P178 The regulatory role of L-glutamic acid in T-and B-cell immunity

Abstract

Introduction The glutamic acid (L-Glu) plays an important role in maintaining of lymphocytes homeostasis. It was found that deficiency of L-Glu reduces resistance to infections. Additional input of L-Glu enhances the activity of lymphocytes, including increased synthesis of interleukin (IL)-2 and interferon (IFN)- γ , which stimulates antibody production and proliferation of T-and B-lymphocytes. The presence of L-Glu receptors in immune cells suggests that it is not only neuro-, but immunomodulator. Study of mechanisms of immunomodulatory action of L-Glu is important in the fight against stress and in the treatment of many diseases. Methods Studies were conducted on albino Wistar rats (males) weighing 200–220 g. They were divided into 3 groups of 10 animals per group. Animals of the first experimental group received an aqueous solution of glutamic acid at the rate of 10% to the amount of L-Glu in the diet per os once a day. Rats of the second group received 30% of the amount of L-Glu in the diet respectively. Rats of the control group were administered by the appropriate amount of saline. Immunological reactivity of the organism was evaluated by the following parameters: the lymphocytes number of specific subpopulations (total T-cell responses were measured in rosette formation with sheep red blood cells, B cells – in the reaction of rosette formation in the presence of complement, T-helper cells – in response to rosette with sheep erythrocytes after incubation with theophylline, T-suppressors were calculated as the difference between the total T-lymphocytes and T-helpers, immunoregulatory index (IRI). Rosette activity was determined by the density of receptors. There were measured cells with low, average and high receptor density. Results Our results show that the introduction of glutamic acid at a higher dose (the second experimental group) changes the receptor apparatus of T-lymphocytes, in particular, the number of lymphocytes with an average density of receptors. We observed that the glutamic acid affected the functional activity of T-helper cells, what may indicate a significant increase in T-helper cells with a low density of receptors in animals of the two experimental groups, respectively, and the average density of receptors in the second experimental group of rats compared with control animals. The number of B-lymphocytes increased in the first and in the second experimental groups compared with controls. This increase can be explained by B-lymphocytes with an average density of receptors. The use of glutamic acid causes the increase of the ratio index of T-helpers to the cytotoxic T-lymphocytes, the relative content of which is significantly higher in the second experimental group of animals relative to controls. The number of T-suppressors significantly decreased in animals of two experimental groups. Conclusion The introduction of glutamic acid affects the T-and B-cell immunity. Glutamic acid entered in larger doses promotes increase protective forces of organism, which may indicate a likely increase in T-helper cells with low and medium density of receptors. The increase of theophylline-resistant T-helper cells in the blood affect the activation of B-lymphocytes, which numbers increased in the animals of first and second experimental groups.