Dietary fat modulation of in vitro lymphocyte function.

Abstract

Mitogen responsiveness of spleen cells from NZB/NZW mice fed one of three defined diets was compared. The fat source of one diet was 20% lard (L, saturated fat), the second 20% polyunsaturated (corn oil), and the third 20% polyunsaturated (fish oil, FO). No differences in stimulation indices were observed. To determine whether the lipid components in media serum supplements were altering our results, we compared splenic mitogen responses in nonautoimmune mice fed either the FO or the L diet with in vitro culture in serum-free medium, alone, or with different serum supplements. Supplements included 10% fetal calf serum and 1 and 5% mouse sera from rodent chow-fed, L-fed or FO-fed mice. Spleen cells from BALB/c mice fed FO had consistently lower stimulation levels as compared to the other diet groups regardless of media supplementation. Capping experiments designed to directly assess membrane fluidity in lymphocytes from mice fed either the L, FO or lab chow diets revealed no differences. Although in vitro membrane turnover undoubtedly occurs during blastogenesis, we found that culturing cells in media with different serum supplements did not alter relative mitogen responses.