Novel regulatory role of miR-146a identified in Lyme arthritis and macrophage phagocytosis of Borrelia burgdorferi.
Peritoneal macrophages from miR-146a-/- mice were incubated with GFP-labeled B. burgdorferi and phagocytic uptake monitored by confocal microscopy. Apparent in the overlay are cell nuclei (gray), lysosomes (red), cell membranes (blue), and B. burgdorferi (green). B. burgdorferi are identified as bright GFP puncta associated with intracellular lysosomes and as spiral shaped bacteria on the cell surface. Uptake of B. burgdorferi was greater in macrophages lacking miR-146a than wild type macrophages, consistent with the reduced bacterial presence and increased Lyme arthritis severity in joint tissue of infected miR-146a-/- mice. See Lochhead et al.
Image Credit: Robert B Lochhead, Janis J Weis