Patricia J. Johnson
University of California, Los Angeles
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Primary Section: 61, Animal, Nutritional, and Applied Microbial Sciences Secondary Section: 44, Microbial Biology Membership Type:
Member
(elected 2019)
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Biosketch
Patricia J. Johnson is a parasitologist recognized for her research on Trichomonas vaginalis, the eukaryotic microbe responsible for the most prevalent, non-viral, sexually-transmitted infection worldwide. Her research has focused on organelle biogenesis & evolution, gene expression, drug resistance, genomics and host: pathogen interactions. Johnson grew up in a small farming community in the Appalachian Mountains of Virginia. She attended the University of Virginia and graduated from Murray State University with a BS degree in biology and the University of Michigan with a PhD degree in Cellular and Molecular Biology. She was a postdoctoral fellow at The Netherlands Cancer Institute and The Rockefeller University before joining the faculty of the University of California, Los Angeles. Johnson is a member of both the American Academy of Microbiology and the National Academy of Sciences.
Research Interests
Patricia J. Johnson's laboratory has studied many aspects of the human-infective parasite Trichomonas vaginalis, including organelle evolution, gene expression and host: parasite interactions. Dr. Johnson also led an international team to sequence and annotate the parasite's genome, uncovering new biological properties and opening new avenues of research. T. vaginalis represents the earliest-diverging lineage of extant eukaryotes and is considered an ?ancient eukaryote?. Studying the biogenesis & evolution of an unusual organelle in T. vaginalis, her group demonstrated that these ancient eukaryotes possessed the precursor organelle that gave rise to mitochondria. The Johnson lab also defined structural and functional components critical for gene regulation in T. vaginalis. These components are highly divergent from those in other eukaryotes, revealing properties that can be used for therapeutic exploitation. Host: parasite interactions were characterized through studies of parasite surface glycans and host receptors that recognize these glycans. These interacting molecules play critical roles in infection by mediating parasite adherence and lysis of host cells. Professor Johnson's group has also examined small microvesicles, called exosomes, that are secreted by the parasite and deliver cargo to the host cell. Exosomes assist in parasite colonization and elicit immune responses that may combat parasite clearance. Her group recently showed that human neutrophils use trogocytosis, a process in which neutrophils kill T vaginalis by taking 'bites' out of the parasite, thus revealing a new mechanism used by immune cells to kill a pathogen.
