Parasitic Free Pass

Sleeping sickness kills thousands of people annually in sub-Saharan Africa. Usually transmitted by the tsetse fly, the culprit is a parasite called Trypanosoma brucei, which multiplies wildly in the blood before moving on to the brain. Scientists are figuring out how the parasite undermines the host’s immune system. They’ve found that it tricks the body’s protectors to give it a free meal and an easy ride. During the early stages of infection in mice, T. brucei releases a protein called TbKHC1. This gloms onto a receptor on myeloid white blood cells – pictured here in a mouse liver, with T. brucei in blue – to stimulate the production of parasite-sustaining nutrients. The same protein later stops myeloid cells from making nitric oxide to kill the parasite. If researchers can find a way to block TbKHC1, they could potentially boost immunity against this deadly invader.

Written by Daniel Cossins

Daniel Cossins

Writer

As a freelance science writer, Dan's work has been published in award-winning magazines including BBC Focus, Wired UK, Cosmos, BBC Knowledge, BBC History and Men's Health.

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• Image provided courtesy of Science Photo Library
• Any re-use of this image must be authorised by Science Photo Library
• Research published in PLoS Pathogens, October 2013