Influence of Reverse Transcriptase Variants, Drugs, and Vpr on Human Immunodeficiency Virus Type 1 Mutant Frequencies
AUTOR(ES)
Mansky, Louis M.
FONTE
American Society for Microbiology
RESUMO
The evolution of drug resistance is a major complication of human immunodeficiency virus type 1 (HIV-1) chemotherapy. HIV-1 reverse transcriptase (RT) is a major target of antiretroviral therapy and ultimately the target of drug resistance mutations. Previous studies have indicated that drug-resistant HIV-1 RTs can alter HIV-1 mutant frequencies. In this study, we have tested a panel of HIV-1 RT variants for their ability to influence virus mutant frequencies. The RT variants tested included drug-resistant RT variants as well as other variants analyzed in enzyme fidelity studies with the lacZα gene as a mutation target and/or implicated as being important for enzyme fidelity by structural studies. Combinations of mutations that alone had a statistically significant influence on virus mutant frequencies resulted in different mutant frequency phenotypes. Furthermore, when virus replication occurred in the presence of drugs [e.g., 3′-azido-3′-deoxythymidine, (−)2/,3′-dideoxy-3′-thiacytidine, hydroxyurea, thymidine, or thioguanine] with selected RT variants, virus mutant frequencies increased. Similarly, Vpr variants deficient for binding to the uracil DNA glycosylase repair enzyme were observed to influence HIV-1 virus mutant frequencies when tested alone or in combination with RT variants. In summary, these observations indicate that HIV-1 mutant frequencies can significantly change by single amino acid substitutions in RT and that these effects can be altered by additional mutations in RT, by drugs, and/or by expression of Vpr variants. Such altered virus mutant frequencies could impact HIV-1 dynamics and evolution in small population sizes.
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=140916Documentos Relacionados
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