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

Background: Between peripheral blood and tissue-infiltrating lymphocytes th ere is an intermediate compartment, the blood of the organ-draining vessels , which could show unusual features. The aim of the present study was to an alyse the characteristics of the lymphocytes from the stomach-draining vess els and the cytokine secretion by these lymphocytes. The CagA-mediated lymp hocyte 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 t he CagA antigen and cytokine production and IgG anti-CagA by means of an en zyme-linked immunosorbent assay in peripheral blood and gastric-vein blood obtained during surgical intervention. Results: We showed higher proliferat ive response and cytokine production in lymphocytes from the gastric vein. The mitogenic response to the CagA antigen was highly specific but poorly s ensitive for the H. pylori infection in both the compartments. The overall cytokine profile in our patients affected by non-ulcer disease was of the T h0 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 o f the lymphocytes with the mucosal environment could activate the synthetic mechanisms, making the cells more 'responsive' to the stimulation. The Cag A antigen is able to induce a specific T-lymphocyte response and is therefo re a valid candidate antigen for the development of a vaccine.