Because HIV-1 infection is associated with a progressive increase of pro-inflammatory cytokines, including IL-6 [67,68] and IL-8 [69,70], we set up a first experiment to assess whether HIV-1 Tat protein was involved in the production of these cytokines by primary monocytes isolated from either healthy volunteers or from HIV-1 infected patients. Here, IL6 is linked to HIV-1 infection.