Structural Comparison of Diverse HIV-1 Subtypes using Molecular Modelling and Docking Analyses of Integrase Inhibitors

The process of viral integration into the host genome is an essential step of the HIV-1 life cycle. The viral Integrase (IN) enzyme catalyses integration. IN is an ideal therapeutic enzyme targeted by several drugs; raltegravir (RAL), elvitegravir (EVG), dolutegravir (DTG) and bictegravir (BIC) having been approved by the USA Food and Drug Administration (FDA). Due to high HIV-1 diversity, it is not well understood how specific naturally occurring polymorphisms (NOPs) in IN may affect the structure/function and binding affinity of Integrase Strand Transfer Inhibitors (INSTIs). In this study, we applied computational methods of molecular modelling and docking to analyse the effect of NOPs on the full-length IN structure and INSTI binding. We identified 16 NOPs within the Cameroonian derived CRF02_AG IN sequences and further identified 17 NOPs within HIV-1C South African sequences. The NOPs in the IN structures did not show any effect on INSTI binding. INSTIs displayed similar binding affinities to each IN structure. All INSTIs are clinically effective against diverse HIV-1 strains from INSTI treatment naïve populations. This study supports the use of second-generation INSTI DTG as part of first-line combination antiretroviral therapy (cART) regimens, due to DTG possessing a stronger genetic barrier to the emergence of drug resistance.