HIV Biology ..........

Human immunodeficiency retrovirus known has HIV causes AIDS. HIV consists of outer biolipid envelope taken from infected cells plasma membrane with protruding GP 120 Receptor. Inside a protein coats surrounds the cone shaped viral coat containing two identical positive strands of RNA and enzyme called reverse Transcriptase.Upon entrance into the blood stream these virus attach to any cell that has CD4 receptors such has those found in T4cells also known has helper cells, GP120 receptor on the viral outer envelope attach to the CD4 molecule on the plasma membrane of the T4 membrane. Virus fuses with cell when the trans membrane component GP41 penetrates into T4 cell wall, This fusion results in the delivery of cone shape capsid into the cytoplasm of the host cell, once inside the protein layer enclosing the viral code dissolves. The two viral rna stands accompanying with reverse transcriptase enzyme are released into the cytoplasm. The enzymes move along the RNa transcribing it into the strand of DNA which circularizes .the circular cell DNA now enters the host cell nucleus where it integrates into one of cell of chromosome to become a pro virus where it can remain latent for long period of time. When activated a transcriptase enzyme transcribes the pro virus DNA into series of different size mRNA’s, the largest is for replication of viral Rna the smallest fragments are transcribed into a protein, which is used to built the new virus, New protein capsids develop around RNA strand pairs and move toward the cell membrane. These new virus components move towards the surface of the cell .where they bud through the cell membrane acquire their envelope repeated budding damages or kills the host cells, upon release the new virus is ready to invade another tcell with cd4 receptors and process begins again.http://bioisolutions.blogspot.com/2007/02/hiv-biology.html