In:
eLife, eLife Sciences Publications, Ltd, Vol. 6 ( 2017-09-19)
Abstract:
There is a huge international effort to combat malaria, but even today almost half a million people die from the disease each year, mostly young children in Africa. Malaria infections are caused by the parasite Plasmodium, which is spread by mosquitoes. The Fulani are an ethnic group of people from West Africa that are naturally better at fighting malaria infections with the most dangerous form of the parasite, Plasmodium falciparum. Fulani show fewer symptoms of malaria and carry fewer parasites when they are infected. They also have fewer cases of sickle cell disease, a condition that is known to protect against malaria. Yet, no one understands what it is that makes Fulani more resistant to malaria than other people, such as people of other ethnic groups that live in the same region of West Africa but who do not intermarry with the Fulani. Past studies that looked at likely genes, such as those involved in the immune response, could not find any differences between the Fulani and people who have a normal susceptibility to malaria. Quin, Bujila et al. performed a pilot study to look at the activity of all the genes in immune cells from Fulani people who had become naturally infected with P. falciparum to see which genes are switched on or off after an infection. If some genes are used differently in the Fulani compared to other ethnic groups, then it is likely that these genes are responsible for the Fulani’s more effective immune response to P. falciparum. First, Quin, Bujila et al. looked for chemical markers that are naturally added to DNA to influence the activity of nearby genes, and used other methods to determine which genes are switched on and at what level. Unexpectedly, for those markers looked at, no difference was found between the ethnic groups investigated. However, the other experiments did show that in a certain type of immune cell in the Fulani over 1,000 genes become notably more active, or less active, after P. falciparum infection. These cells, called monocytes, are important for the immune system’s first line of defence, which begins the attack against an infection and alerts the rest of the immune system. Lastly, inflammation is a common part of the body’s immune response to many parasites. When Quin, Bujila et al. measured the level of inflammatory molecules, they found that Fulani have higher levels of molecules that promote inflammation than other ethnic groups. Together these results suggest that a group of genes in the monocytes of Fulani are set in a ‘primed’ state, which helps monocytes to drive the fight against P. falciparum more effectively. The cause for the heightened primed state remains unclear, but previous studies looking into bacterial and fungal infections have shown early infections can prime the immune system to promote more inflammation during a second infection. These new findings suggest that such processes might also occur for malaria infections, and so might represent a new avenue of research in the quest for better treatments for malaria.
Type of Medium:
Online Resource
ISSN:
2050-084X
DOI:
10.7554/eLife.29156.001
DOI:
10.7554/eLife.29156.002
DOI:
10.7554/eLife.29156.003
DOI:
10.7554/eLife.29156.004
DOI:
10.7554/eLife.29156.005
DOI:
10.7554/eLife.29156.006
DOI:
10.7554/eLife.29156.007
DOI:
10.7554/eLife.29156.008
DOI:
10.7554/eLife.29156.011
DOI:
10.7554/eLife.29156.009
DOI:
10.7554/eLife.29156.010
DOI:
10.7554/eLife.29156.012
DOI:
10.7554/eLife.29156.014
DOI:
10.7554/eLife.29156.013
DOI:
10.7554/eLife.29156.015
DOI:
10.7554/eLife.29156.016
DOI:
10.7554/eLife.29156.017
DOI:
10.7554/eLife.29156.018
DOI:
10.7554/eLife.29156.021
DOI:
10.7554/eLife.29156.022
Language:
English
Publisher:
eLife Sciences Publications, Ltd
Publication Date:
2017
detail.hit.zdb_id:
2687154-3
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