Date of Award
Doctor of Philosophy (PhD)
IgA is the primary antibody response at mucosal surfaces and is reported to inhibit adaptive immune responses against gut bacteria. Here, we utilize an in vitro system to expand and screen IgA memory B cells for their ability to recognize gut bacteria in the context of secretory IgA (sIgA) deficiency in polymeric Ig receptor (Pigr–/–) mice. Contrary to the prevailing hypothesis that IgA provides an immune exclusionary function, we found that mice lacking sIgA showed decreased anti-bacterial IgA specificities as assessed using flow cytometry. IgA B cell responses against certain taxa such as those of order Bacteriodales showed greater dependence on sIgA. Notably, sIgA also facilitated the generation of anti-bacterial IgG B cells, which provided increased resistance to intraperitoneal infection by commensal bacteria. Together, these data suggest that sIgA can facilitate the immune priming of gut commensals to increase anti-bacterial IgA and IgG and enhance immunity.
Chair and Committee
Chyi S. Hsieh
Michael S. Diamond, Ali Ellebedy, Thaddeus S. Stappenbeck, Gregory F. Wu,
Zhou, You, "Secretory IgA Enhances Gut B Cells Priming and Systemic IgG Responses Towards Commensals" (2019). Arts & Sciences Electronic Theses and Dissertations. 1972.