Modulation of the primary and secondary antifluoresceyl antibody response in rats by 17 beta-estradiol.
Estradiol (E2) enhances humoral immunity, but the quantitative and temporal relationship between serum E2 and antibody titers is unclear. The present study was therefore designed to determine whether the sex of the animal, ovariectomy (OVX), and replacement with various tonic levels of serum E2 influenced the primary and secondary antifluorescein antibody titers of rats. Two experiments were performed. In Exp I, intact male and intact female Lewis inbred rats were given primary and booster (secondary) immunizations with fluorescein-keyhole limpet hemocyanin. Primary and secondary bleedings for antifluorescein antisera were obtained. In Exp II female Lewis inbred rats were randomly distributed among the following treatment groups: sham OVX, sham implanted; OVX, sham implanted; and three groups of OVX and implanted with E2-filled Silastic capsules of 0.5, 1.5, or 5.0 cm lengths. Immunization with fluorescein-keyhole limpet hemocyanin and bleedings for antifluorescein antisera followed the same schedule as in Exp I. In Exp I, females had significantly higher antifluorescein antibody titers than males during the primary and secondary response. In Exp II, OVX significantly depressed the primary and secondary antifluorescein antibody titers relative to sham OVX controls. During the primary antifluorescein antibody response, a significant quadratic relationship was seen between antibody titers and serum E2 when measurements included the pharmacological range of the serum E2 concentrations. A significant linear relationship existed between serum E2 and antifluorescein antibody titers when the same data were examined over a range of 15-130 pg E2/ml. This linear relationship is more significant during the primary response than the secondary response. It is concluded that females generate higher antifluorescein antibody titers than males; OVX significantly depresses the antifluorescein antibody response; E2 is immunoenhancing in the physiological range and immunosuppressive in the pharmacological range; and the presence of E2 during the primary response may be more critical to immunoenhancement.
D R
DR
Trawick
J M
JM
Bahr
D000818:Animals; D000906:Antibodies / Q000032:analysis / Q000276:immunology*; D000917:Antibody Formation / Q000187:drug effects; D000941:Antigens / Q000276:immunology; D004958:Estradiol / Q000494:pharmacology*; D005260:Female; D019793:Fluorescein; D005452:Fluoresceins / Q000276:immunology*; D006433:Hemocyanins / Q000276:immunology; D008297:Male; D010052:Ovariectomy; D051381:Rats; D011919:Rats, Inbred Strains; D012727:Sex Characteristics
D000906:Antibodies; D000941:Antigens; D005452:Fluoresceins; D004958:Estradiol; D006433:Hemocyanins; C032808:keyhole-limpet hemocyanin; D019793:Fluorescein