Chemoattractant factors (IP-10, MIP-1 alpha, IL-16) mRNA expression in mononuclear cells from different tissues during acute SIVmac251 infection of macaques

We have used semiquantitative RT-PCR to monitor the expression of mRNA encoding chemoattractant factors IP-10, MIP-1 alpha, and IL-16 in freshly isolated peripheral blood mononuclear cells (PBMCs), lymph node mononuclear cells (LNMCs), and mononuclear cells obtained after bronchoalveolar lavages (BALMCs) of two cynomolgus macaques inoculated intravenously with a pathogenic isolate of simian immunodeficiency virus, SIVmac251. Concomitant with the peak of systemic viral replication (two weeks after experimental inoculation) and proinflammatory cytokine IL-6 mRNA expression, high levels of MIP-1 alpha and IP-10 mRNA were produced in LNMCs and BALMCs. In BALMCs, in which we have reported a marked progressive overexpression of IFN-gamma mRNA coinciding with an increase in the CD8+ lymphocyte percentages, we noticed a progressive overexpression of IL-16 mRNA. Our results suggest the role of chemokines IP-10, MIP-1 alpha, and IL-16 in the development of inflammatory and immune responses during the early stages of lentiviral infection.