Toxoplasmosis: new research findings from the Sheiner Group

Toxoplasmosis: new research findings from the Sheiner Group

Issued: Mon, 20 Feb 2017 12:00:00 GMT

Mitochondria are important structures within cells that synthesise and process nutrients as well as other types of molecules that are essential for cell function.  The activities of a cell are influenced by the distribution of mitochondria and the sub-cellular ‘contacts’ mitochondria make with other cell components.

New research carried out by the Sheiner Lab and published in Nature Scientific Reports has investigated the shape, location and distribution of Toxoplasma mitochondria during the lytic cycle. This is the phase of the Toxoplasma lifecycle where the parasite invades the cell of another organism. The aim of this study was to determine if any consistent mitochondrial behaviours occur that might be linked to other changes that are observed during the lytic cycle.

Experimental work showed that the parasite mitochondrion undergoes significant changes of shape and distribution when it is within the host cell.  It also appears to interact with the parasite’s unique pellicle – the thin layer that supports the cell membrane. This interaction suggests an exchange of nutrients or signalling between the organelles.  However, once the parasite is out of the host cell, this interaction is significantly reduced.

Toxoplasma Sheiner Nature paper

This work also highlights a potential link between the observed mitochondrion behaviour and the concentration of calcium. Calcium levels are known to play an important role the movement of the parasite, and thus influences its virulence.

The work has raised a number of important questions which are currently being investigated by the Sheiner Lab. Of particular interest, is the relationship between the mitochondria and the pellicle at the various stages of the Toxoplasma lifeycle. Addressing these fundamental questions will advance our understanding of how the parasite’s components function to enable its survival.  This work may also shed light on how mitochondria in any cell type communicates with other organelles. An area that has yet to be explored in detail.