Biology of the HIV Nef protein.
The accessory Nef protein is expressed by all primate lentiviruses--HIV-1,HIV-2 and simian immune deficiency virus (SIV). Its expression in the early stages of the viral life cycle ensures two basic attributes of HIV infection. These are T-cell activation and the establishment of a persistent state of infection. Nef has a positive effect on viral infection and replication by promoting the survival of infected cells. Its role in HIV persistence is based largely on the ability of Nef to downmodulate the surface levels of important molecules at the immune synapse. These include major histocompatibility complex-I (MHC I) and (MHC II) present on antigen-presenting cells (APCs) and target cells, and CD4 and CD28 present on helper T cells. In this review we present these biological properties of Nef from a mechanistic point of view, and relate them to the structural attributes and interactions of the Nef protein. A brief outline of the limited studies on Nef from Indian subtype C HIV-1 isolates is also presented.
Das
Suman Ranjan
SR
Virology Group, International Centre for Genetic Engineering & Biotechnology, Aruna Asaf Ali Marg, New Delhi 100 067, India.
Jameel
Shahid
S
D000595:Amino Acid Sequence; D015693:Gene Products, nef / Q000737:chemistry / Q000502:physiology*; D006678:HIV / Q000472:pathogenicity / Q000502:physiology; D008969:Molecular Sequence Data; D017386:Sequence Homology, Amino Acid; D014771:Virion / Q000472:pathogenicity; D014779:Virus Replication / Q000502:physiology; D054311:nef Gene Products, Human Immunodeficiency Virus
D015693:Gene Products, nef; D054311:nef Gene Products, Human Immunodeficiency Virus