Clinical relevance of substitutions in the connection subdomain and RNase H domain of HIV-1 reverse transcriptase from a cohort of antiretroviral treatment-naïve patients

• Published in: Antiviral research Vol. 82; no. 3; pp. 115 - 121
• Main Authors: Hachiya, Atsuko, Shimane, Kazuki, Sarafianos, Stefan G., Kodama, Eiichi N., Sakagami, Yasuko, Negishi, Fujie, Koizumi, Hirokazu, Gatanaga, Hiroyuki, Matsuoka, Masao, Takiguchi, Masafumi, Oka, Shinichi
• Format: Journal Article
• Language: English
• Published: Kidlington Elsevier B.V 01-06-2009; Elsevier
• Subjects: Adult; Amino Acid Substitution - genetics; Anti-HIV Agents - pharmacology; Anti-HIV Agents - therapeutic use; Antibiotics. Antiinfectious agents. Antiparasitic agents; Antiretroviral Therapy, Highly Active; Antiretroviral treatment-naïve patient; Antiviral agents; Biological and medical sciences; Connection subdomain; Drug Resistance, Viral; Female; HIV Infections - drug therapy; HIV Infections - virology; HIV Reverse Transcriptase - antagonists & inhibitors; HIV Reverse Transcriptase - genetics; HIV-1; HIV-1 - drug effects; HIV-1 - genetics; HIV-1 - isolation & purification; Human immunodeficiency virus 1; Human viral diseases; Humans; Immunodeficiencies; Immunodeficiencies. Immunoglobulinopathies; Immunopathology; Infectious diseases; Male; Medical sciences; Middle Aged; Mutation, Missense; Pharmacology. Drug treatments; Resistant mutation; Reverse Transcriptase Inhibitors - pharmacology; Reverse Transcriptase Inhibitors - therapeutic use; RNase H domain; Viral diseases; Viral diseases of the lymphoid tissue and the blood. Aids; Viral Load; HIV-1; Connection subdomain; Resistant mutation; RNase H domain; Antiretroviral treatment-naïve patient; RNA-directed DNA polymerase; HIV-1 virus; Esterases; Substitution; Antiviral; Antiretroviral treatment-naive patient; Mechanism of action; Human; Immunopathology; Enzyme; Transferases; Treatment efficiency; Retroviridae; Patient; AIDS; Calf thymus ribonuclease H; Immune deficiency; Lentivirus; Infection; Virus; Nucleotidyltransferases; Sensitivity resistance; Viral disease; Hydrolases; Human immunodeficiency virus; Mutation
• ISSN: 0166-3542; 1872-9096
• DOI: 10.1016/j.antiviral.2009.02.189

Some mutations in the connection subdomain of the polymerase domain and in the RNase H domain of HIV-1 reverse transcriptase (RT) have been shown to contribute to resistance to RT inhibitors. However, the clinical relevance of such mutations is not well understood. To address this point we determined the prevalence of such mutations in a cohort of antiretroviral treatment-naïve patients (
n
=
123) and assessed whether these substitutions are associated with drug resistance
in vitro and
in vivo. We report here significant differences in the prevalence of substitutions among subtype B, and non-subtype B HIV isolates. Specifically, the E312Q, G333E, G335D, V365I, A371V and A376S substitutions were present in 2–6% of subtype B, whereas the G335D and A371V substitutions were commonly observed in 69% and 75% of non-B HIV-1 isolates. We observed a significant decline in the viral loads of patients that were infected with HIV-1 carrying these substitutions and were subsequently treated with triple drug regimens, even in the case where zidovudine (AZT) was included in such regimens. We show here that, generally, such single substitutions at the connection subdomain or RNase H domain have no influence on drug susceptibility
in vitro by themselves. Instead, they generally enhance AZT resistance in the presence of excision-enhancing mutations (EEMs, also known as thymidine analogue-associated mutations, TAMs). However, N348I, A376S and Q509L did confer varying amounts of nevirapine resistance by themselves, even in the absence of EEMs. Our studies indicate that several connection subdomain and RNase H domain substitutions typically act as pre-therapy polymorphisms.