 Progressive HIV or HIV infection seems to be related to a preferential loss of CD4 T lymphocytes, especially Th17, within the mucosal intestinal lymphoid tissue, and with intestinal mucosal damage and bacterial product translocation, which correlates with the hyperactivation of the immune system, therefore with CD4 T cell loss and prognosis. The objectives of this project are to investigate the correlation between the IL12IL-23 imbalance and bacterial product translocation, and to study the polarization, infection or depletion of intestinal Th17 ex vivo. The investigators will test the effect of neutralizing anti-IL23 antibodies directed against p40, or less classically, anti- IL-23 p19. 