Research also shows HIV-2 and related simian immunodeficiency virus (SIVsm / mac) are able to overcome the protection mechanism of myeloid cells by using the proteins they encode VPX, for SAMHD1, allowing and infection by these viruses. Interestingly, viruses with VPX, such as HIV-2, are much less pathogenic HIV-1. This could be due to the fact of being able to establish infection in myeloid cells that cause reactions much more robust immune system against HIV-1 only, since HIV-1 can not infect cells efficiently Dr. Skowroński said.Researchers at Case Western Reserve University School of Medicine have discovered a long sought cellular factor that functions to inhibit HIV infection of myeloid cells, certain white blood cells that display antigens and are therefore important for the immune response against viruses and other pathogens.
‘The identification of SAMHD1 and function may help explain why some infected individuals can control HIV infection better than others,’ said Dr. Skowroński. ‘Finally, it could also provide a basis for the development of new therapies and therapeutic approaches to block HIV infection and / or its replication in infected individuals, the body and stimulate the immune response to HIV.’
Prior to this research, the normal operation of SAMHD1 was thought to be the prevention of inappropriate activation of a class of anti-viral response mediated by the production of antiviral factors called interferons, in the absence of infection with the virus. SAMHD1 and other mutations in two genes that encode cellular nucleases, TREX1 and RNase H2, causing a condition called Syndrome-Acairdi Goutieres (AGS). The condition mimics congenital viral infection and is due to induction of immune interferon unjustified absence of the virus. SAMHD1 and other proteins in AGS cells, causing work to remove cell debris, nucleic acids, thus preventing the inappropriate activation of the interferon system.
As a result, ‘It could be that the treatment of SAMHD1 function in the context of HIV-1 can lead to more robust immune response to this virus,’ said Dr. Skowroński.
The results are displayed in a manuscript published in the June 30 issue of Nature with Dr. Skowroński as the main newspaper. The research was conducted in his laboratory at Case Western Reserve, in collaboration with a research team led by Michael P. Washburn, Ph.D., Stowers Institute for Medical Research in Kansas City.
In the work described in the manuscript of Nature, researchers led by Dr. Skowroński found that in addition to preventing inappropriate autoimmune reactions, such as those seen in AGS, SAMHD1 has the ability to inhibit HIV infection by myeloid cells effectively interfering with the production of viral nucleic acids. With this action may prevent activation SAMHD1 effective immune responses to HIV-1 infected individuals, said Dr. Skowroński.
Factor, a protein called SAMHD1, is part of the nucleic acid detection in machinery of the body’s immune system. Keeps the cells the activation of immune responses specific nucleic acids in cells, preventing certain forms of autoimmunity to develop.