Relevance of Resistance Mutations for the Susceptibility to Broadly Neutralizing Antibodies Against HIV-1

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Project Summary/ Abstract Novel therapeutic strategies to end the HIV epidemic are urgently needed. Broadly neutralizing antibodies (bNAbs) have emerged as highly promising tools in HIV treatment, and early-phase clinical trials have been conducted or are under way. We propose to study resistance mutations to broadly neutralizing antibodies in HIV-1 with a focus on subtypes other than subtype B. While subtype B, prevalent in North America and Europe, has historically been investigated the most, it only affects ~12% of HIV positive people globally. There is a knowledge gap regarding non-subtype B HIV-1 infection which is endemic in resource-limited settings, like sub-Saharan Africa. Minority variant resistance mutations have been found to be associated with treatment failure of ART. There is evidence that similar mechanisms are involved in bNAb resistance, but the role of minority variants for resistance to bNAbs is less defined, particularly in resource-limited areas. We therefore propose to use a large collection of viremic plasma samples obtained from HIV-1 infected individuals from two studies (ACTG A5288 and REVAMP) to determine the prevalence of resistance mutations to bNAbs in HIV-1 subtypes A, C, and D which together represent the majority of infections worldwide. As minority variants typically are missed on routine Sanger sequencing, we propose to use deep sequencing to analyze the plasma samples for majority and minority resistance variants. We will process the obtained sequencing data using a pipeline similar to what has recently been used by our group for resistance mutation analysis which will be adapted to the current project. We will then compare the resistance mutation in these HIV-1 subtype C samples with previously published resistance mutations to at least four widely used bNAbs (VRC01, 3BNC117, PGT121 and 10-1074). For example, we expect to find baseline resistance mutations at the glycan binding N332 and N334 sites as previously described. In a second aim of the study, we will confirm the resistance against these bNAbs in phenotypic tests using subtype-specific pseudoviruses by introducing resistance mutations that we have identified as minority variants. We will use these pseudoviruses to determine the half maximal inhibitory concentrations (IC50) against the named antibodies. In aim 3 we will look for resistance mutations at baseline and with any observed viral rebound in children with perinatal HIV infection that will be treated with dual bNAb therapy and undergo ART treatment interruption. The candidate is a physician-scientist and has completed clinical fellowship training at the combined Massachusetts General Hospital and Brigham and Woman’s Hospital Infectious Diseases Program. He has research experience in basic and translational science in innate immunity, host-pathogen interactions, chronic viral diseases (previous work on hepatitis C) and has now been applying his research skills to the virology of HIV. His goal is to become an independent investigator in translational HIV research and an expert on HIV resistance. The career development plan as outlined in this proposal will provide the necessary additional training, mentoring and time for research to achieve this goal.