General goal of our Unit is the dissection of the pathogenic consequences resulting from HIV infection of CD4+ T lymphocytes, macrophages, and dendritic cells. HIV perturbs the homeostatic role of the network of cytokines and chemokines whereas this latter regulates the efficiency of virus infection and propagation among immune cells by interfering at multiple levels with the virus life cyce. Pharmacological molecules, such as pertussis toxin, urokinase-type plasminogen activator, as well as cytokines and chemokines, are potent tools to unravel the crucial elements of the mutual interaction between the virus and the host. In addition, they also allow to pursue the potential goal of identifying novel antiretroviral agents acting either by preventing virus replication or by restoring the damaged immune system of infected individuals.