ER-Coordinated Activities of Rab22a and Rab5a Drive Phagosomal Compaction and Intracellular Processing of Borrelia burgdorferi by Macrophages

Publication date: Available online 3 September 2015 Source:Cell Reports Author(s): Xenia Naj, Stefan Linder Borrelia burgdorferi is the causative agent of Lyme disease, a multisystemic disorder affecting the skin, joints, and nervous system. Macrophages and dendritic cells counteract Borrelia dissemination through internalization and degradation of spirochetes. We now show that Borrelia internalization by primary human macrophages involves uptake and compaction into Rab22a-positive phagosomes that are in close contact with Rab5a-positive vesicles. Compaction of borreliae involves membrane extrusion from phagosomes, is driven by Rab22a and Rab5a activity, and is coordinated by ER tubules forming contact sites of Rab22a phagosomes with Rab5a vesicles. Importantly, Rab22a and Rab5a depletion leads to reduced localization to lysosomes and to increased intracellular survival of spirochetes. These data show that Rab22a- and Rab5a-driven phagosomal uptake is a crucial step in the vesicular cascade that leads to elimination of spirochetes by macrophages. Rab22a and Rab5a thus present as potential molecular targets for the modulation of intracellular processing of borreliae in human immune cells. Graphical abstract Teaser Borrelia burgdorferi is the causative agent of Lyme disease. Naj and Linder show that borreliae internalized by macrophages are compacted in Rab22a-positive phagosomes, which is driven by membrane tubulation, controlled by Rab22a and Rab5a, and coordinate...
Source: Cell Reports - Category: Cytology Source Type: research