Activation of circulating gamma delta T-lymphocytes by autologous sperm from men sensitized to sperm

The in vitro proliferative responses to sperm of T-lymphocytes bearing the alpha beta or gamma delta form of the antigen receptor were investigated. Peripheral blood mononuclear cells from five men without antisperm antibodies and eight men with antisperm antibodies both on sperm and in serum were incubated for 72 h in the presence of an equal concentration of autologous live sperm, freeze-thawed sperm and heat-killed sperm. Prior to incubation and after 72 h, aliquots were applied to Teflon coated microscope slides, which were subsequently incubated with monoclonal antibodies to the beta chain and delta chain of the human T-cell receptor. Urethral samples were cultured for bacteria and tested for Chlamydia trachomatis by direct staining and by ELISA. The four men with chlamydial infections had the highest concentrations of circulating gamma delta T-cells (P = 0.0008). The concentration of gamma delta T-cells from men with antisperm antibodies increased 245% over the buffer control in response to live sperm (P < 0.0001). Proliferation of gamma delta T-cells was also seen to a lesser extent in response to freeze-thawed (P = 0.002) and heat killed (P = 0.03) sperm. In contrast, gamma delta T-cells from men without antisperm antibodies proliferated only marginally (36%) in response to live sperm (P = 0.05) and were unresponsive to non-viable sperm. Only from men sensitized to sperm were alpha beta T-cells responsive, to a small extent, to live sperm (P = 0.04). Thus, in men with antisperm antibodies, peripheral gamma delta and alpha beta T-cells appeared to be sensitized to antigens on the surface of viable sperm. The immune response of gamma delta T-cells to sperm may be a useful in vitro system to examine the mechanism of gamma delta T-cell activation.