Cochlin produced by follicular dendritic cells promotes antibacterial innate immunity

Immunity. 2013 May 23;38(5):1063-72. doi: 10.1016/j.immuni.2013.01.015. Epub 2013 May 16.


Cochlin, an extracellular matrix protein, shares homologies with the Factor C, a serine protease found in horseshoe crabs, which is critical for antibacterial responses. Mutations in the COCH gene are responsible for human DFNA9 syndrome, a disorder characterized by neurodegeneration of the inner ear that leads to hearing loss and vestibular impairments. The physiological function of cochlin, however, is unknown. Here, we report that cochlin is specifically expressed by follicular dendritic cells and selectively localized in the fine extracellular network of conduits in the spleen and lymph nodes. During inflammation, cochlin was cleaved by aggrecanases and secreted into blood circulation. In models of lung infection with Pseudomonas aeruginosa and Staphylococcus aureus, Coch(-/-) mice show reduced survival linked to defects in local cytokine production, recruitment of immune effector cells, and bacterial clearance. By producing cochlin, FDCs thus contribute to the innate immune response in defense against bacteria.

Publication types

  • Research Support, N.I.H., Extramural

MeSH terms

  • Animals
  • Dendritic Cells, Follicular / metabolism*
  • Endopeptidases / metabolism
  • Extracellular Matrix Proteins / blood
  • Extracellular Matrix Proteins / genetics
  • Extracellular Matrix Proteins / metabolism*
  • Immunity, Innate*
  • Inflammation
  • Mice
  • Mice, Inbred C57BL
  • Mice, Knockout
  • Pseudomonas Infections / immunology*
  • Pseudomonas aeruginosa / immunology
  • Spleen / metabolism
  • Staphylococcal Infections / immunology*
  • Staphylococcus aureus / immunology*


  • Coch protein, mouse
  • Extracellular Matrix Proteins
  • Endopeptidases
  • aggrecanase