Effect Of Antisperm Antibodies Research Articles

Reaction to damage of connective tissue in immunoprivileged organ (testis)

Microenvironment of sperm and its precursors includes various immune cell populations. This indicates not only their importance for immune privileged state within testes, but it concerns a regulatory role of these structures in performance of the most important physiological functions. Despite sufficient knowledge on the immune privileged state in the organ, the regulatory function are scarcely studied, and existing literature virtually does not cover the issues of local spermatogenesis regulation by various components of testicular microenvironment in the course of their regeneration. Purpose of the present study was to define the reactions of connective tissue in rat testis following traumatic lesion. Materials and methods: the study was carried out in mature male Wistar rats. Experimental animals were divided into 2 groups: intact animals and animals with blunt trauma to the left testicle. The animals were removed from the experiment on the 7th and 30th days. Blunt trauma was simulated by squeezing the organ with forceps with a force of 15 N for 3 seconds. For histological examination, the testes were excised, preparations were made by the standard scheme, stained with hematoxylin/ eosin, toluidine blue (to identify mast cells), and according to Van Gieson (to detect collagen fibers). Distinct components of connective tissue and spermatogenesis were evaluated in testicular preparations. Quantitative indexes were calculated using the ImageJ program. Total testosterone levels in the blood were determined by chemiluminescence technique. Statistical evaluation was performed with Statistica 8.0 software. Comparison of groups was performed using Mann-Whitney test. We have found that restoration of spermatogenesis in the damaged testis did not occur within 30 days after the injury. While the reaction of connective tissue was noted in the both testes, it was more pronounced in the damaged organ, and manifests as changes in testicular microvasculature, stimulation of fibroblastic response, multidirectional effects of mast cells and Leydig cells, depending on the duration of exposure. Changes in various components of microenvironment in the damaged testis led to similar changes in the intact organ. The mechanism of this change is usually associated with effect of antisperm antibodies and development of autoimmune processes, but another possible mechanism for impairment of spermatogenesis in the second paired intact organ may include effects of connective tissue microenvironment upon the spermatogenic epithelial cells.

Antisperm antibodies and sterility: insoluble problem or perspective trend of research?

Conflicting opinions about the effects of antisperm antibodies on fertilization can be due to inadequacy of experimental approaches in evaluating the antisperm immunity. Detection of antisperm antibodies bound to the surface of live spermatozoa can be associated with aggregation of surface antigen-antibody complexes followed by metabolic activation of spermatozoa and acrosomal reaction, which impair cell resistance. New concept of antisperm immunity and its influence on reproduction can be formulated only after comprehensive studies of the mechanisms of spermatozoon response to binding of antisperm antibodies. Further improvement of quantitative assays of antisperm antibodies and evaluation of their effect on spermatozoon function should be aimed at selection of experimental conditions preventing changes in spermatozoa coated with antisperm antibodies during in vitro manipulations.

Interference of antisperm antibodies with the induction of the acrosome reaction by zona pellucida (ZP) and its relationship with the inhibition of ZP binding

Objective: To determine whether antisperm antibodies can interfere with the induction of the acrosome reaction (AR) by the zona pellucida (ZP) and whether this interference also can occur in the absence of an inhibitory effect on ZP binding. Design: Prospective in vitro study. Setting: A tertiary care center, the Andrologic Clinic, University of L'Aquila. Patient(s): Sera from 12 infertile patients with high titers of circulating antibodies directed against the sperm head were studied. Intervention: None Main Outcome Measure(s): The effect of antisperm antibodies on ZP binding was evaluated by matching antibody-exposed and nonexposed donor sperm suspensions labeled with fluorescein or rhodamine, respectively, and incubated with the same salt-stored human ZPs. The effect of antibodies on ZP-induced AR was determined by challenging antibody-exposed and nonexposed donor sperm suspensions with human ZPs disaggregated with acidic NaH 2PO 4. Acrosomal status was evaluated using fluorescein-labeled Pisum sativum agglutinin and supravital stain Hoechst 33258. In some selected cases, the effect of antisperm antibodies on the acrosomal status of sperm bound to intact ZP also was evaluated using transmission electron microscopy. Result(s): Five of 12 sera exhibited an inhibitory effect on ZP binding. An inhibition of AR induction by disaggregated ZPs (ranging from 64% to 98%) was produced by all 5 sera with an inhibitory effect on ZP binding and by 2 of 7 sera without an inhibitory effect on ZP binding. The different effects of antisperm antibodies on AR induction by disaggregated ZP were confirmed by comparing with ultrastructural evaluations on the acrosomal status of sperm bound to intact ZP. Conclusion(s): Antisperm antibodies can interfere with the induction of AR by ZP. This inhibition can occur even in the absence of an inhibitory effect on ZP binding. Neither effect may occur.

Antisperm antibody-mediated alterations in the cellular activity of human trophoblast cells in culture.

Immune recognition of the fetus is well documented, yet the immunological basis of pregnancy loss awaits elucidation. Identification of trophoblast membrane epitopes as non-self either by preformed immunoglobulins or by circulating immunocompetent cells would lead to immunological rejection of the tissue. Such an event may occur in cases of cross-reacting antibodies developed as a consequence of exposure of sperm surface antigens. This hypothesis was tested by developing specific antibodies in rabbits against intact sperm surface antigens. These were subjected to different schedules of IgG purification and characterization. By means of nuclide precursor incorporation, the effect of antisperm antibody on DNA, RNA and protein synthesis of trophoblast cells in culture were studied. The results showed that the antibody inhibits incorporation into cells but after a delay of 72 hours some cells gradually recover. The interaction also led to a reduced rate of hCG production. Lysosomal enzyme activity was inhibited in the spent medium of antibody-treated cells but lysosome rich fractions showed no effect. This indicated that the major effect of the antibody was growth inhibitory rather than cytolytic.

Effect of antisperm antibodies on postcoital results and effect of intrauterine insemination on pregnancy outcome.

The effect of antisperm antibodies (ASA) in males was determined in 59 men using the direct immunobead test (IBT). Postcoital tests were evaluated in couples for whom all female factors appeared to be corrected. Pregnancy rates in 6 months were compared in couples with good postcoital tests vs. those with poor results; the latter group was treated with timed intrauterine insemination (IUI). Thirty-one percent of males with positive ASA (greater than or equal to 50%) had normal postcoital tests and all four achieved pregnancies. Fifty-six percent of men with positive ASA and poor postcoital scores achieved pregnancies following IUI therapy of their wives in 6 months; 83% of couples with normal postcoital tests achieved pregnancies as did couples treated with IUI when the postcoital was poor but the male ASA negative.

Effects of Antisperm Antibodies on Early Cleavage of Fertilized Ova1

Early cleavage of zygotes was abnormal after oocytes were fertilized with sperm cells from one of 64 infertile couples studied in our human in vitro fertilization and embryo development procedure. The abnormal cleavage, which did not affect fertilization, was not due to polyspermy or parthenogenetic activation of oocytes, but to antisperm antibodies present on the sperm cells. These antibodies did not react with zona-intact or zona-free human oocytes, although they reacted with the acrosomal (strongly) and tail (weakly) regions of human sperm. The antibodies recognized a double band comprising two glycoproteins of 14 +/- 3 and 18 +/- 3 kDa and a protein band of 22 +/- 3 kDa on the Western blot of lithium diiodosalicylate-solubilized human sperm extract. Antisera were raised in rabbits against the double band (14 +/- 3- and 18 +/- 3-kDa antigens) and the 22 +/- 3-kDa protein. Passive transfer of affinity-purified human or rabbit immunoglobulins directed against the double band (14 +/- 3- and 18 +/- 3-kDa antigens), but not those directed against the 22 +/- 3-kDa protein, caused a significant inhibition of early cleavage of oocytes without affecting pronuclear formation in mice. These results suggest that the sperm surface antigens of 14 +/- 3 and 18 +/- 3 kDa may provide an extranuclear signal to oocytes to divide in mice and humans. These antigens may also find clinical applications in the management of immunoinfertility and in the development of an antisperm contraceptive vaccine for humans.

Effects of human antisperm antibodies on development of preimplantation embryos.

The effects of antisperm antibodies (ASAs) present in sera of immunoinfertile patients and vasectomized men were investigated on preimplantation embryonic development in mice. Of the nine immunoinfertile sera tested, two were effective in inhibiting blastulation rates of in vitro cultured murine 2-cell embryos (p less than .05 to .002). Similarly, sera from two of the three vasectomized men were capable of affecting early embryonic development in mice (p less than .05 to .002). Specificities of the embryotoxic effects of ASAs were further confirmed by culturing embryos in the presence of affinity-purified monovalent Fab' antibodies isolated from these sera. Fab' antibodies from only one of the two immunoinfertile patients whose sera affected blastulation rates, and from one of the three vasectomized men were effective in influencing blastulation rates of in vitro cultured 2-cell murine embryos (p less than .05 to .001), mainly due to an arrest of development at 2 to 8-cell and morula stages. In the Western blot procedure, none of the immunoinfertile Fab' antibodies recognized any specific band on blots of extracts from murine ova or 2-cell embryos. However, all the immunoinfertile Fab', but not fertile control Fab', specifically recognized a protein band in the M(r) 25 +/- 2 kD region, on the Western blots of extract from murine blastocyst stage embryos. In addition, Fab' from one immunoinfertile serum, which inhibited embryonic development, reacted specifically with a protein band in the lower molecular range (approximate M(r) 12 kD) on Western blot involving exact from blastocysts. Fab' antibodies of sera from vasectomized men did not react with any specific protein band on blots of extracts from murine ova, 2-cell embryo, or blastocyst. These results suggest that ASAs from some immunoinfertile patients and vasectomized men, especially those reacting with 12-kD blastocyst protein, are capable of affecting preimplantation embryonic development in mice, and thus may contribute toward immunologically medicated infertility both at fertilization and postfertilization stages.

Effect of Sperm‐Antibodies on Acrosome Reaction of Human Sperm Used for the Hamster Egg Penetration Assay

The effect of anti-sperm antibodies (ASA) on the rate of acrosome reactions (AR) during "in vitro" capacitation of human sperm used for the hamster egg penetration assay (HEPA) was assessed. Motile sperm suspensions from donors were exposed to several sera and seminal plasma with sperm head-directed ASA, then they were washed and capacitated "in vitro." After capacitation, the proportion of acrosome-reacted viable sperm was assessed by staining with Fluoresceinated Pisum Sativum Agglutinin and supravital stain Hoechst 33258. ASA of any immunoglobulin class did not significantly affect either the AR rate, or the hamster egg penetration rate. In conclusion, interference of ASA on spontaneous AR rate during "in vitro" capacitation can not be advocated as an explanation of the impairment of the interaction of human sperm with egg or its vestments, which have been reported in several studies.

Effect of Antisperm Antibodies on Computerized Semen Analysis

The effect of antisperm antibodies (ASA) in males was determined in 239 men by the use of a computerized semen analyzer (CASA). ASA was assessed using the direct immunobead test (IBT). Sperm variables for men with positive ASA were significantly lower than those with negative results in percentages of motility, velocity, and linearity.