Influence of genotype on the phospholipid fatty acid composition of splenic T and B lymphocytes in MRL/MpJ-lpr/lpr mice.

The MRL/MpJ-lpr/lpr mice manifest a T cell proliferative and autoimmune disorder. Similar changes occur much later in the life of MRL/MpJ-+/+ mice. MRL/MpJ-lpr/lpr (lpr/lpr) and MRL/MpJ-+/+ (+/+) mice were fed for six weeks nutritionally adequate semipurified diets containing 20% (w/w) fat, but differing in linoleic acid content. The phospholipid fatty acid composition of T and B cells was found to be dependent on genetic background of mice and level of linoleic acid in the diet. Changes in the levels of specific fatty acids like 16:0, 18:2 omega 6, 22:5 omega 3 and 22:6 omega 3 in some of the phospholipid components were observed in the MRL/MpJ-lpr/lpr strain in both the B and T cell types as compared with their normal +/+ counterpart strain. T cells of lpr/lpr mice exhibited significantly higher levels of 20:4 omega 6 than did T cells of other strain. High levels of dietary linoleic acid significantly increased incorporation of 18:2 omega 6 in T and B cells, while the effect on other fatty acids of the two types of cells varied with the phospholipid classes and fatty acids when compared with the low linoleic acid fed-group. Differences observed in the phospholipid fatty acid composition of the T and B cells of the congenic mice might contribute to differences in rate of progression of age-related changes suggesting that the autoimmune disorder might be mitigated by dietary manipulation.