Recognition of an immunoglobulin VH epitope by influenza virus-specific class I major histocompatibility complex-restricted cytolytic T lymphocytes.

Summary There are two immunogenic sites on the type A influenza A/Japan/57 (H2N2) hemagglutinin (HA) that can be recognized by class I major histocompatibility complex (MHC), H-2K arestricted cytolytic T lymphocytes (CTLs). One of these sites encompasses two distinct partially overlapping epitopes, which span HA residues 204-212 and 210-219. During the analysis of the fine specificity of CTL clones directed to the HA 210-219 epitope, we found that one clone 40-2 also recognized the myeloma cell line P3x63-Ag8. P3x63-Ag8 is derived from the MOPC 21 myeloma and expresses an immunoglobulin (Ig) heavy chain variable region (V.) gene which is a member of the murine 7183 V. gene family. Recognition was specific for the endogenously processed MOPC 21 heavy chain in association with the K a molecules, since the SP2/0 derivative of P3x63-Ag8, which does not make a functional Ig H chain, is not recognized. The V. epitope recognized by clone 40-2 could be mapped to a 10 amino acid peptide spanning MOPC 21 V. residues 49-58. Cross-reactivity for the V, gene product was also demonstrable in some heterogeneous populations of CTL generated in response to influenza virus infection. These results represent the first demonstration of cross-reactivity for an endogenously processed product of a self-Ig by the CTL directed to a foreign antigen and raise the possibility that the Ig V. expression may regulate the CD8 § T cell response to foreign antigens.