A recombinant virus assay using full-length envelope sequences to detect changes in HIV-1 co-receptor usage

Area of Science:

• Virology
• Molecular Biology
• Immunology

Background:

• Clinical management of HIV-1 infection relies on molecular characterization of drug resistance and viral phenotyping.
• Highly Active Antiretroviral Therapy (HAART) monitoring involves tracking drug resistance variants to adjust treatment regimens.
• Understanding HIV-1 drug resistance evolution improves drug development and in vitro antiviral compound evaluation.

Purpose of the Study:

• To develop a recombinant virus assay (RVA) for phenotypic determination of drug resistance against entry inhibitors (EI).
• To assess the utility of an envelope-based RVA for monitoring HIV co-receptor usage and resistance development.

Main Methods:

• Constructed an env-deleted HIV-1 clone using the NL-4.3 molecular clone.
• Amplified and ligated complete envelope genes (NL-4.3, BaL, primary) into a deletion clone (pNL-deltaK).
• Transfected PM1 cells to generate recombinant virus, then determined co-receptor usage.

Main Results:

• The envelope-based RVA was successfully constructed and functional.
• Co-receptor usage determination of the recombinant virus swarm showed no difference compared to individual patient-derived clones.
• The assay is practicable for monitoring HIV co-receptor usage at specific time points.

Conclusions:

• An envelope-based RVA is a viable tool for monitoring HIV co-receptor usage.
• This assay can track resistance development against current and future entry inhibitors.
• The RVA will improve the clinical management of HIV-1 therapy.