U.S. patent application number 10/634895 was filed with the patent office on 2004-03-11 for pro-apoptotic fragments of the dengue virus envelope glycoproteins.
This patent application is currently assigned to INSTITUT PASTEUR. Invention is credited to Catteau, Adeline, Courageot, Marie-Pierre, Despres, Philippe, Deubel, Vincent.
Application Number | 20040049016 10/634895 |
Document ID | / |
Family ID | 22789669 |
Filed Date | 2004-03-11 |
United States Patent
Application |
20040049016 |
Kind Code |
A1 |
Despres, Philippe ; et
al. |
March 11, 2004 |
Pro-apoptotic fragments of the dengue virus envelope
glycoproteins
Abstract
The present invention relates to pro-apoptotic fragments of the
Dengue virus pRM and E glycoproteins, methods of screening for
molecules capable of inducing apoptosis and methods of inducing
apoptosis in a cell.
Inventors: |
Despres, Philippe; (La
Garenne-Colombes, FR) ; Courageot, Marie-Pierre;
(Paris, FR) ; Deubel, Vincent; (Vanves, FR)
; Catteau, Adeline; (Savigny Sur Orge, FR) |
Correspondence
Address: |
OBLON, SPIVAK, MCCLELLAND, MAIER & NEUSTADT, P.C.
1940 DUKE STREET
ALEXANDRIA
VA
22314
US
|
Assignee: |
INSTITUT PASTEUR
Paris
FR
75724
|
Family ID: |
22789669 |
Appl. No.: |
10/634895 |
Filed: |
August 6, 2003 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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10634895 |
Aug 6, 2003 |
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09881710 |
Jun 18, 2001 |
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6673895 |
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60212129 |
Jun 16, 2000 |
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Current U.S.
Class: |
530/395 |
Current CPC
Class: |
A61K 38/00 20130101;
Y02A 50/386 20180101; A61P 31/14 20180101; Y02A 50/30 20180101;
Y02A 50/394 20180101; A61P 43/00 20180101; A61K 39/00 20130101;
C12N 2770/24122 20130101; A61P 35/00 20180101; A61K 48/00 20130101;
C07K 14/005 20130101 |
Class at
Publication: |
530/395 ;
514/008 |
International
Class: |
A61K 038/16; C07K
014/005 |
Claims
1. An isolated polypeptide of the sequence in SEQ ID NO:1.
2 The isolated polypeptide of claim 1, wherein said peptide induces
apoptosis in a cell.
3. An isolated polynucleotide which encodes the polypeptide of
claim 1.
4. A vector comprising the polynucleotide of claim 3.
5. A prokaryotic cell comprising the polynucleotide of claim 3.
6. A eukaryotic cell comprising the polynucleotide of claim 3.
7. A composition comprising the polynucleotide of claim 3 and a
physiologically acceptable carrier.
8. A composition comprising the peptide of claim 1 and a
physiological acceptable carrier.
9. An isolated polypeptide of the sequence in SEQ ID NO:2.
10. An isolated polynucleotide which encodes the polypeptide of
claim 9.
11. A vector comprising the polynucleotide of claim 10.
12. A prokaryotic cell comprising the polynucleotide of claim
10.
13. A eukaryotic cell comprising the polynucleotide of claim
10.
14. A composition comprising the polynucleotide of claim 10 and a
physiologically acceptable carrier.
15. A composition comprising the peptide of claim 9 and a
physiological acceptable carrier.
16. An isolated polypeptide of the sequence SEQ ID NO:1 operably
linked to the sequence SEQ ID NO:2.
17. An isolated polynucleotide which encodes the polypeptide of
claim 16.
18. A vector comprising the polynucleotide of claim 17.
19. The vector of claim 18 which is the plasmid
p[95-114]EGFP[206-245] deposited in the CNCM on Jan. 21, 2000 under
the accession number I-2380.
20. The vector of claim 18 which is the plasmid p[95-114][211-245]
deposited in the CNCM on May 10, 2000 under the accession number
I-2475.
21. A prokaryotic cell comprising the polynucleotide of claim
17.
22. A eukaryotic cell comprising the polynucleotide of claim
17.
23. A composition comprising the polynucleotide of claim 17 and a
physiological acceptable carrier.
24. A composition comprising the polypeptide of claim 16 and a
physiological acceptable carrier.
25. A method of inducing apoptosis in a cell comprising
administering an effective amount of the polypeptide of claim 16 to
the cell to induce apoptosis.
26. The method of claim 25, wherein said cell is in a human
patient.
27. The method of claim 25, wherein said patient is suffering from
cancer.
28. The method of claim 25, wherein said patient is infected with a
Flavivirus
29. A method of inducing apoptosis in a cell comprising delivering
the polypeptide of claim 16 in an amount sufficient to induce
apoptosis.
30. The method of claim 29, wherein said delivering comprises
delivering a polynucleotide encoding said polypeptide to the cell,
wherein said polynucleotide is in an expression vector suitable to
express said polypeptide in the cell.
31. The method of claim 29, wherein said cell is in a human
patient.
32. The method of claim 31, wherein said patient is suffering from
cancer.
33. The method of claim 31, wherein said patient is infected with a
Flavivirus.
34. A method of screening for peptides capable of inducing
apoptosis comprising introducing a recombinant protein into a cell,
wherein said recombinant protein comprises the peptide to be
screened operably linked SEQ ID NO:2; and detecting apoptosis in
the cell.
35. The method of claim 34, wherein said introducing step comprises
introducing an expression vector comprising a polynucleotide which
encodes said recombinant protein.
36. The method of claim 34, wherein said recombinant protein
further comprises a green fluorescent protein.
37. A method of screening for molecules which inhibit apoptosis
induced by the polypeptide of the sequence SEQ ID NO:1 comprising
introducing said polypeptide into a cell; contacting said cell
containing said polypeptide, with the molecule to be screened; and
detecting the presence or absence of apoptosis in the cell.
38. The method of claim 37, wherein said polypeptide is operably
linked to the polypeptide of the sequence SEQ ID NO:2.
39. The method of claim 37, wherein said polypeptide is operably
linked to a green fluorescent protein.
40. The method of claim 37, wherein said polypeptide is not linked
to a green fluorescent protein.
41. The method of claim 37, wherein said introducing comprises
introducing a polynucleotide which encodes said polypeptide,
wherein said polynucleotide is an expression vector capable of
expressing the polypeptide in a cell.
42. An isolated polypeptide of the sequence in SEQ ID NO:3.
43. The isolated polypeptide of claim 42, wherein said peptide
induces apoptosis in a cell.
44. An isolated polynucleotide which encodes the polypeptide of
claim 42.
45. A vector comprising the polynucleotide of claim 44.
46. The vector of claim 45 which is the plasmid
p[95-114]EGFP[206-245]DEN-- 2 deposited in the CNCM on Jan. 29,
2001 under the accession number I-2620.
47. A prokaryotic cell comprising the polynucleotide of claim
44.
48. A eukaryotic cell comprising the polynucleotide of claim
44.
49. A composition comprising the polynucleotide of claim 44 and a
physiologically acceptable carrier.
50. A composition comprising the peptide of claim 42 and a
physiological acceptable carrier.
51. A method of inducing apoptosis in a cell comprising
administering an effective amount of the polypeptide of claim 42 to
the cell to induce apoptosis.
52. The method of claim 51, wherein said cell is in a human
patient.
53. The method of claim 51, wherein said patient is suffering from
cancer.
54. The method of claim 51, wherein said patient is infected with a
Flavivirus.
55. A method of screening for molecules which inhibit apoptosis
induced by the polypeptide of the sequence SEQ ID NO:3 comprising
introducing said polypeptide into a cell; contacting said cell
containing said polypeptide, with the molecule to be screened; and
detecting the presence or absence of apoptosis in the cell.
56. The method of claim 55, wherein said polypeptide is operably
linked to the polypeptide of the sequence SEQ ID NO:3.
57. The method of claim 55, wherein said polypeptide is operably
linked to a green fluorescent protein.
58. The method of claim 55, wherein said polypeptide is not linked
to a green fluorescent protein.
59. The method of claim 55, wherein said introducing comprises
introducing a polynucleotide which encodes said polypeptide,
wherein said polynucleotide is an expression vector capable of
expressing the polypeptide in a cell.
60. Monoclonal antibodies raised against DEN-1 viral M protein.
61. Monoclonal antibodies raised against DEN-2 viral M protein.
62. The plasmid [95-114]EGFP[M10-M40]DEN-2 deposited at the CNCM
under the accession number I-2684.
63. The plasmid pTrip.DELTA.U3[95-114]EGFP[206-245]DEN-2 deposited
at the CNCM under the accession number I-2686.
64. The plasmid pTrip.DELTA.U3[95-114]EGFP[206-245]DEN-1 deposited
at the CNCM under the accession number I-2685.
Description
CROSS-REFERENCE TO RELATED APPLICATION
[0001] The present application claims priority to U.S. Provisional
Application Serial No. 60,212,129 filed Jun. 16, 2000, the entire
contents of which are incorporated herein by reference.
FIELD OF THE INVENTION
[0002] The present invention relates to fragments of the Dengue
virus glycoproteins prM and E which induce apoptosis and can be
used as a therapeutic agent against Flavivirus infection and
cancer.
BACKGROUND OF THE INVENTION
[0003] Dengue (DEN) is the major arbovirus transmissible to humans
in most tropical and subtropical zones. At present neither
treatments nor vaccines are available to counter the disease. The
infectious agent is the DEN virus, a member of the Flaviviridae
family, which includes viruses that are highly pathogenic for
humans, such as yellow fever virus, West Nile virus, tick-borne
encephalitis viruses, Japanese encephalitis virus and hepatitis C
and G viruses. The DEN virus is an enveloped virus of 40 to 60 run
diameter, whose genome is a single-stranded RNA molecule of
positive polarity containing about 11000 nucleotides. The viral
genome is associated with the C capsid protein to form the
nucleocapsid (NC). The NC is surrounded with an envelope consisting
of a double lipid layer issued from membranes of the endoplasmic
reticulum (ER), in which the envelope glycoprotein E and the
membrane protein M are anchored. The glycoproteins prM (precursor
of protein M) and E of the viral envelope are translocated in the
lumen of the ER and remain anchored to the ER membranes by their
transmembrane domains (TMD) (FIG. 1A). The first stage of viral
morphogenesis is non-covalent association of prM and E as a
heterodimeric complex within the ER. The viral particle is probably
assembled by a budding process in the ER. The provirions are
carried in the vesicles, which transport them toward the plasmic
membrane by passing through the Golgi complex. Cleavage of prM to M
by proteases of the furine type in the trans-Golgi complex permits
the virions to become fully infectious.
[0004] In vivo infection of murine neurons and of human hepatocytes
by the DEN virus induces cell death by apoptosis. In vitro, the
induction of the apoptotic process by infection with the DEN-1 and
DEN-2 viruses have been reproduced in murine neuroblastoma cells
(Neuro 2a) and in human hepatoma cells (HepG2), in human Hela
cells, CHO, 293T and the primate cell line VERO. We have formulated
the hypothesis that accumulation of glycoproteins of the envelope
of the DEN virus in the ER would lead to a stress which induces
apoptosis. In the case of human hepatomas, this stress would lead
to activation of the transcription factor NF-.kappa.B, which would
control the expression of pro-apoptotic genes.
[0005] Apoptosis, or programmed cell death (PCD) is a type of cell
death that is fundamentally distinct from degenerative death or
necrosis. It is an active process of gene-directed cellular
self-destruction which in some instances, serves a biologically
meaningful homeostatic function. This can be contrasted to necrosis
which is cell death occurring as the result of severe injurious
changes in the environment of infected cells. For a general review
of apoptosis, see Tomei, L. D. and Cope, F. O. Apoptosis: The
Molecular Basis of Cell Death (1991) Cold Spring Harbor Press,
N.Y.; Tomei, L. D. and Cope, F. O. Apoptosis II: The Molecular
Basis of Apoptosis in Disease (1994) Cold Spring Harbor Press,
N.Y.; and Duvall and Wyllie (1986) Immun. Today 7(4):115-119.
[0006] Morphologically, apoptosis is characterized by the rapid
condensation of the cell with preservation of membranes.
Synchronistically with the compaction of chromatin, several
biochemical changes occur in the cell. Nuclear DNA is cleaved at
the linker regions between nucleosomes to produce fragments which
are easily demonstrated by agarose gel electrophoresis wherein a
characteristic ladder develops.
[0007] Apoptosis has been linked to many biological processes,
including embryogenesis, development of the immune system,
elimination of virus-infected cells, and the maintenance of tissue
homeostasis. Apoptosis also occurs as a result of human
immunodeficiency virus (HIV) infection of CD4.sup.+ T lymphocytes
(T cells). Indeed, one of the major characteristics of AIDS is the
gradual depletion of CD4.sup.+ T lymphocytes during the development
of the disease. Several mechanisms, including apoptosis, have been
suggested to be responsible for the CD4 depletion. It is speculated
that apoptotic mechanisms might be mediated either directly or by
the virus replication as a consequence of the HIV envelope gene
expression, or indirectly by priming uninfected cells to apoptosis
when triggered by different agents.
[0008] Reference is made to standard textbooks of molecular biology
that contain definitions and methods and means for carrying out
basic techniques, encompassed by the present invention. See, for
example, Maniatis et al., Molecular Cloning: A Laboratory Manual,
Cold Spring Harbor Laboratory, New York (1982) and Sambrook et al.,
Molecular Cloning: A Laboratory Manual, Cold Spring Harbor
Laboratory, New York (1989) and the various references cited
therein.
[0009] We have studied what viral morphogenesis in the cytotoxity
of the DEN virus might mean for the murine neuronal cell. The first
stages of assembly of the viral particle, in other words the
heterodimeric association of the envelope glycoproteins prM and E
in the lumen of the ER, were characterized in Neuro 2a cells
infected by the FGA/89 strain of the DEN-1 virus (the viral
sequence numbering begins at Met.sub.1 of the DEN polyprotein, FIG.
1B), or by starting from the established line N2aprM+E (a stable
clone of the Neuro 2a cells), which contains cDNA coding for the
two viral glycoproteins under the control of an inducible promoter
(ecdysone expression system).
[0010] The expression of the recombinant glycoproteins prM and E in
N2aprM+E cells causes cell death by apoptosis after 35 hours of
induction. We attempted to identify the pro-apoptotic sequences in
glycoproteins prM and E. The three-dimensional structure of protein
E ectodomain of flaviviruses revealed the existence of three
domains. Two predicted .alpha.-helices (FGA/89 polyprotein residues
680 to 692, 710 to 727) positioned between the ectodomain (390
amino acids) and the TMD (FGA/89 polyprotein residues 737 to 775)
of protein E (FIG. 2A). Little information is available on the
spatial structure of protein prM. Protein M (FGA/89 polyprotein
residues 206 to 280) produced by posttranslational cleavage of the
glycoprotein prM in the trans Golgi network, is a non-glycosylated
polypeptide of 75 amino acids composed of a predicted .beta.-sheet
(FGA/89 polyprotein residues 206 to 224), a predicted .alpha.-helix
(FGA/89 polyprotein residues 224 to 245) and two TMDs (FGA/89
polyprotein residues 246 to 280) (FIG. 2B).
SUMMARY OF THE INVENTION
[0011] An object of the present invention is to provide a
polypeptides from the Dengue virus glycoproteins which induces
apoptosis.
[0012] Another object of the present invention is to provide a
polynucleotide which encodes the polypeptide.
[0013] Another object of the present invention is a method of
inducing apoptosis in a cell comprising administering the
polypeptide to a cell.
[0014] Another object of the present invention is a method of
screening for polypeptides which are capable of inducing
apoptosis.
[0015] Another object of the present invention is a method of
screening for molecules capable inhibiting apoptosis induced by the
polypeptide from the Dengue virus glycoproteins which induces
apoptosis.
[0016] Another object of the present invention is pro-apoptotic
sequences in glycoproteins prM (DEN polyprotein residues 115 to
280) and E (DEN polyprotein residues 281 to 775) of the FGA/89
strain of DEN-1 virus (Genbank Data Library under accession
AF226687).
[0017] Another object of the present invention is pro-apoptotic
sequences of the strain DEN-2 virus Jamaica.
[0018] The invention also relates to monoclonal antibodies raised
against DEN-1 and DEN-2 virus M proteins and their utilization for
the prevention of disease and diagnostic purposes.
BRIEF DESCRIPTION OF THE DRAWINGS
[0019] FIG. 1: A. Schematic representation of DEN polyprotein
maturation. B. Schematic representation of recombinant prM and E
proteins,
[0020] FIG. 2: A. Schematic representation of E protein structure.
B. Schematic representation of prM protein structure.
[0021] FIG. 3: The C-terminal 20 amino acids of the BR/90 C protein
(residues 95 to 114) function as a sequence signal to direct the
translocation of prM into the lumen of the ER. The two alanine
residues at the position C-112 and C-114 provide a functional
signal peptidase site. The C residues 95 to 114 followed 6
vector-specified amino-acids fused to the N-terminus of EGFP
encoded by the plasmid pFGFP-NI (Clontech, # 6085-1) produce the
[95-114]EGFP fusion protein. The regions of the FGA/89 polyprotein
corresponding either the M protein (or its deletion variants) or
the predicted .alpha.-helix and TMDs of the E protein were fused to
the C-terminus of the [95-114]EGFP fusion construct.
[0022] FIG. 4: A. Two sets of Neuro 2a cells are transfected during
25 hours and stained by POD-TUNEL method. The (95-114]EGFP fusion
proteins are indicated on the y axis and the number of TUNEL.sup.+
cells per 50,000 cells is indicated on the x axis. Data were
compared to the result of [95-114]EGFP[206-280] data with the
Fisher and Yates t test. Only significant data (P<0.05) are
indicated. B. Three sets of Neuro 2a cells were transfected during
20 hours. The free oligonucleosomes are quantified by ELISA method.
Data were compared to the result of [95-114]EGFP[206-280] data with
the Fisher and Yates t test. Only significant data (P<0.05) are
indicated. C. Two sets of Neuro 2a cells expressed the
[95-114]EGFP[206-245] fusion construct during different times of
transfection. Apoptotic cells are stained by POD-TUNEL method. D.
Neuro 2a cells expressing the [95-114]EGFP[206-280], the
[95-114]EGFP[206-245] or the EGFP[206-245] during 25 hours are
stained by Cy.TM.3-TUNEL and analyzed by confocal method.
[0023] FIG. 5: A. Three sets of HepG2 cells were transfected during
20 hours. The free oligonucleosomes are quantified by ELISA method.
Data were compared to the result of [95114]EGFP[673-727] data with
the Fisher and Yates t test. Only significant data (P<0.05) are
indicated. B. HepG2 cells expressing the [95-114]EGFP[206-280], the
[95-114]EGFP[206-245] or the EGFP[206-245] during 25 hours are
stained by Cy.TM.3-TUNEL and analyzed by confocal method.
[0024] FIG. 6: The sequence of the plasmid p[95-114]EGFP[206-245]
encompassing the DEN-1 virus strain BR/90 encoding the C protein
residues 95 to 114 upstream of the EGFP gene, and the sequence of
the DEN-1 virus strain FGA/89 encoding the M protein residues 206
to 245 downstream of the EGFP gene, in the pEGFP-N1.
[0025] FIG. 7: The sequence of the plasmid p[95-114][211-245]
encompassing the DEN-1 virus strain BR/90 encoding the C protein
residues 95 to 114 fused to the N-terminus of the sequence of the
DEN-1 virus strain FGA/89 encoding the M protein residues 211 to
245 in the pEGFP-N1.
[0026] FIG. 8: HepG2 and Neuro 2a cells expressing the
[95-114][211-280] during 25 hours are stained by Cy.TM.3-TUNEL and
analyzed by confocal method.
[0027] FIG. 9: The regions of IS-98 ST1 strain of West Nile (WN)
virus encoding the M Protein residues 215 to 255 are fused to the
C-terminus of the [95-114]EGFP fusion construct. The sequence
identity and similarity of M protein of DEN-1 virus strain FGA/89
and WN virus strain IS-98 ST1 are indicated.
[0028] FIG. 10: Sequence similarity and identity of M protein
between FGA/89 strain of DEN-virus and the residues 56 to 95 of
CD72 protein, the BH2 domain of Bax protein, and the other
flaviviruses.
[0029] FIG. 11: Sequence of plasmid
p[95-114]EFGP[206-245]DEN-2.
[0030] FIG. 12: Deletion mutants of ectoM DEN-2.
[0031] FIG. 13: Recombinant lentiviral vectors.
[0032] FIG. 14: Cell-death inducing activity of trip ectoM
DEN-1.
[0033] FIG. 15: Cytotoxicity of ectoM molecules.
DETAILED DESCRIPTION OF THE INVENTION
[0034] The 40 amino-acid long sequence of the dengue virus M
protein (DEN-1 virus strain FGA/89, residues 206-245) fused to the
C-terminus of the [95-114]EGFP fusion product to produce
[95-114]EGFP [206-245] fusion protein is shown in FIG. 6 (SEQ ID
NO:1).
[0035] The inventors determined that the sequences (40 amino acids)
of the DEN-1 and DEN-2 M proteins are 83% identical as shown in the
following alignment:
1 SVALAPHVGLGLETRTETWMSSEGAWKQIQKVETWALRHP DEN-1 M ecto- domain
----V----M-----------------HA-RI---I---- DEN-2 M ecto- domain
[0036] The amino acid sequence of the DEN-2 M polypeptide is shown
in FIG. 11 and is SEQ ID NO:3) Polynucleotides encoding the amino
acid sequence can be determined from the standard genetic code
disclosed for example in Molecular Cloning: A Laboratory Manual,
Second Edition, Sambrook, Fritsch, and Maniatis, Cold Spring Harbor
Laboratory Press, 1989.
[0037] The amino acid sequence of Den-1-C amino acids 95-114 is
shown in FIG. 1B (SEQ ID NO:2).
[0038] The plasmid p[95-114]EGFP[206-245] has been deposited at the
Collection Nationale de Cultures de Microorganismes, 25 Rue de
Docteur Roux, F-75724 Paris Cedex 15 on Jan. 21, 2000 under the
number 1-2380. The plasmid p[95-114][211-245] has been deposited at
the Collection National de Cultures de Microrganismes, 25 Rue de
Docteur Roux F-75724 Paris, Cedex 15 on May 10, 2000 under the
accession number I-2475.
[0039] To produce p[95-114][211-245], the EGFP gene was deleted
from plasmid p[95-114]EGFP[206-245] so that the 35 amino acid long
sequence of the dengue virus M protein (DEN-1 virus strain FGA/89,
residues 211-245) was directly fused in frame to the C-terminus of
the 15 amino acid long sequence of the C protein (DEN-1 virus
strain BR/90, residues 95-114) as shown in FIG. 7.
[0040] "Consisting essentially of", in relation to amino acid
sequence of a protein or peptide, is a term used hereinafter for
the purposes of the specification and claims to refer to a
conservative substitution or modification of one or more amino
acids in that sequence such that the tertiary configuration of the
protein or peptide is substantially unchanged.
[0041] "Conservative substitutions" is defined by aforementioned
function, and includes substitutions of amino acids having
substantially the same charge, size, hydrophilicity, and/or
aromaticity as the amino acid replaced. Such substitutions, known
to those of ordinary skill in the art, include
glycine-alanine-valine; isoleucine-leucine; tryptophan-tyrosine;
aspartic acid-glutamic acid; arginine-lysine; asparagine-glutamine;
and serine-threonine.
[0042] "Modification", in relation to amino acid sequence of a
protein or peptide, is defined functionally as a deletion of one or
more amino acids which does not impart a change in the
conformation, and hence the biological activity, of the protein or
peptide sequence.
[0043] "Consisting essentially of", in relation to a nucleic acid
sequence, is a term used hereinafter for the purposes of the
specification and claims to refer to substitution of nucleotides as
related to third base degeneracy. As appreciated by those skilled
in the art, because of third base degeneracy, almost every amino
acid can be represented by more than one triplet codon in a coding
nucleotide sequence. Further, minor base pair changes may result in
variation (conservative substitution) in the amino acid sequence
encoded, are not expected to substantially alter the biological
activity of the gene product. Thus, a nucleic acid sequencing
encoding a protein or peptide as disclosed herein, may be modified
slightly in sequence (e.g., substitution of a nucleotide in a
triplet codon), and yet still encode its respective gene product of
the same amino acid sequence.
[0044] The term "expression vector" refers to an oligonucleotide
which encodes the peptide of the invention and provides the
sequences necessary for its expression in the selected host cell.
Expression vectors will generally include a transcriptional
promoter and terminator, or will provide for incorporation adjacent
to an endogenous promoter. Expression vectors will usually be
plasmids, further comprising an origin of replication and one or
more selectable markers. However, expression vectors may
alternatively be viral recombinants designed to infect the host, or
integrating vectors designed to integrate at a preferred site
within the host's genome. Examples of viral recombinants are
Adeno-associated virus (AAV), Adenovirus, Herpesvirus, Poxvirus,
Retrovirus, and other RNA or DNA viral expression vectors known in
the art. Examples of other expression vectors are disclosed in
Molecular Cloning: A Laboratory Manual, Second Edition, Sambrook,
Fritsch, and Maniatis, Cold Spring Harbor Laboratory Press,
1989.
[0045] Since its amino acid sequence has been disclosed by the
present invention, the peptide of the present invention can be
produced by a known chemical synthesis method (see, for example, a
liquid phase synthesis method, a solid phase synthesis method,
etc.; Izumiya, N., Kato, T., Aoyagi, H., Waki, M., "Basis and
Experiments of Peptide Synthesis", 1985, Maruzen Co., Ltd.) based
on that sequence.
[0046] The peptide of the present invention may contain one or more
protected amino acid residues. The protected amino acid is an amino
acid whose functional group or groups is/are protected with a
protecting group or groups by a known method and various protected
amino acids are commercially available.
[0047] It is preferred that each protective group be selected
appropriately from those known per se depending on the conditions
of peptide synthesis.
[0048] The binding of the protected amino acid is achieved by usual
condensation methods, for example, a DCC (dicyclohexylcarbodiimide)
method, a DIPCDI (diisopropylcarbodiimide) method (Tartar, A., et
al.; J. Org. Chem., 44, 5000 (1979)), an activated ester method, a
mixed or symmetric acid anhydride method, a carbonyldiimidazole
method, a DCC-HONSu (N-hydroxysuccinimide) method (Weygand, F., et
al., Z. Naturforsch., B, 21, 426 (1966)), a DCC-HOBt
(1-hydroxybenzotriazole) method (Koenig, W., et al.; Chem. Ber.,
103, 788, 2024, 2034 (1970)), a diphenylphosphorylazide method, a
BOP-HOBt method (Hudson, D., J. Org. Chem., 53, 617 (1988)) using a
BOP reagent (benzotriazolyl-N-hydroxytrisd- imethylaminophosphonium
hexafluorophosphide), a HBTU
(2-(1H-benzotriazol-1-yl)-1,1,3,3-tetramethyluronium
hexafluorophosphate)-HOBt method (Knorr, R., et al., Tetrahedron
Lett., 30, 1927 (1989)), a TBTU
(2-(1H-benzotriazol-1-yl)-1,1,3,3-tetramethyluro- nium
tetrafluoroborate)-HOBt method (Knorr, R., et al., Tetrahedron
Lett., 30, 1927 (1989)), etc. However, among these methods,
preferred are the DCC method, the DCC-HOBt method, the BOP-HOBt
method, the HBTU-HOBt method, and the symmetric acid anhydride
method.
[0049] The condensation reaction is usually carried out in an
organic solvent such as dichloromethane, dimethylformamide (DMF),
N-methylpyrrolidone (NMP) and the like or a mixed solvent composed
of them.
[0050] As the eliminating reagent for the protective group of
.alpha.-amino group, there can be used trifluoroacetic
acid/dichloromethane, HCl/dioxane, piperidine/DMF or
piperidine/NMP, etc. and these are selected appropriately depending
on the kind of the protecting group.
[0051] The degree of progress of condensation reaction in each
stage of synthesis can be examined by the method of E. Kaiser, et
al. [Anal. Biochem., 34, 595 (1970)] (ninhydrin reaction).
[0052] As described above, a protected peptide resin having a
desired amino acid sequence can be obtained.
[0053] Treatment of the protected peptide resin with hydrogen
fluoride, TFMSA (trifluoromethanesulfonic acid) [E. Gross ed.,
Yajima, H., et al.; "The Peptide" 5, 65 (1983), Academic Press],
TMSOTf (trimethylsilyl triflate [Fujii, N., et al.; J. Chem. Soc.,
Chem. Commun., 274 (1987)], TMSBr (trimethylsilylbromide [Fujii,
N., et al.; Chem. Pharm. Bull., 35, 3880 (1987)], trifluoroacetic
acid, or the like can eliminate the resin and protecting group
simultaneously. The above-described eliminating reagent is selected
appropriately depending on the strategy used (Boc or Fmoc) and the
kinds of the resin and the protecting group. The peptide of the
present invention can be produced by a series of the methods
described above.
[0054] Alternatively, the peptide of the present invention can be
produced by producing a polynucleotide (DNA or RNA) which
corresponds to the amino acid sequence of the peptide of the
present invention and producing a peptide by a genetic engineering
technique using the polynucleotide. Polynucleotide coding sequences
for amino acid residues are known in the art and are disclosed for
example in Molecular Cloning: A Laboratory Manual. Second Edition,
Sambrook, Fritsch, and Maniatis, Cold Spring Harbor Laboratory
Press, 1989.
[0055] The peptide of the present invention thus produced can be
purified by isolation/purification methods for proteins generally
known in the field of protein chemistry. More particularly, there
can be mentioned, for example, extraction, recrystallization,
salting out with ammonium sulfate, sodium sulfate, etc.,
centrifugation, dialysis, ultrafiltration, adsorption
chromatography, ion exchange chromatography, hydrophobic
chromatography, normal phase chromatography, reversed-phase
chromatography, gel filtration method, gel permeation
chromatography, affinity chromatography, electrophoresis,
countercurrent distribution, etc. and combinations of these.
[0056] The peptide of the present invention which is produced can
be hydrolyzed with an acid, for example, hydrochloric acid,
methanesulfonic acid or the like and its amino acid composition can
be examined by a known method. By this, it can be presumed whether
or not the peptide of the present invention is produced
correctly.
[0057] More strictly, the amino acid sequence of the produced
peptide is determined by a known amino acid sequence determination
method (for example, Edman degradation technique, etc.) to confirm
whether the peptide of the present invention is produced
correctly.
[0058] The peptide of the present invention includes a form of a
salt thereof. As described later on, the peptide of the present
invention is particularly useful as a medicine and hence the salt
of the peptide is preferably a pharmaceutically acceptable
salt.
[0059] The peptide of the present invention may form a salt by
addition of an acid. Examples of the acid include inorganic acids
(such as hydrochloric acid, hydrobromic acid, phosphoric acid,
nitric acid, and sulfuric acid) or organic carboxylic acids (such
as acetic acid, propionic acid, maleic acid, succinic acid, malic
acid, citric acid, tartaric acid, and salicylic acid), acidic
sugars such as glucuronic acid, galacturonic acid, gluconic acid,
ascorbic acid, etc., acidic polysaccharides such as hyaluronic
acid, chondroitin sulfates, alginic acid, or organic sulfonic acids
(such as methanesulfonic acid, and p-toluenesulfonic acid), and the
like. Of these salts, preferred is a pharmaceutically acceptable
salt.
[0060] The peptide of the present invention may form a salt with a
basic substance. Examples of the salt include, for example,
pharmaceutically acceptable salts selected from salts with
inorganic bases such as alkali metal salts (sodium salt, lithium
salt, potassium salt, etc.), alkaline earth metal salts, ammonium
salts, and the like or salts with organic bases, such as
diethanolamine salts, cyclohexylamine salts, and the like.
[0061] The pharmaceutically acceptable carrier which can be used in
the present invention is not limited particularly and includes an
excipient, a binder, a lubricant, a colorant, a disintegrant, a
buffer, an isotonic agent, a preservative, an anesthetic, and the
like which can be used in a medical field.
[0062] The medicine of the present invention can be applied by any
suitable administration method depending on the purpose of
treatment and selected from injection (subcutaneous,
intracutaneous, intravenous, intraperitoneal, etc.), eye dropping,
instillation, percutaneous administration, oral administration,
inhalation, and the like.
[0063] Also, the dosage form such as injectable preparations
(solutions, suspensions, emulsions, solids to be dissolved when
used, etc.), tablets, capsules, granules, powders, liquids,
liposome inclusions, ointments, gels, external powders, sprays,
inhalating powders, eye drops, eye ointments, suppositories,
pessaries, and the like can be selected appropriately depending on
the administration method, and the peptide of the present invention
can be accordingly formulated. Formulation in general is described
in Chapter 25.2 of Comprehensive Medicinal Chemistry, Volume 5,
Editor Hansch et al, Pergamon Press 1990.
[0064] The dose of the medicine of the present invention should be
set up individually depending on the purpose of administration
(prevention, maintenance (prevention of aggravation), alleviation
(improvement of symptom) or cure); the kind of disease; the
symptom, sexuality and age of patient; the administration method
and the like and is not limited particularly.
[0065] The polypeptide and polynucleotide encoding the polypeptide
included in these pharmaceutical formulations or medicines may be
useful for treating patients infected with members of the
Flavivirus genre.
[0066] Furthermore, the induction of apoptosis by the pro-apoptotic
fragment may be useful for treating patients with cancer. In
particular, by specifically targeting cancer cells and inducing
apoptosis in those cancer cells. Included in the present invention
are the monoclonal antibodies raised against DEN-1 and DEN-2 viral
M proteins and their utilization for prevention of disease and
diagnostic purposes.
[0067] Included in this invention are methods of screening for
molecules capable of inducing apoptosis. In particular, the
molecules are proteins. This method can be accomplished by
attaching the protein to be screened to amino acids 95-114 of the
C-protein of Dengue virus; introducing the fusion protein into a
cell; and detecting the presence or absence of apoptosis. This
method can also be performed by introducing the polypeptide
containing the protein to be screened to amino acids 95-114 of the
C-protein of Dengue virus directly to the cell.
[0068] Polynucleotides may be introduced by a number of well-known
methods in the art. Examples of which are Calcium phosphate,
DEAE-Dextran, liposomes, viral vectors, etc. These and other
methods of introducing polynucleotides into cells are disclosed in
Sambrook et al., Molecular Cloning: A Laboratory Manual, Cold
Spring Harbor Laboratory, New York (1989).
[0069] The present invention further includes methods for screening
for molecules which inhibit the cytotoxic activity of the
pro-apoptotic fragment of the Dengue virus M protein. This method
includes introducing the polypeptide or a polynucleotide encoding
the polypeptide into a cell, contacting the cell with the molecule
to be screened and detecting the presence or absence of apoptosis.
Molecules to be screened can be proteins or any other organic or
inorganic substance which may be found to inhibit apoptosis
mediated by the amino-terminal 40 amino acids of the Dengue virus M
protein.
[0070] Antibodies which react specifically with the inventive
peptides are also included in the present invention. Methods of
generating antibodies directed to a specific peptide fragment are
known in the art. Examples of such methods are disclosed in
Antibodies, A Laboratory Manual, Harlow and Lane, Cold Spring
Harbor Press, 1988, herein incorporated by reference.
[0071] Methods of detecting apoptosis include the TUNEL assay and
ELISA assay. These and other methods are disclosed in Tomei, L. D.
and Cope, F. O. Apoptosis: The Molecular Basis of Cell Death (1991)
Cold Spring Harbor Press, N.Y.; Tomei, L. D. and Cope, F. O.
Apoptosis II: The Molecular Basis of Apoptosis in Disease (1994)
Cold Spring Harbor Press, N.Y.; Duvall and Wyllie (1986) Immun.
Today 7(4):115-119 and Sambrook et al., Molecular Cloning: A
Laboratory Manual, Cold Spring Harbor Laboratory, New York
(1989).
[0072] Having generally described this invention, a further
understanding can be obtained by reference to certain specific
examples which are provided herein for purposes of illustration
only, and are not intended to be limiting unless otherwise
specified.
EXAMPLES
[0073] 1. Cells
[0074] The Neuro 2a murine neuroblastoma cell line (ATCC Ref.
CCL131) was cultured in minimum essential medium (MEM) supplemented
with 10% fetal bovine serum (FBS) heat-inactivated for 30 minutes
at 56.degree. C. and with nonessential amino acids. The cells were
cultured at 37.degree. C. under CO.sub.2 on the basis of 10.sup.4
cells per cm.sup.2.
[0075] The human hepatoma cell line (ATCC Ref HB8065) was cultured
in Eagle medium modified by Dulbecco (D-MEM) supplemented with 10%
FBS heat-inactivated for 30 minutes at 56.degree. C., with 4 mM of
glutamine and with antibiotics (mixture of penicillin and
streptomycin). The cells were cultured at 37.degree. C. under
CO.sub.2 on the basis of 5.times.10.sup.4 cells per cm.sup.2.
[0076] 2. Plasmids and Transfectant Agent
[0077] In order to identify potential pro-apoptotic sequences in
prM and E, we constructed the chimeric proteins known as Enhanced
Green Fluorescent Protein (EGFP)/DEN. Amino acids 95 to 114 of the
C-terminus of the C protein of the DEN-1 virus strain BR/90
function as a signal sequence for translocation of protein prM into
ER. This viral signal protein was fused in phase at the N-terminus
of the EGFP protein expressed by the pEGFP-N1 expression vector
(Clontech #6085-1) to produce the chimeric protein [95-114]EGFP
fusion protein (FIG. 2). The peptide segments corresponding to the
a helices and to the transmembrane domains of the prM and E
glycoproteins were fused in phase at the C-terminus of the chimeric
protein [95-114]EGFP (see FIG. 1).
[0078] The Neuro 2a and HepG2 cells were transfected by different
plasmids recombined by means of FuGENE.TM. 6 (Roche Molecular
Biochemicals #1 814 443) according to the recommended protocol of
the commercial kit.
[0079] 3. TUNEL Detection
[0080] During cell death by apoptosis, the genomic DNA is cleaved
by activated cellular endonucleases, thus liberating
oligonucleosomes. The TUNEL technique permits the oligonucleosomes
to be labeled at their free 3'-OH end with modified nucleotides by
means of enzyme reaction.
[0081] TUNEL-POD labeling was achieved by means of the "In Situ
Cell Death Detection" kit (Roche Molecular Biochemicals #1 684
817). The transfected Neuro 2a and HepG2 cells were treated
according to the recommended protocol of the commercial kit.
[0082] For TUNEL-Cy3 labeling, the Neuro 2a and HepG2 cells
transfected for 25 hours were fixed in 3% (w/v) paraformaldehyde
(PFA) in PBS. The cells were permeabilized in ethanol then
rebydrated in H.sub.2O. The cells were then incubated for 15
minutes at 37.degree. C. in the reaction mixture containing 12.5
units of terminal transferase (Roche Molecular Biochemicals #220
582), 2.5 nmol of biotin-16-dUTP (Roche Molecular Biochemicals #1
093 070), 2.5 mM of CoCl.sub.2 0.2 M of potassium cacodylate, 25 mM
of Tris Cl and 0.25 mg/ml of bovine serum albumin (BSA). The
reaction was stopped by incubation for 15 minutes at room
temperature in 2.times. sodium citrate buffer. The cells were
washed in H.sub.2O between the different stages. To limit
nonspecific fixations, the cells were treated with 20 mg/ml of BSA
in H.sub.2O. The cells were then labeled for 30 minutes at
37.degree. C. using streptavidine conjugated with fluorochrome
Cy.TM.3 (Jackson ImmunoResearch Laboratories, Inc., #016-160-084).
The tests were observed by confocal microscopy.
[0083] 4. ELISA
[0084] When apoptotic death is induced in a cell, cellular
endonucleases are activated, and cleave the genomic DNA into
oligonucleosomes, The ELISA technique permits quantification of the
oligonucleosomes by use of monoclonal antibodies directed against
the histones and DNA.
[0085] ELISA was performed with the "Cell Death Detection
ELISA.sup.PLUS" kit (Roche Molecular Biochemicals #1 774 425). The
transfected Neuro 2a and HepG2 cells were treated according to the
recommended protocol of the commercial kit.
[0086] 5. Staining with Propidium Iodide
[0087] During the apoptotic process, the cell undergoes several
characteristic morphological modifications. The cell condenses and
separates into apoptotic bodies containing DNA fragments. Propidium
iodide is a fluorescent agent which becomes inserted between
nucleic acids: it permits visual detection of the apoptotic bodies.
A cell undergoing apoptosis is defined by the presence of at least
three nuclear bodies.
[0088] After 20 hours of transfection, the Neuro 2a and HepG2 cells
were fixed in 3% (w/v) paraformaldehyde (PFA) in PBS (Table 1). The
cells were washed in PBS between the different stages. The cells
were treated with 50 mM NH.sub.4Cl in PBS for 10 minutes in order
to neutralize the acid vesicles of the trans-Golgi complex, then
permeabilized in 0.1% Triton X-100 in PBS for 4 minutes.
Degradation of the RNAs was achieved by treatment with 10 .mu.g/ml
DNase-free RNase in PBS for 30 minutes at 37.degree. C. The cells
were then stained with 1 .mu.g/ml propidium iodide (PI) in 0.1%
citrate buffer of pH 6.0. The tests were then observed by
fluorescence microscopy.
[0089] In order to identify potential pro-apoptotic sequences in
prM and E, the inventors have constructed chimeric proteins in the
form of Enhanced Green Fluorescent Protein (EGFP/DEN). The
C-terminal 20 amino acids of the BR/90 C protein (residues 95 to
114) function as a sequence signal to direct the translocation of
prM into the lumen of the ER. The two residues alanine at the
positions C-112 and C-114 provide a functional signal peptidase
site. The C residues 95 to 114 followed by 6 vector-specified amino
acids fused to the N-terminus of EGFP encoded by the plasmid
pEGFP-N1 (Clontech, # 6085-1) produce the [95-114]EGFP fusion
protein. The regions of the FGA/89 polyprotein corresponding either
the M protein (or its deletion variants) or the predicted
.alpha.-helices and TMDs of the E protein were fused to the
C-terminus of the [95-114]EGFP fusion construct (FIG. 3).
[0090] To produce p[95-114][211-245], the EGFP gene was deleted
from plasmid p[95-114]EGFP[206-245] so that the 35 amino acid long
sequence of the dengue virus M protein (DEN-1 virus strain FGA/89,
residues 211-245) was directly fused to the C-terminus of the 15
amino acid long sequence of the C protein (DEN-I virus strain
BR/90, residues 95-114) as it is shown in FIG. 7.
[0091] The cytotoxicity of the EGFP/DEN chimeric proteins was
tested by transfecting Neuro 2a and HepG2 cells by different
plasmids recombined by means of FuGENE.TM. 6. The expression of
different chimeric proteins was observed by the autofluorescence of
the EGFP and by radioimmunoprecipitation by means of anti-EGFP
antibody. The apoptosis induced by the different chimeric proteins
derived from the [95-114] EGFP fusion construct was detected
visually by the TUNEL technique and quantified by ELISA, two
methods which permit detection of DNA in apoptotic condition (FIGS.
4 and 5).
2 TABLE 1 Neuro 2a cells HepG2 cells POD-TUNEL.sup.+a P.sup.c
POD-TUNEL.sup.+b P [95-114]EGFP 29,85 .+-. 1,15.sup.d 44,117 .+-.
2,09 [206-280] [95-114]EGFP 59,30 .+-. 1,000 <0,01.sup.e 66,67
.+-. 7,88 <0,02 [206-245] [95-114] 55,50 .+-. 0,50 <0,01
79,00 .+-. 8,64 <0,03 [211-245] .sup.aNeuro 2a cells are
transfected during 22 hours with the [95-114]EGFP[206-280], the
[95-114]EGFP[206-245] or the [95-114][211-245] construct. Cells are
stained with the POD-TUNEL method, those presented an apoptotic
morphology are noted POD-TUNEL.sup.+. .sup.bHepG2 cells are
transfected during 20 hours with the [95-114]EGFP[206-280], the
[95-114]EGFP[206-245] or the [95-114][211-245] construct. Cells are
stained with the POD-TUNEL method, those presented an apoptotic
morphology are noted POD-TUNEL.sup.+. .sup.cFisher and Yates t
test, comparison of two averages. .sup.dPOD-TUNEL.sup.+ cells are
counted of 5000 cells and expressed as the average of two distinct
assays. .sup.eDatawere compared to values of 95-114]EGFP[206-280]
assays. P < 0,05 was considered significant.
[0092] The cytotoxicity of the EGFP/WN chimeric proteins were
tested by transfecting Neuro 2a and HepG2 cells with the plasmid
[95-114]EGFP[215-255]WNV (deposited at the CNCM under the deposit
number 1-2485 on May 31, 200) (FIG. 9).
3 TABLE 2 Neuro 2a cells.sup.a HepG2 cells.sup.b P1.sup.+ P.sup.c
POD-TUNEL.sup.+ P [95-114]EGFP 160.0 .+-. 3.0.sup.d 107.0 .+-.
0.0.sup.d [206-280] [95-114]EGFP 338.0 .+-. 25.0 <0,02.sup.e
218.0 .+-. 15.0 <0,02 [206-245] [95-114]EGFP 148.0 .+-. 5.0 n.s.
96.5 .+-. 16.5 n.s. [211-255].sub.WNV .sup.aNeuro 2a cells
transfected during 22 hours with the [95-114]EGFP[206-280], the
[95-114]EGFP[206-245] or the [95-114]EGFP[211-255].sub.WNV
construct. Cells are stained with the PI method, those presented an
apoptotic morphology are noted PI.sup.+. .sup.bHepG2 cells are
transfected during 20 hours with the [95-114]EGFP[206-280], the
]95-114]EGFP[206-245] or the [95-114]EGFP[211-255].sub.WNV
contruct. Cells are stained with the POD-TUNEL method, those
presented an apoptotic morphology are noted POD-TUNEL.sup.+.
.sup.cFisher and Yates t test, comparison of two averages.
.sup.dPI.sup.+ or POD-TUNEL.sup.+ cells are counted of 50,000 cells
and expressed as the average of two distinct assays. .sup.eData
were compared to the values of [95-114]EGFP[206-280] assays. P <
0.05 was considered significant: n.s., not significant.
[0093] Transient expression analysis with a series of DEN-EGFP
fusion constructs revealed that only the construct in which the
amino-terminal 40 amino acids of the M protein (DEN polyprotein
residues 211 to 245) is fused to the C-terminus of the
[95-114]EGFP, significantly induces apoptosis in Neuro 2a and HepG2
cells as early as 20 hours post-transfection. Similar to what has
been found for [95-114]EGFP[206-245], transient-expression with the
[95-114][211-245] fusion constructs involving the deletion of the
EGFP triggers apoptosis efficiently. Since the proteosome inhibitor
(PSI, Calbiochem # 539160) delays apoptosis in Neuro 2a cells
transfected with plasmid p[95-114]EGFP[206-245], it is presumed
that ubiquitin system contributes to cell death process.
[0094] It is expected that the 20 amino acid long sequence
LETRTETWMSSEGAWKQIQK of the M protein (FGA/89 polyprotein residues
217-236) bears significant homology with a region of the Bcl-2
protein family which includes pro-apoptotic proteins such as Bax,
since [144-165]Bax versus the M sequence has 23% identity and 64%
similarity. The [144-165]Bax region contains the Bcl-2 Homology
domain number 2, termed BH2. (Swissprot access:Q07812).
[0095] It is expected that the N-terminal 39 amino acids
SVALAPHVHLHLETRTETWMSSEGAWKQIQKVETWALRH of the M protein (FGA/89
polyprotein residues 206-244) share 40% identity with the 50 amino
acid long sequence (residues 46 to 95) in the cytosolic domain
(residues 1 to 95) at the N-terminus of B-CELL DIFFERENTIATION
ANTIGEN LYB-2 (CD72), a type II membrane protein. (Swissprot
access: P21855).
[0096] Plasmid p[95-114]EGFP[206-245]DEN-2
[0097] PCR products were prepared from DEN-2 genomic RNA using
Expand Reverse Transcriptase and the Expand High Fidelity PCR
system (Roche Molecular Biochemicals, Inc.). Oligonucleotide
primers including the recognition sites for restriction enzymes
BsrGI and NotI, were used to amplify the specific sequence of the
DEN-2 RNA encoding the entire M protein. The DEN-2 virus strain
Jamaica (Deubel et al., Virology, 196:209-219, 1993) encoding the M
protein (DEN-2 polyprotein 206-280) was introduced into
BsrGI/NotI-digested p[95-114]EGFP. The resulting plasmid
p[95-114]EGFP[206-280]DEN-2 was used as a template to amplify the
specific sequence encoding the DEN-2 M ectodomain (DEN-2
polyprotein 206-245) by PCR. The PCR product was cloned in
p[95-114]EGFP. The resulting plasmid p[95-114]EGFP[206-245]DEN-2
contains the DEN-2 M ectodomain (DEN-2 polyprotein 206-245) fused
in frame to the fusion protein [95-114]EGFP. The sequences were
confirmed by automated sequencing. The plasmid
p[95-114]EGFP[206-245]DEN-2 has been deposited at the Collection
Nationale de Cultures de Microorganismes, 25, rue du Dr Roux,
F-75724 Paris Cedex 15 on Jan. 29, 2001 under the number
1-2620.
[0098] To test the pro-apoptotic activity of the DEN-2 M
ectodomain, the inventors employed the chimeric protein
[95-114]EGFP[206-245]DEN-2. Amino acids 95-114 of the C-terminus of
the C protein of the DEN-1 virus strain BR/90 act as a signal
sequence for translocation of protein M into the ER. This viral
signal polypeptide was fused in phase to the N-terminus of the EGFP
protein expressed by the pEGFP-N1 expression vector (Clontech #
6085-1) to produce the chimeric protein [95-114]EGFP. The region of
the DEN-2 virus strain Jamaica corresponding the M ectodomain
(DEN-2 polyprotein 206-245) was fused to the C-terminus of the
[95-114]EGFP fusion construct. This construct is depicted in FIG.
11.
[0099] The cytotoxicity of the [95-114]EGFP[206-245]DEN-2 chimeric
protein was tested by transfecting cells with FuGENE.TM. 6. The
expression of the chimeric protein was observed by the
autofluorescence of the EGFP and apoptotic cell death was detected
visually by staining with propidium iodide as described above.
Intracellular expression of the [95-114]EGFP[206-245]DEN-2 chimeric
protein resulted in cell death. DEN-2 M ectodomain has the ability
to induce rapid apoptosis in Neuro 2a, HepG2, HeLa and VERO cells.
Apoptosis was more pronounced after transfection with plasmid
p[95-114]EGFP[206-245]DEN-2 than after transfection with the
plasmid [95-114]EGFP[206-245]containing the sequence of the DEN-1 M
ectodomain.
[0100] The inventors also tested the ability of the DEN-1, DEN-2
and WN M ectodomains to induce apoptosis in transiently-transfected
human cell lines HeLa (ATCC N.degree. CCL-2), 293T (provided by
Pierre Chameau, see his patent on retroviral vector) and the
non-human primate cell line VERO (ATCC N.degree. CCL-81; kindly
provided by Marie Flamand).
[0101] The expression of the EGFP/DEN and EGFP/WN chimeric proteins
was observed by the autofluorescence of the EGFP and apoptosis was
detected visually by staining with Hoechst or propidium iodide
after 25 h of transfection.
[0102] The chimeric proteins [95-114]EGFP[206-245]DEN-1 and
[95-114]EGFP[206-245]DEN-2 were present in large fluorescent masses
in HeLa, 293T and VERO. There was no large fluorescent bodies in
transfected cells expressing the chimeric protein
[95-114]EGFP[215-255]WN.
[0103] The chimeric proteins [95-114]EGFP[206-245]DEN-1 and
[95-114]EGFP[206-245]DEN-2 induced apoptosis in HeLa and VERO cells
at 25 h of transfection whereas chimeric protein
[95-114]EGFP[215-255]WN did not cause cell death (FIG. 15).
[0104] Intracellular expression of the chimeric proteins
[95-114]EGFP[206-245]DEN-1, [95-114]EGFP[206-245]DEN-2, and
[95-114]EGFP[215-255]WN did not induce apoptosis in 293T cells. The
chimeric proteins accumulated in transiently-transfected 293T cells
after 72 h of transfection. Thus, the 293T cell line is mainly
resistant to the death-inducing activity of the DEN M ectodomains.
The cell clone 293T was generated by introducing the SV40 T-antigen
coding sequence into the human epithelial cell line 293 (ATCC
N.degree. CRL-1573) which carries the Adenovirus 5 transforming
genes.
[0105] Deletion Variants of the DEN-2 M Ectodomain
[0106] The inventors also studied elements of the sequence which
contribute to the efficient death-inducing activity of the DEN M
ectodomain. Variants were constructed in which either the
C-terminal region or the N-terminal region of the DEN-2 M
ectodomain was removed by PCR deletion mutagenesis.
[0107] The deletion variants of the sequence MI->M40 of the
DEN-2 ectodomain:
4 1 10 20 30 40 SVALVPHVGMGLETRTETWMSSEGAWKHAQRIETWILRHP
[0108] included either the segment M1->M30
([95-114]EGFP[M1->M30]DEN- -2), the segment M1->M20
([95-114]EGFP[M1->M20]DEN-2), the segment M10->M40
([95-114]EGFP[M10->M40]DEN-2), the M20->M40
([95-114]EGFP[M20->M40]DEN-2), the segment M10->M30
([95-114]EGFP[M10->M30]DEN-2) or the segment M30->M40
([95-114]EGFP[M30->M40]DEN-2). The deletion mutants of plasmid
p[95-114]EGFP[206-245]DEN-2 are shown in FIG. 12.
[0109] The expression of these deletion variants of the DEN-2 M
ectodomain was examined by transient transfection of 293T cells.
The deletion variants were tested for their ability to cause cell
death upon the transfection of HeLa cells. Transiently-transfected
cells were analyzed for apoptosis by staining with Hoechst.
[0110] Transient expression of the deletion variants of the
chimeric protein [95-114]EGFP[206-245]DEN-2 demonstrated that amino
acids M10->M40 of the M ectodomain
([95-114]EGFP[M10->M40]DEN-2) significantly contribute to the
efficient formation of the fluorescent masses in the secretory
pathway (FIG. 12). The death-inducing activity of DEN-2 M
ectodomain is also attribuable to the amino acids M10 to M40 (FIG.
12). The plasmid [95-114]EGFP[M10-M40]DEN-2 has been deposited at
the Collection Nationale De Cultures De Microorganismes (CNCM),
Institut Pasteur, 28, rue du Dr Roux, 75724 Paris Cedex 15, France
on Jun. 14, 2001 under the accession number I-2684.
[0111] DEN M Ectodomain Tends to Form Reversible Aggregates In
Vitro
[0112] The procaryotic expression vector pIVEX-2.4a (Roche
Molecular Biochemicals, Inc.) with T7 promoter was tested for in
vitro synthesis of the fusion construct EGFP[206-245]DEN-2. The PCR
product was prepared from the plasmid p[95-114]EGFP[206-245]DEN-2
using the Expand High Fidelity PCR system (Roche Molecular
Biochemicals, Inc.). Oligonucleotide primers including the
recognition sites for restriction enzymes KspI and SmaI, were used
to amplify the specific sequence encoding the fusion construct
EGFP[206-245]DEN-2 by PCR.
[0113] The PCR product was introduced into KspI/SmaI-digested
pIVEX-2.4a (Roche Molecular Biochemicals, Inc.) to generate
pIVEX-EGFP[206-245]DEN-2- . The RTS 500 system (Roche Molecular
Biochemicals, Inc.) was used to produce large amount of the
chimeric protein EGFP[206-245]DEN-2 tagged with [His]6 by using the
plasmid pIVEX-EGFP[206-245]DEN-2 as transcription template.
[0114] In vitro, the newly synthesized molecules EGFP[206-245]DEN-2
tend to aggregate as autofluorescent precipitates. The aggregates
were solubilized by incubating with 8 M urea, suggesting that the
formation of these high-order structures required hydophobic
interactions. The inventors have shown that the above expression
system is useful to produce ectoM molecules. These molecules are
useful to produce antibodies specific of the ectoM molecules
according to known protocols of producing antibodies (Harlow and
Lane, Antibodies: A Laboratory Manual, Cold Spring Harbor
Laboratory Press, Cold Spring Harbor, N.Y., 1988).
[0115] Intracellular Expression of DEN M Ectodomain by
Transduction
[0116] The plasmid pTRIP.DELTA.U3CMVEGFP (International Patent
Application WO 99/55892, the contents of which are incorporated by
reference) was required for intracellular expression of DEN M
ectodomains after transduction. The PCR products were prepared
either from plasmids p[95-114]EGFP[206-245] which contains DEN-1 M
ectodomain or p[95-114]EGFP[206-245]DEN-2 using the Expand High
Fidelity PCR system (Roche Molecular Biochemicals, Inc.).
Oligonucleotide primers including the recognition sites for
restriction enzymes BglII and KpnI, were used to amplify the
specific sequences encoding the fusion constructs EGFP/DEN. The PCR
products were introduced into BamHI/KpnI-digested
pTRIP(U3CMVEGFP.
[0117] The resulting plasmids
pTRIP.DELTA.U3CMV[95-114]EGFP[206-245]DEN-1 and
pTRIP.DELTA.U3CMV[95-114]EGFP[206-245]DEN-2 were used to generate
non-replicative retroviruses carrying the sequences coding for the
chimeric proteins EGFP/DEN M ectodomain as described in the
International patent application WO 99/55892, (Pierre Charneau's et
al.).
[0118] Large flasks of 293T cell monolayers were co-transfected 2
days with pTRIP.DELTA.U3CMV[95-114]EGFP[206-245]DEN-1 or
pTRIP.DELTA.U3CMV[95-114]EGFP[206-245]DEN-2 and plasmids which
carry sequences coding either for VSV envelope G protein or HIV
proteins.
[0119] The plasmid pTrip.DELTA.U3[95-114]EGFP[206-265]DEN-2 has
been deposited at the Collection Nationale De Cultures De
Microorganismes (CNCM), Institut Pasteur, 28, rue du Dr Roux, 75724
Paris Cdex 15, France on Jun. 14, 2001 under the accession number
I-2686.
[0120] The plasmid pTrip.DELTA.US[95-114]EGFP[206-245]DEN-1 has
been deposited at the Collection Nationale De Cultures De
Microorganismes (CNCM), Institut Pasteur, 28, rue du Dr Roux, 75724
Paris Cdex 15, France on Jun. 14, 2001 under the accession number
I-2685.
[0121] The production and the purification of recombinant
retroviruses were essentially performed as described in the
International patent application WO 99/55892, (the contents of
which are incorporated herein by reference).
[0122] The production of recombinant virus particles
pTRIP(U3CMV[95-114]EGFP[206-245]DEN-1 and
pTRIP(U3CMV[95-114]EGFP[206-245- ]DEN-2 was determined in measuring
the amount of soluble p24 by ELISA. At dose as low as 1 ng of
recombinant retrovirus pTRIP(U3CMV[95-114]EGFP[206- -245]DEN-1 per
3.104 cells, more than 80% of 293T cells were positive for EGFP
after 48 h of transduction (FIG. 13).
[0123] Obviously, numerous modifications and variations on the
present invention are possible in light of the above teachings. It
is therefore to be understood that within the scope of the appended
claims, the invention may be practiced otherwise than as
specifically described herein.
Sequence CWU 1
1
30 1 76 PRT Dengue virus 1 Met Asn Arg Arg Lys Arg Ser Val Thr Met
Leu Leu Met Leu Leu Pro 1 5 10 15 Thr Ala Leu Ala Arg Glu Pro Pro
Val Ala Thr Met Leu Ala Met Glu 20 25 30 Glu Leu Tyr Ser Ser Val
Ala Leu Ala Pro His Val Gly Leu Gly Leu 35 40 45 Glu Thr Arg Thr
Glu Thr Trp Met Ser Ser Glu Gly Ala Trp Lys Gln 50 55 60 Ile Gln
Lys Val Glu Thr Trp Ala Leu Arg His Pro 65 70 75 2 20 PRT Dengue
virus 2 Met Asn Arg Arg Lys Arg Ser Val Thr Met Leu Leu Met Leu Leu
Pro 1 5 10 15 Thr Val Leu Ala 20 3 30 PRT Dengue virus 3 Pro His
Val Gly Met Gly Leu Glu Thr Arg Thr Glu Thr Trp Met Ser 1 5 10 15
Ser Glu Gly Ala Trp Lys His Val Gln Arg Ile Glu Thr Trp 20 25 30 4
91 DNA Dengue virus 4 gctagcgcta ccggactcag atctcgagct caagcttcga
attctgcagt cgacggtacc 60 gcgggcccgg gatccaccgg tcgccaccat g 91 5 91
DNA Dengue virus 5 gctagcaatg aacaggagga aaagatccgt gaccatgctc
ctcatgctgc tgcccacagc 60 cctggcccgg gatccaccgg tcgccaccat g 91 6 42
DNA Dengue virus 6 ctcggcatgg acgagctgta caagtaaagc ggccgcactc ta
42 7 73 DNA Dengue virus 7 ctcggcatgg acgagctgta cagttccgtg
gctctggccg ctttgagaca cccatgattc 60 gcggccgcga ctc 73 8 42 DNA
Dengue virus 8 ctcggcatgg acgagctgta caagtaaagc ggccgcactc ta 42 9
8 PRT Dengue virus 9 Leu Ala Met Glu Glu Leu Tyr Asn 1 5 10 20 PRT
Dengue virus 10 Met Asn Arg Arg Lys Arg Ser Val Thr Met Leu Leu Met
Leu Leu Pro 1 5 10 15 Thr Val Leu Ala 20 11 30 PRT Dengue virus 11
Pro His Val Gly Met Gly Leu Glu Thr Arg Thr Glu Thr Trp Met Ser 1 5
10 15 Ser Glu Gly Ala Trp Lys His Val Gln Arg Ile Glu Thr Trp 20 25
30 12 39 PRT Dengue virus 12 Ser Val Ala Leu Ala Pro His Val Gly
Leu Gly Leu Glu Thr Arg Thr 1 5 10 15 Glu Thr Trp Met Ser Ser Glu
Gly Ala Trp Lys Gln Ile Gln Lys Val 20 25 30 Glu Thr Trp Ala Leu
Arg His 35 13 39 PRT Mus musculus 13 Ser Pro Ala Leu Ala Asp Lys
Ala Gly Val Ser Glu Gln Pro Thr Ala 1 5 10 15 Thr Trp Ser Ser Val
Lys Ser Ser Ala Leu Arg Gln Ile Pro Arg Cys 20 25 30 Pro Thr Val
Cys Leu Gln Asn 35 14 20 PRT Homo sapiens 14 Leu Arg Glu Arg Leu
Leu Gly Trp Ile Gln Asp Gln Gly Gly Trp Asp 1 5 10 15 Gly Leu Leu
Ser 20 15 20 PRT Dengue virus 15 Leu Glu Thr Arg Thr Glu Thr Trp
Met Ser Ser Glu Gly Ala Trp Lys 1 5 10 15 His Ala Gln Arg 20 16 20
PRT Dengue virus 16 Leu Asp Thr Arg Thr Gln Thr Trp Met Ser Ala Glu
Gly Ala Trp Arg 1 5 10 15 Gln Val Glu Lys 20 17 20 PRT Dengue virus
17 Leu Glu Thr Arg Ala Glu Thr Trp Met Ser Ser Glu Gly Ala Trp Lys
1 5 10 15 His Ala Gln Arg 20 18 20 PRT Kunjin virus 18 Leu Ser Asn
Lys Lys Gly Ala Trp Met Asp Ser Thr Lys Ala Thr Arg 1 5 10 15 Tyr
Leu Val Lys 20 19 20 PRT Japanese encephalitis virus 19 Leu Val Asn
Lys Lys Glu Ala Trp Leu Asp Ser Thr Lys Ala Thr Arg 1 5 10 15 Tyr
Leu Met Lys 20 20 20 PRT Murray Valley encephalitis virus 20 Leu
Val Asn Lys Lys Asp Ala Trp Leu Asp Ser Thr Lys Ala Thr Arg 1 5 10
15 Tyr Leu Thr Lys 20 21 20 PRT West Nile virus 21 Leu Ala Asn Lys
Lys Gly Ala Trp Met Asp Ser Thr Lys Ala Thr Arg 1 5 10 15 Tyr Leu
Val Lys 20 22 20 PRT St. Louis encephalitis virus 22 Leu Ala Thr
Lys Asn Thr Pro Trp Leu Asp Thr Val Lys Thr Thr Lys 1 5 10 15 Tyr
Leu Thr Lys 20 23 20 PRT Vesicular stomatitis virus 23 Leu Lys Thr
Arg Gln Glu Lys Trp Met Thr Gly Arg Met Gly Glu Arg 1 5 10 15 Gln
Leu Gln Lys 20 24 20 PRT Tick-borne encephalitis virus 24 Leu Thr
Gly Arg Gly His Lys Trp Leu Glu Gly Asp Ser Leu Arg Thr 1 5 10 15
His Leu Thr Arg 20 25 20 PRT Flavivirus langat 25 Leu Thr Gly Arg
Gly His Gln Trp Leu Glu Gly Glu Ala Val Lys Ala 1 5 10 15 His Leu
Thr Arg 20 26 20 PRT Powassan virus 26 Met Val Gly Thr Gly His Ala
Trp Leu Lys Gly Asp Asn Ile Arg Asp 1 5 10 15 His Val Thr Arg 20 27
41 PRT West Nile virus 27 Arg Ser Leu Thr Val Gln Thr His Gly Glu
Ser Thr Leu Ala Asn Lys 1 5 10 15 Lys Gly Ala Trp Met Asp Ser Thr
Lys Ala Thr Arg Tyr Leu Val Lys 20 25 30 Thr Glu Ser Trp Ile Leu
Arg Asn Pro 35 40 28 40 PRT Dengue virus 28 Ser Val Ala Leu Ala Pro
His Val Gly Leu Gly Leu Glu Thr Arg Thr 1 5 10 15 Glu Thr Trp Met
Ser Ser Glu Gly Ala Trp Lys Gln Ile Gln Lys Val 20 25 30 Glu Thr
Trp Ala Leu Arg His Pro 35 40 29 40 PRT Dengue virus 29 Ser Val Ala
Leu Val Pro His Val Gly Met Gly Leu Glu Thr Arg Thr 1 5 10 15 Glu
Thr Trp Met Ser Ser Glu Gly Ala Trp Lys His Ala Gln Arg Ile 20 25
30 Glu Thr Trp Ala Leu Arg His Pro 35 40 30 39 PRT Dengue virus 30
Ser Val Ala Leu Ala Pro His Val His Leu His Leu Glu Thr Arg Thr 1 5
10 15 Glu Thr Trp Met Ser Ser Glu Gly Ala Trp Lys Gln Ile Gln Lys
Val 20 25 30 Glu Thr Trp Ala Leu Arg His 35
* * * * *