Spermatozoal cells in human semen do not stimulate allogeneic leucocytes in culture

Lymphocyte proliferative response to fertilization antigen in patients with antisperm antibodies

The fertilization antigen, immunopurified from human testes, activated lymphocytes from three of the six men and women with antisperm antibodies. Lymphocytes from none of the six men and women without antibodies were activated with fertilization antigen. Another sperm surface antigen, the germ cell antigen, immunopurified from murine testes, did not activate lymphocytes from any of the individuals with or without antisperm antibodies. These results indicate that the men and women with antisperm antibodies are sensitized against fertilization antigen and not germ cell antigen. These results reinforce our previous findings on the involvement of fertilization antigen in immunoinfertility in humans.

Analysis of HLA antigens on germ cells in human semen

Nucleated cells other than sperm (NCOS) were isolated from human semen by centrifugation on a Ficoll density gradient. Using tissue-specific monoclonal antibodies (mAb) greater than 99% of the NCOS were found to be sperm cell precursors (SpP). These cells were tested for the expression of class I and II (DR, DP and DQ) HLA antigens by using specific mAb. The anti-HLA class I and II and anti-beta 2-microglobulin mAb reacted with less than 1% of the NCOS. This was demonstrated by indirect immunofluorescence microscopy and fluorescence-activated cell sorter analysis. These results were similar to those obtained from testing germ cells in frozen sections of normal adult testis using the same panel of mAb. In mixed lymphocyte-NCOS cultures, the SpP failed to stimulate allogeneic lymphocytes even when different concentrations of cells were used. These results indicate little or no expression of HLA class I and II including the HLA-D (T cell-defined) determinant on the SpP, a phenomenon which could be of biological importance.

Production of interferon gamma by lymphocytes exposed to antibody-coated spermatozoa: a mechanism for sperm antibody production in females

The ability of sperm to induce lymphocytes from female donors to produce interferon gamma (IFN) was measured. Of nine samples where immunoglobulin was bound to ejaculated motile sperm, five (55.6%) induced IFN production. In contrast, only 1 of 35 (2.9%) sperm samples lacking bound immunoglobulins induced IFN (P less than 0.005). Incubation of donor sperm with sperm antibody containing sera from nine male patients led, in seven cases (77.8%), to acquisition by sperm of the ability to induce IFN. Lymphocytes from eight of eight females tested all responded to sperm with bound antibodies. IFN induction of Ia antigen expression on macrophage may be required for recognition of processed sperm antigens by the female's T helper cells.