Cross-reactive cytotoxic T cells to serologically distinct vesicular stomatitis virus.

Target cells infected with either of the two distinct serotypes of vesicular stomatitis virus (VSV), VSV-In-diana (VSV-Ind) or VSV-New Jersey (VSV-NJ), are lysed by syngeneic cytotoxic T lymphocytes (CTL) generated against one particular serotype of VSV. This cross-reactive lysis demonstrates some virus specificity since target cells infected with widely different viruses or Chandipura, a distinct human rhabdovirus, are not lysed by VSV-immune spleen cells. The cross-reactive lysis of VSV-infected targets is mediated by T cells as demonstrated by sensitivity to anti-θ and complement treatment. Interestingly, the cross-reactive lysis in a primary anti-VSV cell-mediated immune response appears asymmetrical. CTL generated to VSV-Ind are able to lyse syngeneic target cells infected with VSV-Ind as efficiently as targets infected with VSV-NJ, whereas effector cells to VSV-NJ lysed VSV-Ind infected target cells poorly. Results of cold target competition assays support the observed asymmetry of cross-reactivity. Cross-reactive lysis occurred by using both VSV-infected continuous lymphoid or fibroblast cell lines as targets and was not influenced by background genes of the effector spleen cells. The inability of effectors to VSV-NJ to cause marked lysis of VSV-Ind-infected targets could be overcome by using secondary CTL generated in vivo or in vitro from mice that had previously been injected with VSV-Ind. Thus, the asymmetry may merely reflect quantitative differences in the frequency of precursor T cells activated by the different VSV serotypes. Furthermore, these results suggest that CTL and antibodies to VSV recognize distinct antigenic determinants.