Dietary beta-carotene stimulates cell-mediated and humoral immune response in dogs.
The role of beta-carotene on immune response in domestic dogs is not known. Female Beagle dogs were fed 0, 2, 20 or 50 mg beta-carotene/d; blood was sampled at wk 0, 1, 2, 4 and 8 for analysis of the following: lymphoproliferation, leukocyte subpopulations and concentrations of interleukin-2 (IL-2), immunoglobulin (Ig)G and IgM. Delayed-type hypersensitivity (DTH) response was assessed at wk 0, 3 and 7. beta-Carotene supplementation increased plasma beta-carotene concentrations in a dose-dependent manner. Compared with unsupplemented dogs, those fed 20 or 50 mg of beta-carotene had higher CD4+ cell numbers and CD4:CD8 ratio. However, there was no treatment difference in CD8+, CD21+ and major histocompatability complex (MHC) class II+ cells. Plasma IgG, but not IgM concentration was higher in dogs fed beta-carotene throughout the study period. The DTH response to phytohemagglutinin (PHA) and vaccine was heightened in beta-carotene-supplemented dogs. beta-Carotene feeding did not influence mitogen-induced lymphocyte proliferation or IL-2 production. Immune response was impaired in dogs classified as low beta-carotene absorbers compared with similar dogs fed the same amount of beta-carotene. Therefore, dietary beta-carotene heightened cell-mediated and humoral immune responses in dogs.
Department of Animal Sciences, Washington State University, Pullman, WA 99164-6351, USA.
B P
BP
Chew
J S
JS
Park
T S
TS
Wong
H W
HW
Kim
B B
BB
Weng
K M
KM
Byrne
M G
MG
Hayek
G A
GA
Reinhart
D000818:Animals; D000917:Antibody Formation / Q000187:drug effects*; D000975:Antioxidants / Q000494:pharmacology*; D002851:Chromatography, High Pressure Liquid; D004285:Dogs / Q000276:immunology*; D005260:Female; D006968:Hypersensitivity, Delayed / Q000276:immunology; D007111:Immunity, Cellular / Q000187:drug effects*; D007074:Immunoglobulin G / Q000096:biosynthesis; D007376:Interleukin-2 / Q000096:biosynthesis; D007962:Leukocytes / Q000187:drug effects / Q000276:immunology; D008213:Lymphocyte Activation / Q000187:drug effects; D019207:beta Carotene / Q000494:pharmacology*
D000975:Antioxidants; D007074:Immunoglobulin G; D007376:Interleukin-2; D019207:beta Carotene