APOPTOSIS RESISTANCE IN HIV-1 PERSISTENTLY INFECTED CELL LINES AS A MODEL OF HIV SURVIVAL IN RESERVOIR CELLS

P. N. FERNÁNDEZ LARROSA; D. A. RIVA; M. BIBINI; S. E. MERSICH; L. A. MARTÍNEZ PERALTA

Paris, Francia

Conferencia; Death, Danger & Immunity; 2007

Institut Pasteur

HIV-1 is the causative agent of AIDS disease, characterized by CD4+ T cells depletion. Apoptosis occurs predominantly in uninfected bystander T CD4+ cells, while necrosis is mainly described in acutely infected cells. In order to analyse the viral effect over reservoir cells, persistently infected cells were treated with different apoptosis inducers and results were compared with those of uninfected cells. Uninfected H9, Jurkat and U937 cells lines and persistently infected H9/HTLVIIIB, J1.1 and U1 cell lines were treated with different concentrations of H2O2 or Staurosporine (STS) and collected 24 hours post treatment. Cellular viability was assayed by MTT reactive and normalized to the respective cell control (C) as percentage. Apoptosis was evaluated by dual staining with annexin-V-FITC and Propidium Iodure (PI), or APO-BRDU, and revealed by FACS. Antigen p24 production was quantified. Induction of viral production was assayed in J1.1 and U1 cell lines with TNF-á and PMA respectively.  When treated with both inducers, persistently infected H9/HTLVIIIB, J1.1 and U1 cells showed significantly lower early apoptosis (annexin-V+/PI- cells) levels than uninfected H9, Jurkat and U937 cells respectively. These results were confirmed by MTT and APO-BRDU assays. Infected cells showed significant decreases in p24 production levels in both treatments. Induction of viral production in J1.1 and U1 did not show significant differences in cell viability with respect to uninduced cells. Our results suggest that, when treated with H2O2 and STS, persistently infected cell lines were resistant to dying by apoptosis compared with uninfected cell lines, and this effect was independent of active viral replication. At the momment, we are studing the viral and cellular mechanisms involved in this apoptosis resistance. This in vitro resistance could help to understand the in vivo HIV reservoir persistence.