Minor viral population with drug-resistant mutation and risk of persistent low-level viremia or ‘blips’ in HIV-1 subtype C

AIDS ◽  
2015 ◽  
Vol 29 (2) ◽  
pp. 251
Author(s):  
&NA;
Keyword(s):  
Viral Population ◽  
Drug Resistant ◽  
Subtype C ◽  
Low Level ◽  
Drug Resistant Mutation ◽  
Hiv 1 ◽  
Resistant Mutation

scholarly journals Impact of Novel Resistance Profiles in HIV-1 Reverse Transcriptase on Phenotypic Resistance to NVP

2012 ◽  
Vol 2012 ◽  
pp. 1-8
Author(s):  
Liyan Jiao ◽  
Hanping Li ◽  
Lin Li ◽  
Daomin Zhuang ◽  
Yongjian Liu ◽  
...  
Keyword(s):  
Drug Resistance ◽  
Site Directed Mutagenesis ◽  
Drug Resistant ◽  
Wild Type ◽  
Phenotypic Resistance ◽  
Drug Resistant Mutation ◽  
The Impact ◽  
Hiv 1 ◽  
Resistant Mutation ◽  
Phenotypic Drug Resistance

Objective. To clarify the impact of H221Y mutation on drug resistance to NVP.Methods. 646 bp HIV-1polgene fragments (from 592 to 1237 nucleotide) with different NNRTIs mutation profiles from AIDS patients receiving antiretroviral therapy containing NVP regimens were introduced into pNL4-3 backbone plasmid. H221Y and (or) Y181C mutations were reverted to wild type amino acids by site-directed mutagenesis, then strains containing various mutation patterns were packaged. Phenotypic drug resistance was analyzed on TZM-bl cells.Results. 12 strains containing different drug-resistant mutation profiles were constructed, including the K101Q series (K101Q/Y181C/H221Y, K101Q/Y181C, K101Q/H221Y, and K101Q), the V179D series (V179D/Y181C/H221Y, V179D/Y181C, V179D/H221Y, and V179D), and the K103N series (K103N/Y181C/H221Y, K103N/Y181C, K103N/H221Y, K103N). For strains containing the mutation profiles (K101Q/Y181C, K101Q, V179D/Y181C, V179D, K103N/Y181C, and K103N), the presence of H221Y reduced NVP susceptibility by2.1±0.5to3.6±0.5fold. To the mutation profiles K101Q/H221Y, K101Q, V179D/H221Y, V179D, K103N/H221Y, and K103N, the presence of Y181C reduced NVP susceptibility by41.9±8.4to1297.0±289.1fold. For the strains containing K101Q, V179D, and K103N, the presence of Y181C/H221Y combination decreased NVP susceptibility by100.6±32.5to3444.6±834.5fold.Conclusion. On the bases of various NNRTIs mutation profiles, Y181C remarkably improved the IC50to NVP, although H221Ymutation alone just increases 2.1 ∼ 3.6-fold resistance to NVP, the mutation could improve 100.6 ∼ 3444.6-fold resistance to NVP when it copresent with Y181C, the phenotypic drug resistance fold was improved extremely. For strains containing the mutation profiles (K101Q/Y181C, K101Q, V179D/Y181C, V179D, K103N/Y181C, and K103N), the presence of H221Y reduced NVP susceptibility by2.1±0.5to3.6±0.5fold.

A structural and thermodynamic escape mechanism from a drug resistant mutation of the HIV-1 protease

2004 ◽  
Vol 55 (3) ◽  
pp. 594-602 ◽  
Author(s):  
Sonia Vega ◽  
Lin-Woo Kang ◽  
Adrian Velazquez-Campoy ◽  
Yoshiaki Kiso ◽  
L. Mario Amzel ◽  
...  
Keyword(s):  
Drug Resistant ◽  
Escape Mechanism ◽  
Drug Resistant Mutation ◽  
Hiv 1 ◽  
Resistant Mutation

scholarly journals Replication and drug resistant mutation of HIV-1 subtype B' (Thailand B) variants isolated from HAART treatment individuals in China

2009 ◽  
Vol 6 (1) ◽  
pp. 201 ◽  
Author(s):  
Jianping Sun ◽  
Liying Ma ◽  
Xiaoling Yu ◽  
Yang Huang ◽  
Lin Yuan ◽  
...  
Keyword(s):  
Drug Resistant ◽  
Subtype B ◽  
Drug Resistant Mutation ◽  
Hiv 1 ◽  
Resistant Mutation

scholarly journals Impact of Temozolomide on Immune Response during Malignant Glioma Chemotherapy

2012 ◽  
Vol 2012 ◽  
pp. 1-7 ◽  
Author(s):  
Sadhak Sengupta ◽  
Jaclyn Marrinan ◽  
Caroline Frishman ◽  
Prakash Sampath
Keyword(s):  
Immune Response ◽  
Malignant Glioma ◽  
Dna Methyltransferase ◽  
Opportunistic Infections ◽  
Immune Surveillance ◽  
Drug Resistant ◽  
Methylguanine Dna Methyltransferase ◽  
Drug Resistant Mutation ◽  
Resistant Mutation

Malignant glioma, or glioblastoma, is the most common and lethal form of brain tumor with a median survival time of 15 months. The established therapeutic regimen includes a tripartite therapy of surgical resection followed by radiation and temozolomide (TMZ) chemotherapy, concurrently with radiation and then as an adjuvant. TMZ, a DNA alkylating agent, is the most successful antiglioma drug and has added several months to the life expectancy of malignant glioma patients. However, TMZ is also responsible for inducing lymphopenia and myelosuppression in malignant glioma patients undergoing chemotherapy. Although TMZ-induced lymphopenia has been attributed to facilitate antitumor vaccination studies by inducing passive immune response, in general lymphopenic conditions have been associated with poor immune surveillance leading to opportunistic infections in glioma patients, as well as disrupting active antiglioma immune response by depleting both T and NK cells. Deletion of O6-methylguanine-DNA-methyltransferase (MGMT) activity, a DNA repair enzyme, by temozolomide has been determined to be the cause of lymphopenia. Drug-resistant mutation of the MGMT protein has been shown to render chemoprotection against TMZ. The immune modulating role of TMZ during glioma chemotherapy and possible mechanisms to establish a strong TMZ-resistant immune response have been discussed.

scholarly journals Long-Acting Rilpivirine (RPV) Preexposure Prophylaxis Does Not Inhibit Vaginal Transmission of RPV-Resistant HIV-1 or Select for High-Frequency Drug Resistance in Humanized Mice

2020 ◽  
Vol 94 (8) ◽  
Author(s):  
Kevin Melody ◽  
Chandra N. Roy ◽  
Christopher Kline ◽  
Mackenzie L. Cottrell ◽  
Dwayne Evans ◽  
...  
Keyword(s):  
High Frequency ◽  
Low Frequency ◽  
Humanized Mice ◽  
Drug Resistant ◽  
Low Level ◽  
Preexposure Prophylaxis ◽  
Vaginal Transmission ◽  
Long Acting ◽  
Hiv 1 ◽  
Level Resistance

ABSTRACT As a long-acting formulation of the nonnucleoside reverse transcriptase inhibitor rilpivirine (RPV LA) has been proposed for use as preexposure prophylaxis (PrEP) and the prevalence of transmitted RPV-resistant viruses can be relatively high, we evaluated the efficacy of RPV LA to inhibit vaginal transmission of RPV-resistant HIV-1 in humanized mice. Vaginal challenges of wild-type (WT), Y181C, and Y181V HIV-1 were performed in mice left untreated or after RPV PrEP. Plasma viremia was measured for 7 to 10 weeks, and single-genome sequencing was performed on plasma HIV-1 RNA in mice infected during PrEP. RPV LA significantly prevented vaginal transmission of WT HIV-1 and Y181C HIV-1, which is 3-fold resistant to RPV. However, it did not prevent transmission of Y181V HIV-1, which has 30-fold RPV resistance in the viruses used for this study. RPV LA did delay WT HIV-1 dissemination in infected animals until genital and plasma RPV concentrations waned. Animals that became infected despite RPV LA PrEP did not acquire new RPV-resistant mutations above frequencies in untreated mice or untreated people living with HIV-1, and the mutations detected conferred low-level resistance. These data suggest that high, sustained concentrations of RPV were required to inhibit vaginal transmission of HIV-1 with little or no resistance to RPV but could not inhibit virus with high resistance. HIV-1 did not develop high-level or high-frequency RPV resistance in the majority of mice infected after RPV LA treatment. However, the impact of low-frequency RPV resistance on virologic outcome during subsequent antiretroviral therapy still is unclear. IMPORTANCE The antiretroviral drug rilpivirine was developed into a long-acting formulation (RPV LA) to improve adherence for preexposure prophylaxis (PrEP) to prevent HIV-1 transmission. A concern is that RPV LA will not inhibit transmission of drug-resistant HIV-1 and may select for drug-resistant virus. In female humanized mice, we found that RPV LA inhibited vaginal transmission of WT or 3-fold RPV-resistant HIV-1 but not virus with 30-fold RPV resistance. In animals that became infected despite RPV LA PrEP, WT HIV-1 dissemination was delayed until genital and plasma RPV concentrations waned. RPV resistance was detected at similar low frequencies in untreated and PrEP-treated mice that became infected. These results indicate the importance of maintaining RPV at a sustained threshold after virus exposure to prevent dissemination of HIV-1 after vaginal infection and low-frequency resistance mutations conferred low-level resistance, suggesting that RPV resistance is difficult to develop after HIV-1 infection during RPV LA PrEP.

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