REGULATION OF IMMUNE HOMEOSTASIS OF THE HUMAN INTESTINE BY METABOLITES OF BIFIDOBACTERIA UNDER CONDITIONS OF MICROBIAL RECOGNITION

Aim. To study the production of cytokins on the model of peripheral blood lymphocytes under the activity of Bifidobacterium bifidum 791 strain induced by Lactobacillus fermentum 90T-C4, Escherichia coli 157 and Staphylococcus aureus 209 metabolites. Materials and methods. Reference strains of «self» and «поп-self» types of bacteria were used in the investigation. «Self/non-self» microbial recognition method (Bukharin O.V., Perunova N.B., 2011). Mononuclear leukocytes were isolated from the blood of healthy donors by gradient centrifugation in ficoll-verographin density gradient (Pharmacia, Sweden). Production of pro-(IFN-y, TNF-a, IL-6, IL-17) and anti-inflammatory (IL-10) cytokins was investigated in mononuclear culture by ELISA method. The results are statistically processed. Results. Similarities in the direction of lymphocyte reaction and «self» and «поп-self» microbial differentiation of bifidobacteria were found. It was determined that in reaction to «поп-self» reference cultures the lymphocytes increased pro-inflammatory potential and increased anti-inflammatory potential in reaction to «self» bacteria. Preliminary co-incubation of bifidobacteria with L.fermentum metabolites 90T-C4 increased anti-inflammatory effect of B. bifldum 791, whereas lymphocyte reaction to E. coli and staphylococcus induced bifidobacteria was changed to pro-inflammatory. Conclusion. Combined unidirectional influence of microbiota and its metabolic activity on cytokine level might enhance defence effect of intestinal immune response. The capacity of bifidoflora to carry out primary selection of microsymbionts on account of intermicrobial «recognition» and differentiated exposure to lymphocyte pro- and anti-inflammatory potential evidences the key role of bifidoflora in the human intestine homeostasis maintenance.

bifidobacteria, microbial «self/non-self» recognition, microbial metabolites, mononuclear leukocytes, cytokins