MRC National Institute for Medical Research, London

Science for Health

Migrating neurons in the cerebral cortex

Main navigation

Research areas

Genetics and Development

Infections and Immunity

Neurosciences

Structural Biology

Eva Frickel group project:

Identification and characterization of other mechanisms that modulate the PVM to enhance antigen presentation and restrict Toxoplasma replication

Different strains of Toxoplasma have been shown to differ in their ability to evade IFNγ-mediated destruction in vitro. In mice, Type I Toxoplasma (RH strain) is highly virulent with an LD100 of 1 parasite, while type II (Pru, ME49) and III strains (CL14) are less virulent, with an LD50 greater than 1000 parasites/mouse. The time course of parasite elimination in vivo is not understood.

We will identify transcriptionally activated or suppressed host targets, and look for expression profile differences between the various Toxoplasma strains. This could unveil novel mechanisms that curb the parasite's growth in vivo, and show variation between the different parasite strains that might help explain the difference in virulence.

Click image to view at full-size

Toxoplasma-vaccine strain-primed mice do not eliminate Toxoplasma in a completely strain-dependent fashion in vivo. B6 mice were primed with 10⁶ tachyzoites of RH cps 1-1 (replication deficient) on day 0, followed by a boost with 10⁵ parasites on day 4. On day 7 the animals were infected with luciferase expressing versions of Toxoplasma type I (RH), type II (ME49) and type III (CL14). A) At the indicated times p. i. mice were dosed with 3 mg firefly luciferase and imaged using an in vivo imaging system (IVIS, Xenogen). B) Total number of photons per second were measured by drawing a region of interest around each mouse. The resulting numbers are plotted versus the time p.i..