| Salinispora tropica |
| PARASITOLOGY Dinner at 7? Of the various tricks that parasites use to fool host immune systems, here is a new one: the parasite that causes leishmaniasis (kala azar), coaxes the immune system to feed it instead of killing it. When an infected sandfly bites a human it transfers the parasites along with a sticky gel produced by them. Immune cells are then released at the site. These cells usually produce nitric oxide to kill the pathogens. In this case, the researchers found they produced polyamines--food for the parasite. On further research, they found the sticky gel responsible in helping the parasite establish this connection with the immune cells. The same gel protects the parasites from the fly's defences. (PLoS Pathogens, August 20) |