Dr. Joseph A. Horzempa receives grant support from WV-INBRE

Dr. Joseph A. Horzempa, Assistant Professor in the Department of Natural Sciences and Mathematics at West Liberty University, is receiving grant support from WV-INBRE as he studies the mechanism of erythrocyte invasion by Francisella tularensis. Dr. Horzempa's work is also supported by a WV-NASA Space Grant Consortium and a K22 Career Development Grant from NIAID. This funding provides support to investigate how and why F. tularensis invades red blood cells, antibiotic resistance, and vaccine development. Francisella tularensis is a highly infectious microorganism; <10 bacteria can result in the severe disease tularemia. This bacterium has been weaponized and could be used for bioterrorism, prompting the Center for Disease Control and Prevention (CDC) to classify F. tularensis as a category A biodefense agent. In addition, F. tularensis causes a variety of naturally occurring human infections that can be acquired by inhalation, arthropod bites, oropharyngeal exposure, or contact. Many seminal studies have shown that the ability of F. tularensis to replicate within macrophages is a feature of this organism during infection. Only recently it has been appreciated that interactions with non-macrophages are also extremely important during infection as these cells provide a niche for immune protection, proliferation, and other unexplored roles. Although much of the work in the field of F. tularensis has focused on the intra-macrophage biology of this organism, interactions with other cell types have not been thoroughly investigated. Dr. Horzempa and colleagues discovered that F. tularensis invades human erythrocytes in vitro. Their research is published in the prestigious Journal of Infectious Diseases (J Infect Dis. 2011 Jul 1;204(1):51-9. Invasion of erythrocytes by Francisella tularensis. Horzempa J, O'Dee DM, Stolz DB, Franks JM, Clay D, Nau GJ.). The erythrocyte invasion enhances resistance to antibiotics and is involved in the pathogenesis of F. tularensis. The members of the Horzempa lab have generated and obtained F. tularensis mutants that are both incapable of erythrocyte invasion and attenuated for virulence. This finding is consistent with the hypothesis that erythrocyte invasion is associated with the pathogenesis of F. tularensis. Currently, Dr. Horzempa along with students working in his lab are comparing strains having mutations with wild-type bacteria to further elucidate the bacterial mechanism of erythrocyte invasion. Invasion of erythrocytes is dependent upon both heat-labile and heat-stable components of serum. The Horzempa lab is investigating the role of specific components of serum in erythrocyte invasion by F. tularensis. Dr. Horzempa reports that the students at West Liberty are very enthusiastic and enjoy conducting research in his laboratory. He currently mentors ten undergraduate researchers, one post-doc, and employs a full time technician. Several of his students have received research fellowships, presented research at scientific meetings, and have decided to pursue research as a career.