Chair’s Corner

Pathology is a medical specialty that provides the scientific foundation for all medical practice. The pathologist works with each of the clinical specialties, using the tools of laboratory medicine to provide information essential to problem solving in clinical practice.”

Michael E. Selsted, MD, PhD
Chair, Department of Pathology


Michael E. Selsted, MD, PhD, is an internationally renowned scholar in the field of innate immunity and pathogenesis whose research discoveries have resulted in more than 20 U.S. patents. Selsted’s research has focused on defensins, antimicrobial peptides produced by the body that provide a first line of defense against potentially invasive pathogens. He has published more than 130 scholarly articles and has been lauded with numerous academic honors, including a National Institutes of Health MERIT (Method to Extend Research in Time) award, which recognizes researchers who have demonstrated superior competence and outstanding productivity in research endeavors. The award provides long-term support to investigators with impressive records of scientific achievement in research areas of special importance or promise. Fewer than 5 percent of NIH-funded investigators are selected to receive MERIT Awards. In addition to his pioneering research and clinical science, Dr. Selsted is a prolific author and experienced administrator.

About Michael E. Selsted, MD, PhD

Current Research

The research focus of the Selsted laboratory is on peptidic effectors of mammalian innate immunity, specifically the discovery, characterization, and biological roles of defensins. Defensins are antimicrobial peptides expressed in granulocytic leukocytes and epithelial cells. In vitro experiments demonstrate that defensins possess microbicidal activities against bacteria, fungi, and viruses, and transgenic mouse experiments demonstrate that defensins to play a central role in as first line defenders against potentially invasive pathogens in vivo. Three structural defensin subfamilies (α, β, and θ) have been characterized by Selsted and colleagues, each of which possesses a different tri-disulfide motif stabilizing the peptide backbone. α-defensins, the first defensins to be isolated, are expressed predominantly in neutrophils and intestinal Paneth cells. β-defensins, the most ancient of the defensin sub-families (expressed in birds and reptiles), are expressed widely in mammalian epithelia. More recently the Selsted lab isolated θ-defensins from monkey leukocytes. When characterized, these peptides were found to be cyclic molecules, wherein the peptide chain is folded upon itself in a head-to-tail configuration.

Current projects in the lab focus on the regulation of α- and θ-defensin expression in leukocyte subsets; post-translational processing pathways; structure-function analysis of natural and synthetic θ-defensins; and the role of defensins as pro- and anti-inflammatory mediators in systemic disease. The lab employs a multidisciplinary approach to questions of defensin biology, employing solid-state chemical synthesis, molecular and cell biology, medical microbiology, structural analyses, and good old fashioned biochemistry.