Researchers have found a gene in Africans that slows the development of HIV
Geneticists have explained why some people of African descent have lower HIV viral loads and slower disease progression.An international team of researchers has discovered a genetic variation that slows HIV replication in the body cells of some people. The discovery explains the reason for the low viral load and transmission risk, as well as the slower progression of the disease in these people. The gene could be used to develop new therapies for HIV.
Geneticists analyzed the DNA of nearly 4,000 people of African descent living with HIV-1, the most common type of the virus. They found the CHD1L gene on chromosome 1, which correlates with a reduced viral load in carriers of this variant. An estimated 4-13% of people of African descent have this gene modification.
CHD1L has previously been shown to play a role in repairing damaged DNA. To investigate why it has an effect on reducing viral load, the researchers created cells with stem cells that could be infected with HIV. In some of them, the researchers turned off CHD1L; in others, its activity was artificially reduced.
The analysis showed that in the immune cells macrophages, in which CHD1L was turned off, HIV replicated better. Meanwhile, in the other defense component, T cells, the genetic change had no effect on how the virus worked. This is surprising, the scientists note, because most HIV replication occurs in these cells.
"Although we don't yet know how it (the gene, Haitech notes) does it, every time we discover something new about HIV control, we learn something new about the virus and the cell. The link between HIV replication in macrophages and viral load is particularly interesting and unexpected," Harriet Groom, co-author of the study.