Antiviral antibodies inhibit the lysis of tumour cells by anti-H–2 sera

Abstract

RECENT experiments have indicated that the cytolysis of virus-infected, chemically modified, or neoplastic cells by murine T lymphocytes is restricted to target cells carrying one or more of the H–2 antigens possessed by the cells against which the cytotoxic T cells were generated^1–10. Two general hypotheses have been proposed to explain the participation of H–2 antigens in T–cell-mediated cytolysis. According to one hypothesis, T lymphocytes possess two different types of receptors, one which recognises the abnormal antigens of the target cell, and a second which interacts with the H–2 antigens of that cell. In the alternative hypothesis, the T cell has only one specific receptor that is directed against a complex antigenic determinant made of of H–2 antigens and viral antigens, for example, tumour antigens induced by viral infection. Neither of these hypotheses has yet been satisfactorily proven. In support of the one-receptor hypothesis, we have found that anti-H–2 and antiviral sera show copatching and cocapping of H–2 and viral antigens on the surface of EL4 leukaemia cells⁹, suggesting that viral and H–2 antigenic determinants can be in close physical association on the cell surface. Here we provide new evidence for the existence of a close association between H–2 antigens and viral antigens on murine leukaemia cells.