The human immunodeficiency virus type-2 envelope glycoprotein and viral particle assembly

The Human Immunodeficiency Virus (HIV) is the agent responsible for the acquired immunodeficiency syndrome (AIDS), a disease characterized by destruction of the body's immune cells resulting in an inability of the body to fight off opportunistic infections and some cancers. At this time, while there has been much progress made in diagnosis and treatment since the virus was first discovered in the early 1980's, there is no effective vaccine or definitive cure for HIV infection.; We are interested in the assembly process of HIV-1 components since it is clear that appropriate assembly of the virus particle is necessary for efficient and productive infection. Several proteins have been shown to be involved late in the assembly process, including the HIV-1 Vpu accessory protein, small segments within the Gag core protein which have been termed L-domains, and the HIV-2 Env glycoprotein. HIV-2 Env protein is a transmembrane protein of the mature virus particle that, among its described functions, is important for directed infection of CD4 positive immune cell types.; In this dissertation, I confirmed that in addition to the HIV-2 Env glycoprotein's role in membrane fusion, this protein can also play an important role in late virus particle assembly and budding events. Specifically, I found that in certain cell types, the expression of HIV-2 Env increased the amount of virus released from the cell surface in a manner similar to Vpu. I showed that this increase of virus production is dependent not only upon a specific sequence within the cytoplasmic domain of Env, but also an additional region present within the extracellular domain of the protein. Finally, I compared the budding enhancement mediated by HIV-2 Env with that of Vpu and the HIV-1 L-domains and suggest that HIV-2 Env enhances budding by a distinct mechanism.; Increased knowledge presented within this dissertation regarding these processes of particle assembly and budding may help in the advancement of novel anti-HIV therapeutics, as well as have impact on further development of retroviral and lentiviral vectors for gene therapy.