HIV-like Virus May Have Infected Primates for 16 Million Years

It turns out that apes may have been infected by a HIV-like virus for millions of years. Researchers have taken a closer look at viruses and found that primates in Africa may have had this virus as far back as 16 million years.

The researchers, in this case, were interested in the history of lentiviruses, which is the group of retroviruses to which HIV and its simian relatives, SIVs, belong. In order to learn a bit more about this group, the researchers focused on an antiviral gene called TRIM5. TRIM5 is part of a group of antiviral genes called "restriction factors," which have evolved to protect host cells from infection by viruses. Its product, the TRIM5 protein, interacts directly with the outer shell of lentivirus particles after they enter the host cells and prevents the virus from multiplying there.

The researchers hypothesized that the evolution of TRIM5 in African monkeys should reveal selection by lentiviruses closely related to modern SIVs. To derive an evolutionary tree of the TRIM5 gene, they analyzed and compared its complete protein-coding DNA sequences from 22 African primate species. In the end, they identified a cluster of adaptive changes unique to the TRIM5 proteins of a subset of African monkeys. This suggests that ancestral lentiviruses closely related to modern SIVs began colonizing primates in Africa as far back as 11 to 16 million years ago.

"The correlation between lineage specific adaptations and ability to restrict viruses endemic to the same hosts supports the hypothesis that lentiviruses closely related to modern SIVs were present in Africa and infecting the ancestors of cercopithecine primates as far back as 16 million years ago, and provides insight into the evolution of TRIM5 specificity," write the researchers in a news release.

The findings are published in the journal PLOS Pathogens.

Related Stories

HIV: Despite Treatment, Virus Silently Grows Still

HIV Protein Structure Unraveled by Scientists: New Treatments Possible

For more great science stories and general news, please visit our sister site, Headlines and Global News (HNGN).