Julien van Grevenynghe
INRS-Institut Armand Frappier, Canada
Title: Kynurenine reduces memory CD4 T-cell survival early in HIV-1 infection
Biography
Biography: Julien van Grevenynghe
Abstract
Immunology and metabolism have always been considered as distinct disciplines. However, recent advances in the understanding of immune functions under HIV-1 infection associate these branches with intricate networks. Today, we show that inflammation and kynurenines whose plasma levels are higher in HIV-1-infected subjects when compared to those of uninfected controls reduced the ability of memory CD4 T-cells to respond properly to IL-2. We found that in vitro treatment of memory CD4 T-cells with kynurenine results in oxygen reactive species (ROS) production that was responsible for inhibiting the phosphorylation of STAT5 factor following IL-2 stimulation. Interestingly, we found that memory CD4 T-cells from HIV-1-infected subjects, even those with less than 3 months of presumed infection, displayed reduced ability to protect themselves against Fas-mediated apoptosis in the presence of IL-2 help. The effect of kynurenines and subsequent oxidative stress was abrogated when HIV-1-infected subjects were treated with combined antiretroviral therapy (cART) early during the time course of their infection. Collectively, these data highlight the key role of inflammation and perturbed metabolism during HIV-1 infection, particularly in the survival of memory cells and the nature of HIV-1 reservoir.