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Cross-reactive influenza-specific antibody-dependent cellular cytotoxicity antibodies in the absence of neutralizing antibodies.

Jegaskanda S, Job ER, Kramski M, Laurie K, Isitman G, de Rose R, Winnall WR, Stratov I, Brooks AG, Reading PC, Kent SJ

  • Journal Journal of immunology (Baltimore, Md. : 1950)

  • Published 14 Jan 2013

  • Volume 190

  • ISSUE 4

  • Pagination 1837-48

  • DOI 10.4049/jimmunol.1201574


A better understanding of immunity to influenza virus is needed to generate cross-protective vaccines. Engagement of Ab-dependent cellular cytotoxicity (ADCC) Abs by NK cells leads to killing of virus-infected cells and secretion of antiviral cytokines and chemokines. ADCC Abs may target more conserved influenza virus Ags compared with neutralizing Abs. There has been minimal interest in influenza-specific ADCC in recent decades. In this study, we developed novel assays to assess the specificity and function of influenza-specific ADCC Abs. We found that healthy influenza-seropositive young adults without detectable neutralizing Abs to the hemagglutinin of the 1968 H3N2 influenza strain (A/Aichi/2/1968) almost always had ADCC Abs that triggered NK cell activation and in vitro elimination of influenza-infected human blood and respiratory epithelial cells. Furthermore, we detected ADCC in the absence of neutralization to both the recent H1N1 pandemic strain (A/California/04/2009) as well as the avian H5N1 influenza hemagglutinin (A/Anhui/01/2005). We conclude that there is a remarkable degree of cross-reactivity of influenza-specific ADCC Abs in seropositive humans. Targeting cross-reactive influenza-specific ADCC epitopes by vaccination could lead to improved influenza vaccines.