Interferon production in lymphocyte cultures after rubella infection in humans

When stimulated with rubella virus irradiated with ultraviolet light, cultures of lymphocytes from individuals immune to rubella responded with production of 12-14 times more interferon than did cultures of lymphocytes from individuals susceptible to rubella. This property may be retained throughout life, since it was seen in individuals who had had rubella in their recent and remote pasts. Peak levels of interferon were detected six days after stimulation of lymphocytes with rubella virus antigen. In contrast, phytohemagglutinin induced production of interferon equally well in cultures of lymphocytes from persons immune and persons susceptible to rubella, with levels peaking three days after stimulation. Since there was a positive correlation among titers of hemagglutination-inhibiting antibody to rubella virus, incorporation of [14C]thymidine, and production of interferon after stimulation of lymphocyte cultures by rubella virus, interferon synthesis may be considered to be another measurable parameter of cell-mediated immunity in rubella.