Dietary β-Carotene Stimulates Cell-Mediated and Humoral Immune Response in Dogs

Abstract

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.

Assessing the immune state of dogs suffering from pituitary gland dependent hyperadrenocorticism by determining changes in peripheral lymphocyte subsets

“…Various reports have demonstrated the use of measuring lymphocyte subsets to investigate immune states in dogs (Blount et al 2005;Greeley et al 2006;Chew et al 2000). It has also been shown that the distribution of peripheral T lymphocyte subsets is impaired in human suffering PDH, both at diagnosis and during the course of the disease (Kronfol et al 1996).…”

Changes in Peripheral Lymphocyte Subsets in the Type 1 Diabetic Dogs Treated with Insulin Injections

“…In the diabetic dogs, infectious diseases such as conjunctivitis and cystitis are frequently observed accompanying depression of immunocompetence [9]. Lymphocyte subsets have been measured in past various reports to investigate immune states in dogs [2,3,7]. Several studies have shown that distribution of peripheral T lymphocyte subsets are impaired in diabetic humans, both at diagnosis and during the course of the disease [13,15].…”

“…Analysis of peripheral blood lymphocyte subsets were considered to reflect immune states in dogs [2,3,7]. We considered that the diabetic dogs may have abnormalities of lymphocyte subsets.…”

Immunostimulatory effect of β-cryptoxanthin in vitro and in vivo

“…So, it seems that substances in a carotenoid-like structure such as b-Crp have Ig production-stimulating activity. Chew et al (Chew et al, 2000) reported that a higher concentration of IgG, but not IgM, was found in blood of the bcarotene-administered female Beagle dogs than in nonadministered dogs. The result in this paper is very similar to our data in productions of IgG and IgM, implying that the b-carotene structure might have an effect on the tendency of the Ig productions.…”