Live Vaccine for Toxoplasmosis: CRISPR in Action

Around a third of the world's population carries Toxoplasma gondii, a parasite that puts people with a weakened immune system at risk and can trigger malformations in the womb.

Modified CRISPR-Cas9 gene editing scissors are enabling researchers to make alterations to the genetic material of single-cell organisms that are indistinguishable from natural mutations. This method is making it possible to develop a (harmless) experimental live vaccine for the widespread parasite Toxoplasma gondii.

Using CRISPR-Cas9, University of Zurich researchers have developed a live vaccine for Toxoplasma gondii, a common parasite.

The team handled CRISPR-Cas9 differently from previous methods and assembled it outside of the cell. The genetic material, which is placed directly in the parasites, is completely fragmented very quickly, allowing the genomic sequence to be changed without leaving a trace in the cell.

The study, published in the Journal of Biological Methods, says we can now produce experimental live vaccines without plasmids or creating resistance genes.

Reference: Rahel R. Winiger and Adrian B. Hehl. A streamlined CRISPR/Cas9 approach for fast genome editing in Toxoplasma gondii and Besnoitia besnoiti. Journal of Biological Methods, 2020. http://doi.org/10.14440/jbm.2020.343
https://www.media.uzh.ch/en/Press-Releases/2020/Toxoplasmosis.html