Defective HIV-1 proviruses produce novel protein-coding RNA species in HIV-infected patients on combination antiretroviral therapy

H Imamichi, RL Dewar… - Proceedings of the …, 2016 - National Acad Sciences
H Imamichi, RL Dewar, JW Adelsberger, CA Rehm, U O'doherty, EE Paxinos, AS Fauci
Proceedings of the National Academy of Sciences, 2016National Acad Sciences
Despite years of plasma HIV-RNA levels< 40 copies per milliliter during combination
antiretroviral therapy (cART), the majority of HIV-infected patients exhibit persistent
seropositivity to HIV-1 and evidence of immune activation. These patients also show
persistence of proviruses of HIV-1 in circulating peripheral blood mononuclear cells. Many of
these proviruses have been characterized as defective and thus thought to contribute little to
HIV-1 pathogenesis. By combining 5′ LTR-to-3′ LTR single-genome amplification and …
Despite years of plasma HIV-RNA levels <40 copies per milliliter during combination antiretroviral therapy (cART), the majority of HIV-infected patients exhibit persistent seropositivity to HIV-1 and evidence of immune activation. These patients also show persistence of proviruses of HIV-1 in circulating peripheral blood mononuclear cells. Many of these proviruses have been characterized as defective and thus thought to contribute little to HIV-1 pathogenesis. By combining 5′LTR-to-3′LTR single-genome amplification and direct amplicon sequencing, we have identified the presence of “defective” proviruses capable of transcribing novel unspliced HIV-RNA (usHIV-RNA) species in patients at all stages of HIV-1 infection. Although these novel usHIV-RNA transcripts had exon structures that were different from those of the known spliced HIV-RNA variants, they maintained translationally competent ORFs, involving elements of gag, pol, env, rev, and nef to encode a series of novel HIV-1 chimeric proteins. These novel usHIV-RNAs were detected in five of five patients, including four of four patients with prolonged viral suppression of HIV-RNA levels <40 copies per milliliter for more than 6 y. Our findings suggest that the persistent defective proviruses of HIV-1 are not “silent,” but rather may contribute to HIV-1 pathogenesis by stimulating host-defense pathways that target foreign nucleic acids and proteins.
National Acad Sciences