C. R., et al., Analytical
Chemistry-News & Features 70 (1998) 322A-327A, which is
incorporated herein by reference.
[0167] A "chip" is a solid, non-porous material, such as metal,
glass or plastics. The material may optionally be coated, entirely
or in certain areas. On the surface of the material any array of
spots is present, either visible or in coordinates. On each spot a
defined polypeptide, with or without linker or spacer to the
surface of the material, may be immobilized. All documents
mentioned herein, both supra and infra, are hereby incorporated
herein by reference.
[0168] Preferably, the method of the present invention comprises
determining in the biological sample the presence or absence of the
one or more markers of the present invention, wherein said markers
are antibodies specific for said amino acid sequence of interest,
and wherein said method comprises the steps of: [0169] a.
contacting the biological sample with a capture reagent immobilized
to a solid support, wherein the capture reagent is selected from
the group consisting of [0170] i. a protein comprising the amino
acid sequence of interest, [0171] ii. a peptide comprising or
consisting of the amino acid sequence of interest; [0172] b.
separating the biological sample from the immobilized capture
reagent; [0173] c. contacting the immobilized capture
reagent-antibody complex with a detectable agent that binds to the
antibody of the reagent-antibody complex; and [0174] d. measuring
the level of antibody bound to the capture reagent using a
detection means for the detectable agent, and wherein the measuring
step (D) preferably further comprises a comparison with a standard
curve to determine the level of antibody bound to the capture
reagent.
[0175] Preferably, said detectable agent that binds to the antibody
of the reagent-antibody complex is a detectable antibody, more
preferably a labelled secondary antibody.
[0176] The method of the present invention preferably further
comprises the step of determining in the biological sample the
presence of one or more analytes selected from the group consisting
of: [0177] antibodies specific for a polypeptide which comprises or
consists of an amino acid sequence having at least 90% sequence
identity with the amino acid sequence of SEQ ID NO:2 or SEQ ID
NO:3.
[0178] Within the context of the method of the present invention,
the immunogenic composition is preferably the immunogenic
composition as described underneath.
[0179] The term "biological sample" as used herein refers to any
sample that is taken from an individual (e.g., from a pig or a
bird) and includes, without limitation, cell-containing bodily
fluids, peripheral blood, blood plasma or serum, saliva, tissue
homogenates, lung and other organ aspirates, and lavage and enema
solutions, and any other source that is obtainable from a human or
animal subject. For animals, examples of a "biological sample"
include blood, cells, feces, diarrhea, milk, mucus, phlegm, pus,
saliva, semen, sweat, tear, urine, tears, ocular fluids, vaginal
secretions, and vomit, if present in that animal.
[0180] The biological sample, as referred to herein, has preferably
been isolated from a pig and/or is particular selected from the
group consisting of whole blood, blood plasma, serum, urine, and
oral fluids. Herein, the term "serum" is meant to be equivalent to
"blood serum".
[018