Inhibition of HIV-1 replication with stable RNAi-mediated knockdown of autophagy factors

Abstract

Autophagy is a cellular process leading to the degradation of cytoplasmic components such as organelles and intracellular pathogens. It has been shown that HIV-1 relies on several components of the autophagy pathway for its replication, but the virus also blocks late steps of autophagy to prevent its degradation. We generated stable knockdown T cell lines for 12 autophagy factors and analyzed the impact on HIV-1 replication. RNAi-mediated knockdown of 5 autophagy factors resulted in inhibition of HIV-1 replication. Autophagy analysis confirmed a specific defect in the autophagy pathway for 4 of these 5 factors. We also scored the impact on cell viability, but no gross effects were observed. Upon simultaneous knockdown of 2 autophagy factors (Atg16 and Atg5), an additive inhibitory effect was scored on HIV-1 replication. Stable knockdown of several autophagy factors inhibit HIV-1 replication without any apparent cytotoxicity. We therefore propose that targeting of the autophagy pathway can be a novel therapeutic approach against HIV-1

Enhanced autophagy in pulmonary endothelial cells on exposure to HIV-Tat and morphine: Role in HIV-related pulmonary arterial hypertension

“…24 Depending on cell type, the effect of HIV-1 on autophagy varies with the course of productive infection or bystander effect of viral proteins. Although autophagy proteins are required for virus replication in CD4 C T lymphocytes, 43 the autophagy process is reported to restrict HIV infection in these cells. Recently Sagnier et al report inhibition of virus replication in CD4 C T cells by autophagymediated degradation of Tat.…”

Viruses and the autophagy pathway

“…(Nardacci et al, 2014) However, it has also been shown that knockdown of autophagy factors in T-cell lines can inhibit HIV replication. (Eekels et al, 2012) Certainly there is a complex relationship between HIV and autophagy, and the nature of the interactions between virus and pathway depend on the cell and the circumstances. This may be true for most viruses, which are often studied in easy-to-grow cell lines.…”

Detection of the HIV-1 Minus-Strand-Encoded Antisense Protein and Its Association with Autophagy

“…This LC3 isoform is cleaved as the cytoplasmic LC3-I form, which, upon induction of autophagy, is linked to phosphatidylethanolamine at its C terminus and is associated with the autophagosomal membrane as the LC3-II form (38,39). In recent years, several studies have demonstrated the implications of autophagy in virus replication (40)(41)(42) and, more specifically, in HIV-1 infection and pathogenesis (43)(44)(45)(46)(47)(48)(49). In T cells, HIV-1-induced autophagy has been suggested to depend on the surface expression of Env proteins, leading to apoptosis of infected and uninfected CD4 ϩ T cells (43,45,46,50).…”