title: Effect of sex hormones on human T cell activation by concanavalin A.
abstract: The effect of sex hormones on concanavalin A (Con A)-activated human T cells was studied. We show that neither 17 beta-estradiol (E2) nor progesterone, in concentrations of up to 10(-6) M, alters the proliferative response of peripheral-blood mononuclear cells (PBMC) of healthy postmenopausal women. Furthermore, the hormones had no effect on the composition of T cell populations and on the expression of activation markers. We extended our study to a unique T cell population that is characterized by the ability to form rosettes with human erythrocytes, following Con A activation (designated autorosette-forming cells; ARFC) and known to manifest suppressive activity. Indeed, the in vitro addition of E2 (neither progesterone nor testosterone) to Con A-stimulated PBMC brought an about 2- to 4-fold increase in the frequency of ARFC. Tamoxifen, an antiestrogen drug, reduced the frequency of estrogen-stimulated ARFC to the original low level. Furthermore, the inhibitory effect of growth medium from ARFC cultures originally stimulated with Con A + E2 was found to be higher than that of ARFC cultures originally stimulated with Con A alone.
authors.affiliation: Department of Microbiology, Moise and Frida Eskenasy Institute for Cancer Research, Tel Aviv, Israel.
authors.forename: I
authors.initials: I
authors.lastname: Yron
authors.forename: A
authors.initials: A
authors.lastname: Langer
authors.forename: T
authors.initials: T
authors.lastname: Weinstein
authors.forename: E
authors.initials: E
authors.lastname: Sahar
authors.forename: Y
authors.initials: Y
authors.lastname: Lidor
authors.forename: Y
authors.initials: Y
authors.lastname: Pardo
authors.forename: I
authors.initials: I
authors.lastname: Katz
authors.forename: L
authors.initials: L
authors.lastname: Shohat
authors.forename: Y
authors.initials: Y
authors.lastname: Kalechman
authors.forename: J
authors.initials: J
authors.lastname: Ovadia
mesh_terms: D003208:Concanavalin A / Q000494:pharmacology; D004958:Estradiol / Q000494:pharmacology; D005260:Female; D012739:Gonadal Steroid Hormones / Q000494:pharmacology*; D006801:Humans; D066298:In Vitro Techniques; D008213:Lymphocyte Activation / Q000187:drug effects*; D011374:Progesterone / Q000494:pharmacology; D012397:Rosette Formation; D013601:T-Lymphocytes / Q000187:drug effects* / Q000276:immunology; D013629:Tamoxifen / Q000494:pharmacology
chemical_list: D012739:Gonadal Steroid Hormones; D013629:Tamoxifen; D003208:Concanavalin A; D011374:Progesterone; D004958:Estradiol