Antiapoptotic Clone 11-Derived Peptides Induce In Vitro Death of CD4+ T Cells Susceptible to HIV-1 Infection

Abstract

HIV-1 successfully establishes long-term infection in its target cells despite viral cytotoxic effects. We have recently shown that cell metabolism is an important factor driving CD4⁺ T cell susceptibility to HIV-1 and the survival of infected cells. We show here that expression of antiapoptotic clone 11 (AAC-11), an antiapoptotic factor upregulated in many cancers, increased with progressive CD4⁺ T cell memory differentiation in association with the expression of cell cycle, activation, and metabolism genes and was correlated with susceptibility to HIV-1 infection. Synthetic peptides based on the LZ domain sequence of AAC-11, responsible for its interaction with molecular partners, were previously shown to be cytotoxic to cancer cells. Here, we observed that these peptides also blocked HIV-1 infection by inducing the death of HIV-1-susceptible primary CD4⁺ T cells across all T cell subsets. The peptides targeted metabolically active cells and had the greatest effect on effector and transitional CD4⁺ T cell memory subsets. Our results suggest that the AAC-11 survival pathway is potentially involved in the survival of HIV-1-infectible cells and provide proof of principle that some cellular characteristics can be targeted to eliminate the cells offering the best conditions to sustain HIV-1 replication.IMPORTANCE Although antiretroviral treatment efficiently blocks HIV multiplication, it cannot eliminate cells already carrying integrated proviruses. In the search for an HIV cure, the identification of new potential targets to selectively eliminate infected cells is of the outmost importance. We show here that peptides derived from antiapoptotic clone 11 (AAC-11), whose expression levels correlated with susceptibility to HIV-1 infection of CD4⁺ T cells, induced cytotoxicity in CD4⁺ T cells showing the highest levels of activation and metabolic activity, conditions known to favor HIV-1 infection. Accordingly, CD4⁺ T cells that survived the cytotoxic action of the AAC-11 peptides were resistant to HIV-1 replication. Our results identify a new potential molecular pathway to target HIV-1 infection.

Keywords: AAC-11; CD4 T cells; apoptosis; cell metabolism; human immunodeficiency virus; susceptibility to infection.