Publications & Reports

Fc-dependent functions are redundant to efficacy of anti-HIV antibody PGT121 in macaques.

Parsons MS, Lee WS, Kristensen AB, Amarasena T, Khoury G, Wheatley AK, Reynaldi A, Wines BD, Hogarth PM, Davenport MP, Kent SJ
Department of Microbiology and Immunology, Peter Doherty Institute for Infection and Immunity, and.


A considerable body of evidence suggests that Fc-dependent functions improve the capacity of broadly neutralizing antibodies (BnAbs) to protect against and control HIV-1 infection. This phenomenon, however, has not been formally tested in robust cell-associated macaque simian-human immunodeficiency virus (SHIV) models with newer-generation BnAbs. We studied both the WT BnAb PGT121 and a LALA mutant of PGT121 (which has impaired Fc-dependent functions) for their ability to protect pigtail macaques from an i.v. high-dose cell-associated SHIVSF162P3 challenge. We found that both WT and LALA PGT121 completely protected all 12 macaques studied. Further, partial depletion of NK cells, key mediators of Fc-dependent functions, did not abrogate the protective efficacy of PGT121 in 6 macaques. Additionally, in animals with established SHIVSF162P3 infection, SHIV viremia levels were equally rapidly reduced by LALA and WT PGT121. Our studies suggest that the potent neutralizing capacity of PGT121 renders the Fc-dependent functions of the Ab at least partially redundant. These findings have implications for Ab-mediated protection from and control of HIV-1 infection.

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Full text available at PubMed Central


  • Journal: The Journal of Clinical Investigation
  • Published: 02/01/2019
  • Volume: 129
  • Issue: 1
  • Pagination: 182-191