Role of Th17 T‐Lymphocytes in Advanced AIDS Patients with Marked CD4+ T Cell Depletion

In the final stages of an HIV infection (AIDS), the human immune system is unable to produce an effective response due to severe depletion of CD4+ T cells. Our preliminary research indicates that though there is CD4+ T cell depletion, the Th17 T‐cells, as a percentage of the T cell population, increase in the final stages of AIDS. Peripheral blood samples from 23 different patients with AIDS (CD4+ T cell count below 200/μL) were measured using flow cytometry. In humans, the classic Th17 T cell falls within a CD161+ subgroup, and are also positive for CD3, CD4 and CCR6. In our 6 healthy controls, the Th17 T cell population as a percentage of the CD161 subgroup had a mean of 0.16% of the CD161 population. Of those AIDS patients with a CD4+ T cell count below 20 (n=12), the mean Th17 T cell population of the CD161 subgroup was 13.99%. In AIDS patients with CD4+ T cell count below 10 (n=8), the mean Th17 T cell population of the CD161 subgroup was 20.01%. Our hypothesis is that the altered immune state in AIDS induces the differentiation of Th17 T cells from those remaining naïve T cells in order to repel the opportunistic infections occurring in these patients. However, due to a lack of Th1 T cells to transition from the Th17 response, the body attempts to increase that initial physiologic inflammatory response by differentiating more Th17 T cells.