Title | IgG3 subclass antibodies recognize antigenically drifted influenza viruses and SARS-CoV-2 variants through efficient bivalent binding. |
Publication Type | Journal Article |
Year of Publication | 2023 |
Authors | Bolton MJ, Santos JJS, Arevalo CP, Griesman T, Watson M, Li SHang, Bates P, Ramage H, Wilson PC, Hensley SE |
Journal | Proc Natl Acad Sci U S A |
Volume | 120 |
Issue | 35 |
Pagination | e2216521120 |
Date Published | 2023 Aug 29 |
ISSN | 1091-6490 |
Keywords | Antibodies, Monoclonal, Antibodies, Viral, COVID-19, Humans, Immunoglobulin G, Orthomyxoviridae, SARS-CoV-2 |
Abstract | The constant domains of antibodies are important for effector functions, but less is known about how they can affect binding and neutralization of viruses. Here, we evaluated a panel of human influenza virus monoclonal antibodies (mAbs) expressed as IgG1, IgG2, or IgG3. We found that many influenza virus-specific mAbs have altered binding and neutralization capacity depending on the IgG subclass encoded and that these differences result from unique bivalency capacities of the subclasses. Importantly, subclass differences in antibody binding and neutralization were greatest when the affinity for the target antigen was reduced through antigenic mismatch. We found that antibodies expressed as IgG3 bound and neutralized antigenically drifted influenza viruses more effectively. We obtained similar results using a panel of SARS-CoV-2-specific mAbs and the antigenically advanced B.1.351 and BA.1 strains of SARS-CoV-2. We found that a licensed therapeutic mAb retained neutralization breadth against SARS-CoV-2 variants when expressed as IgG3, but not IgG1. These data highlight that IgG subclasses are not only important for fine-tuning effector functionality but also for binding and neutralization of antigenically drifted viruses. |
DOI | 10.1073/pnas.2216521120 |
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Alternate Journal | Proc Natl Acad Sci U S A |
PubMed ID | 37603748 |
PubMed Central ID | PMC10469028 |
Grant List | 75N93021C00015 / AI / NIAID NIH HHS / United States R01 AI108686 / AI / NIAID NIH HHS / United States |