Osteopontin Prevents Monocyte Recirculation and Apoptosis
Tricia H. Burdo, Malcolm R. Wood, Howard S. Fox
J Leukoc Biol. 2007 June ; 81(6): 1504–1511.
Cells of the monocyte/macrophage lineage have been shown to be the principal targets for productive HIV-1 replication within the central nervous system. In addition, HIV-1-associated dementia (HAD) has been shown to correlate with macrophage abundance in the brain.
While increased entry of monocytes into the brain is thought to initiate this process, mechanisms that prevent macrophage egress from the brain and means that prevent macrophage death may also contribute to cell accumulation.
We hypothesized that osteopontin (OPN) was involved in the accumulation of macrophages in the brain in neuroAIDS. Utilizing in vitro model systems, we have demonstrated role of OPN in two distinct aspects of macrophage accumulation: prevention from recirculation, and protection from apoptosis. In these unique mechanisms, osteopontin would aid in macrophage survival and accumulation in the brain, the pathological substrate of HAD.