Long-term non-progressors display a greater number of Th17 cells than HIV-infected typical progressors

Interleukin 17 (IL17) secreting T (Th17) cells play a protective role against bacterial infections at mucosal surfaces. Recent reports show Th17 cells are depleted in the gut associated lymphoid tissue of HIV+ patients, but their role in HIV disease progression is not well understood. Expression of the IL17 receptor (IL17R) and the production of IL17 were compared between two groups of HIV patients with different disease progression (long-term-nonprogressors, LTNP and typical-progressors, TP). IL17R expression was similar in LTNP and TP, whereas Th17 cell number was greater in LTNP than TP (p = 0.015). An inverse correlation between the plasma HIV-RNA and both IL17R expression and Th17 cell number was found (p = 0.001 and p = 0.002, respectively). The increased number of Th17 cells in LTNP could lead to a more preserved immune response against bacterial infections. As a result, lower microbial translocation could explain the reduced immune activation and slower disease progression seen in LTNP.