Scientists have figured out why the indigenous people of the Amazon almost never suffer from the Chagas infection. Reported by the Spanish University Pompeu Fabra.
Chagas disease, or American trypanosomiasis, is a dangerous disease caused by single-celled parasites. Trypanosoma cruzi. It is common in Latin America and is mainly carried by triatomine beetles. Trypanosomiasis is one of the leading causes of death in the region, but indigenous peoples of the Amazon Basin have an innate immunity to it.
The study analyzed genomic data of 118 modern humans from 19 different indigenous populations of the Amazon to find traces of genetic adaptation to rainforest environments. As a result, the scientists found signs that the PPP3CA gene was responsible for this. This gene encodes a key protein that is important for immune cell activation, innate immune response, and parasite internalization. T. cruzi in human cells. In Amazon residents, a particular variant of this gene appeared to be expressed in heart tissues and immune cells.
The scientists conducted functional studies of heart tissue mimicry using stem cells, some of which contain the desired variant of the PPP3CA gene. It turned out that in the presence of this genetic trait, the internalization of the parasite in heart cells was less pronounced.
“Presence [защитного] The scientists explain that a variant of the PPP3CA gene may be responsible for a milder form of the disease or fewer infections in these populations.
According to the authors, natural selection of people resistant to Chagas disease began 7,500 years before the Amazon population split from the populations of the Andes and Pacific coasts.