A High-Throughput, Systems-based Neutralizing Antibody Assay Identifies Humoral Features Linked with Compartmentalized Neutralization 2304404

Abstract Introduction Antibodies leverage both their fragment antigen binding (Fab) and fragment crystallizable (Fc) domains to confer protection against pathogens. Recent work has shown that the Fc-domain can contribute to breadth of antibody-mediated recognition. Because of this, we sought to identify antibody features correlated to neutralization capacity using a systems serology approach. Moreover, it is unclear if signatures of neutralization are conserved across anatomical sites. We thus employed a newly-developed, systems-predicted neutralizing antibody assay to profile how neutralization signatures against influenza virus were shaped by their milleu. Methods We developed a systems-based predictive neutralizing antibody (SNAb) titer assay to simultaneously quantify influenza neutralization across multiple subtypes and isolates using specimens from H1- and H5-vaccinated non-human primates. We incorporated these results into a systems serology framework to assess the contribution of antibody features to neutralization capacity. Results We find that Fcγ-receptor binding features are strongly associated with neutralization capacity against H1 and H5 influenza clades in serum, while IgG, IgM, and IgA were enriched at the lower respiratory tract mucosa. Features correlating with the neutralization response appeared highly influenced by vaccination priming compositions and boosting route. Neutralization titers were not correlated to the targets of vaccination between serum and lower respiratory tract mucosa. Conclusion Influenza virus neutralization can be quantified in a high-throughput manner and correlated with antibody features in distinct tissues in non-human primates through a modified systems serology approach. Our results are in tight agreement with other neutralizing antibody titer assays such as microneutralization assays and hemagglutinin inhibition assays. Funding Source National Institutes of Health Grant CA260476 National Institutes of Health Grant P01AI165072 National Institutes of Health Grant U19AI135995 National Institutes of Health Contract 75N93021C00029 Topic Categories Technological Innovations in Immunology (TECH)