Antigen-specific immune response impairment in the chick as influenced by dietary vitamin A.
The effects of a broad range of dietary vitamin A levels on antigen-specific immune responses of the chick were studied. Vitamin A deficiency and long-term excess caused impairment of the immune response as demonstrated by antigen-specific antibody production and T-lymphocyte proliferation in vitro. Immune responsiveness was correlated with both hepatic and blood vitamin A levels, and was affected prior to other physiological manifestations of hypo- or hypervitaminosis. In contrast to the effects of long-term vitamin excess, a large vitamin A bolus did not cause immune response impairment and, on the contrary, restored normal immune functions in previously vitamin A-depleted chicks. This finding implied a regulatory role for vitamin A in the immune system rather than a constitutive one.
Friedman
A
A
Department of Animal Science, Faculty of Agriculture, Hebrew University of Jerusalem, Rehovot, Israel.
Sklan
D
D
D000818:Animals; D000831:Animals, Newborn; D000917:Antibody Formation / Q000187:drug effects; D000941:Antigens / Q000276:immunology*; D002455:Cell Division; D002478:Cells, Cultured; D002645:Chickens; D004032:Diet; D008297:Male; D013601:T-Lymphocytes / Q000166:cytology; D014801:Vitamin A / Q000008:administration & dosage* / Q000378:metabolism / Q000494:pharmacology
D000941:Antigens; D014801:Vitamin A