Colony-stimulating factor 1-dependent cells protect against systemic infection with Listeria monocytogenes but facilitate neuroinvasion.

By using mice genomically lacking the mononuclear phagocytic growth factor colony-stimulating factor 1 and thereby deficient in macrophage and dendritic cell populations, we show that these cells play a dual role: they constitute a major defense against systemic infection but also facilitate cerebral bacterial invasion by Listeria monocytogenes.