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Principal Investigator: Manhattan E Charurat
Organization: UNIVERSITY OF MARYLAND BALTIMORE
Fiscal Year: 2024
Award: $313,674
Funding agency: National Institute of Allergy and Infectious Diseases
Abstract of research
The finding that most patients with virologic failure (HIV-1 RNA >=1,000cp/mL) on second-line PI-
containing regimens lack PI-resistance mutations in the protease (PR) gene is one of the main
enigmas of antiretroviral drug resistance research. We hypothesized that env and gag sequences
from these patients contain compensatory mutations, specifically in the Env, that confer PI
resistance. A role of the gp41 CT in PI resistance may be linked to the role of virus maturation,
triggered by PR, in activating Env fusion activity. In recent years, increasing numbers of clinical
reports have observed failure of DTG-containing therapy in the absence of integrase (IN)
mutations, suggesting that mutations outside IN may confer resistance in these patients. Our
studies demonstrated the first instance of de novo selection of Env mutations that confer
resistance to Dolutegravir (DTG) in vitro (unpublished data). We attribute this phenotype to the
ability of the Env mutants to mediate highly efficient cell-to-cell transmission, resulting in an
increase in the multiplicity of infection. In addition, up to 20-, 6- and 24-fold reduction in
susceptibility to ATV, DRV and LPV, respectively, was observed in absence of PR mutations
among HIV-1 CRF_02AG and subtype G infected patients. These findings have broad
implications for our understanding of Env and Gag functions and the evolution of HIV-1 drug
resistance. Our goal is to identify factors that predict virological failure (VF) on ATV/r or LPV/r as
patients with VF on a PI-containing regimens have suboptimal future treatment and may be at an
increased risk for developing integrase resistance inhibitor on a third-line regimen. A collaborative
team involving investigators led by the Institute of Human Virology Nigeria will exploit robust
longitudinal cohorts (Cameroon, Nigeria and Uganda) of patients on 2L regimens, coupled to well-
characterized and archived clinical specimens that underpin a rigorous nested case-control study
design.
To test these interlocking hypotheses, we propose to: (i) use our newly developed HIV-xGen next
generation sequencing method to extend understanding of viral evolution and HIV drug resistance
across the viral genome and to determine whether there is effect modification by non-B HIV-1
subtypes, (ii) characterize recombinant viruses carrying mutations identified in Aim 1, using
established phenotypic assays to determine their effect on drug susceptibility and site-directed
mutagenesis, and lastly (iii) determine differences in replicative fitness on drug susceptibility with
use of a yeast recombination-based cloning system. Our plans to study these patients and their
viruses (subtype A, C, D, G, and CRF02_AG, CRF43_02G, HIV-1 O and HIV-1 N) provides a
unique opportunity to determine the phenotypic and clinical significance of genotypic changes in
HIV-1 gag, gag-pol and env genes. All in all, this proposal will permit exciting epidemiological,
clinical, and public health research opportunities.
Terms: <AIDS Virus><Acquired Immune Deficiency Syndrome Virus><Acquired Immunodeficiency Syndrome Virus><Address><Adherence><Affect><Africa><Anti-HIV resistance><Anti-HIV resistant><Anti-Retroviral Agents><Anti-retroviral drug resistance><Antiproteases><Archives><Area><Assay><Binding><Bioassay><Biological Assay><Blood Plasma><Cameroon><Cell Body><Cells><Clinical><Cloning><Code><Coding System><Coupled><DNA Recombination><Data><Drug Therapy><Drug resistance><Drug resistance in HIV><Drug resistance pathway><Drug resistant viral><Drugs><EC 2.7.7.49><Endopeptidase Inhibitors><Epidemiology><Esteroproteases><Evolution><Failure><Future><GAG><GAG Gene><Genes><Genetic><Genetic Alteration><Genetic Change><Genetic Diversity><Genetic Polymorphism><Genetic Recombination><Genetic Variation><Genetic defect><Genomic Segment><Genotype><Goals><HIV><HIV 1 drug resistance><HIV Infections><HIV drug resistance><HIV drug resistant><HIV resistance><HIV resistant><HIV-1><HIV-1 drug resistance><HIV-1 drug resistant><HIV-I><HIV1><HIV1 drug resistance><HIV1 drug resistant><HTLV-III Infections><HTLV-III-LAV Infections><Human><Human Immunodeficiency Virus Type 1><Human Immunodeficiency Viruses><Human T-Lymphotropic Virus Type III Infections><Human immunodeficiency virus 1><In Vitro><Infection><Infrastructure><Integrase><Investigators><LAV-HTLV-III><Laboratories><Link><Long-term cohort><Longitudinal cohort><Longterm cohort><Lymphadenopathy-Associated Virus><Measures><Mediating><Medication><Methods><Modern Man><Modification><Molecular Interaction><Multi-Drug Resistance><Multidrug Resistance><Multiple Drug Resistance><Multiple Drug Resistant><Mutation><NGS Method><NGS system><NNRTI><Nested Case-Control Study><Nigeria><Nigerian><Non-Polyadenylated RNA><Outcome><Pathway interactions><Patients><Pattern><Peptidase Inhibitors><Peptidases><Peptide Hydrolase Inhibitors><Peptide Hydrolases><Peptide Peptidohydrolase Inhibitors><Pharmaceutical Preparations><Pharmacies><Pharmacotherapy><Pharmacy facility><Phenotype><Plasma><Plasma Serum><Poland><Predictive Factor><Predisposition><Protease Antagonists><Protease Gene><Protease Inhibitor><Proteases><Proteinase Inhibitors><Proteinases><Proteolytic Enzymes><Public Health><Publications><RNA><RNA Gene Products><RNA Transcriptase><RNA-Dependent DNA Polymerase><RNA-Directed DNA Polymerase><Recombinants><Recombination><Regimen><Reporting><Research><Research Design><Research Personnel><Research Specimen><Researchers><Resistance><Resistance to Multi-drug><Resistance to Multidrug><Resistance to Multiple Drug><Resistant to Multiple Drug><Resistant to multi-drug><Resistant to multidrug><Reticuloendothelial System, Serum, Plasma><Reverse Transcriptase><Revertase><Ribonucleic Acid><Risk><Role><Sampling><Scientific Publication><Site-Directed Mutagenesis><Site-Specific Mutagenesis><Specimen><Study Type><Susceptibility><System><Targeted DNA Modification><Targeted Modification><Testing><Transmission><Treatment Failure><Uganda><Variant><Variation><Viral><Viral Genome><Virus><Virus Replication><Virus-HIV><Yeasts><anti-retroviral><anti-retroviral drug resistant><case control><case-controlled><clinical significance><clinically significant><cohort><design><designing><drug resistance in HIV 1><drug resistance in HIV-1><drug resistant><drug resistant HIV><drug resistant HIV 1><drug resistant HIV-1><drug resistant pathway><drug resistant virus><drug treatment><drug/agent><env Genes><epidemiologic><epidemiological><fitness><genome mutation><genome segment><genomic region><improved><inhibitor><multi-drug resistant><multidrug resistant><mutant><next gen sequencing><next generation sequencing><nextgen sequencing><non-nucleoside RT inhibitors><non-nucleoside reverse transcriptase inhibitors><nonnucleoside reverse transcriptase inhibitors><novel><pathway><pol genes><polymorphism><public health research><recombinant virus><resistance mutation><resistance to Drug><resistance to HIV drug><resistance to HIV-1 drug><resistance to HIV1 drug><resistance to anti-HIV><resistance to anti-retroviral drug><resistant><resistant mutation><resistant to Drug><resistant to HIV drug><resistant to HIV-1 drug><resistant to HIV1 drug><resistant to anti-retroviral drug><response><social role><study design><success><therapy failure><transmission process><viral multiplication><viral replication><virology><virus genome><virus multiplication>