A review on CRISPR/Cas9 system for the research and control of helminth parasites

2020-11-20 11:51

Globally, parasitic helminths afflict billions of people and die of resulting complications every year. Currently, no effective vaccines are available for human use against any of these parasitic worms. The limited chemotherapy options for treatment of the diseases caused by parasitic helminths increase the risk that drug resistance will develop. It is, thus, important that improved control strategies be developed using advanced techniques that can mitigate this 21st-century threat to global health through the identification of novel drugs or vaccine intervention targets.

Recent reports of CRISPR/Cas9 (Clustered Regularly Interspaced Short Palindromic Repeats/CRISPR-associated protein form adaptive immunity system of bacteria and archaea to prevent bacteriophage) gene editing technology in parasitic helminths open up new avenues for research on these dangerous pathogens. It has been successfully established in four free-living nematodes, three parasitic nematodes and two parasitic trematodes (Table 1).

However, the complex morphology and life cycles inherent to these parasites present obstacles for the efficient application of CRISPR/Cas9-targeted mutagenesis. This is especially true with the trematode flukes where only modest levels of gene mutation efficiency have been achieved. Major challenges in the application of CRISPR/Cas9 for study of parasitic worms thus lie in enhancing gene mutation efficiency and overcoming issues involved in host passage so that mutated parasites survive, and developing strategies of gene editing using CRISPR/Cas9 system on them, for example, novel delivery methods, the choice of selectable markers and refining mutation precision represent novel tactics. Recently, Du X et al. review and summarize information of helminth parasites genome editing [1].


Table 1 Use of CRISPR/Cas9 editing system in helminths



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