In vitro stimulation of lymphocytes of donors seronegative for Epstein-Barr virus by preparations of inactivated Epstein-Barr virus.

Heat-inactivated preparations of Epstein-Barr virus stimulated human lymphocytes as assayed by incorporation of [(3)H]thymidine. The inactivated Epstein-Barr virus stimulated the lymphocytes of all five seropositive donors, 11 of 14 seronegative donors (aged eight to 26 years), and none of 15 neonates. Control antigens prepared from a human lymphoid cell line devoid of the Epstein-Barr virus genome did not stimulate the lymphocytes of seronegative donors. Fetal calf serum at the concentration used for suspension of Epstein-Barr virus did not stimulate or only minimally stimulated the lymphocytes of seronegative donors. The reactivity of the histocompatibility antigens found on human lymphocytes was abolished by procedures used for inactivation of the virus.