Article révisé par les pairs
Résumé : The cell-mediated immune response to retrovirus antigens related to Mason-Pfizer virus (M-P V) and to baboon endogenous virus (BeV) was studied by lymphocyte transformation in blood samples from 90 women. Mitomycin C-treated infected cells and killed purified virions were used as antigens and were added on one or two occasions during in vitro stimulation. The number of activated lymphocytes was estimated by thymidine incorporation and by a virus plaque assay. The latter detected more responses to BeV antigens than the former, while the reverse was true with M-P V antigens. Assaying lymphocyte activity after one and two in vitro stimulations detected more responses than either test alone, but a high stimulation index after a first antigen addition was often followed by absence of response to a second antigen stimulus, indicating a possible in vitro suppressor mechanism. Human lymphocytes as well as those from experimentally infected monkeys responded to M-P V antigens present in infected cells but not to purified virions, while responses to the latter were found only in rabbits inoculated with the virus but not productively infected. Humoral antibodies are appeared in inoculated animals, as detected by 3 tests. Neutralization of syncytium forming units of M-P V showed sensitivity similar to an enzyme-linked immunosorbent assay and a radioimmunoassay but with both the latter specific results were obtained only when human and animal sera were preadsorbed with cell and calf serum antigens. © 1979.