NEW ROLES FOR PROTEASES IN THE INFECTION BIOLOGY OF COCCIDIAN PARASITES

FABIOLA PARUSSINI; CHIN FEN TEO; JILL HARPER; EMILY BINDER; KAMI KIM; VERN B. CARRUTHERS

Foz do Iguassu, Paraná

Conferencia; The IXth International Coccidiosis Conference; 2005

Fundação APINCO de Ciência e Tecnologia Avícolas

Coccidian parasites including Toxoplasma gondii cause widespread infections and disease in humans and animals. The need for new therapeutic agents along with the fascinating biology of these parasites has fueled a keen interest in understanding how key steps in the life cycle are regulated. Proteolysis is intimately associated with cell and tissue invasion by these obligate intracellular parasites and recent studies have begun to identify the proteases involved in these processes. Based on clues from inhibitor experiments and cleave site mapping studies, we and others are using emerging genome information and molecular genetics to identify and validate proteases that regulate secretory organelle biogenesis and invasion protein activity. These studies are revealing roles for a variety of proteases including cathepsins, subtilases, and rhomboids in cell and tissue invasion. The identification of highly selective inhibitors for these proteases has the potential to not only further dissect their role in infection but also to potentially prevent or ameliorate disease.