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Immunogenetic studies have shown that specific HLA-B residues (67, 70, 97, and 156) mediate the impact of HLA class I on HIV infection, but the molecular basis is not well understood. Here we evaluate the function of these residues within the protective HLA-B ∗ 5701 allele. While mutation of Met67, Ser70, and Leu156 disrupt CD8 + T cell recognition, substitution of Val97 had no significant impact. Thermal denaturation of HLA-B ∗ 5701-peptide complexes revealed that Met67 and Leu156 maintain HLA-peptide stability, while Ser70 and Leu156 facilitate T cell receptor (TCR) interactions. Analyses of existing structures and structural models suggested that Val97 mediates HLA-peptide binding to inhibitory KIR3DL1 molecules, which was confirmed by experimental assays. These data thereby demonstrate that the genetic basis by which host immunity impacts HIV outcomes occurs by modulating HLA-B-peptide stability and conformation for interaction with TCR and killer immunoglobulin receptor (KIR) molecules. Moreover, they indicate a key role for epitope specificity and HLA-KIR interactions to HIV control., Competing Interests: Declaration of interests B.D.W. and G.D.G have filed patent application PCT/US2020/022403. G.D.G. also reports research funding from Moderna and Merck., (Copyright © 2024 The Author(s). Published by Elsevier Inc. All rights reserved.)

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) monoclonal antibodies (mAbs) are among the treatments recommended for high-risk ambulatory persons with coronavirus 2019 (COVID-19). Here, we study viral culture dynamics post-treatment in a subset of participants receiving the mAb bamlanivimab in the ACTIV-2 trial (ClinicalTrials.gov: NCT04518410). Viral load by qPCR and viral culture are performed from anterior nasal swabs collected on study days 0 (day of treatment), 1, 2, 3, and 7. Treatment with mAbs results in rapid clearance of culturable virus. One day after treatment, 0 of 28 (0%) participants receiving mAbs and 16 of 39 (41%) receiving placebo still have culturable virus (p < 0.0001). Recrudescence of culturable virus is detected in three participants with emerging mAb resistance and viral RNA rebound. While further studies are necessary to fully define the relationship between shed culturable virus and transmission, these results raise the possibility that mAbs may offer immediate (household) and public-health benefits by reducing onward transmission., Competing Interests: Declaration of interests J.B., M.C.C., R.D., J. Regan, J.P.F., C.R.C., M.D.H., J. Ritz, C.M., J.A.D., A.C.J., R.W.C., J.S.C., and A.K.B. report no competing interests. K.W.C. reports research grant support to the institution from Merck Sharp & Dohme. A.N. and P.K. are employees and shareholders of Eli Lilly. A.L.G. declares central testing contracts with Abbott and research support from Gilead and Merck outside of the submitted work. W.A.F. reports research funding from Ridgeback Biopharmaceuticals and consultancy fees from Roche and Merck and serves on adjudication committees for Janssen and Syneos. E.S.D. reports consulting fees from Gilead Sciences and Merck and research support to the institution from Gilead Sciences and ViiV. J.J.E. reports serving as an ad hoc consultant to GSK/VIR and as data monitoring committee (DMC) chair for Adagio Phase III studies. D.M.S. reports consulting fees from the following companies: Fluxergy, Kiadis, Linear Therapies, Matrix BioMed, Arena Pharmaceuticals, VxBiosciences, Model Medicines, Bayer Pharmaceuticals, Signant Health, and Brio Clinical. J.Z.L. reports consulting for Abbvie and Recovery Therapeutics., (Copyright © 2022 The Author(s). Published by Elsevier Inc. All rights reserved.)