U.S. patent application number 13/266561 was filed with the patent office on 2012-07-12 for vaccine for prophylaxis or treatment of an allergen-driven airway pathology.
This patent application is currently assigned to INSTITUT PASTEUR DE LILLE. Invention is credited to Heather Kavanagh, Camille Locht, Bernard Mahon.
Application Number | 20120177688 13/266561 |
Document ID | / |
Family ID | 41057387 |
Filed Date | 2012-07-12 |
United States Patent
Application |
20120177688 |
Kind Code |
A1 |
Locht; Camille ; et
al. |
July 12, 2012 |
Vaccine for Prophylaxis or Treatment of an Allergen-Driven Airway
Pathology
Abstract
The present invention relates to a life attenuated Bordetella
pertussis vaccine which is deficient for tracheal cytotoxin (TCT),
pertussis toxin (PTX), and dermonecrotic toxin (DNT) for
prophylaxis or treatment of an allergen-driven airway
pathology.
Inventors: |
Locht; Camille; (Lille
Cedex, FR) ; Mahon; Bernard; (Maynooth, IE) ;
Kavanagh; Heather; (Maynooth, IE) |
Assignee: |
INSTITUT PASTEUR DE LILLE
Lille
FR
INSERM (Institu National de la Sante et de la Recherche
Medicale)
Paris
FR
NATIONAL UNIVERSITY OF IRELAND MAYNOOTH
Kildare
IE
|
Family ID: |
41057387 |
Appl. No.: |
13/266561 |
Filed: |
April 26, 2010 |
PCT Filed: |
April 26, 2010 |
PCT NO: |
PCT/EP2010/055507 |
371 Date: |
March 30, 2012 |
Current U.S.
Class: |
424/240.1 |
Current CPC
Class: |
A61K 2039/522 20130101;
A61P 31/04 20180101; A61K 2039/523 20130101; A61K 2039/543
20130101; A61K 39/099 20130101; A61K 2039/544 20130101 |
Class at
Publication: |
424/240.1 |
International
Class: |
A61K 39/10 20060101
A61K039/10; A61P 11/06 20060101 A61P011/06; A61P 11/00 20060101
A61P011/00; A61P 37/08 20060101 A61P037/08 |
Foreign Application Data
Date |
Code |
Application Number |
Apr 28, 2009 |
EP |
09305371.8 |
Claims
1. A vaccine for the prophylaxis or treatment of an allergen-driven
airway pathology, said vaccine comprising a live attenuated
Bordetella pertussis strain which is deficient for tracheal
cytotoxin (TCT), pertussis toxin (PTX), and dermonecrotic toxin
(DNT)
2. The vaccine according to claim 1, wherein the allergen-driven
airway pathology is selected from the group consisting of allergic
asthma, Hay fever and interstitial lung diseases.
3. The vaccine according to claim 1, wherein the subject is a
neonate or an infant.
4. The vaccine according to claim 1, wherein the live attenuated
Bordetella pertussis vaccine is the BPZE1 strain.
5. The vaccine according to claim 1, wherein the live attenuated
Bordetella pertussis strain comprises a heterologous antigen.
6. A live life attenuated Bordetella pertussis vaccine according to
claim 1, wherein the live attenuated Bordetella pertussis vaccine
is administered by nasal administration or by inhalation.
7. The vaccine according to claim 1, wherein the vaccine comprises
an adjuvant and a pharmaceutically acceptable carrier or
diluent.
8. A method of vaccination or treatment of an allergen driven
airway pathology in a subject comprising administering to said
subject a composition comprising a vaccine of claim 1.
9. The method of claim 8 wherein the allergen-driven airway
pathology is selected from the group consisting of allergic asthma,
Hay fever and interstitial lung diseases.
10. The method of claim 8, wherein the subject is a neonate or an
infant.
11. The method of claim 8, wherein the live attenuated Bordetella
pertussis vaccine comprises the BPZE1 strain.
12. The method of claim 8, wherein the live attenuated Bordetella
pertussis vaccine comprises a heterologous antigen.
13. The method of claim 8, wherein the live attenuated Bordetella
pertussis vaccine is administered by nasal administration or by
inhalation.
14. A method for the preparation of a vaccine for the prophylaxis
or treatment of an allergen-driven airway pathology comprising
preparing a live Bordetella pertussis strain which is deficient for
tracheal cytotoxin (TCT), pertussis toxin (PTX), and dermonecrotic
toxin (DNT) and admixing said Bordetella pertussis strain with and
adjuvant and/or a pharmaceutically acceptable carrier or diluent
for nasal or inhalational administration.
15. The method of claim 14 wherein the allergen-driven airway
pathology is selected from the group consisting of allergic asthma,
Hay fever and interstitial lung diseases.
16. The method of claim 14, wherein the live attenuated Bordetella
pertussis vaccine comprises the BPZE1 strain and optionally,
wherein the live attenuated Bordetella pertussis vaccine comprises
a heterologous antigen.
17. A method of protecting a subject from an allergen-driven airway
pathology comprising administering to said subject a vaccine
comprising a live Bordetella pertussis strain which is deficient
for tracheal cytotoxin (TCT), pertussis toxin (PTX), and
dermonecrotic toxin (DNT) in an amount effective to vaccinate
against said allergen-driven airway pathology.
18. The method of claim 17 wherein the allergen-driven airway
pathology is selected from the group consisting of allergic asthma,
Hay fever and interstitial lung diseases.
19. The method of claim 17, wherein the live attenuated Bordetella
pertussis vaccine comprises the BPZE1 strain and optionally,
wherein the live attenuated Bordetella pertussis vaccine comprises
a heterologous antigen.
Description
FIELD OF THE INVENTION
[0001] The present invention relates to a vaccine for prophylaxis
or treatment of an allergen-driven airway pathology.
BACKGROUND OF THE INVENTION
[0002] The pathogenesis of allergic asthma remains unclear,
however, the current understanding involves the expansion of CD4+
Th2 cells, and a breakdown in tolerance to otherwise innocuous
environmental allergens (Romagnani et al. J Allergy Clin Immunol
2004;113(3):395-400). Genetic predisposition, coupled with
environmental influences appears to affect the regular suppression
of Th2-mediated responses. It has been hypothesized that
abnormalities in the maturation of the lung during fetal and
neonatal development may render the airways more susceptible to
environmental allergens, favoring polarization towards the Th2
phenotype and thus, predisposing the individual to atopy and
asthma. Allergen-driven production of IL-4, IL-5 and IL-13 are
typical of allergic pathologies and the secretion of such
Th2-cytokines initiates isotype class-switching of B cells towards
IgE, increased mucus production and recruitment of eosinophils to
the airways. Since CD4.sup.+ Th2 cells represent a co-ordinating
cell type in some allergies, it was suggested that the induction of
counterbalancing responses might prevent the subsequent development
of atopic disease. According to this modification of Strachan's
hygiene hypothesis (Romagnani et al. Int Arch Allergy Immunol
1992;98(4):279-85), microbial exposure may activate innate immune
pathways that alter Th1, Th2 and Treg responses. This results in
the suppression of T helper 2 cell expansion, and a consequent
inhibition of isotype switching to IgE. However, several studies
have suggested that viral and bacterial infections play a role in
exacerbation of respiratory disease. For example, respiratory
syncytial virus and Th1 inducing virulent Bordetella pertussis
infection (Ennis et al. Clin Exp Allergy 2004;34(9):1488-97)
exacerbate allergic inflammation in animal models.
[0003] Gram-negative B. pertussis causes whooping cough, a severe
respiratory disease responsible for significant infant morbidity
and mortality worldwide. Although immunizations with either killed
whole cell vaccines (Pw) or more recent acellular subunit vaccines
(Pa) have had success, a re-emergence of the disease in young
adults has been reported (Das P. Lancet Infect Dis 2002;2(6):322).
Typically, B. pertussis does not acutely affect this age group;
however, infected adults can act as reservoirs, and increase the
likelihood of infants contracting the disease prior to vaccination.
Most current vaccination regimes require three doses, beginning at
2 months of age necessitating 6 months for optimal protection.
Therefore, there is a need for vaccines that induce strong
protection against B. pertussis in neonates.
[0004] Virulent B. pertussis infection exacerbates airway pathology
in a murine model of allergen driven inflammation, despite the
induction of Th1 immunity (Ennis et al. Clin Exp Allergy
2004;34(9):1488-97). Th2 inducing Pa vaccines protect against B.
pertussis-induced exacerbation of allergic asthma, but induce IL-13
both at a systemic and local level (Ennis et al. Clin Diagn Lab
Immunol 2005;12(3):409-17). In contrast, systemic immunization with
Th1 inducing Pw inhibits allergic airway responsiveness (Mills et
al. Dev Biol Stand. 1998;95:31-41), suggesting that protection from
allergen-driven pathology is not simply modulation of Th1/Th2
responses, but is associated with the degree of airway damage at
the time of priming, such that allergen priming via the respiratory
tract airways during breakdown of the airway epithelial mesenchymal
unit may be a more significant factor than Th1/Th2/Treg
polarization.
[0005] Recently, a genetically-attenuated live vaccine against B.
pertussis, BPZE1, has been developed as a candidate neonatal
vaccine against whooping cough (Mielcarek et al. PLoS Pathog
2006;2(7):e65). This live recombinant B. pertussis strain induces
strong local and systemic immune responses upon intranasal
delivery. Administration via the nasal route mimics natural
infection and is expected to promote long-lasting immunity in
children from 1 month of age (Mascart et al. J Immunology
2003;170(1):1504-9). Three virulence factors have been targeted for
attenuation; pertussis toxin, tracheal cytotoxin and dermonecrotic
toxin. Using allelic exchange, genes encoding these toxins were
deleted or replaced with genetically inactivated analogues in order
to induce protection, without the severe pathology associated with
wild-type infection. However, the influence of BPZE1 administration
on third party allergen priming and allergen induced pathology is
not known.
SUMMARY OF THE INVENTION
[0006] The present invention relates to a life attenuated
Bordetella pertussis vaccine which is deficient for tracheal
cytotoxin (TCT), pertussis toxin (PTX), and dermonecrotic toxin
(DNT) for prophylaxis or treatment of an allergen-driven airway
pathology.
[0007] The present invention relates to a method for prophylaxis or
treatment of an allergen-driven airway pathology in a subject,
comprising administering to said subject an effective amount of a
life attenuated Bordetella pertussis vaccine, wherein said life
attenuated Bordetella pertussis vaccine is deficient for tracheal
cytotoxin (TCT), pertussis toxin (PTX), and dermonecrotic toxin
(DNT).
[0008] The present invention also relates to the use of a life
attenuated Bordetella pertussis vaccine, which is deficient for
tracheal cytotoxin (TCT), pertussis toxin (PTX), and dermonecrotic
toxin (DNT) in the manufacture of a medicament for prophylaxis or
treatment of an allergen-driven airway pathology.
DETAILED DESCRIPTION OF THE INVENTION
[0009] Examples of allergen-driven airway pathology are allergic
asthma, Hay fever, interstitial lung diseases including pulmonary
fibrosis.
[0010] Interstitial lung diseases including pulmonary fibrosis, may
be caused by occupational or environmental exposures. Without
wishing to be bound by theory, a life attenuated Bordetella
pertussis vaccine, which is deficient for TCT, PTX, and DNT would
reduce airway damage and remodelling during a period of
environmental exposure (to the agent triggering Interstitial lung
diseases) and would also protect against virulent B. pertussis
exacerbation of pulmonary fibrosis.
[0011] By "subject" it is meant a human. Typically the subject is a
neonate, an infant or an adult.
[0012] Life attenuated Bordetella pertussis vaccines which are
deficient for tracheal cytotoxin (TCT), pertussis toxin (PTX), and
dermonecrotic toxin (DNT) have been described in WO2007/104451 and
in Mielcarek et al. (PLoS Pathog 2006;2(7):e65).
[0013] Recent advances in the understanding of B. pertussis
virulence at the molecular level have allowed to rationally design
a strategy for attenuation by removing or altering genes that are
involved in the pathogenesis of whooping cough. Three virulence
factors were genetically targeted: tracheal cytotoxin (TCT),
pertussis toxin (PTX), and dermonecrotic toxin (DNT).
[0014] TCT is responsible for the destruction of ciliated cells in
the trachea of infected hosts and may thus be involved in the cough
syndrome. TCT is a breakdown product of peptidoglycan in the cell
wall of Gram-negative bacteria, which generally internalize it into
the cytosol by the AmpG transporter protein to be re-utilized
during cell wall biosynthesis. B. pertussis AmpG is inefficient in
the internalization of peptidoglycan breakdown products. The B.
pertussis ampG gene can be replaced by E. coli ampG. The resulting
strain expressed less than 1% residual TCT activity. Any
heterologous ampG gene from gram-negative bacteria that release
very small amounts of peptidoglycan fragments into the medium, can
be used in the present invention. Examples of suitable heterologous
ampG gene include, but are not limited to ampG gene from
Escherichia coli, Salmonella, Enterobacteriaceae, Pseudomonas,
Moraxella, Helicobacter, Stenotrophomonas, Legionella.
[0015] PTX is a major virulence factor responsible for the systemic
effects of B. pertussis infections and is composed of an
enzymatically active moiety, called S1, and a moiety responsible
for binding to target cell receptors. It is also one of the major
protective antigens. The natural ptx genes can be replaced by a
mutated version coding for an enzymatically inactive toxin. This
can be achieved by replacing Arg-9 by Lys, and Glu-129 by Gly in
S1, two key residues involved in substrate binding and catalysis,
respectively. Allelic exchange can be used to first delete the ptx
operon, and then to insert the mutated version.
[0016] The presence of the relevant toxin in the B. pertussis
culture supernatants can be detected by immunoblot analysis.
[0017] Other mutations can also be made such as those described in
U.S. Pat. No. 6,713,072, as well as any known or other mutations
able to reduce the toxin activity to undetectable levels.
[0018] Allelic exchange can also be used to remove the dnt gene.
Although the role of DNT in the virulence of B. pertussis is not
certain, it has been identified as an important toxin in the
closely related species Bordetella bronchiseptica and displays
lethal activity upon injection of minute quantities.
[0019] In a preferred embodiment, the life attenuated Bordetella
pertussis vaccine is the BPZE1 strain.
[0020] The BPZE1 strain has been deposited with the Collection
Nationale de Cultures de Microorganismes (CNCM, Institut Pasteur,
25 rue du Docteur Roux, F-75724 Paris Cedex 15, FRANCE) on Mar. 9,
2006 under the number CNCM 1-3585.
[0021] Typically, life attenuated Bordetella pertussis vaccines of
the invention may also carry heterologous antigens. The life
attenuated Bordetella pertussis vaccines may be used as vector, to
bear at least one further heterologous nucleic acid sequence
encoding a protein of interest. Typically, the protein encoded by
at least one further heterologous nucleic acid sequence is a
protein for which the expression is desired in the respiratory
tract. Typically, the protein of interest may be an antigen, such
as a viral or a bacterial antigen, against which an immune response
is desired. Examples of life attenuated Bordetella pertussis
vaccines carrying heterologous antigens have been disclosed for
example by Si Ying Ho et al. (Infection and Immunity, 2008, 76(1),
111-119).
[0022] Formulation of the vaccines of the present invention can be
accomplished using art recognized methods. The amount of vaccines
of the invention to be administered to a subject and the regime of
administration can be determined in accordance with standard
techniques well known to those of ordinary skill in the
pharmaceutical and veterinary arts taking into consideration such
factors as the adjuvant (if present), the age, sex, weight, species
and condition of the particular subject and the route of
administration. The administration of the vaccine is usually in a
single dose. Alternatively, the administration of the vaccine of
the invention is made a first time (initial vaccination), followed
by at least one recall (subsequent administration), with the
vaccine.
[0023] Typically the vaccines can be administered by nasal
administration or by inhalation. This type of administration is low
in costs and enables the colonization by the life attenuated
Bordetella pertussis vaccine of the invention of the respiratory
tract. Nasal administration may be accomplished with a life
attenuated Bordetella pertussis vaccine under the form of liquid
solution, suspension, emulsion. Solutions and suspensions are
administered as drops. Solutions can also be administered as a fine
mist from a nasal spray bottle or from a nasal inhaler. Gels are
dispensed in small syringes containing the required dosage for one
application Inhalation may be accomplished with a life attenuated
Bordetella pertussis vaccine under the form of solutions,
suspensions, and powders; these formulations are administered via
an aerosol, droplets or a dry powder inhaler. The powders may be
administered with insufflators or puffers.
[0024] In the following, the invention will be illustrated by means
of the following example as well as the figures.
FIGURE LEGENDS
[0025] FIG. 1. Attenuated B. pertussis BPZE1 reduces the severity
of airway pathology induced by sensitizing allergen. Representative
morphological changes at 38 days in bronchiolar transverse sections
of lungs from (A) Non-sensitized, (B) OVA-sensitized, (C)
OVA-sensitized and infected with B. pertussis, (D) OVA-sensitized
and immunized with BPZE1. Airway inflammation was detected using
haematoxylin and eosin (H&E) staining of fixed lung sections.
Original magnification A, C, E & G.times.100. B, D, F & H
.times.400.
[0026] FIG. 2. Attenuated B. pertussis BPZE1 reduces the severity
of mucus hyperplasia to sensitizing allergen. Representative
morphological changes at 37 days in transverse sections of
bronchioles from (A) non-sensitized, (B) OVA-sensitized, (C)
OVA-sensitized and infected with B. pertussis, (D) OVA-sensitized
and vaccinated with BPZE1. Airway inflammation was detected using
combined Discombes/Alcian blue/PAS staining on lung sections.
Original magnification .times.400.
[0027] FIG. 3. Attenuated B. pertussis BPZE1 reduces the cell
infiltrate of BAL fluid. Effect of virulent BPSM infection,
attenuated BPZE1 challenge and/or OVA sensitization on BAL
composition 24 h after final OVA exposure. Negative controls were
sham infected/sensitized with saline. BAL fluid was examined for
the total cell number (A), or the presence of neutrophils (B),
eosinophils (C) or lymphocytes (D). Results are expressed as
mean.+-.S.E.M. of cell number. *P<0.05.
[0028] FIG. 4. Attenuated B. pertussis BPZE1 reduces
allergen-induced IgE. OVA-specific IgE in serum elicited in
response to OVA sensitization and/or challenge with virulent (BPSM)
or attenuated (BPZE1) B. pertussis. Sera were collected on day 38
and OVA-specific serum IgE levels were measured by ELISA.
Concentrations below 100 pg/ml were considered negative. Results
are expressed as mean antibody concentrations.+-.S.E.M.
P<0.05.
[0029] FIG. 5. Cell-mediated immune responses from splenocytes to
OVA, elicited by OVA sensitization 10 days following prior exposure
to attenuated (BPZE1) or virulent (BPSM) B. pertussis infection.
Negative symbols indicate sham sensitization or challenge with PBS.
Cytokine responses from similar cultures assayed are shown for (A)
IL-5, (B) IL-10, (C) IL-13 and (D) IFN-.gamma.. T-cell
proliferation (E) represents .DELTA.cpm of spleen proliferation
against OVA at 200 .mu.g/ml following subtraction of background
typically 2000-4000cpm. Results are expressed as mean.+-.S.E.M.
TABLE-US-00001 TABLE I Summary of pathological features of B.
pertussis/allergen sensitization. Spleen cell culture Tissue BALF
Goblet cell -- OVA- Group inflammation eosinophils metaplasia IL-5
IL-13 IL-10 IFN-.gamma. IgE Control - - - - - - - - OVA ++ ++ ++
+++ +++ - - ++ ZeOVA + + + - + - ++ + SmOVA ++ +++ +++ + - - - +++
BPZE1 - - - - - - - - BPSM - - - - - - - - Features of airway
inflammation in non-sensitized (Control), OVA-sensitized (OVA),
BPZE1-immunized sensitized mice (ZeOVA) or BPSM-infected sensitized
mice (SmOVA).
EXAMPLE
[0030] Abstract
[0031] This preclinical study examined whether the candidate B.
pertussis vaccine BPZE1 influences third party allergen priming and
pathology, using previously characterized animal models. Unlike
virulent wildtype strains, live attenuated BPZE1 did not exacerbate
but protected against allergen-driven pathology.
[0032] Abbreviations Used
[0033] OVA: Ovalbumin; BAL: Bronchoalveolar lavage; BPZE1: live
attenuated Bordetella pertussis; Pa: Acellular pertussis vaccine;
Pw: Whole-cell pertussis vaccine
[0034] Materials
[0035] Immunization, Sensitization and Airway Delivery of OVA and
B. pertussis
[0036] Eight- to twelve-week old, female BALB/c mice (Harlan, Oxon,
UK) were used and maintained according to the regulations and
guidelines of the Irish Department of Health, and the Research
Ethics Committee of the National University of Ireland, Maynooth.
Mice were exposed to live virulent or attenuated bacteria, and
sensitized to allergen during infection. Virulent B. pertussis BPSM
or attenuated BPZE1 were cultured as previously described (Mills et
al. Dev Biol Stand. 1998;95:31-41). Attenuated or virulent strains
at mid-log growth were administered to mice by aerosol. At the peak
of infection (10 d) and at 24 d, mice were sensitized by
intra-peritoneal injection of 100 .mu.g/ml ovalbumin (OVA) in
adjuvant (AlumImject.TM., Pierce, Ill.). Mice were challenged
intra-nasally with OVA (50 ng/ml) on days 24, 35, 36 and 37.
Various control groups received sham delivery of sterile PBS in
place of the active agent (Ennis et al. Clin Exp Allergy
2004;34(9):1488-97).
[0037] Bronchoalveolar Lavage (BAL) and Respiratory Tract
Histology
[0038] On 37 d, mice were sacrificed by lethal injection of sodium
pentobarbital and BAL fluid collected (Ennis et al. Clin Exp
Allergy 2004;34(9):1488-97). Total leukocytes and differential cell
counts were performed as described, using Diff Quik/Rapi-Diff
II.TM. (Triangle Biomedical Sciences, NC, USA.). Lungs from
non-lavaged mice were removed and fixed in 10% (v/v) formalin/PBS,
embedded in paraffin, sectioned and stained with haemotoxylin/eosin
(H&E), alcian blue (identification of mucus), Discombes
(identification of eosinophils), or periodic acid-Schiff (for
assessment of basement membrane thickness). Histopathological
changes were graded according to an established semi-quantitative
scoring system as mild, moderate or severe. Pathology was scored by
two independent observers without prior knowledge of the treatment
group as previously described (Ennis et al. Clin Diagn Lab Immunol
2005;12(3):409-17).
[0039] T Cell Proliferation Assay
[0040] Splenocytes from mice were prepared as previously described
(Mahon et al. J Exp Med 1997;186(11):1843-1851) and incubated for
72 h with either medium (negative control), OVA (200 .mu.g/ml), or
concanavalin A (5 .mu.g/ml). Supernatants were removed at 48 h for
cytokine analysis, and cultures received fresh medium. Cells were
incubated for the final 6 h with [.sup.3H]-thymidine and
proliferation was measured by radioactivity incorporated by liquid
scintillation.
[0041] Measurement of Cytokines and Antibody Responses
[0042] Analysis of IL-5, IL-10, IL-13 and IFN-.gamma. from BAL
fluid and splenocyte supernatant was carried out using Cytometric
Bead Array Flex Sets (BD Biosciences, Franklin Lakes, N.J.)
according to manufacturer's instructions, and analysed by flow
cytometry (Becton-Dickinson, N.J., USA). Standard curves and raw
data were generated for each cytokine using FCAP Array v1.0.1
software (BD Biosciences). OVA-specific serum IgE was measured by
ELISA as previously described (Morokata Tet al. Immunology
1999;98(3):345-351) using a rat anti-mouse IgE monoclonal antibody
(BD Pharmingen, San Diego, Calif., USA). IgE concentration was
expressed as .mu.g/ml after comparison to murine IgE standards (BD,
Pharmingen, San Diego, Calif., USA).
[0043] Statistical Analysis
[0044] Values for all measurements were expressed as the
mean.+-.standard error of the mean (SEM). Statistical analysis was
performed using GraphPad Prism.TM. software (GraphPad, San Diego,
Calif.). Comparison was made using the Kruskal Wallis test, or the
Mann Whitney test as appropriate. Significance was denoted by P
value<0.05.
[0045] Results
[0046] The Attenuated B. pertussis BPZE1 Prevents Exacerbated
OVA-Driven Allergic Airway Pathology
[0047] Virulent B. pertussis can exacerbate third party allergen
priming in animal models (Ennis et al. Clin Exp Allergy
2004;34(9):1488-97) and has been associated with exacerbation of
allergy in humans (Harju et al. Thorax 2006;61(7):579-584).To
assess the influence of attenuated B. pertussis on third party
allergen priming, mice were primed with virulent or attenuated
strains of B. pertussis, and sensitized to OVA at the peak of
bacterial carriage (a model previously shown to uncover the
influence of infection on allergen-driven inflammation). In the
absence of infection, OVA sensitized mice exhibited typical
peribronchial and perivascular inflammation at day 38, which was
not observed in naive control mice (FIGS. 1A and B). At this time
point, pathology due to virulent bacterial infection alone has
resolved. Priming at the peak of virulent B. pertussis infection
enhanced airway pathology when compared to OVA sensitization alone,
with mice displaying epithelial hyperplasia and moderate mucus
metaplasia (FIG. 1C). In contrast, minimal pathology was observed
in sensitized mice infected with attenuated BPZE1, compared to
those sensitized to OVA alone (FIG. 1D). An examination of
mucus-containing goblet cells demonstrated that prior immunization
with BPZE1 in OVA-sensitized mice reduced mucus secretion and
hyperplasia, compared to those sensitized to OVA alone (FIG. 2).
Thus unlike infection with virulent B. pertussis, immunization with
the candidate live attenuated B. pertussis vaccine BPZE1 did not
enhance, but reduced the pathology associated with allergen
sensitization.
[0048] The Attenuated B. pertussis Vaccine Strain BPZE1 Prevents
OVA-Driven Allergic Airway Inflammation
[0049] Immunization with live attenuated B. pertussis BPZE1
moderated the quality of the OVA-induced inflammatory influx to the
respiratory tract. Control mice showed minimal cellularity in
bronchoalveolar lavage (FIG. 3), whereas OVA
sensitization/challenge resulted in significant infiltration by
inflammatory cells (>3.times.10.sup.6 cells, FIG. 3A,
p<0.05). There were few remarkable differences in the numbers of
lymphocytes or neutrophils. BPZE1 immunization alone did not
support a neutrophil infiltration at 38d and infiltration of
neutrophils in combined BPZE1/OVA sensitized mice was typically
lower than either OVA alone or in combination with virulent
bacteria, however this did not achieve statistical significance in
this study. The key observations were that prior infection with
virulent B. pertussis increased cellular infiltration compared to
sensitization by OVA alone accompanied by increased eosinophilia
(FIG. 3C) as previously observed (Ennis et al. Clin Exp Allergy
2004;34(9):1488-97). However in marked contrast immunization with
live attenuated BPZE1 prior to OVA sensitization resulted in
significantly reduced OVA driven eosinophil infiltration of the
airways (FIG. 3C, p<0.05). Thus, the candidate live attenuated
B. pertussis vaccine BPZE1 prevents OVA-driven allergic airway
eosinophilia--a key feature of inflammation in this model.
[0050] The Candidate Live B. pertussis Vaccine BPZE1 Does Not
Enhance Serum IgE Responses to Sensitizing Allergen
[0051] OVA sensitization in mice is known to induce IgE and a
powerful specific Th2 response, whereas B. pertussis infection
induces a strong Th1 response. However, pertussis toxin alone can
elevate IgE concentrations. Therefore, it was important to explore
whether attenuated BPZE1 had an adjuvant effect or enhanced
allergen-specific IgE. The influence of BPZE1 on allergic
sensitization was examined by measuring the concentration of
OVA-specific IgE in serum from mice sensitized to OVA, infected
with BPSM, immunized with BPZE1, or receiving combinations of these
treatments (FIG. 4). OVA sensitization induced significant levels
of IgE as is well documented. Previously, a significant increase in
OVA-specific IgE following infection with virulent B. pertussis W28
was observed in OVA-sensitized mice (Ennis et al. Clin Exp Allergy
2004;34(9):1488-97). IgE responses in mice exposed to attenuated
BPZE1 prior to OVA sensitization did not differ significantly to
those receiving OVA alone. However, in marked contrast, attenuated
BPZE1 immunization resulted in significantly reduced induction
(p<0.05) of OVA-induced IgE compared to mice infected with
virulent BPSM in combination with OVA sensitization (FIG. 4).
Therefore, the candidate live attenuated B. pertussis vaccine BPZE
1 delivered prior to allergen priming demonstrated no enhanced IgE
response as observed with B. pertussis W28.sup.11 and BPSM.
[0052] The Live Attenuated B. pertussis Vaccine BPZE1 Modulates
Recall Cytokine Responses to Sensitizing Allergen
[0053] It is clear that attenuated BPZE 1 has a radically different
effect on allergen-driven airway pathology compared to virulent B.
pertussis. In order to uncover the mechanistic basis of this
effect, the influence of bacterial exposure on the pattern of
allergen-induced immune responses was characterized.
Allergen-specific cytokine induction by spleen cell preparations
was assessed following immunization with BPZE1 and OVA
sensitization/challenge in order to evaluate the influence of BPZE1
on allergen-induced priming. As expected, OVA sensitization alone
induced high levels of the Th2 cytokines IL-5 and IL-13 (FIG. 5) on
recall to OVA. Neither virulent BPSM nor attenuated BPZE1 alone
induced any recall response to OVA (FIG. 5E), but did produce
strong Th1 responses to B. pertussis antigens. BPSM challenge did
not modulate the immune response to sensitizing allergen, with no
significant reduction in OVA specific IL-5, IL-13 or proliferative
responses observed in mice co-sensitized to OVA, and no significant
increase in IFN-.gamma. (FIG. 5). In contrast, attenuated BPZE1
altered the pattern of cytokines induced by sensitizing allergen.
BPZE1 significantly reduced the levels of OVA-induced IL-5
(p<0.005) and IL-13 (p<0.05), as well as OVA specific
proliferative responses (p<0.001), but induced significantly
increased IFN-.gamma. in response to OVA (p<0.05). In summary,
BPZE1 did not promote Th2 cytokine induction to third party antigen
but rather modulated this to a Th1 like response.
[0054] Discussion
[0055] The present study used combined infection/sensitization
models to demonstrate that an attenuated strain of B. pertussis,
BPZE1, did not enhance but reduced allergen-driven airway
pathology. Attenuated B. pertussis reduced allergen-driven lung
eosinophilia and decreased the severity of airway inflammation.
Furthermore, BPZE1 prevented an increase in OVA-induced IL-5 and
IL-13 and modulated recall responses to allergen to a Th1 like
response. BPZE1 demonstrated reduced allergen-induced serum IgE
responses when compared to mice infected with virulent B. pertussis
prior to OVA sensitization (see Table I). Taken together these data
demonstrate that attenuated BPZE1 does not exacerbate
allergen-induced airway pathology in a murine model and supports
the use of this candidate vaccine for populations where atopy is
prevalent.
[0056] The hygiene hypothesis suggests that Th1-inducing infections
may have an inhibitory effect on the development of atopy. However,
previous studies have demonstrated that virulent B. pertussis
enhances the severity of airway pathology (Ennis et al. Clin Exp
Allergy 2004;34(9):1488-97) despite induction of Th1 immunity. In
contrast, systemic immunization with a Th1-inducing Pw vaccine
inhibited allergic airway responsiveness, suggesting that
protection from allergen-driven pathology is linked not just to
CD4.sup.1 T cell profile, but also to the degree of airway damage
at the time of priming.
[0057] The purpose of this study was to investigate whether
immunization with a genetically attenuated strain of B. pertussis
could protect against OVA-induced airway inflammation. Previously,
the potential of other vaccines to moderate the risk of atopy has
been investigated and a number of studies have found an inverse
relationship between immunization and an increased risk of allergic
disease. Ennis et at found that a Pw vaccine protected against B.
pertussis-exacerbation of OVA-induced airway hyperresponsiveness in
a murine model of allergic airway inflammation (Mills et al. Dev
Biol Stand. 1998;95:31-41). Likewise, Gruber et at found no
allergy-promoting effect in response to common childhood vaccines
including pertussis vaccines (Gruber et al. Allergy
2008;63(11):1464-72). The relationship between childhood
immunization and the development of atopic diseases in a
population-based sample of 718 adolescents found that live
attenuated vaccines inhibited the development of asthma and
allergic diseases (Martignon et al. Pediatr Allergy Immunol.
2005;16(3):193-200). The current study demonstrates that the
vaccine candidate BPZE1 suppresses allergen-driven pathology
through a mechanism that modulates cell-mediated responses against
OVA at both a mucosal and systemic level.
[0058] IL-5-mediated recruitment of eosinophils to the lung
contributes to allergen-induced airway pathology by generating
potent cytotoxic products, including major basic protein (MBP) and
eosinophil peroxidase, which collectively contribute to tissue
damage (Gleich G. J Allergy Clin Immunol 2000;105(4):651-63).
Infection with virulent B. pertussis exacerbates the extent of the
OVA-induced inflammatory influx to the respiratory tract, with an
increase in eosinophils (FIG. 3C), accompanied by a marked increase
in the severity of airway pathology (FIG. 1G). Conversely,
administration of attenuated BPZE 1 prior to allergen sensitization
resulted in a significant reduction in eosinophil infiltration.
This study demonstrates that BPZE1 prevents the adjuvant-associated
increase in OVA-induced IL-5 (FIG. 1A) seen when animals are
infected with virulent B. pertussis strains. IL-13 also contributes
to the pathogenesis of asthma by promoting Th2 responses,
increasing eosinophil recruitment, and contributing to IgE-mediated
inflammation (Humbert et al. J Allergy Clin Immunol.
1997;99(5):657-65; Temann et al. Am J Respir Cell Mol Biol
1997;16(4):471-8). Attenuated BPZE1 significantly decreased OVA
induced IL-13 in sensitized mice (FIG. 5C). Airway mucus
hypersecretion is also linked to IL-13 and is a major
pathophysiological feature of both allergic asthma and whooping
cough. It is not surprising therefore that mucus production
mirrored IL-13 levels in this study and was significantly reduced
in sensitized mice previously exposed to BPZE1 (FIG. 5C).
[0059] This study suggests that one, or a combination, of the
attenuated virulence factors in BPZE 1 (pertussis toxin, tracheal
cytotoxin and dermonecrotic toxin) play a role in the adjuvant
effect observed with virulent B. pertussis strains, via the
induction of either IL-5 or IL-13, or both.
[0060] The protection against allergen-driven pathology seen here
is associated with three genetic modifications contained within
BPZE1 and modulation of the allergic immune response is consistent
with some versions of the hygiene hypothesis. However, the
mechanisms underlying the beneficial influence of attenuated BPZE1
on allergen-driven pathology may be multiple and inter-linked.
Previous studies have demonstrated a significant increase in total
serum IgE as a result of OVA sensitization in animal models
(Holgate et al. J Allergy Clin Immunol 2005;115(3):459-465;
Hamelmann et al. Allergy 1999;54(4):297-305). Here,
allergen-specific IgE responses induced by respiratory
sensitization were significantly reduced in mice receiving
attenuated compared to virulent B. pertussis. This is consistent
with the modulation of systemic immune responses to OVA induced by
attenuated BPZE1 away from IL-5 and IL-13 towards IFN-.gamma., a
response which is associated with reduced IgE (Lack et al. J
Immunol 1994;152(5):2546-54). Nevertheless allergic airway
inflammation is not simply a balance between Th1 and Th2 responses.
Hansen et at have shown that modulation of airway CD4' Th responses
does not necessarily reduce airway pathology (Hansen et al. J Clin
Invest 1999;103(2):175-183). It might be that the key beneficial
feature of BPZE1 is the combination of a Th1 skewed response
combined with the absence of induced airway pathology. This is
consistent with previous reports in which exacerbation of airway
pathology to allergen was associated with allergen priming during a
period of airway damage or remodelling (Marsland et al. Clin Exp
Allergy 2004;34(8):1299-306; Gern. J Allergy Clin Immunol
2000:105(2 Pt 2):S497-502).
[0061] This combined benefit makes life attenuated Bordetella
pertussis vaccine which is deficient for TCT, PTX, and DNT an
attractive candidate as a protective agent against atopy.
REFERENCES
[0062] Throughout this application, various references describe the
state of the art to which this invention pertains. The disclosures
of these references are hereby incorporated by reference into the
present disclosure.
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