Current Research and Scholarly Interests
Studies on the cell and molecular biology of parasitic protozoa are critically important for two reasons; first, these organisms are major pathogens of humans and anaimals and, second, they have proven to be a source of some remarkable phenomena that have challenged much of the dogma thought to be universal in eukaryotic biology. We have been studying two of these single-celled eukaryotes, Trypanosoma brucei and Toxoplasma gondii. Each has its own features that make it interesting to the scientist and both are major pathogens, trypanosomes being the cause of sleeping sickness in Africa and Toxoplasma being a major opporunistic pathogen of AIDS patients. As of, 1998, however, we have focused our entire effort on Toxoplasma because of its growing importance and our results developing this system for modern genetic analysis (we now have a full genetic "toolbox" for this intracellular parasite including a genetic map, efficient genetic transformation and gene knock-out).
The major areas where the lab is currently working are:
(i) Intracellular parasitism: how does this parasite attach, invade and reproduce within virtually any nucleated cell.
(ii) Protein trafficking; how are proteins destined for novel secretory organelles specifically targeted and, ultimately, injected into the host cell during invasion?
(iii) Developmental biology; what genes are crucial for asexual development from the actively dividing to the latent form of the parasite and what are the cis- and trans-elements that control that expression.
(iv) Host-pathogen interaction: what changes occur in the host cell in response to infection?
(v) Pathogenesis: what properties make certain strains more virulent than others?