Research

Chaperone safeguards Leishmania's survival

Although it is usually very hot in their homelands, parasites that are transmitted by insects must survive a heat shock when they encounter humans or other warm-blooded organisms. With temperatures exceeding 40°C, our bodies are much hotter than the insects’ or the tropics.

Leishmania at body temperature. Its nucleus (n) and a DNA-containing organelle (k) is marked in blue and chaperone HSP23 labelled in red. HSP23 is concentrated around the nucleus.
Leishmania at body temperature. Its nucleus (n) and a DNA-containing organelle (k) is marked in blue and chaperone HSP23 labelled in red. HSP23 is concentrated around the nucleus.

A „heat shock“ is well known from experimental research – it is a standard method to subject living cells to stress. The cells then produce an entire range of proteins known as chaperones, which prevent other proteins from clumping and the cell from dying. The heat shock encountered by the transmission from insects to humans helps Leishmania parasites to survive an additional gross change in their living conditions: while they can move freely in the sandfly insects, in humans they prefer to live inside cells, namely phagocytic cells of the immune system. We have now found that a small chaperone called HSP23 is essential for the survival of Leishmania in human cells. If it is eliminated by gene knock-out, the parasites die at body temperature and when re-introduced, the gene enables them to survive again. Accordingly, the chaperone protects the nucleus of the parasite from heat damage and is therefore a promising target for new anti-parasitic drugs.

 


Hombach A. et al., J Cell Sci 2014, 127:4762-73

Antje Hombach, Gabi Ommen, Andrea MacDonald and Joachim Clos