Unraveling the role of IgA during respiratory virus infections

IgA is the major type of antibody found in our lungs, and the second most prevalent antibody found in blood. Despite this, the role played by IgA in mediating protection against respiratory virus infections is poorly understood. IgA, like other antibodies, can protect against viral infections in two ways. First, IgA can neutralize virus and prevent it from entering host cells. In addition, IgA bound to virus and/or virus-infected cells can be recognized by specific receptors found of the surface of certain immune cells. Upon recognition, these immune cells become stimulated to eliminate virus and virally infected cells. Mice do not naturally express receptors that recognize IgA. This has been a major barrier to understanding how interactions between IgA and immune cells contribute to protection from viral infections. Using a new mouse model that expresses the human IgA receptor (CD89), we will determine the contribution of IgA to protection against influenza virus and SARS-CoV-2. These studies will generate knowledge that will contribute to the development of new antibody-based therapeutics and better vaccines.