Vitamin A prevents the decline in immunoglobulin A and Th2 cytokine levels in small intestinal mucosa of protein-malnourished mice.
We examined whether vitamin A improved mucosal immune depression in mice with wasting protein deficiency. In male C3H/HeN mice fed a semi-purified 1% protein diet for 2 wk, plasma retinol and immunoglobulin A (IgA) concentrations in the small intestinal mucosa were 50 and 55%, respectively, of those in mice fed a semi-purified 20% protein diet, (P < 0.05). Daily supplementation of 0.3 mg of retinyl acetate to protein-deficient mice for 2 wk increased the plasma retinol level to the value in the protein-sufficient mice. However, 1 mg/d of retinyl acetate was required to prevent the decline of the IgA level caused by the protein deficiency. Mice fed the low-protein diet had lower concentrations of IL-4 and IL-5 in the small intestinal mucosa and fewer IL-4- and IL-5-containing cells in the lamina propria (P < 0. 05). Retinyl acetate (1 mg) significantly restored the IL-5 level and the number of IL-4- and IL-5-containing cells. After immunization with 20 microg of cholera toxin (CT), the intestinal mucosa of protein-deficient mice contained significantly less CT-specific IgA than control mice. Treatment with 1 mg of retinyl acetate prevented the decline of anti-CT IgA level in the protein-deficient mice, improving their survival rate after an exposure to 0.1 mg of CT. These results suggest that large oral supplements of vitamin A may preserve mucosal IgA level during protein malnutrition, possibly by stimulating Th2 cytokine production and thereby, inducing resistance against infection.
Nikawa
T
T
Department of Nutrition, School of Medicine, The University of Tokushima, 3-18-15 Kuramoto-cho, Tokushima 770-8503, Japan.
Odahara
K
K
Koizumi
H
H
Kido
Y
Y
Teshima
S
S
Rokutan
K
K
Kishi
K
K
D000818:Animals; D002772:Cholera Toxin / Q000276:immunology; D004224:Diterpenes; D007070:Immunoglobulin A / Q000378:metabolism*; D007150:Immunohistochemistry; D015847:Interleukin-4 / Q000378:metabolism*; D015848:Interleukin-5 / Q000378:metabolism*; D007413:Intestinal Mucosa / Q000276:immunology*; D007421:Intestine, Small / Q000276:immunology; D008297:Male; D051379:Mice; D008809:Mice, Inbred C3H; D009752:Nutritional Status; D011488:Protein Deficiency / Q000276:immunology*; D000084562:Retinyl Esters; D014801:Vitamin A / Q000008:administration & dosage / Q000031:analogs & derivatives / Q000097:blood / Q000627:therapeutic use*
D004224:Diterpenes; D007070:Immunoglobulin A; D015848:Interleukin-5; D000084562:Retinyl Esters; D014801:Vitamin A; C014794:retinol palmitate; D015847:Interleukin-4; C009166:retinol acetate; D002772:Cholera Toxin