SV40 large T antigen-specific human T cell memory responses

✍ Scribed by Sharon Coleman; Allen Gibbs; Eric Butchart; Malcolm D. Mason; Bharat Jasani; Zsuzsanna Tabi

• Publisher: John Wiley and Sons
• Year: 2008
• Tongue: English
• Weight: 118 KB
• Volume: 80
• Category: Article
• ISSN: 0146-6615
• DOI: 10.1002/jmv.21216

✦ Synopsis

Abstract

The continued presence of simian virus 40 (SV40), a monkey polyomavirus, in man is confirmed by the regular detection of SV40‐specific antibodies in 5–10% of children who are unlikely to have received contaminated polio‐vaccines. The aim of our experiments was to find cellular immunological evidence of SV40 infection in humans by testing memory T cell responses to SV40 large T antigen (Tag). As there is some indication that the virus may be present in malignant pleural mesothelioma (MPM) cells, we analyzed T cell responses in MPM patients and in healthy donors. The frequencies of responding T cells to overlapping Tag peptides were tested by cytokine flow cytometry. CD8^+^ T cells from 4 of 32 MPM patients responded (above twofold of control) to SV40 Tag peptides, while no positive responses were detected in 12 healthy donors. Within SV40 Tag we identified three 15 amino acid‐long immunogenic sequences and one 9 amino acid‐long T cell epitope (p138) (138FPSELLSFL146), the latter including a HLA‐B7‐restriction motif. T cell responses to p138 were SV40‐specific as T cells stimulated with p138 did not cross‐react with the corresponding sequences of Tag of human polyomaviruses BKV and JCV. Similarly, the relevant BKV and JCV Tag peptides did not generate T cell responses against SV40 TAg p138. Peptide‐stimulated T cells also killed SV40 Tag‐transfected target cells. This article demonstrates the presence, and provides a detailed analysis, of SV40‐specific T cell memory in man. J. Med. Virol. 80:1497–1504, 2008. © 2008 Wiley‐Liss, Inc.