We generated a lymphoid cell line (Sup-T1-Rev/Env) that stably expresses a 19-bp short hairpin RNA (shRNA) targeting a conserved region of HIV-1 encoding for the Envelope and Rev proteins, which potently inhibited viral replication. However, continuous passage of HIV-1 in Sup-T1-Rev/Env generated virus mutants able to overcome the RNAi restriction. Sequence analysis of the emerging viruses showed that mutations were located at positions 5 and 17 of the target sequence. Both mutations are silent in the Env frame, but the mutation 5 generated an amino acid change (V47M) in the Rev reading frame. We have analyzed the impact of these two mutations on the RNAi mechanism, showing a more crucial role of the mutation 17 in the resistance to RNAi. We show that even targeting a conserved region of the HIV-1 genome involved in the biosynthesis of two essential genes, env and rev, the virus could evolve to escape by single point mutations in the target sequence, without a significant fitness cost. © 2007 Elsevier Inc. All rights reserved.
Senserrich, J., Pauls, E., Armand-Ugón, M., Clotet-Codina, I., Moncunill, G., Clotet, B., & Esté, J. A. (2008). HIV-1 resistance to the anti-HIV activity of a shRNA targeting a dual-coding region. Virology, 372(2), 421–429. https://doi.org/10.1016/j.virol.2007.10.045