Immunization of mice with vaccinia virus-M2 recombinant induces epitope-specific and cross-reactive Kd-restricted CD8+ cytotoxic T cells.
The M2 protein of respiratory syncytial virus (RSV) is a protective antigen in H-2d, but not H-2b or H-2k mice. None of the other RSV proteins, excluding the surface glycoproteins that induce neutralizing antibodies, is protective in mice bearing these haplotypes. Thus, the M2 protein stands alone as a nonglycoprotein-protective antigen of RSV. The M2 protein is a target for murine Kd-restricted cytotoxic T lymphocytes (CTLs), and the resistance induced by infection with a vaccinia virus-RSV M2 (vac-M2) recombinant is mediated by CD8+ CTLs. Since the nonameric consensus sequence for H-2 Kd-restricted T-cell epitopes and the amino acid sequence of the M2 protein of subgroup A and B strains of RSV are known, the present study sought to identify the specific epitope(s) on the M2 protein recognized by CD8+ CTLs. This was done by examining the ability of four predicted Kd-specific motif peptides present in the M2 amino acid sequence of an RSV subgroup A strain to sensitize target cells for lysis by pulmonary or splenic CTLs obtained from mice infected with RSV or vac-M2. The following observations were made. First, two of the four peptides sensitized target cells for lysis by pulmonary or splenic CTLs induced by infection with either vac-M2 or RSV. Second, one of the two peptides, namely the 82-90 (M2) peptide, sensitized targets at a very low peptide concentration (10(-10) to 10(-12) M). Third, cold-target competition experiments revealed that the predominant CTL population induced by infection with vac-M2 or RSV recognized the 82-90 (M2) peptide, and this CTL population appeared to recognize the 71-79 (M2) peptide in a cross-reactive manner. Fourth, CTL recognition of targets sensitized with either the 71-79 (M2) or the 82-90 (M2) peptide was Kd restricted. Fifth, CTLs induced by infection with RSV subgroup A or B strains recognized the two M2 peptides. The findings suggest that the M2 protein of RSV contains an immunodominant Kd-restricted CTL epitope consisting of amino acid residues 82 to 90 (SYIGSINNI), which are shared by subgroup A and B RSVs.
Kulkarni
A B
AB
Respiratory Viruses Section, National Institute of Allergy and Infectious Diseases, Bethesda, Maryland 20892.
Morse
H C
HC
Bennink
J R
JR
Yewdell
J W
JW
Murphy
B R
BR
D000483:Alleles; D000595:Amino Acid Sequence; D000818:Animals; D003429:Cross Reactions; D003602:Cytotoxicity, Immunologic; D000939:Epitopes; D005260:Female; D005822:Genetic Vectors; D006183:H-2 Antigens / Q000276:immunology; D015707:HN Protein; D051379:Mice; D008807:Mice, Inbred BALB C; D008969:Molecular Sequence Data; D009842:Oligopeptides / Q000276:immunology; D012136:Respiratory Syncytial Viruses / Q000276:immunology*; D013602:T-Lymphocytes, Cytotoxic / Q000276:immunology*; D014614:Vaccines, Synthetic / Q000276:immunology*; D014616:Vaccinia virus; D014759:Viral Envelope Proteins; D014764:Viral Proteins / Q000276:immunology*; D014765:Viral Vaccines / Q000235:genetics* / Q000276:immunology
D000939:Epitopes; D006183:H-2 Antigens; D015707:HN Protein; D009842:Oligopeptides; D014614:Vaccines, Synthetic; D014759:Viral Envelope Proteins; D014764:Viral Proteins; D014765:Viral Vaccines; C116204:attachment protein G