Comparative effect of the calcium antagonist verapamil and the synthetic steroids gestrinone and danazol on human monocyte phagocytosis in vitro.

Recent evidence suggested that periovulatory treatment with an immunomodulatory agent such as verapamil might be an effective alternative to conventional treatment for endometriosis-associated subfertility. In particular, it has been reported that the drug might reduce the accentuated macrophage peritoneal activation demonstrated in patients with endometriosis. In this study, we compared the effect of the calcium antagonist verapamil with those of gestrinone, danazol and testosterone on human monocyte phagocytosis in an attempt to evaluate any significant differences in their ability to influence a parameter of cell inflammatory activation. Peripheral blood monocytes were isolated from 37 healthy women. Monocyte function was determined by phagocytosis of fluorescent microspheres after an overnight incubation in the presence or absence of the various agents. This study indicates that verapamil at the pharmacological concentration of 0.4 micrograms/ml, the systemic level in patients taking 40-80 mg/8 h p.o., significantly inhibits monocyte function. A lower immunosuppressive but still significant effect was achieved in this assay system with gestrinone at a concentration of 3 x 10(-8) M). The pharmacological concentration of danazol (10(-6) M) and the physiologic concentration of testosterone (10(-8) M) did not significantly affect this immunologic test system. These results provide evidence that verapamil is able to exert a slightly greater immunosuppressive effect than steroidal drugs on monocyte phagocytosis. However, due to the small differences observed, further studies on the biological mechanism of the drug seem to be necessary to completely elucidate its potential role in endometriosis-associated subfertility.

Expression of intercellular adhesion molecule-1 (ICAM-1) on cultured human endometrial stromal cells and its role in the interaction with natural killers.

PROBLEM: Recent evidence emphasizes the role of natural killer cells (NKs) as potential effectors of peritoneal immune surveillance directed against the outgrowth of endometrial cells, refluxed with menstrual debris, in ectopic sites. This NK-mediated cytotoxicity toward autologous endometrial antigens seems to be significantly decreased in endometriosis patients. METHOD: We set up experiments to clarify which molecules are involved in NK-endometrial cell interaction. In particular, we evaluated the surface expression and functional activity of intercellular adhesion molecule-1 (ICAM-1), a cell surface glycoprotein that has been identified as one of the ligands for lymphocyte function-associated antigen-1 (LFA-1), present on almost all leucocyte cell types. Immunofluorescence flow cytometry was used to assess ICAM-1 expression on resting and IL 1 beta-activated endometrial stromal cells in culture. Dermal fibroblasts were used as control cells. Cytotoxicity and binding assays by 51Cr release in presence and absence of a specific monoclonal antibody (mAb) against ICAM-1 were then performed in order to determine the effect of this molecule on NK-mediated cytotoxic and binding activity toward endometrial stromal cells. RESULTS: The results of this study indicated that ICAM-1 expression on endometrial stromal cells seems to be constitutively higher than on dermal fibroblasts and can be up-regulated upon exposure to IL 1 beta. Furthermore, a mAb against ICAM-1 strongly inhibits the binding but not the cytotoxicity of NKs toward endometrial cells. No difference in the expression of this molecule was observed throughout the cycle. CONCLUSIONS: The presence of ICAM-1 on human endometrium might relate to the action of the immunocompetent cells in human specific reproductive events.

Gestrinone inhibits macrophage function and mitogen-stimulated lymphocyte proliferation in vitro.

Clinical and experimental evidence supports the hypothesis that some steroidal drugs with androgenic effects might influence the immune system. The present study investigated whether gestrinone is able to affect macrophage and lymphocyte activity in vitro. Macrophage function was determined by phagocytosis of fluorescent microspheres, whilst lymphocyte proliferation was assessed by cell counting. Macrophage phagocytosis was evaluated after an overnight incubation in the presence or absence of gestrinone at serial dilutions; lymphocyte proliferation was detected in basal conditions and after stimulation with Concanavalin A (Con A) in the presence or absence of gestrinone. The results of this study showed that gestrinone significantly inhibited macrophage phagocytosis at the concentrations of 10(-8), 3 x 10(-8) and 10(-7) M. Furthermore, a significant suppression of lymphocyte blastogenesis was observed when lymphocytes were incubated with gestrinone at the concentration of 10(-7) M for 6 days. The biological significance of gestrinone as an inhibitor of immune functions under experimentally defined conditions is discussed in relation to its potential mechanism for fertility enhancement.