Definition of a human T cell epitope from influenza A non-structural protein 1 using HLA-A2.1 transgenic mice.
Previous results from this laboratory demonstrated that the dominant influenza A epitope recognized by HLA-A2.1-restricted cytotoxic T lymphocytes (CTL) from HLA-A2.1 transgenic mice was the matrix protein 1 (M1) peptide epitope that is immunodominant in human CTL responses. However, analysis of a large number of CTL lines revealed a subset of influenza A/PR/8/34-specific murine CTL that recognized an HLA-A2.1-restricted epitope distinct from M1. Using recombinant vaccinia viruses encoding different influenza gene segments, the epitope recognized by these CTL was shown to be derived from A/PR/8 non-structural protein 1 (NS1). Because these CTL did not recognize targets infected with the A/Alaska/6/77 strain of influenza, candidate peptide epitopes were synthesized based on sequences that included an HLA-A2.1-specific binding motif, and that differed between A/PR/8 and A/Alaska. All of these CTL recognized a nonamer and a decamer peptide which contained a common eight amino acid sequence and two distinct sets of binding motif residues. However, the nonamer peptide was able to sensitize CTL for half-maximal lysis at 80- to 2500-fold lower doses than either the octamer or decamer. The homologous peptide derived from A/Alaska NS1 contained conservative amino acid changes at positions 4 and 8, and was not recognized at any tested concentration, although it bound with higher affinity to HLA-A2.1 than the peptide from A/PR/8. The A/PR/8 NS1 nonamer epitope was also recognized by human influenza A-specific CTL derived from two individuals. These results substantiate the general utility of HLA class I transgenic mice for the identification of human CTL epitopes for other pathogens.
Man
S
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Department of Microbiology, University of Virginia, Charlottesville 22908, USA.
Newberg
M H
MH
Crotzer
V L
VL
Luckey
C J
CJ
Williams
N S
NS
Chen
Y
Y
Huczko
E L
EL
Ridge
J P
JP
Engelhard
V H
VH
D000595:Amino Acid Sequence; D000818:Animals; D015789:HLA-A2 Antigen / Q000235:genetics* / Q000276:immunology; D006801:Humans; D016056:Immunodominant Epitopes / Q000276:immunology*; D009980:Influenza A virus / Q000276:immunology*; D051379:Mice; D008822:Mice, Transgenic / Q000276:immunology; D008969:Molecular Sequence Data; D010455:Peptides / Q000276:immunology; D013602:T-Lymphocytes, Cytotoxic / Q000276:immunology*; D017361:Viral Nonstructural Proteins / Q000032:analysis / Q000276:immunology*
D015789:HLA-A2 Antigen; C085820:INS1 protein, influenza virus; D016056:Immunodominant Epitopes; D010455:Peptides; D017361:Viral Nonstructural Proteins