SIV Env RhmAbs + N-803 at ART initiation prolongs viral decay without disrupting reservoir establishment in SIV-infected infant macaques

PLoS Pathog. 2025 Jan 10;21(1):e1012863. doi: 10.1371/journal.ppat.1012863. eCollection 2025 Jan.

Abstract

The latent viral reservoir remains the major barrier to HIV cure, placing the burden of strict adherence to antiretroviral therapy (ART) on people living with HIV to prevent recrudescence of viremia. For infants with perinatally acquired HIV, adherence is anticipated to be a lifelong need. In this study, we tested the hypothesis that administration of ART and viral Envelope-specific rhesus-derived IgG1 monoclonal antibodies (RhmAbs) with or without the IL-15 superagonist N-803 early in infection would limit viral reservoir establishment in SIV-infected infant rhesus macaques. Following initiation of ART at 1-2 weeks after oral SIVmac251 infection, we observed biphasic decay of viremia, with first phase decay significantly faster in the ART + SIV RhmAbs-treated group compared to controls that received only ART. In contrast, the addition of N-803 to ART + SIV RhmAbs significantly slowed both the first and second phase viral decay compared to the ART only group. Treatment with a single dose of N-803 resulted in increased frequency of Ki67 expressing NK, CD8+, and CD4+ T cells. Levels of intact SIV proviruses in CD4+ T cells from blood, lymph nodes, and rectum at week 48 of ART did not differ across groups. Similarly, the time to viral rebound following ART interruption was not impacted by the experimental treatments. These results support the concept that the rebound-competent viral reservoir is formed within days after infection and that targeting only productively infected cells for clearance near the time of ART initiation, even during acute infection, may be insufficient to limit reservoir establishment.

MeSH terms

  • Animals
  • Anti-Retroviral Agents* / therapeutic use
  • Antibodies, Monoclonal*
  • Antibodies, Viral / immunology
  • CD4-Positive T-Lymphocytes / immunology
  • CD4-Positive T-Lymphocytes / virology
  • Disease Reservoirs / virology
  • Immunoglobulin G
  • Macaca mulatta*
  • Simian Acquired Immunodeficiency Syndrome* / drug therapy
  • Simian Acquired Immunodeficiency Syndrome* / virology
  • Simian Immunodeficiency Virus* / drug effects
  • Viral Load* / drug effects
  • Viremia / drug therapy
  • Virus Latency / drug effects

Substances

  • Antibodies, Monoclonal
  • Anti-Retroviral Agents
  • Antibodies, Viral
  • Immunoglobulin G

Grants and funding

This work was supported with federal funds from the U.S National Institutes of Health (https://www.nih.gov/) UM1AI164566 and P30AI050409 to AC; RR000165/OD011132 to the Emory National Primate Research Center; P01AI131365 and P01AI169768 ALH; and U24AI143502 to GL. The funders had no role in the study design, data collection and analysis, decision to publish, or preparation of the manuscript and the content is solely the responsibility of the authors and does not necessarily represent the official views of the National Institutes of Health.