ABSTRACT
The expression of gp120 on the surface of HIV-infected cells is responsible for cytotoxic effects which can destroy T-lymphocytes in a mechanism separate from viral replication. Helpter T-lymphocytes which have been specifically produced to combat the AIDS virus may express T-cell receptor/CD4 complexes which are targeted to antigen-presenting cells carrying class II MHC proteins with bound gp120 epitopes. Such T-lymphocytes may therefore recognize infected, gp120-presenting cells in error and thus be selectively eliminated. Vasoactive Intestinal Peptide is a potent bioactive peptide of 28 amino acids which has been shown to have activity in the gut, the cardiovascular system, the central nervous system, the respiratory system and the immune system. The transduction mechanism of VIP is the stimulation of production of intracellular 5',6'-cyclic AMP resulting in smooth muscle relaxation and neurostimulation. VIP coexists with acetylcholine in the neurons innervating salivary glands.
