The MicroRNA War

Both parasites and host defense mechanisms use microRNA for their own ends, say Mohamed-Ali Hakimi and Robert Ménard in The Scientist. The researchers write that there is evidence that hosts use miRNA to fend off attacks from parasites including Plasmodium falciparum, Cryptosporidium parvum, and Toxoplasma gondii. But the parasites may have evolved ways to circumvent those attacks. Toxoplasma, they say, has "an elaborate RNA silencing machinery" and "it's possible that Toxoplasma uses its own host-like miRNAs to hijack the target cell's miRNA defense pathway."