The identification and developmental requirements of colonic CD169⁺ macrophages

Immunology. 2014 Jun;142(2):269-78. doi: 10.1111/imm.12251.

Abstract

CD169-positive macrophages in the marginal zone of the spleen and subcapsular sinus of lymph nodes play an important role as gatekeepers, strategically located to capture pathogens. Here we identified a population of CD169-positive macrophages in the colon and investigated which factors influenced their development. Murine colonic CD115+ F4/80(lo) CD11c(lo) macrophages expressing CD169 were present in the lamina propria, mainly surrounding the crypts. In spite of the high levels of bacterial flora in the colon and the importance of Toll-like receptor signalling in mucosal homeostasis, the presence of CD169+ macrophages was not affected in mice that were deficient in MyD88-mediated Toll-like receptor signalling and in mice in which the bacterial flora was eradicated. Whereas the development of splenic CD169+ macrophages was dependent on lymphotoxin α, colonic CD169+ macrophages were present in normal numbers in lymphotoxin α-deficient mice. In contrast, reduced numbers of CD169+ macrophages were found in the colon of mice deficient in vitamin A, whereas CD169+ macrophages in the spleen were unaffected. In conclusion, we identified a new macrophage subset in the lamina propria of the colon characterized by the expression of CD169. Its differentiation, unlike CD169+ macrophages in lymphoid organs, is independent of lymphotoxin α signalling, but requires vitamin A.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Colon / cytology*
  • Colon / immunology*
  • Colon / microbiology
  • Female
  • Lymphotoxin-alpha
  • Macrophages / cytology*
  • Macrophages / immunology*
  • Mice
  • Mice, Inbred C57BL
  • Mice, Knockout
  • Mucous Membrane / cytology
  • Mucous Membrane / immunology
  • Myelopoiesis*
  • Sialic Acid Binding Ig-like Lectin 1 / immunology*
  • Vitamin A / metabolism

Substances

  • Lymphotoxin-alpha
  • Sialic Acid Binding Ig-like Lectin 1
  • Vitamin A