A new study reports SIV strains worn-chimpanzees can infect human cells -
Nobody knows exactly how it happened. He may have entered through a cut or bite, blood oozing from a chimpanzee in a finger or forearm or foot exposed.
But in the early 100s, probably near a tropical forest in West Africa, it is believed that a hunter or seller of bushmeat - wild game which may include primates - the acquisition of the first strain of simian immunodeficiency virus that virologists consider the ancestor of HIV
a new study by the University of Nebraska-Lincoln has supported this. hypothesis by comparing the first in vivo evidence that the SIV strains of worn-chimpanzees can infect human cells. They include SIV ancestor of HIV-1 M - the strain responsible for the global HIV -. And one ancestral strain of HIV found that among residents of Cameroon
However, the researchers found further that the ancestors of SIV two unidentified strains of HIV in humans have also managed to invade cells human after multiple exposures in the laboratory.
"the question was whether the SIV strains that were not found in humans have the potential to cause another HIV-like," said lead author Li Qingsheng, associate professor of biological sciences and a member of the Nebraska Center for Virology. "the answer is that in fact they do. They reproduce at a very high level. It is surprising. "
Li and his colleagues came to the conclusions after inoculation of mice that were implanted with human tissues and stem cells, which stimulated the growth of other essential cells the human immune system. to explore why humans have developed some HIV strains, while avoiding others, the team injected low doses of four SIV strains in mouse separate groups.
the authors found that SIV inferred precursors of HIV-1 M and Cameroon specific strain required fewer opportunities to infect the mice that did both SIV strains whose descendants HIV have not been found in humans.
According to Li, this may be because the genetic makeup of the latter two strains more different HIV-1 M than does the Cameroon strain, which shares many genes with the pandemic cousin.
"based on our experiences, we see clearly the differences between the strains," said Li, whose team collaborated with Frederick for Cancer Research National Laboratory. "This implies that there may be differences in the probability of interspecies transmission when a person is exposed to a strain with respect to another." The team also found evidence of the concept of long suspected that SIV strains mutate into entering cells humanity to overcome specific barriers to infection. Within 14 weeks, the same viral gene in two different SIV strains - including the ancestor of HIV-1 M - has regularly undergone mutations in two key positions on this gene
Li and principal author Zhe Yuan, PhD student. in biological sciences, said the recent outbreak of Zika virus - which has remained relatively quiet for decades after its 1947 discovery in a monkey - highlights the value of pre-emptively virus identification that can jump from animals to humans
. "The emergence and reemergence of infectious diseases has become a constant threat to global health, social stability, security and economic systems," said Li. "Bill Gates said recently that nuclear war is the ( bigger) threat to our security; .. emerging infectious diseases are This is probably true "
the experimental approach used by the team could help assess the threat posed by additional SIVs and many other animal viruses transported, Yuan said. This could be particularly important given the dynamic nature of HIV and other zoonotic diseases, he said, many of which have caused new epidemics or even pandemics.
"I think that analysis of the disease is very important for public health," said Yuan, noting that a new group of strains of HIV was discovered in 09. "We want to explore this platform Platform for the evaluation of new, emerging infectious diseases. "
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