A Novel Assay for Antibody-Dependent Cell-Mediated Cytotoxicity against HIV-1-or SIV-Infected Cells Reveals Incomplete Overlap with Antibodies Measured by Neutralization and Binding Assays

Research output: Contribution to journalArticle

Abstract

The resistance of human immunodeficiency virus type 1 (HIV-1) to antibody-mediated immunity often prevents the detection of antibodies that neutralize primary isolates of HIV-1. However, conventional assays for antibody functions other than neutralization are suboptimal. Current methods for measuring the killing of virus-infected cells by antibody-dependent cell-mediated cytotoxicity (ADCC) are limited by the number of natural killer (NK) cells obtainable from individual donors, donor-to-donor variation, and the use of nonphysiological targets. We therefore developed an ADCC assay based on NK cell lines that express human or macaque CD16 and a CD4(+) T-cell line that expresses luciferase from a Tat-inducible promoter upon HIV-1 or simian immunodeficiency virus (SIV) infection. NK cells and virus-infected targets are mixed in the presence of serial plasma dilutions, and ADCC is measured as the dose-dependent loss of luciferase activity. Using this approach, ADCC titers were measured in plasma samples from HIV-infected human donors and SIV-infected macaques. For the same plasma samples paired with the same test viruses, this assay was approximately 2 orders of magnitude more sensitive than optimized assays for neutralizing antibodies-frequently allowing the measurement of ADCC in the absence of detectable neutralization. Although ADCC correlated with other measures of Env-specific antibodies, neutralizing and gp120 binding titers did not consistently predict ADCC activity. Hence, this assay affords a sensitive method for measuring antibodies capable of directing ADCC against HIV- or SIV-infected cells expressing native conformations of the viral envelope glycoprotein and reveals incomplete overlap of the antibodies that direct ADCC and those measured in neutralization and binding assays.

Details

Authors
  • Michael D. Alpert
  • Lisa N. Heyer
  • David E. J. Williams
  • Jackson D. Harvey
  • Thomas Greenough
  • Maria Allhorn
  • David T. Evans
Organisations
Research areas and keywords

Subject classification (UKÄ) – MANDATORY

  • Infectious Medicine
Original languageEnglish
Pages (from-to)12039-12052
JournalJournal of Virology
Volume86
Issue number22
Publication statusPublished - 2012
Publication categoryResearch
Peer-reviewedYes