A leading pharmacological strategy toward HIV cure requires "shock" or activation of HIV gene expression in latently infected cells with latency reversal agents (LRAs) followed by their subsequent clearance. In a screen for novel LRAs, we used fungal secondary metabolites as a source of bioactive molecules. Using orthogonal mass spectrometry (MS) coupled to latency reversal bioassays, we identified gliotoxin (GTX) as a novel LRA. GTX significantly induced HIV-1 gene expression in latent ex vivo infected primary cells and in CD4+ T cells from all aviremic HIV-1+ participants. RNA sequencing identified 7SK RNA, the scaffold of the positive transcription elongation factor b (P-TEFb) inhibitory 7SK small nuclear ribonucleoprotein (snRNP) complex, to be significantly reduced upon GTX treatment of CD4+ T cells. GTX directly disrupted 7SK snRNP by targeting La-related protein 7 (LARP7), releasing active P-TEFb, which phosphorylated RNA polymerase II (Pol II) C-terminal domain (CTD), inducing HIV transcription.

doi.org/10.1126/sciadv.aba6617, hdl.handle.net/1765/129980
Science advances
Department of Biochemistry

Stoszko, M.L, Al-Hatmi, A.M.S, Skriba, A. (Anton), Roling, M. (Michael), Ne, E. (Enrico), Crespo, R. (Raquel), … Mahmoudi, T. (2020). Gliotoxin, identified from a screen of fungal metabolites, disrupts 7SK snRNP, releases P-TEFb, and reverses HIV-1 latency. Science advances, 6(33). doi:10.1126/sciadv.aba6617