LIMP-2 links late phagosomal trafficking with the onset of the innate immune response to Listeria monocytogenes: a role in macrophage activation

J Biol Chem. 2011 Feb 4;286(5):3332-41. doi: 10.1074/jbc.M110.146761. Epub 2010 Dec 1.

Abstract

The innate immune response to Listeria monocytogenes depends on phagosomal bacterial degradation by macrophages. Here, we describe the role of LIMP-2, a lysosomal type III transmembrane glycoprotein and scavenger-like protein, in Listeria phagocytosis. LIMP-2-deficient mice display a macrophage-related defect in Listeria innate immunity. They produce less acute phase pro-inflammatory cytokines/chemokines, MCP-1, TNF-α, and IL-6 but normal levels of IL-12, IL-10, and IFN-γ and a 25-fold increase in susceptibility to Listeria infection. This macrophage defect results in a low listericidal potential, poor response to TNF-α activation signals, impaired phago-lysosome transformation into antigen-processing compartments, and uncontrolled LM cytosolic growth that fails to induce normal levels of acute phase pro-inflammatory cytokines. LIMP-2 transfection of CHO cells confirmed that LIMP-2 participates in the degradation of Listeria within phagosomes, controls the late endosomal/lysosomal fusion machinery, and is linked to the activation of Rab5a. Therefore, the role of LIMP-2 appears to be connected to the TNF-α-dependent and early activation of Listeria macrophages through internal signals linking the regulation of late trafficking events with the onset of the innate Listeria immune response.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Biological Transport / immunology
  • CD36 Antigens / immunology*
  • Cells, Cultured
  • Fibroblasts / cytology
  • Immunity, Innate*
  • Listeria monocytogenes / immunology*
  • Listeriosis / immunology
  • Lysosomal Membrane Proteins / immunology*
  • Macrophage Activation / immunology*
  • Mice
  • Mice, Mutant Strains
  • Phagosomes / metabolism*
  • Tumor Necrosis Factor-alpha / immunology

Substances

  • CD36 Antigens
  • Lysosomal Membrane Proteins
  • Scarb2 protein, mouse
  • Tumor Necrosis Factor-alpha