Virus-immune and alloreactive response characteristics of thymocytes and spleen cells from young mice.

Thymocytes from 3-day-old mice generate a strong, virus-immune cytotoxic T lymphocyte (CTL) response when primed in irradiated, vaccinia-infected recipients. Effector potential is not detected in spleen until day 4 or 5, when alloreactive precursors may also be present. Mice of 8 days or older survive inoculation with large doses of vaccinia virus, and generate significant CTL activity in spleen. There is, unlike the situation described by others for Listeria antigens, no major defect in stimulator function for spleens of 1-wk-old mice. This is true for both the virus-specific and alloreactive CTL responses.