New intermediate protein which facilitate attachment of HIV over CD4 and its 3D structure reveled.
An intermediate temporary protein found in the process of infection of HIV virus to CD4 cell, this protein can be used in the development of vaccine against HIV. This temporary protein is occurs just before the attachment of HIV virus to CD4 cell.
The finding of this intermediate protein is very important for further development of antiretroviral drugs and vaccines; this can be very successful target for developing antiretroviral drug of category attachment inhibitors, and for further developments of neutralizing antibodies against HIV, and HIV vaccine as well.
The process of infection of HIV to CD4 cell is a complex one, it involves various steps, there are proteins over HIV core which first unbound and attach themselves over CD4 receptors over surface of lymphocytes followed by penetration and so on.
Developing a vaccine against HIV, which when given to human can stimulate development of antibody response in human body against incoming HIV infection through out human life, which will successfully protect human from incoming HIV virus infection is still a dream , which is yet to be achieved since the protein envelop of HIV keep on changing, Still there are certain points over HIV virus envelop which do not change but they are hindered by proteins preventing their presentation to immune system.
To overcome these hurdles in developing HIV vaccine a team from NIH's National Cancer Institute (NCI) led by Dr Dr. Sriram Subramaniam studied the structures of all proteins in the process of HIV infection, they used a technique known as cryo-electron microscopy where in the whole virus or purified viral proteins are frozen rapidly so that the Ice stays liquid like, in this technique proteins do not alter in there special orientation and do not get any damage still making available as rigid sample for observation this special frozen sample enable us to see the life like images of these proteins when observed under electron microscope.
Dr. Sriram Subramaniam and his team compared there dimensional structure of HIV virus envelop as well as protein which binds with CD4 receptor as well as to an antibody which mimics CD4 co- receptor, it was found that when HIV envelop is bound by any one of receptor the gycoprotien is transformed in to an activated state where 3 helical spring out in the center of HIV envelop, This activated protein is found between inactive position (which is not bound) and the immediate next structure of HIV Envelop, which occurs just after fusion.
Dr. Sriram Subramaniam and his team also studied portion of HIV envelop which binds with HIV neutralizing antibody VRC01 which were recently discovered in Aug 2011 and are capable of neutralizing many HIV strains. With these findings we will have information of events and proteins facilitating infection of HIV, just prior to HIV attachment to cd4 receptor.
Authored by : B V Waghmare
Last updated: 09-Aug-2012