Charlotte S Kaetzel, PhD

Immunoglobulin A (IgA) antibodies are the first line of immune defense in mucous membranes, protecting the respiratory, gastrointestinal and genitourinary tracts from inhaled, ingested and sexually transmitted pathogens. Transport of IgA across mucosal epithelial cells into external secretions is mediated by the polymeric immunoglobulin receptor (PIGR). Our laboratory studies regulation of the expression and function of PIGR and other immune regulatory factors in intestinal epithelial cells during health and disease. Inflammatory bowel disease (IBD) results from a dysregulated immune response to the commensal microbiota in genetically susceptible individuals. Our recent studies have focused on the role of commensal gut bacteria in regulating epithelial gene expression, and how this balance becomes dysregulated in IBD. To this end we utilize a variety of genetic and transgenic mouse models, as well as human intestinal biopsies and cell-lines. Our long-term goal is to increase our understanding of immune mechanisms that regulate intestinal homeostasis and inflammation, and to develop novel approaches for the diagnosis and treatment of IBD.