title: Aberrant T-cell function in vitro and impaired T-cell dependent antibody response in vivo in vitamin A-deficient rats.
abstract: We have previously reported that vitamin A deficiency resulted in a reduced IgA antibody response to cholera toxin (CT) after per-oral immunization. In the present investigation we have studied the in vivo and in vitro immune response in vitamin A-deficient rats to two parenterally applied antigens, beta-lactoglobulin (beta-LG) and picrylsulphonic acid (TNP)-Ficoll. The serum IgG and IgM antibody responses to the T-cell dependent antigen beta-LG were significantly lower in the vitamin A-deficient rats than in the pair-fed control rats. No such differences were seen with the IgG and IgM responses to the T-cell independent antigen TNP-Ficoll. However, the biliary IgA and the serum IgE antibodies against both antigens were decreased in the vitamin A-deficient rats. In vitro lymphocyte stimulation with concanavalin A (Con A) or beta-LG gave higher T-cell proliferation rates in the vitamin A-deficient than in the control rats. Interleukin-2 (IL-2) and interferon-gamma (IFN-gamma) levels in supernatants from Con A-stimulated mesenteric lymph node cells were also higher in the vitamin A-deficient rats, while IL-6 levels were decreased, which is consistent with an up-regulated Th1 activity. Proliferation studies on purified accessory cells and T cells from the deficient and the control rats, mixed in different combinations, showed that the T cells, but not the accessory cells, were disturbed in the vitamin A-deficient rats. Despite the increased T-cell activity in vitro the vitamin A-deficient rats had a lower delayed-type hypersensitivity (DTH) reaction than the pair-fed control rats. In conclusion, the increased IL-2 and IFN-gamma levels may reflect an up-regulation of Th1 cell function, while the decreased IgA, IgE and IL-6 levels indicate a suppression of Th2 cells. The disturbed T-lymphocyte function is manifested in vivo as a decreased DTH reaction and suppressed antibody production, the latter possibly due to a lack of B-cell switching and proliferation factors in vitamin A-deficient rats.
authors.affiliation: Department of Clinical Immunology, University of Göteborg, Sweden.
authors.forename: U
authors.initials: U
authors.lastname: Wiedermann
authors.forename: L A
authors.initials: LA
authors.lastname: Hanson
authors.forename: H
authors.initials: H
authors.lastname: Kahu
authors.forename: U I
authors.initials: UI
authors.lastname: Dahlgren
mesh_terms: D000818:Animals; D000938:Antigen-Presenting Cells / Q000276:immunology; D002455:Cell Division / Q000276:immunology; D002478:Cells, Cultured; D003208:Concanavalin A / Q000276:immunology; D016207:Cytokines / Q000096:biosynthesis; D005362:Ficoll / Q000031:analogs & derivatives / Q000276:immunology; D006968:Hypersensitivity, Delayed / Q000276:immunology; D007108:Immune Tolerance / Q000276:immunology*; D007136:Immunoglobulins / Q000096:biosynthesis*; D007782:Lactoglobulins / Q000276:immunology; D008297:Male; D051381:Rats; D017208:Rats, Wistar; D013601:T-Lymphocytes / Q000276:immunology*; D014301:Trinitrobenzenes / Q000276:immunology; D014802:Vitamin A Deficiency / Q000276:immunology*
chemical_list: D016207:Cytokines; D007136:Immunoglobulins; D007782:Lactoglobulins; C020529:TNP-ficoll; D014301:Trinitrobenzenes; D003208:Concanavalin A; D005362:Ficoll