An SV40 VP1-derived epitope recognized by CD8+ T cells is naturally processed and presented by HLA-A⁎0201 and cross-reactive with human polyomavirus determinants

The CD8+ T cell responses directed toward the VP1 antigens of human polyomaviruses JC and BK recently were shown to be cross-reactive. Two HLA-A⁎0201-restricted determinants from each virus have been defined and include JCp100–108 (ILMWEAVTL) and BKp108–116 (LLMWEAVTV) as well as JCp36–44 (SITEVECFL) and BKp44–52 (AITEVECFL). We asked whether VP1 from the related SV40 contains similar HLA-A⁎0201-restricted determinants. In this study, we demonstrate that CD8+ T cells specific for SV40 VP1 p110–118 (ILMWEAVTV), but not p46–54 (SFTEVECFL), can be induced in HLA-A⁎0201-transgenic mice and that these CD8+ T cells cross-react with the corresponding determinants from JC and BK virus. The SV40 p110 determinant was found to be processed and presented in SV40-infected cells. These results indicate that the JCp36/BKp44 determinants are distinctive for the human polyomaviruses while the JCp100/BKp108/SVp110 determinants are shared by all three viruses, providing a target for CD8+ T cell cross-reactivity.