<i>In vitro</i> cellular immunity to epstein‐barr virus in normal human subjects

Abstract

Abstract Leukocyte migration inhibition was employed to study cell‐mediated immunity (CMI) to Epstein‐Barr virus (EBV) in 29 normal subjects. Anti‐EBV capsid antibody titres in these subjects ranged from 0 to 1:160. Extracts of seven human lymphoblastoid cell lines carrying EBV were evaluated as the source of test antigen. Of these cell lines studied, only P 3 HR‐1 proved suitable as a source of EBV antigen for use in the test. Undiluted tissue‐culture supernatant fluids of the EBV‐carrying cell lines P 3 HR‐1 and SH‐T 1 caused only weak or equivocal migration inhibition in normal subjects; others tested were without effect. Antigen controls consisted of extracts of the Raji cell line, which contains the EBV genome but produces no EBV antigen, and cultured human cells with no known association with EBV, all of which failed to induce migration inhibition. Cellular controls consisted of EBV sero‐negative adult leukocytes and foetal cord blood leukocytes which did not respond to P 3 HR‐1 extract, although two of the five cord sera contained anti‐EBV capsid antibody. The migration inhibition response was antigen‐dose‐dependent and was not affected by anti‐EBV antibody capable of neutralizing the infectivity of EBV. These results show that CMI to EBV is present in normal individuals who have antibody to EBV capsid antigen.