Cytotoxic T cells specific for a single peptide on the M2 protein of respiratory syncytial virus are the sole mediators of resistance induced by immunization with M2 encoded by a recombinant vaccinia virus (original) (raw)
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Journal of Virology, 1992
It was previously demonstrated that the vaccinia virus recombinants expressing the respiratory syncytial virus (RSV) F, G, or M2 (also designated as 22K) protein (Vac-F, Vac-G, or Vac-M2, respectively) induced almost complete resistance to RSV challenge in BALB/c mice. In the present study, we sought to identify the humoral and/or cellular mediators of this resistance. Mice were immunized by infection with a single recombinant vaccinia virus and were subsequently given a monoclonal antibody directed against CD4+ or CD8+ T cells or gamma interferon (IFN-gamma) to cause depletion of effector T cells or IFN-gamma, respectively, at the time of RSV challenge (10 days after immunization). Mice immunized with Vac-F or Vac-G were completely or almost completely resistant to RSV challenge after depletion of both CD4+ and CD8+ T cells prior to challenge, indicating that these cells were not required at the time of virus challenge for expression of resistance to RSV infection induced by the re...
Vaccine, 2008
Cytotoxic T lymphocytes are critical for the control of respiratory syncytial virus infection in humans and mice. Recently, we identified a new H-2K d restricted subdominant epitope in the RSV M2 protein. In this study, we investigated if modification of anchor residues at positions 2 and 9 in the dominant M2 82-90 epitope in the M2 protein would alter the CTL epitope dominance hierarchy following immunization with plasmid DNA encoding M2 proteins. We showed that immunogenicity of the subdominant epitope M2 127-135 was enhanced when the anchor residues of the dominant epitope were mutated, suggesting that the immunodominant epitope induces a suppression of response to the subdominant epitope.
Virology, 2005
Cytotoxic T lymphocytes (CTL) play a significant role in the clearance of respiratory syncytial virus (RSV) infection in humans and mice. Identification of class I MHC-restricted CTL epitopes is critical in elucidating mechanisms of CTL responses against viral infections. However, only four H-2 d -restricted epitopes have been reported in mice. Because of the diversity of transgenic and knockout mice available to study immune responses, new epitopes in additional strains of mice must be identified. We therefore attempted to discover novel CTL epitopes in C57Bl/6 mice. Our efforts revealed a new H-2D b -restricted CTL epitope from the RSV M protein, corresponding to aa [187][188][189][190][191][192][193][194][195]. Also, M187 -195-specific CTLs were activated with kinetics similar to the immunodominant BALB/c epitope, M2 82 -90. This is the first RSV-specific CTL epitope described in a strain of mice other than BALB/c. Furthermore, identification of this H-2 b -restricted CTL epitope provides access to genetically modified H-2 b mice for more detailed studies of CTL mechanisms in RSV infection. Published by Elsevier Inc.
Journal of General Virology
Respiratory syncytial virus (RSV)-specific cytotoxic T lymphocytes (CTL) or neutralizing antibodies can protect against RSV infection when induced separately by immunization with synthetic peptides. In the work described here, RSV-specific neutralizing antibodies and CTLs were induced after immunization with a cocktail of peptides consisting of a B-cell mimotope (S1S-MAP), a T-helper epitope (SH:45-60) and a CTL epitope linked to a fusion (F) peptide (F/M2:81-95) that were comparable to those induced by the peptides alone. Following challenge, a 190-fold reduction in RSV titre was observed in the lungs of peptide cocktail-immunized mice. The combination of RSV-specific humoral and cellular immunity induced by the peptide cocktail was thus more effective at clearing RSV than peptide-induced humoral or cellular immunity alone.
Characterization of Respiratory Syncytial Virus M- and M2-Specific CD4 T Cells in a Murine Model
Journal of Virology, 2009
CD4 T cells have been shown to play an important role in the immunity and immunopathogenesis of respiratory syncytial virus (RSV) infection. We identified two novel CD4 T-cell epitopes in the RSV M and M2 proteins with core sequences M 213-223 (FKYIKPQSQFI) and M2 27-37 (YFEWPPHALLV). Peptides containing the epitopes stimulated RSV-specific CD4 T cells to produce gamma interferon (IFN-γ), interleukin 2 (IL-2), and other Th1- and Th2-type cytokines in an I-A b -restricted pattern. Construction of fluorochrome-conjugated peptide-I-A b class II tetramers revealed RSV M- and M2-specific CD4 T-cell responses in RSV-infected mice in a hierarchical pattern. Peptide-activated CD4 T cells from lungs were more activated and differentiated, and had greater IFN-γ expression, than CD4 T cells from the spleen, which, in contrast, produced greater levels of IL-2. In addition, M 209-223 peptide-activated CD4 T cells reduced IFN-γ and IL-2 production in M- and M2-specific CD8 T-cell responses to D b...
Journal of General Virology, 1996
Vaccinia virus (vv) recombinants expressing either wildtype (VA-F) or mutant forms (VA-FT, VA-FR47, VA-FS 1 to VA-FS6) of the fusion (F) protein of respiratory syncytial (RS) virus were examined for their ability to elicit antibody, cytotoxic T lymphocytes (CTL) and protection against RS virus infection in BALB/c mice. Cells infected with the VA-F and VA-FT recombinants expressed the F protein on their surface and mice vaccinated with these recombinants developed RS virus neutralizing antibodies. The VA-FR47 recombinant expressed a mutant form of the F protein (with six amino acid changes from the wild-type) in which both proteolytic processing of the F 0 precursor and its transport to the cell surface were inhibited. These mutants induced transient protection against RS virus infection although they did not induce RS virus neutralizing antibodies, or
PloS one, 2012
Respiratory syncytial virus (RSV) is an important cause of severe upper and lower respiratory disease in infants and in the elderly. There are 2 main RSV subtypes A and B. A recombinant vaccine was designed based on the central domain of the RSV-A attachment G protein which we had previously named G2Na (aa130-230). Here we evaluated immunogenicity, persistence of antibody (Ab) response and protective efficacy induced in rodents by: (i) G2Na fused to DT (Diphtheria toxin) fragments in cotton rats. DT fusion did not potentiate neutralizing Ab responses against RSV-A or cross-reactivity to RSV-B. (ii) G2Nb (aa130-230 of the RSV-B G protein) either fused to, or admixed with G2Na. G2Nb did not induce RSV-B-reactive Ab responses. (iii) G2Na at low doses. Two injections of 3 µg G2Na in Alum were sufficient to induce protective immune responses in mouse lungs, preventing RSV-A and greatly reducing RSV-B infections. In cotton rats, G2Na-induced RSV-reactive Ab and protective immunity against...
The Journal of general virology, 2002
We describe 15-mer peptide P8:F92-106 from the F protein of respiratory syncytial virus (RSV) that can act as an MHC class I-restricted (H-2K(d)) epitope for RSV-specific CD8(+) CTL. This peptide is interesting because not only is it the first murine CTL epitope to be identified in the F protein but also because it does not contain a known allele-specific motif, as all 15 amino acids appear to be required for effective presentation to CTL. In in vitro MHC class I refolding experiments, peptide P8:F92-106 induced complex formation with H-2K(d) heavy chains and beta2-microglobulin. Immunization of BALB/c mice with P8:F92-106 resulted in the induction of peptide and RSV-specific CTL responses as well as peptide-specific proliferative responses. Following intranasal challenge with RSV, P8:F92-106-immunized mice showed a significant reduction in viral load in the lungs compared to that seen in unimmunized mice. Furthermore, passive transfer of purified CD8(+) lymphocytes into BALB/c scid...
Viral Immunology, 2007
We have developed and evaluated an immunodominant respiratory syncytial virus (RSV) F antigen in a mouse model. The antigenic region corresponding to amino acids 255-278 of the RSV F protein was cloned into a vector containing the ctxA 2 B gene of cholera toxin (CT). The recombinant protein was expressed in Escherichia coli and analyzed on sodium dodecyl sulfate-polyacrylamide gels. The purified protein was evaluated by immunoblot and ganglioside GM 1 enzyme-linked immunosorbent assay to confirm the expression of the RSV F protein and to correct association of the recombinant protein to form a holotoxin-like chimera, respectively. We hypothesized that genetic fusion of modified CT-based adjuvant with RSV F immunodominant epitopes (rRF-255) would induce protective humoral and cellular immune responses in mice. Intranasal immunization of mice with rRF-255 overall induced higher concentrations of anti-RSV F-specific antibodies in both serum and saliva as compared with mice immunized intranasally with RSV or phosphate-buffered saline (PBS). Antibody isotype analysis (IgA, IgG1, IgG2a, and IgG2b) was also performed. The predominant IgG2a antibody isotype response in combination with cytokine analysis of helper T cell type 1 (interferon-␥, interleukin [IL]-2, IL-12 p70, and tumor necrosis factor-␣) and helper T cell type 2 (IL-4 and IL-10) responses revealed that rRF-255 antigen induces a prominent helper T cell type 1 immune response in mice. The rRF-255 antigen also induced serum neutralizing antibodies in immunized mice. Analysis of RSV load in lungs showed that rRF-255 immunization provided significant protection compared with PBS control animals.