Department of Microbiology and Immunology
Professor of Microbiology and Immunology, Adjunct Professor of Oral Biology
Allergy and Immunology; Bacterial Pathogenesis; Gene Expression; Genomics and proteomics; Immunology; Infectious Disease; Medical Microbiology; Microbial Pathogenesis; Microbiology; Molecular and Cellular Biology; Molecular Basis of Disease; Molecular genetics; Protein Function and Structure; Signal Transduction
Research efforts in my laboratory are focused in the fields of immunology and bacterial pathogenesis, two diverse fields of biomedical research for which I have two separate research groups. Projects in both fields are performed by undergraduates, doctoral and master’s degree students, postdoctoral fellows and senior research associates.
One major focus of my laboratory is studying the regulation of mucosal immune responses. We investigate the cellular and molecular events by which Type II heat-labile enterotoxins (HLTs), produced by certain strains of Escherichia coli, modulate immune responses. We have demonstrated that LT-Ilia, LT-IIb and LT-IIc, when co-administered with an antigen, have the capacity to enhance antibody and cellular immune responses to that antigen. Using a variety of immunological and cellular technologies, including flow cytometry, fluorescence resonance energy transfer (FRET) detection, cytokine multiplex analysis, mutagenesis, quantitative Reverse Transcription PCR (qRT-PCR), RNA-sequencing (RNA-Seq) and a variety of transgenic mice, we are investigating the mechanisms by which these immunomodulators productively interact with various immunocompetent cells (T cells, B cells, dendritic cells, macrophages) to induce or suppress cytokine production, costimulatory ligand expression and cellular proliferation. A practical outgrowth of these experiments is the potential to engineer novel recombinant vaccines by genetically fusing antigens from different pathogens to the enterotoxins. Recent experiments have shown that these HLT are lethal for triple-negative breast cancer cells, which has opened a new area of oncological research for the lab.
A second focus of my laboratory is to investigate the molecular mechanisms by which adherent-invasive Escherichia coli (AIEC) induce, exacerbate or prolong the symptoms of inflammatory bowel disease (IBD) and Crohn’s disease, two acute and chronic inflammatory diseases of the human gut. In vitro, AIEC strains invade into the cytoplasm of several epithelial cell lines. Using recombinant screening methods and RNA-Seq technologies, we are identifying the genes of AIEC that are required to attach and to invade gut cells.