Study of the lymphocyte in vitro response to rubella antigen and phytohemagglutinin by a whole blood method.

A whole blood culture method was used to study lymphocyte in vitro responses to rubella antigen and to phytohemagglutinin (PHA) in rubella infection. The acute phase of infection in four cases was characterized by high spontaneous incorporation of 14C-thymidine in the cultures, unresponsiveness of lymphocytes to rubella antigen, and absence of response, or relatively low response, to PHA. Cells showing vigorous in vitro response to rubella antigen appeared at about two weeks after the onset of rash. Lymphocyte PHA response returned to normal by day 31. Three rubella vaccinees exhibited a similar response. The use of whole blood lymphocyte cultures stimulated with multiple doses of mitogen and with antigen appears to be a promising technique for studies of "general" and "specific" cell-mediated immunity in viral infections.