title: Preexisting Antibody-Dependent Cellular Cytotoxicity-Activating Antibody Responses Are Stable Longitudinally and Cross-reactive Responses Are Not Boosted by Recent Influenza Exposure.
abstract: Cross-reactive influenza virus-specific antibody-dependent cellular cytotoxicity (ADCC)-activating antibodies are readily detected in healthy adults. However, little is known about the kinetics of these ADCC responses. We used retrospective serial blood samples from healthy donors to investigate this topic. All donors had ADCC responses against 2009 pandemic influenza A(H1N1) virus (A[H1N1]pdm09) and avian influenza A(H7N9) virus hemagglutinins (HAs) despite being seronegative for these viruses in standard hemagglutination inhibition and microneutralization serological assays. A(H1N1)pdm09 exposure did not boost ADCC responses specific for H7 HA antigens. H7 HA ADCC responses were variable longitudinally within donors, suggesting that these cross-reactive antibodies are unstable. We found no correlation between ADCC responses to the H7 HA and either influenza virus-specific immunoglobulin G1 concentration or age.
authors: HKU-Pasteur Research Pole School of Public Health, University of Hong Kong.
authors: Sophie A
authors: SA
authors: Valkenburg
authors: School of Public Health, University of Hong Kong.
authors: Yanyu
authors: Y
authors: Zhang
authors: School of Public Health, University of Hong Kong.
authors: Ka Y
authors: KY
authors: Chan
authors: School of Public Health, University of Hong Kong.
authors: Kathy
authors: K
authors: Leung
authors: School of Public Health, University of Hong Kong.
authors: Joseph T
authors: JT
authors: Wu
authors: School of Public Health, University of Hong Kong.
authors: Leo L M
authors: LL
authors: Poon
mesh_terms: D000818:Animals; D000914:Antibodies, Viral / Q000276:immunology*; D000917:Antibody Formation / Q000276:immunology*; D000920:Antibody-Dependent Cell Cytotoxicity / Q000276:immunology*; D001717:Birds; D003429:Cross Reactions / Q000276:immunology*; D006385:Hemagglutination Inhibition Tests / Q000379:methods; D019267:Hemagglutinin Glycoproteins, Influenza Virus / Q000276:immunology; D006801:Humans; D007074:Immunoglobulin G / Q000276:immunology; D053118:Influenza A Virus, H1N1 Subtype / Q000276:immunology*; D064766:Influenza A Virus, H7N9 Subtype / Q000276:immunology*; D005585:Influenza in Birds / Q000276:immunology; D007251:Influenza, Human / Q000276:immunology*; D008137:Longitudinal Studies; D012189:Retrospective Studies
chemical_list: D000914:Antibodies, Viral; D019267:Hemagglutinin Glycoproteins, Influenza Virus; D007074:Immunoglobulin G
keywords: ADCC; NK cells; antibody; influenza