Activation of NK cells by HIV-specific ADCC antibodies: Role for granulocytes in expressing HIV-1 peptide epitopes

Vijaya Madhavi, Marjon Navis, Amy W. Chung, Gamze Isitman, Leia H. Wren, Robert De Rose, Stephen J. Kent, Ivan Stratov

Research output: Contribution to journalArticleResearchpeer-review

15 Citations (Scopus)

Abstract

HIV-specific ADCC antibodies could play a role in providing protective immunity. We have developed a whole blood ADCC assay that measures NK cell activation in response to HIV peptide epitopes. These HIV peptide-specific ADCC responses are associated with escape from immune recognition and slower progression of HIV infection and represent interesting HIV vaccine antigens. However, the mechanism by which these epitopes are expressed and whether or not they induce NK-mediated killing of cells expressing such peptide-antigens is not understood. Herein, we show that fluorescent-tagged ADCC peptide epitopes associate with blood granulocytes. The peptide-associated granulocytes become a specific target for antibody-mediated killing, as shown by enhanced expression of apoptosis marker Annexin and reduction in cell numbers. When HIV Envelope gp140 protein is utilized in the ADCC assay, we detected binding to its ligand, CD4. During the incubation, cells co-expressing gp140 and CD4 reduce in number. We also detected increasing Annexin expression in these cells. These data indicate that blood cells expressing HIV-specific ADCC epitopes are targeted for killing by NK cells in the presence of ADCC antibodies in HIV+ plasma and provide a clearer framework to evaluate these antigens as vaccine candidates.

Original languageEnglish
Pages (from-to)1011-1018
Number of pages8
JournalHuman Vaccines & Immunotherapeutics
Volume9
Issue number5
DOIs
Publication statusPublished - May 2013
Externally publishedYes

Keywords

  • ADCC
  • Apoptosis
  • Granulocytes
  • HIV
  • NK cells

Cite this