Abstract

α-defensins are reported to be a soluble component of innate immunity actively participating in host defense against HIV. In order to further investigate the role of α-defensins in innate immunity during HIV infection, we analyzed CD8+ T lymphocytes and neutrophils obtained from 34 HIV-infected and 14 uninfected subjects. CD8+ T cells and neutrophils were labelled for evaluating α-defensin expression by flow cytometric analysis using a dual laser FACScalibur. Culture supernatants and plasma were also collected for ELISA quantification of α-defensins. The results showed a significantly increased production of α-defensins in plasma, neutrophils and CD8 T-lymphocytes of patients with HIV infection in comparison with healthy controls. The expression of α -defensins, by CD8+ cells probably reflects both the intrinsic production and the uptake from cocultured cells that release defensins. The upregulation of α-defensin expression within neutrophils could account for the increased release of such peptides in the systemic circulation. Antiretroviral treatment did not have any effect on plasma levels and expression of α-defensins by neutrophils. Overall, our findings suggest that the increased production/expression of α-defensins could be correlated with the chronic process of immune activation seen in HIV infection.

Keywords: HIV, α-defensins, innate immunity, CD8, neutrophils