A team of researchers led by the University of Nebraska-Lincoln found that the simian immunodeficiency virus (SIV) from chimpanzees, the ancestor of HIV, can infect humans. This discovery supports the theory that HIV originated from chimpanzees.

It is widely supported that HIV came from chimpanzees, although it remains unclear whether the virus got passed on through blood contact, cut or bite wound. The first person who got infected is believed to be a hunter or vendor of bush meat, which included primates, residing near a West African rainforest.

The findings now published in the Journal of Virology supports this hypothesis. The researchers found that the SIV ancestor of the HIV-1 M, the strain that caused the global HIV pandemic, can be transmitted to human cells.


From left, Wenjin Fan, Qingsheng Li, Zhe Yuan and Guobin Kang. Credit: University Communications|University of Nebraska-Lincoln

The team also found that the SIV ancestor of the HIV strain only found among Cameroon residents can also transmit to humans. Moreover, the SIV ancestors of two HIV strains not known to infect humans have also been observed to infect human cells after multiple experiments.

“The question was whether SIV strains that have not been found in humans have the potential to cause another HIV-like infection,” points out the study’s senior author Qingsheng Li, an associate professor of biological sciences and member at the Nebraska Center for Virology. “The answer is that, actually, they do. They get replicated at a very high level. It’s surprising.”

The study involved using mice implanted with human tissues and stem cells. The human tissues and stem cells allowed the growth of other cells necessary to build a human immune system.

The findings could help scientists accurately estimate the potential threat other SIVs and many animal-carried viruses can have on humans. Lead author Zhe Yuan believes that their study can be used to evaluate new and emerging infectious diseases. This knowledge can help prevent epidemics or pandemics that take too many lives.