DIETARY-FAT INFLUENCES IA-ANTIGEN EXPRESSION, CYTOKINES AND PROSTAGLANDIN E(2) PRODUCTION OF IMMUNE CELLS IN AUTOIMMUNE-PRONE NZBXNZW F1-MICE

To elucidate further the influences of dietary fat on autoimmune disea ses, two groups of NZB/W F1 mice were fed with diets containing 200 g dietary fat/kg and 50 g dietary fat/kg (control) respectively, The dif ference in energy intake between these two groups was compensated with carbohydrate, Mice were bled regularly every month and some of them w ere killed for in vitro experiments after 5 months experimental diets, Higher immunoglobulin (Ig)M and IgG anti-double stranded DNA antibody levels, shortened life span and worsened proteinuria were noted in mi ce fed on the high-fat diet compared with those fed on 50 g dietary fa t/kg, Phenotypic analyses of spleen cells and peritoneal exudate cells showed that the percentage of CD5(+) B cells and the mean fluorescent intensity of major histocompatibility molecules on the surface of bot h types of cells were higher in mice fed on the high-fat diet, In gene ral, higher type 2 T-helper cell activity,vas noted in mice fed on the high-fat diet, In addition, cytokines such as interleukin-6, tumour n ecrosis factor-cc and prostaglandin E(2) (PGE(2)) produced by lipopoly saccharide-stimulated peritoneal exudate cells were also higher in the high-dietary-fat group, These studies suggest that high dietary fat a nd its related PGE(2) level might have a critical effect on the freque ncy of CD5(+) B cells, cytokine production, macrophage function and su bsequent autoimmune regulation in autoimmune mice.