Phagocytosis by an HIV antibody is associated with reduced viremia irrespective of enhanced complement lysis

David A. Spencer, Benjamin S. Goldberg, Shilpi Pandey, Tracy Ordonez, Jérémy Dufloo, Philip Barnette, William F. Sutton, Heidi Henderson, Rebecca Agnor, Lina Gao, Timothée Bruel, Olivier Schwartz, Nancy L. Haigwood, Margaret E. Ackerman, Ann J. Hessell

Research output: Contribution to journalArticlepeer-review

Abstract

Increasingly, antibodies are being used to treat and prevent viral infections. In the context of HIV, efficacy is primarily attributed to dose-dependent neutralization potency and to a lesser extent Fc-mediated effector functions. It remains unclear whether augmenting effector functions of broadly neutralizing antibodies (bNAbs) may improve their clinical potential. Here, we use bNAb 10E8v4 targeting the membrane external proximal region (MPER) to examine the role of antibody-mediated effector and complement (C’) activity when administered prophylactically against SHIV challenge in rhesus macaques. With sub-protective dosing, we find a 78–88% reduction in post-acute viremia that is associated with 10E8v4-mediated phagocytosis acting at the time of challenge. Neither plasma nor tissue viremic outcomes in vivo is improved with an Fc-modified variant of 10E8v4 enhanced for C’ functions as determined in vitro. These results suggest that effector functions inherent to unmodified 10E8v4 contribute to efficacy against SHIVSF162P3 in the absence of plasma neutralizing titers, while C’ functions are dispensable in this setting, informing design of bNAb modifications for improving protective efficacy.

Original languageEnglish (US)
Article number662
JournalNature communications
Volume13
Issue number1
DOIs
StatePublished - Dec 2022
Externally publishedYes

ASJC Scopus subject areas

  • Chemistry(all)
  • Biochemistry, Genetics and Molecular Biology(all)
  • Physics and Astronomy(all)

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