EFFECTS OF GLUTAMINE ON THE IMMUNE-SYSTEM - INFLUENCE OF MUSCULAR EXERCISE AND HIV-INFECTION

Glutamine increased the proliferative response and the lymphokine-acti vated killer cell activity of blood mononuclear cells isolated from no rmal healthy subjects (n = 6) in a dose-dependent manner, with optimum at 0.3-1.0 mM. The relative fraction of CD3+, CD4+, CD8+, CD14+, CD16 +, and CD19+ cells was not changed by glutamine at a concentration of 0.6 mM, except in the phytohemagglutinin-stimulated proliferation expe riment where the fraction of CD4+, and therefore CD3+ cells, increased . The natural killer cell activity was not influenced by glutamine. Hu man immunodeficiency virus (HIV)seropositive subjects (n = 8) who perf ormed concentric bicycle exercise for 1 h at 75% of maximal O-2 consum ption had an overall lower phytohemagglutinin-stimulated proliferative response, compared with the HIV-seronegative control group (n = 7). T he proliferation during exercise was lower in both the HIV-seropositiv e and the HIV-seronegative group. Addition of glutamine in vitro did n ot normalize the lower proliferation in the HIV-seropositive group or the attenuated proliferation seen during exercise in both groups.