EFFECT OF PROTEIN CALORIE MALNUTRITION ON THE LEVELS OF NATURAL AND INDUCIBLE CYTO-TOXIC ACTIVITIES IN MOUSE SPLEEN-CELLS

Abstract

Six-week-old C57Bl/6 female mice were fed a normal (24% protein) or an isocaloric but protein-deficient (4% protein) diet. At different time periods after the initiation of diets, basal natural killer (NK) activity, interleukin-2 (IL-2) and concanavalin-A (Con-A)-induced cytotoxic activity, Con-A-induced (IL-2) production and levels of allospecific cytotoxic T cell activity generated in a mixed lymphocyte culture (MLC), were studied in spleen cells derived from control and protein deficient (PD) mice. Results indicated that levels of spleen NK activity increased initially in PD mice, but after 7 wk on PD diet declined to normal and subnormal levels. IL-2 generation in response to Con-A as well as IL-2 activation of NK activity were comparable in spleen cells of control and PD mice at all time points tested, Con-A-induced cytotoxic activity was significantly greater in spleen cells from PD mice, the difference being greater at higher doses of Con-A and generation of alloimmune cytotoxic T cells in a MLC reaction was normal in PD mouse spleen cells until 4 wk after the beginning of PD diet, but declined markedly thereafter. Relevance of these observations to other related findings in protein calorie malnutrition are discussed.