HIV-1 gp120 Effects on Signal Transduction Processes and Cytokines: Increased src-Family Protein Tyrosine Kinase Activity.

Varying degrees of neurological dysfunction are observed in AIDS patients who develop AIDS dementia complex (ADC). Data from a large number of in vivo and in vitro rodent studies have suggested a role for the HIV envelope glycoprotein gp 120 in this process. These studies were initiated to clarify possible effects of recombinant gp120 on signal transduction systems and the synthesis of specific ADC-related cytokines in human neuroblastoma cells. Out results indicate that gp120 on signal transduction systems and the synthesis of specific ADC-related cytokines in human neuroblastoma cells. Our results indicate that gp120 did not induce the synthesis of cAMP, IPs or NO, nor did it alter agonist-induced synthesis of these molecules. In addition, it did not induce the synthesis of IL-6 and TNFα. However, it did activate a src-family protein tyrosine kinase which phosphorylates several substrates, including prominent proteins in the 115 and 60 kDa range. This gp120-induced tyrosine phosphorylation may contribute to neurological dysfunction since protein tyrosine kinases are known to be involved in processes important for pre- and post-synaptic neuronal function.