IMMUNOBIOLOGICAL ACTIVITIES OF HELICOBACTER-PYLORI PORINS

Studies were carried out on some biological activities of Helicobacter pylori porins in vitro. We extracted and purified a porin with an app arent molecular mass of 30 kDa. Human polymorphonuclear leukocytes pre incubated with H. pylori porins showed a decrease of chemotaxis, of ad herence to nylon wool, and of chemiluminescence. Used as chemotaxins i n place of zymosan-activated serum or as chemotaxinogens in place of z ymosan, the porins induced polymorphonuclear leukocyte migration. Huma n monocytes and lymphocytes cultivated in the presence of H. pylori po rins released cytokines. Release of the various cytokines studied was obtained with differentiated kinetics and at various porin concentrati ons. Starting only 3 h after culture, tumor necrosis factor alpha is r eleased quickly, reaching a peak at 18 h, at a porin concentration of 1 mu g/ml/10(6) cells). Interleukin-6 (IL 6) appears later, with a pea k at 10 mu ml/10(6) cells, while IL-8 is released after 6 h of culture , with a peak at 24 h, at a porin concentration of 10 mu g/ml/10(6) ce lls. Lymphocytes stimulated by H. pylori porins release gamma interfer on after 18 h of culture at higher concentrations of porins (20 mu g/m l/10(6) cells). Granulocyte macrophage colony-stimulating factor is re leased from 6 to 48 h at a concentration of 1 (mu g/ml/10(6) cells, wh ile both IL-3 and IL-4 are released after 18 h of culture at different porin concentrations (0.1 and 1 mu g/ml/10(6) cells, respectively). O ur results lead us to think that during H. pylori infection, surface c omponents, porins in particular, are able to induce a series of chain reactions ranging from the inflammatory to the immunological responses .