Glycosylphosphatidylinositol-anchored receptor-mediated bacterial endocytosis.

An increasing number of pathogens or their toxins appear to utilize glycosylphosphatidylinositol(GPI)-anchored receptors to trigger entry into immune and other host cells. Since these receptors have no transmembrane and intracellular moieties, how endocytosis is initiated is unclear. Recently, CD48 on mast cell membranes was shown to trigger endocytosis of bacteria via a route that avoids fusion with lysosomes and by a mechanism involving discrete cellular entities called caveolae. The localization of CD48 within caveolae appears to be a prerequisite for caveolae-mediated bacterial entry.