The effect of human spermatozoa on antigen and mitogen induced blastogenesis

Cellular sensitization against spermatic and seminal plasma antigens in women after intrauterine insemination

Using an indirect lymphokine-assay, the leucocyte-migration-inhibition-test (LMI-test), the cellular sensitization of fertile and infertile patients before and after homologous and heterologous intrauterine insemination (IUI) was investigated. In this assay several preparations of spermatozoa ("washed"-, "swim-up"- and "pellet"-spermatozoa) in different concentrations (1, 5 and 10 x 10(6) sperms/ml culture medium) and seminal plasma were tested as antigen. In all investigated groups a cellular immune response against spermatic antigen was demonstrable and seemed to be dose dependent. In contrast to fertile women who reacted with an enhancement of the macrophage migration for low concentrations the same concentration of antigen induced an inhibition of macrophage migration in fertile patients. For high concentrations of spermatic antigens there was a difference in the intensity of cell-mediated immune response between fertile and infertile women. Since infertile patients demonstrated an increased level of cell-mediated immune response it is possible that infertility may be caused by this altered immunological reaction. This response changes after multiple IUI-treatment and that change might be caused by the high concentration of spermatic antigens as there was a difference in the intensity of cell-mediated immune response between fertile and infertile women. Since infertile patients demonstrated an increased level of cell-mediated immune response it is possible that infertility may be caused by this altered immunological reaction. This response changes after multiple IUI-treatment and that change might be caused by the high concentration of spermatozoa. The immunological response of infertile patients seems to be similar in those receiving husband and donor IUI.

Immunosuppressive activity and polyamine levels of seminal plasma in azo-ospermic, oligospermic, and normospermic men

Seventy specimens of human seminal plasma obtained from azo-ospermic, oligospermic, and normospermic men were tested for immunosuppressive activity on normal donor lymphocytes. Spermine and spermidine levels in acidic extracts were determined in 32 specimens of seminal plasma from the three groups. The original seminal plasma as well as the neutralized spermine extracts were examined for their effect on the functional activity of the lymphocytes. Seminal plasma obtained from the normospermic and oligospermic semen showed significant immunosuppressive activity, whereas no immunosuppressive activity was induced by seminal plasma from azo-ospermic semen. The latter finding was in accordance with the low spermine levels in azo-ospermic semen, which were about 50% of those found in normospermic and oligospermic seman. Acidic extraction of the seminal plasma of azo-ospermic origin resulted in an increase in spermine levels and also in immunosuppressive activity, demonstrating that in azo-ospermic men spermine is bound probably to a protein and is released after acidification, exerting its immunosuppressive activity only when unbound.

Antibody and complement-binding activity of viable and nonviable human spermatozoa

Antibody and complement fixation by viable and nonviable spermatozoa were studied by means of immunofluorescence and a hemolytic assay (CH-50). Spermatozoa were incubated in sera from fertile male and female donors and in peritoneal fluid from fertile women undergoing laparoscopy. Nonviable spermatozoa were able to bind antibody or complement from sera and peritoneal fluid. There was no evidence of antibody or complement fixation by viable spermatozoa. The antibodies present in the serum that bind to spermatozoa belong to the IgG and IgM class; in peritoneal fluid, only IgG could be found. Complement fixation occurred via the classical (antibody-mediated) and alternative pathway. Viable spermatozoa possess antigenic properties different from nonviable spermatozoa. The lack of immunological reaction of women to viable spermatozoa and a possible mechanism for immunological infertility is considered.

Effect of boar seminal plasma and seminal vesicle fluid on porcine lymphocytes

Boar seminal plasma and seminal vesicle fluid inhibited mitogen-induced blastic transformation of porcine lymphocytes. Chromatographic separation of seminal vesicle fluid on Sephadex G-100 yielded four fractions. Only the SV-1 fraction displayed significant inhibition of blastic transformation. The results demonstrated that the immunosuppressive factor(s) in seminal plasma is secreted in seminal vesicles. Increased inhibition of blastic transformation of lymphocytes stimulated with pokeweed mitogen indicates that seminal plasma inhibits mainly B lymphocytes. Both seminal plasma and seminal vesicle fluid inhibited unstimulated lymphocytes.

Role of histoincompatibility on the blastogenic response of lymphocytes from guinea pigs alloimmunized with sperm cells

The involvement of antigens coded by the major histocompatibility complex in alloimmunization of guinea pigs with sperm has not been fully explored. Some of the "in vitro" correlates of cell-mediated immunity, such as the lymphocyte transformation test in presence of sperm cells, could be influenced, at least partially, by histoincompatibility. Outbred Hartley and inbred strain 13 guinea pigs were alloimmunized with sperm cells emulsified in Freund's complete adjuvant. The degree of histocompatibility between recipients and sperm cell donors was determined by using mixed lymphocyte culture assays. Stimulatory indices higher than four, indicating histoincompatibility, were obtained frequently between members of Hartley strain or between Hartley and strain 13 guinea pigs, but never between strain 13 animals. Sperm cells from histoincompatible guinea pigs failed to stimulate blastogenesis in lymphoid cells from nonimmunized animals. The lymphoblastogenic potential of allo- and isospermatozoa were compared. Lymphoid cells from Hartley and strain 13 guinea pigs alloimmunized with sperm cells were incubated in vitro with histocompatible and histoincompatible sperm cells. Both strain 13 and Hartley sperm cells gave a similar stimulatory index with lymphoid cells belonging to outbred or inbred alloimmunized guinea pigs. The use of fresh spermatozoa was of paramount importance. Frozen specimens lost their stimulatory capacity almost completely. Within the limits of the technique utilized here, we have failed to detect any influence of the antigens coded by the major histocompatibility complex of the guinea pig upon the sperm-induced lymphocyte transformation. These observations point to the sperm-specific autoantigens as being responsible for the lymphocyte proliferation.

Cytotoxic antibodies to lymphocytes: relationship to sperm immunity

Sperm and T lymphocytes share antigens, and sera from infertile subjects with sperm immunity have agglutinating antibodies to T lymphocytes. In the present study, cytotoxic antibody titers to sperm (C-Sp) and lymphocytes (C-Ly) were measured in sera, seminal plasma, cervical mucus and vaginal secretions of 52 infertile couples. The samples were divided into C-Sp negative and C-Sp positive groups. C-Ly titers against control T lymphocytes were significantly elevated in C-Sp positive sera of 35 males (P less than 0.005) and 27 females (P less than 0.05) as compared with C-Sp negative sera. C-Ly titers against autologous or partner T lymphocytes were similarly elevated in the sera of both groups. Titers of C-Ly in C-Sp positive secretions (seminal plasma, cervical mucus and vaginal secretions) against autologous and partner, as well as control, T lymphocytes were significantly elevated. In addition, elevated titers of C-Ly to autologous, partner and control B lymphocytes were observed in sera, cervical mucus and vaginal secretions from females with sperm immunity. The infertile males, however, did not have significant B lymphocyte immunity. Immunofluorescence assays revealed a significantly higher incidence of sperm and T lymphocyte antibodies (primarily IgG) in the C-Sp positive than in the C-Sp negative group. Titration of 100 sera from infertile subjects (50 couples) against a panel of lymphocytes of known HLA specificities failed to reveal a pattern of activity against HLA antigens of the A, B and C loci. Absorption of immune sera with sperm or lymphocytes reduced C-Sp and C-Ly titers significantly (P less than 0.001). These results suggest that infertile subjects with sperm immunity produce antibodies to cross-reactive antigens present on sperm and T lymphocytes.

Stimulation of lymphocytes by spermatozoa-stimulated cells

The mechanism of spermatozoa-lymphocyte interaction was studied using spermatozoa and lymphocytes obtained from 11 healthy individuals and from 2 patients with spermatocoele. The lymphocytes activated by spermatozoa in 3-day cultures were used as inducers of fresh, unstimulated autologous or allogeneic lymphocytes. In 9 cases of 13 tested sperm samples, a slight proliferative response of lymphocytes stimulated by spermatozoa-induced lymphocytes was observed. The final effect did not depend on whether an autologous or an allogeneic system was used in the first and the second incubation. A possible explanation of the observed reaction is discussed.

Immunological consequences of vasectomy

In more than 50% of men, vasectomy leads to auto-immune pathology. The auto-immune response to sperms following vasectomy is triggered by the phagocytosis of sperm in the epididymis. In the humoral immune response, sperm agglutinating, sperm immobilizing, and antibodies to sperm nuclear protamines occur, as early as 3-4 days after vasectomy. The incidence reaches 60-70% within 1 year and remains almost the same even after 20 years. Presence and effects of circulating immune complexes following vasectomy are discussed with reference to reported increased incidence of atherosclerosis and auto-immune orchitis in experimental animals. There is no positive conclusion whether vasectomy leads to cell mediated immunity to spermatozoa.

Cross-reactivity of sperm and T lymphocyte antigens

Evidence is presented for cross-reactivity between antigens on human sperm and T lymphocytes. In 25 infertile couples in which both the males and females had significant antisperm immunity, antibody (Ab) titers to thymocytes (mean +/- S.E.M. 159 +/- 4 and 72 +/- 14, respectively, in males and females), T cell lines CCRF-CEM (69 +/- 5 and 48 +/- 8) and HSB-2 (56 +/- 15) and 41 +/- 8), suppressor-enriched (TG) cells (26 +/- 6 and 66 +/- 28) and helper-enriched (TG-) cells (26 +/- 4 and 46 +/- 14) were significantly elevated, as compared with Ab titers in 45 normal males and 45 normal females without antisperm immunity. Antibody titers to adult B cells, B cell line RAJI, and granulocytes were similar in the two groups. Antisperm Ab titers in sera, sperm extracts, and seminal plasma of the infertile subjects were significantly reduced after absorption with sperm, thymocytes, or T cell line CCRF-CEM but not with the B cell line RAJI. Antithymocyte Ab titers in the sera were significantly reduced (p less than 0.001) after absorption with thymocytes, CCRF-CEM, or sperm, but not RAJI. Lymphocytes from the infertile patients, when stimulated with pokeweed mitogen in vitro, produced antisperm and anti-T-lymphocyte antibodies at significantly higher titers than normal controls.

In vitro studies in reproductive immunology. 3. Restoration of mitogenic activity of lymphocytes inhibited by seminal plasma in man

Human seminal plasma, (HuSePl) is inhibitory to mitogen (PHA-M, Con-A, and PWM) lymphocyte activation. The inhibition does not require the continuous presence of HuSePl. Lymphocyte cultures remain inhibited after 24-hr contact with HuSePl and subsequent washings. Addition of fresh autochthonous lymphocytes or T cells but not B cells can restore the mitogenic activity of HuSePl-inhibited lymphocyte cultures. These observations suggest that T-lymphocyte in the male genital tract are surveilled by HuSePl and lack of inhibitory material could induce an immunologic response by spermatozoal antigens.

In vitro studies in reproductive immunology. - 2. Demonstration of the inhibitory effect of male genital tract constituents on PHA-stimulated mitogenesis and E-rosette formation of human lymphocytes

The effect of male genital tract components (human spermatozoa, intact and chromatographed seminal plasma fractions) on in vitro cell-mediated immune reactions was examined. Their addition to PHA-containing lymphocyte cultures resulted in a marked degree of inhibition of DNA synthesis, the response varying with the fractions employed. The interference by such components with a terminal cell event during blast transformation was suggested by the failure of stimulated cultures to incorporate thymidine irrespective of the time during the incubation period at which the constituents were added. Seminal plasma and sperm extracts were also shown to inhibit T-cell associated E-rosette formation. The inhibitory properties of genital fractions remained unaltered after repetitive freeze-thaw cycling when tested in the transformation and E-rosette assays. Heating to 100 degrees C modified the response with some of the fractions.