melitten and Acquired-Immunodeficiency-Syndrome

Evidence is presented to suggest that HIV-1 accessory protein Nef could be involved in AIDS pathogenesis. When present in extracellular medium, Nef causes the death of a wide variety of cells in vitro and may therefore be responsible for the depletion of bystander cells in lymphoid tissues during HIV infection. When present inside the cell, Nef could prevent the death of infected cells and thereby contribute to increased viral load. Intracellular Nef does this by preventing apoptosis of infected cells by either inhibiting proteins involved in apoptosis or preventing the infected cells from being recognized by CTLs. Neutralization of extracellular Nef could prevent the death of uninfected immune cells and thereby the destruction of the immune system. Neutralization of intracellular Nef could hasten the death of infected cells and help reduce the viral load. Nef is therefore a very important molecular target for developing therapeutics that slow progression to AIDS. The N-terminal region of Nef and the naturally occurring bee venom mellitin have very similar primary and tertiary structures, and they both act by destroying membranes. Chemical analogs of a mellitin inhibitor prevent Nef-mediated cell death and inhibit the interaction of Nef with cellular proteins involved in apoptosis. Naturally occurring bee propolis also contains substances that prevent Nef-mediated cell lysis and increases proliferation of CD4 cells in HIV-infected cultures. These chemical compounds and natural products are water soluble and nontoxic and are therefore potentially very useful candidate drugs.

Topics: Acquired Immunodeficiency Syndrome; AIDS Vaccines; Amino Acid Sequence; Gene Products, nef; Humans; Melitten; Models, Molecular; Molecular Sequence Data; nef Gene Products, Human Immunodeficiency Virus; Protein Conformation; Viral Proteins; Viral Regulatory and Accessory Proteins