title: Delineation between T- and B-suppressive molecules from human seminal plasma: I. Partial characterization of a 180-kD protein inhibiting the B response to T-independent antigens.
abstract: The immunosuppressive activity of fractionated human seminal plasma (SP) was investigated both in vitro (on human lymphocytes) and in vivo with Balb/c mice. SP fractionation by dialysis allowed delineation of the major suppressor factors according to their respective sizes--small (less than 12 kD) or large (greater than 12 kD). In vitro, large molecules were found to suppress the B-cell proliferative response induced by the Nocardia mitogen, while small molecules suppressed the T-cell proliferation induced by phytohemagglutinin. In vivo, immunosuppression was obtained almost exclusively on T-independent responses after preliminary treatments either with unfractionated SP or with large SP molecules. Both type 1 and type 2 T-independent responses were suppressed, as evidenced by plaque-forming cells and antibody assays. In contrast, no immunosuppression was found in vivo after treatment by small SP molecules. Purification of the B-cell suppressor by gel filtration and high-performance liquid chromatography, as well as by preparative isofocusing, indicated that its molecular weight was 180 kD and its isoelectric charge was between pH 5 and 6. This factor is a protein, as evidenced by pronase digestion. A possible role for this molecule in the protection of sperm against the female immune system is discussed.
authors.affiliation: Unité d'Immunologie Microbienne, Institut Pasteur, Paris, France.
authors.forename: J P
authors.initials: JP
authors.lastname: Bouvet
authors.forename: J
authors.initials: J
authors.lastname: Couderc
authors.forename: C P
authors.initials: CP
authors.lastname: Quan
authors.forename: R
authors.initials: R
authors.lastname: Pirès
authors.forename: S
authors.initials: S
authors.lastname: D'Azambuja
authors.forename: J
authors.initials: J
authors.lastname: Pillot
mesh_terms: D000818:Animals; D000917:Antibody Formation; D000955:Antigens, T-Independent / Q000276:immunology; D001402:B-Lymphocytes / Q000276:immunology; D006801:Humans; D066298:In Vitro Techniques; D008213:Lymphocyte Activation; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D008970:Molecular Weight; D011402:Pronase; D012661:Semen / Q000276:immunology*; D013491:Suppressor Factors, Immunologic / Q000302:isolation & purification* / Q000494:pharmacology; D013601:T-Lymphocytes / Q000276:immunology
chemical_list: D000955:Antigens, T-Independent; D013491:Suppressor Factors, Immunologic; D011402:Pronase