In an effort to further understand the spread of HIV, researchers at the Feinberg School of Medicine are dredging up the virus’s century-long history.
New research indicates that the most widespread strain of the virus, HIV-1 group M, began circulating among humans sometime between 1884 to 1924, an estimate that predates the previous approximation of 1930. The study, led by Feinberg and the University of Arizona, was published in the Oct. 2 issue of “Nature.”
The investigation involved the analysis of HIV gene fragments from a lymph node tissue biopsy from an adult female taken in 1960. The sample, obtained from Kinshasa, Democratic Republic of the Congo, is the world’s second-oldest genetic sequence of HIV-1 group M. Along with the biopsy, researchers used a number of other specimens to create “calibration points,” which they use as benchmarks for drawing out the virus’s history.
“We go back in time,” said Dr. Steven Wolinsky, professor in the Division of Infectious Diseases at Feinberg and one of the researchers who worked on the project. “This research gives us a finer perspective on when the virus expanded in the human population.”
The oldest known sequence of the HIV-1 group M sequence came from a blood sample taken in 1959, also in Kinshasa, and provided further evidence of a common ancestor among the many HIV strains that may have emerged around 1900.
“It’s very nice that two data sets both point to the same time frame,” said Bette Korber, a laboratory fellow at Los Alamos National Laboratory and visiting professor at the Santa Fe Institute in New Mexico. Although Korber didn’t work with Wolinsky on the study, she worked with him on similar research conducted nine years ago. Their previous collaboration yielded findings close to those of the current study but used a different methodology.
“Time-wise and geographically, we’re at the right point,” Wolinsky said, referring to the current findings.
The current estimates drawn by Wolinsky cannot definitively state that the first outbreak of HIV occurred during the African period of urbanization around 1900. According to Paul Sharp, professor of genetics at the University of Edinburgh in the United Kingdom, it may be challenging for researchers to figure out when the first human-to-human transmission of HIV occurred. But it may not be possible to locate the first instance of when the primate counterpart of HIV, Simian Immunodeficiency Virus, transferred to humans.
“This work is important in that it provides direct confirmation that HIV-1 had been spreading and diversifying in humans for decades prior to 1960,” Sharp said in an e-mail interview.
Korber called the study “a heroic effort” and a health lesson for the public.
The data revealed in the study could also be used to create a vaccine based on the commonalities all the different HIV strains share, Wolinsky said. Regardless, he said, future research is needed to further understand the full history of HIV.
“It’s like archaeology,” he said. “You just keep on digging.”
