HIV-1 subtype B protease and reverse transcriptase amino acid covariation

Area of Science:

• Virology
• Molecular Biology
• Computational Biology

Background:

• Antiretroviral therapy (ART) for HIV-1 leads to drug resistance through viral mutations.
• Understanding mutation patterns is crucial for predicting treatment outcomes and developing new therapies.

Purpose of the Study:

• To analyze amino acid covariation patterns in HIV-1 protease and reverse transcriptase (RT).
• To investigate the relationship between mutation order and conditional probabilities in HIV-1 drug resistance.

Main Methods:

• Analysis of over 7,000 HIV-1 subtype B protease and RT sequences from the Stanford HIV Drug Resistance Database.
• Examination of longitudinal sequence data to determine mutation development order and conditional probabilities.

Main Results:

• Distinct clustering patterns observed in RT mutations (thymidine analog, Q151M) and protease mutations (nelfinavir, V82A, L90M, amprenavir, darunavir).
• Different covariation patterns noted for distinct mutations at the same amino acid positions.
• Conditional probabilities accurately predicted mutation order, with accessory PI mutations frequently preceding primary PI mutations.

Conclusions:

• Amino acid covariation significantly limits the spectrum of HIV-1 variants under ART.
• Mutation order prediction is feasible using conditional probabilities, aiding in understanding resistance pathways.
• Differential mutation patterns at specific sites highlight complex resistance mechanisms.