SV40 large T antigen-specific human T cell memory responses.
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.
Velindre Hospital, Velindre NHS Trust, Cardiff, United Kingdom.
Sharon
S
Coleman
Allen
A
Gibbs
Eric
E
Butchart
Malcolm D
MD
Mason
Bharat
B
Jasani
Zsuzsanna
Z
Tabi
D000595:Amino Acid Sequence; D000957:Antigens, Viral, Tumor / Q000737:chemistry / Q000276:immunology*; D018414:CD8-Positive T-Lymphocytes / Q000276:immunology*; D018984:Epitopes, T-Lymphocyte / Q000276:immunology*; D005434:Flow Cytometry; D006801:Humans; D007156:Immunologic Memory; D008654:Mesothelioma / Q000276:immunology; D008969:Molecular Sequence Data; D010455:Peptides / Q000737:chemistry / Q000276:immunology; D010997:Pleural Neoplasms / Q000276:immunology; D013539:Simian virus 40 / Q000276:immunology*
D000957:Antigens, Viral, Tumor; D018984:Epitopes, T-Lymphocyte; D010455:Peptides