Mixed cultures of sperm and leukocytes as a measure of histcompatibility in man.

Human peripheral blood leukocyte cultures containing varying numbers of washed fresh sperm were cultured for 4 days. [3H] Thymidine incorporation was used as a measure of lymphocyte transformation. Human sperm cells induce a 4- to 250-fold increase in [3H] thymidine incorporation in allogeneic leuocyte cultures, but no increase was demonstrated in autologous leukocyte cultures. The response was dose-dependent with maximum stimulation obtained at 2 x 10(6) sperm per milliliter of culture. Seminal plasma was inhibitory in a dose-dependent fashion and as little as 0.2 microliter per 200 microliters of culture was inhibitory. The data indicate that tissues other than leukocytes can express the portion of the major histocompatibility complex responsibile for allospecific lymphocyte transformation, and thus have application in transplantation and reproductive biology.