Characteristics of gastric-vein lymphocytes with regard to the immune response to Helicobacter Pylori

BACKGROUND: Between peripheral blood and tissue-infiltrating lymphocytes there is an intermediate compartment, the blood of the organ-draining vessels, which could show unusual features. The aim of the present study was to analyse the characteristics of the lymphocytes from the stomach-draining vessels and the cytokine secretion by these lymphocytes. The CagA-mediated lymphocyte activation in Helicobacter pylori-infected subjects and the humoral response to this antigen were evaluated and correlated with clinical data. METHODS: We studied lymphocyte proliferation either with mitogens or with the CagA antigen and cytokine production and IgG anti-CagA by means of an enzyme-linked immunosorbent assay in peripheral blood and gastric-vein blood obtained during surgical intervention. RESULTS: We showed higher proliferative response and cytokine production in lymphocytes from the gastric vein. The mitogenic response to the CagA antigen was highly specific but poorly sensitive for the H. pylori infection in both the compartments. The overall cytokine profile in our patients affected by non-ulcer disease was of the Th0 type. CONCLUSIONS: Gastric-vein-derived lymphocytes seem to show unusual features, as they behave like peripheral blood lymphocytes but show higher responses to all the tested stimuli. It is possible that the interaction of the lymphocytes with the mucosal environment could activate the synthetic mechanisms, making the cells more 'responsive' to the stimulation. The CagA antigen is able to induce a specific T-lymphocyte response and is therefore a valid candidate antigen for the development of a vaccine.