Toshifumi Daitoh

Significance of D-mannose as a sperm receptor site on the zona pellucida in human fertilization

The role of monosaccharides in human fertilization was studied by testing their effects on penetration of spermatozoa into mature human oocytes (zona penetration test). When oocytes were pretreated with concanavalin A, wheat germ agglutinin, or Ricinus communis agglutinin-I at a concentration of 100 micrograms/ml, no spermatozoa were found to bind to or penetrate through the zona pellucida. Penetration of spermatozoa was restored when the zona pellucida pretreated with wheat germ agglutinin and Ricinus communis agglutinin-I were rinsed with N-acetyl-D-glucosamine (wheat germ agglutinin inhibitor) and D-galactose (Ricinus communis agglutinin inhibitor), respectively. Conversely, the blocking effect of concanavalin A on sperm penetration was not reversed by treatment with D-mannose (concanavalin A inhibitor). Furthermore, pretreatment of spermatozoa with D-mannose (50 mmol/L) completely inhibited sperm penetration through the zona pellucida. However, sperm penetration was clearly demonstrated when the zona pellucida was pretreated with D-mannose. These data suggest that D-mannose residues are essential in, or sterically closely related to, the sperm receptor site on the human zona pellucida.

Etiological implication of autoantibodies to zona pellucida in human female infertility.

PROBLEM: Autoantibodies to zona pellucida (ZP) have been implicated as a cause of infertility in woman by three lines of clinical and laboratory evidence.

High implantation rate and consequently high pregnancy rate by in vitro fertilization-embryo transfer treatment in infertile women with antisperm antibody

OBJECTIVE To examine the effect of antisperm immunity on postfertilization steps, such as implantation of embryos and fetal growth in IVF-ET treatment of women with sperm-immobilizing antibodies. DESIGN Retrospective analysis of clinical laboratory data. SETTING The IVF-ET program of the Department of Obstetrics and Gynecology. The University of Tokushima, School of Medicine. PATIENTS Eighteen women with sperm-immobilizing antibodies and 122 infertile patients with nonimmune etiology as controls. Infertile couples due to a male factor and with unknown etiology were excluded. INTERVENTIONS All patients received the same IVF-ET program with GnRH agonist. MAIN OUTCOME MEASURES Rates of fertilization and cleavage, implantation rate per embryo transferred and pregnancy rate (PR) in both test and comparison groups. RESULTS The rate of fertilization in the antisperm group (61.3%) was significantly lower than that in the comparison group (76.8%). But the implantation rate per embryo transferred (23.5%) and consequently the modified PR per oocyte recovery procedure (34.4%) in immunologically infertile women were significantly higher than those in the comparison group (7.9% and 17.8%, respectively). CONCLUSIONS Although sperm-immobilizing antibodies prevent sperm-egg interaction, they do not seem to have any adverse effects on achievement of pregnancy. Moreover, the existence of antisperm immunity in woman with antisperm antibodies is suggested to be favorable for successful pregnancy by the IVF-ET procedure.

Immunoglobulin Binding Factor in Human Seminal Plasma: Immunological Function

Human seminal plasma contains a protein with an estimated molecular weight of 16 kd that binds serum immunoglobulin gamma (IgG) and is named IgG binding factor (IgBF). Purified IgBF specifically suppressed pokeweed mitogen-induced lymphocyte blastogenesis, having little or no effect on lymphocyte blastogenesis stimulated with phytohemagglutinin or Concanavalin A; antibody-dependent cell-mediated cytotoxicity; natural killer cell activity; or complement-dependent cytotoxicity of antibodies against sperm. It would appear that IgBF may suppress activation of B cells in the male and female genital tract.

Differences in clinical significance of blood group antigens A, B, and H in carcinoma tissue in the uterine cervix

The losses of blood group antigens A, B, and H in carcinoma tissue of the uterine cervix were studied by the avidin-biotin-peroxidase complex (ABC) method and the relations of these losses to invasion and dedifferentiation of primary cancer were examined. The incidence of cases showing complete loss of A or B antigen increased in proportion to the progression of cancer, but in most cases even of invasive cancer, H antigen, the precursor of A and B antigens, was detected. Complete loss of H antigen was not demonstrated in well-differentiated keratinizing invasive carcinomas, but was seen in 15% (15/101) of the cases of large cell non-keratinizing type cancer and 50% (8/16) of those of small cell non-keratinizing type cancer. No relationship was found between losses of A, B, and H antigens and parametrial spread of carcinoma or metastasis to the pelvic lymph nodes, but the incidence of death within 2 years after hysterectomy was higher in H antigen-negative cases than in H antigen-positive cases. These results indicate that loss of A and B antigens depends on some activity of invasion of cancer, while loss of H antigen strongly indicates dedifferentiation of cancer cells and also may indicate a poor prognosis.

Predominant Production of Amniotic Interleukin‐1α in Cases With Premature Rupture of the Membranes

PROBLEM: The physiological significances of the two known subtypes of interleukin‐1 (IL‐1) in amniotic fluid (AF) were examined by measurements of their concentrations and detection of their location.

Immunosuppressive 30-kDa protein in urine of pregnant women and patients with trophoblastic diseases

Urine samples obtained from normal pregnant women and patients with trophoblastic diseases contain 30-kDa protein that suppresses phytohemagglutinin-induced T cell proliferation. The immunosuppressive protein was measured by a newly developed radioimmunoassay. The 30-kDa protein was demonstrated in almost all urine samples examined, fluid from hydatid vesicles and chorionic extracts, but not in any serum samples except at low levels in some sera from patients with choriocarcinoma. During pregnancy, the level of urinary 30-kDa protein was higher in the first (1625.5 +/- 1212.0 ng/ml, mean +/- S.D.) and second (1457.4 +/- 1332.4 ng/ml) trimesters than in the third trimester (460.6 +/- 419.0 ng/ml). The urinary 30-kDa protein/hCG ratios in patients with choriocarcinoma (8.3 +/- 10.9) were significantly higher than those in patients with hydatidiform mole (0.67 +/- 1.00, P < 0.01) and in all trimesters than those of normal pregnant women (0.54 +/- 0.44 in first trimester, P < 0.05; 0.63 +/- 0.46 in the second trimester, P < 0.05; 0.24 +/- 0.17 in the third trimester, P < 0.01). There is no significant difference between the ratios in hydatidiform mole and normal pregnancy. These findings and the fast disappearance of the 30-kDa protein from the circulation suggest that the 30-kDa protein plays a part in proliferation of trophoblastic cells in, or their invasion into the host by locally suppressing the immune reaction of the host and that the increase in the urinary 30-kDa protein level, in cases of choriocarcinoma, may be due to the malignant transformation of trophoblastic cells resulting in their rapid invasion.

Effect of IL‐1 in amniotic fluid on the fetal keratinocyte

IL‐1 α is predominantly increased in amniotic fluid of the patients with premature rupture of the membrane (PROM). In the present study we examined the effect of IL‐1 on the fetal keratinocytes, one of the main tissue exposed to the increased IL‐1. Exposure of IL‐1 at over 0.1 pg/ml IL‐1 significantly (p<0.01) inhibited proliferation of the keratinocytes in low calcium keratinocyte growth medium obtained from the umbilical cord. Immunohistochemical analysis using antibodies to various cytokeratins revealed that the umbilical cord keratinocytes is more similar to the mucosal epithelium than the skin epithelium. These results suggest that IL‐1 α increased in amniotic fluid in the PROM cases leads the immature proliferating mucosal epithelium to maturate for protection of the fetus against environment.

Effect of sperm-immobilizing antibodies on the acrosome reaction of human spermatozoa**Supported by Grants-in-Aid for Scientific Research (Nos. 60570780 and 62570759) from the Ministry of Education, Science and Culture of Japan, Japan.

OBJECTIVE To study by a triple stain technique the effect of sperm-immobilizing antibodies on the acrosome reaction of human spermatozoa. DESIGN The spermatozoa were allowed to swim up and culture in a medium containing 7.5% (vol/vol) serum with sperm-immobilizing antibodies or control serum up to 6 hours. Sperm mobility was analyzed, and the percentage of live acrosome reacted spermatozoa was determined. SETTING Samples were collected from patients referred to university hospital infertility clinics. MATERIALS Serum samples were drawn from seven patients with sperm-immobilizing antibodies. All the sera were heat activated and stored at -40 degrees C until use. Semen samples were taken from two healthy donors. RESULTS During culture for 6 hours, the percentage of live sperm showing the acrosome reaction increased significantly (P less than 0.01) in the control group but not in the sperm-immobilizing antibodies group. However, the inhibitory effect of sperm-immobilizing antibodies on the acrosome reaction was reversed when sperm was reincubated in medium with control serum (P less than 0.01). CONCLUSIONS Sperm-immobilizing antibodies block fertilization at least in part by inhibiting the acrosome reaction of human spermatozoa.