Influence exerted by Helicobacter pylori on regulatory T-cells differentiation

Estimating risks of infections induced by gram-negative Helicobacter pylori, is a vital problem for healthcare due to wide spread of the agent and wide range of induced pathologies which include malignant neoplasms in gastrointestinal tract. The agent is prone to long-term chronic persistence despite its "fragility" and its being greatly demanding to culturing conditions. The persistence issue is of special interest here as it is related to data on Helicobacter pylori capability to change immune response in infected people inducing suppressive regulatory immune reactions which are more favorable for the agent, both in stomach and in a whole body. Our research goal was to estimate Helicobacter pylori capability to induce differentiation of regulatory CD4+CD25+FoxP3+ human T-cells as basic mediators of immune response regulation under direct contact between bacteria and T-cells without any participation of most professional antigen-presenting cells. Our research objects were clinical isolates of Helicobacter pylori and T-lymphocytes samples taken from people who didn't have Helicobacter pylori-infection in their case history; isolates and samples were jointly cultivated in vitro. We applied cytofluorometry to estimate changes in regulatory T-cells content. We detected that if T-lymphocytes and Helicobacter pylori were jointly cultivated during 18 hours in ratios from 1:10 to 1:50, regulatory T-cells content in cultures increased 2.12 times on average. This effects doesn't require any dendritic cells in a culture and obviously affects T-lymphocytes which are originally committed to regulatory T-cells in their development. Also, in our opinion, influence exerted on regulatory T-cells differentiation is a specific feature of Helicobacter pylori.