Increased intracellular accumulation of macrophage inflammatory protein 1 beta and its decreased secretion correlate with advanced HIV disease

Considering that the chemokine macrophage inflammatory protein 1 beta (MIP1 beta) may serve as a competitive inhibitor for HIV entry, the objective of this study was to compare intracellular and extracellular levels of MIP1 b eta, in untreated HIV-infected individuals. HIV patients and healthy contro ls were tested by two-color Row cytometry for intracellular MIP1 beta, in f reshly explanted CD4 and CD8 lymphocytes, and in monocytes. Sera and plasma collected on the same day were tested, respectively, by enzyme-linked immu nosorbent assay (ELISA) for MIP1 beta concentration and for number of HIV-R NA copies, using nucleic acid sequence-based amplification procedure (NASBA ) methodology. Results demonstrate that a high intracellular level of MIP1 beta appears to be linked to a deterioration in the immune status of HIV pa tients (i.e., low CD4 counts) and to a high viral load. Moreover, an invers e relationship exists between the intracellular and the "secreted" form of MIP1 beta, thus leading to the hypothesis that the regulation of cellular a ccumulation and secretion of MIP1 beta and of other chemokines may be disru pted during AIDS development.