Regulation of phagosome maturation by signals from toll-like receptors

JM Blander, R Medzhitov - Science, 2004 - science.org
JM Blander, R Medzhitov
Science, 2004science.org
In higher metazoans, phagocytosis is essential in host defense against microbial pathogens
and in clearance of apoptotic cells. Both microbial and apoptotic cells are delivered on a
common route from phagosomes to lysosomes for degradation. Here, we found that
activation of the Toll-like receptor (TLR) signaling pathway by bacteria, but not apoptotic
cells, regulated phagocytosis at multiple steps including internalization and phagosome
maturation. Phagocytosis of bacteria was impaired in the absence of TLR signaling. Two …
In higher metazoans, phagocytosis is essential in host defense against microbial pathogens and in clearance of apoptotic cells. Both microbial and apoptotic cells are delivered on a common route from phagosomes to lysosomes for degradation. Here, we found that activation of the Toll-like receptor (TLR) signaling pathway by bacteria, but not apoptotic cells, regulated phagocytosis at multiple steps including internalization and phagosome maturation. Phagocytosis of bacteria was impaired in the absence of TLR signaling. Two modes of phagosome maturation were observed, constitutive and inducible; their differential engagement depended on the ability of the cargo to trigger TLR signaling.
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