[CAS NO. 106362-34-9]  Adaptavir (DAPTA)

DAPTA is a non-toxic experimental antiviral entry inhibitor. DAPTA potently inhibits specific CD4-dependent binding of gp120 Bal (IC50 = 0.06 nM) and CM235 (IC50 = 0.32 nM) to CCR5. In co-immunoprecipitation studies, DAPTA (1 nM) blocks formation of the gp120/sCD4 complex with CCR5. Confocal microscopic studies of direct FITC-DAPTA binding to CCR5+, but not CCR5−, cells show that CCR5 is a DAPTA receptor. DAPTA is an antagonist of CCR5-mediated chemotaxis and is most effective as an antiviral agent primarily against R5-tropic HIV-1 isolates, with reduced or absent effect for X4-tropic laboratory isolates. DAPTA does not inhibit fusion in typical assays, which use high local concentrations of virus and cells. The Th2 cytokines IL-4, IL-10,and IL-13, are increased by DAPTA and induce a potent virostatic state in infected macrophages in vitro, as well as inhibit production of the proinflammatory cytokines IL-1 and TNFα, which upregulate virus expression. Thus the elevation of Th2 cytokines by DAPTA treatment would favor less macrophage viral replication.