Delineation Between T and B Suppressive Molecules From Human Seminal Plasma: II. Spermine is the Major Suppressor of T‐Lymphocytes in Vitro

Abstract

The nature of the human semen T-suppressor was investigated in vitro on human lymphocyte proliferations induced by phytohemagglutinin (PHA) or by alloantigens. Purification by ion-exchange chromatography, followed by butanol extraction, showed this factor to be present only in the polyamine-containing fractions. The purified product, obtained by preparative thin-layer electrophoresis, contained almost exclusively spermine and exhibited the same suppressive activity as this polyamine. Human T-lymphocyte suppression occurred in the presence of fetal calf serum, but it did not occur in a serum-free medium. No suppression was observed after preincubation of the fetal calf serum with hydroxylamine, a spermine oxidase inhibitor, whereas a nondialyzable fraction, from normal human serum, decreased the suppression. The semen factor did not act by direct cytotoxicity, as there was no effect of preincubation and suppression could be induced only within the first 6 hr of mitogen activation. These data demonstrate that the in vitro T-suppressive activity of semen can be assigned mainly to spermine and show that in vivo this suppression must require locally the presence of a spermine oxidase or related enzyme.

Immunosuppressive Effect Induced by Intraperitoneal and Rectal Administration Of Boar Seminal Immunosuppressive Factor1

“…Controls received saline in the same manner. On Days 1,3,5,6,7,9,11,13,15,17,19, and 21 after the first injection of ISF, splenocytes and blood samples were obtained from the treated mice and were added to 500 IU of heparin. The splenocytes and WBC were used in the immunofluorescence assay and ELISA.…”

“…Human seminal plasma components can also decrease the antibacterial activity mediated by peripheral blood lymphocytes [9]. In vitro immunosuppressive activity can be assigned to spermine [10], and, as has been shown, the in vivo suppression of T lymphocytes requires the presence of spermine oxidase or a related enzyme locally [11]. Seminal plasma impairs the ability of macrophages and neutrophils to generate oxygen species after being triggered with opsonized zymosan and phagocyte opsonized bacteria [7].…”

Extracellular organelles (prostasomes) are immunosuppressive components of human semen

“…Thus the activity in ihis fraction is likely to be due to prostaglandin adsorbed onto the precipitated protein. Another candidate for a low tnolecular weight immunosuppressive substance is sperminc (Quan et at.. 1990) but this was not responsible here. The inactivity in ihis f ig, 6.…”

Effect of boar seminal immunosuppressive fraction on B lymphocytes and on primary antibody response

“…Human seminal plasma components can also decrease the antibacterial activity mediated by peripheral blood lymphocytes [11]. In vitro immunosuppressive activity can be attributed to spermine [12], and, as has been shown, the in vivo suppression of T lymphocytes requires the presence of spermine or related enzymes locally [13]. Seminal plasma impairs the ability of macrophages and neutrophils to generate oxygen species after being triggered with opsonized zymosan and phagocyte opsonized bacteria [141.…”