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Global Parasitology Seminars

Jeroen Saeij, PhD

Parasitology Seminar Series - Jeroen Saeij, PhD


Parasitology Seminar Series

Title: “Identification of novel Toxoplasma virulence factors using CRISPR/Cas9-mediated loss-of-function screens"

Speaker: Jeroen Saeij, PhD
Associate Professor of Pathology, Microbiology and Immunology
University of California, Davis

Date: Monday, November 11, 2019
Time: 12-1 pm

Lunch with students/speaker, 1:00 p.m. in Hill 111

132 Hill Pavilion
University of Pennsylvania School of Veterinary Medicine
380 S University Avenue, Philadelphia, PA 19104

Abstract: The obligate intracellular parasite Toxoplasma gondii can cause life-threating disease in the developing fetus and in immunocompromised individuals, such as those suffering from AIDS, and blindness in otherwise healthy individuals. The acute stage of infection is caused by rapidly dividing tachyzoites, which disseminate from the site of infection to distant organs. Eventually, the parasite converts to encysted bradyzoites, especially in the brain, that underlie the lifelong chronic phase of the infection. To survive and replicate in its host and reach the brain, Toxoplasma needs to evade the host immune response, acquire host nutrients, disseminate to distant organs, survive and replicate in those organs and convert to encysted bradyzoites. The complete set of Toxoplasma genes involved in these processes is unknown. We have used in vitro and in vivo CRISPR/Cas9-mediated loss-of-function screens in Toxoplasma to identify these genes. Novel Toxoplasma genes that mediate in vivo dissemination, evasion of the immune response, or nutrient acquisition will be discussed.

Brief Bio: Dr. Saeij is interested in host-pathogen interactions and the genetics of susceptibility to infectious disease. As a Ph.D. student he studied the genetics of resistance of carp to infection with blood flagellates (Trypanosoma carassii and Trypanoplasma borelli) in Geert Wiegertjes‘ lab at Wageningen University in The Netherlands. As a postdoctoral fellow in John Boothroyd’s lab at Stanford, he studied the genetics of Toxoplasma strain differences in virulence and modulation of the host cell. Dr. Saeij started my own lab at MIT in 2007 and he received tenure at MIT in 2014. Currently the Saeij lab is at the Department of Pathology, Microbiology & Immunology at The University of California, Davis. His group studies susceptibility to infection with apicomplexan parasites, which is determined by a complex interplay between host and parasite.

Please contact Sue Waddington-Pilder ( to arrange to speak with Dr. Saeij.  

Date and Time


Susan Waddington-Pilder