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-A0201-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-A0201-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-A0201-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.