动物造模,艾滋病样病毒 z-bo 2020-09-09 341

　　Beat Beatrice H. Hearne is a professor of medicine and microbiology at the Perelman School of Medicine at the University of Pennsylvania. Her colleagues have been studying the origin of HIV-1 in non-human primates for decades. They previously found that the Simian Immunodeficiency Virus (SIV) that infects wild chimpanzees and gorillas has crossed the species barrier four times in humans, and one of them caused the AIDS epidemic. Understanding how these viruses spread within and between species may reveal clues to new human vaccine strategies. HIV and SIV die by infecting immune cells called CD4 T cells. A report published this week at the International Conference of the Hahn Institute and the National Academy of Sciences found that in wild chimpanzees, the CD4 surface protein that HIV and SIV use as receptors for entry into immune cells are very different. done. .. They identified the feces of more than 500 chimpanzees in sub-Saharan Africa and were surprised to find 9 CD4 variants. They continue to show that this CD4 diversity can protect chimpanzees from potentially dangerous SIVs carried by their own SIV strains and other monkey species they prey on.

　　SIV has been infected by more than 40 primates in sub-Saharan Africa and can be fatal. Hahn's team has shown in previous studies that wild chimpanzees infected with SIV have a higher mortality rate than uninfected chimpanzees and may develop AIDS like humans. I'm.

　　Said: "It is well known that CD4 develops rapidly in primates, but the reason is not clear." "We have now found that mutations in CD4 of chimpanzees reduce the susceptibility to SIV infection, which may be the apes carrying these CD4 variants. Classes provide selective benefits. The protein binds to the outermost region of the CD4 receptor. “To counteract this, chimpanzees produce several mutations in the CD4 region that interfere with this interaction,” Hahn’s laboratory Said. Ronnie Russell (Ronnieussell), a PhD student research team discovered that these mutations involve amino acid changes in contact residues and the addition of large sugar molecules called glycans to the CD4 envelope binding interface. The Hahn Institute of Microbiology Author Frederic Bibollet-Ruche said: "The glycans of the chimpanzee CD4 compete with the glycans of the SIV envelope to prevent the virus from entering the cell. ".. This type of glycan-glycan interaction has never been considered an antiviral mechanism. Unlike chimpanzees, humans lack protective glycans in the virus-binding domain of the CD4 protein. University of Edinburgh (University of Edinburgh) Evolutionary biologist Paul said: "This may explain our relative sensitivity to SIV interspecies infections that have occurred at least 12 times in the last century. "Dr. Sharp said. Although the SIV height of IV chimpanzees is different from that of human SIV, previous research by Hahn's group has shown that there is unexpected antibody cross-reaction with HIV at the tip or tip of the envelope spike. I will. This finding provides that. The potential of combining HIV and SIV envelopes to focus the protective antibody response on this conservative epitope of the vaccine. The University of Pennsylvania Medicine and Microbiology co-authors, MD, MD, and PhD said: "Understand the differences in chimpanzee CD4 How to affect the structure and function of the chimpanzee SIV envelope is an important part of it. This is actually very important for development. "

　　The research association that conducted this research includes primatologists working to protect chimpanzees in the wild. Khan said: “The many samples provided by our collaborators helped us discover the techniques chimpanzees use to protect themselves from SIV.” “In the end, this may help design better HIV vaccines. This is a long process. , But it combines all our efforts in the biology and evolution of HIV ape precursors."