Antibody conjugation approach enhances breadth and potency of neutralization of Anti-HIV-1 antibodies and CD4-IgG

Julia Gavrilyuk, Hitoshi Ban, Hisatoshi Uehara, Shannon J. Sirk, Karen Saye-Francisco, Angelica Cuevas, Elise Zablowsky, Avinash Oza, Michael S. Seaman, Dennis R. Burton, Carlos F. Barbas

Research output: Contribution to journalArticlepeer-review


Broadly neutralizing antibodies PG9 and PG16 effectively neutralize 70 to 80% of circulating HIV-1 isolates. In this study, the neutralization abilities of PG9 and PG16 were further enhanced by bioconjugation with aplaviroc, a small-molecule inhibitor of virus entry into host cells. A novel air-stable diazonium hexafluorophosphate reagent that allows for rapid, tyrosine-selective functionalization of proteins and antibodies under mild conditions was used to prepare a series of aplaviroc-conjugated antibodies, including b12, 2G12, PG9, PG16, and CD4-IgG. The conjugated antibodies blocked HIV-1 entry through two mechanisms: by binding to the virus itself and by blocking the CCR5 receptor on host cells. Chemical modification did not significantly alter the potency of the parent antibodies against nonresistant HIV-1 strains. Conjugation did not alter the pharmacokinetics of a model IgG in blood. The PG9-aplaviroc conjugate was tested against a panel of 117 HIV-1 strains and was found to neutralize 100% of the viruses. PG9-aplaviroc conjugate IC50s were lower than those of PG9 in neutralization studies of 36 of the 117 HIV-1 strains. These results support this new approach to bispecific antibodies and offer a potential new strategy for combining HIV-1 therapies.

Original languageEnglish (US)
Pages (from-to)4985-4993
Number of pages9
JournalJournal of virology
Issue number9
StatePublished - May 2013
Externally publishedYes

ASJC Scopus subject areas

  • Microbiology
  • Immunology
  • Insect Science
  • Virology


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