HIV-1 resistance to the anti-HIV activity of a shRNA targeting a dual-coding region

• Published in: Virology (New York, N.Y.) Vol. 372; no. 2; pp. 421 - 429
• Main Authors: Senserrich, Jordi, Pauls, Eduardo, Armand-Ugón, Mercedes, Clotet-Codina, Imma, Moncunill, Gemma, Clotet, Bonaventura, Esté, Jose A
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 15-03-2008
• Subjects: Cell Line; Drug Resistance, Viral; env Gene Products, Human Immunodeficiency Virus - genetics; Genes, env - genetics; HIV; HIV-1 - drug effects; HIV-1 - genetics; HIV-1 - physiology; Human immunodeficiency virus 1; Humans; Infectious Disease; Mutation; Resistance; RNA Interference; Viral evolution; Virus Replication - drug effects; Resistance; RNA interference; HIV; Viral evolution
• ISSN: 0042-6822; 1096-0341
• DOI: 10.1016/j.virol.2007.10.045

Abstract 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.