The mouse dendritic cell marker CD11c is down-regulated upon cell activation through Toll-like receptor triggering

Immunobiology. 2013 Jan;218(1):28-39. doi: 10.1016/j.imbio.2012.01.021. Epub 2012 Feb 21.


Dendritic cells (DC) play a key role in regulating immune responses and are the best professional antigen-presenting cells. Two major DC populations are defined in part according to cell surface CD11c expression levels. Unexpectedly, we observed that mouse DC strongly down-regulate the typical DC marker CD11c upon activation. To better characterize DC responses, we have analyzed CD11c expression on mouse and human myeloid DC after Toll-like receptor (TLR) triggering. Here we show that mouse bone marrow-derived DC (BMDC) as well as spleen DC down-regulate cell surface CD11c upon activation by TLR3/4/9 agonists. In all cases, full DC activation was reached, as determined by cytokine secretion, cell stimulation in mixed leukocyte reactions (MLR), and CD40/CD86/major histocompatibility complex (MHC) up-regulation. Interestingly, membrane CD11c down-regulation correlated with increased cytoplasmic pools of CD11c. In contrast to the up-regulation of CD40 and MHC class II molecules, lipopolysaccharide (LPS)-induced CD11c down-regulation was MyD88-dependent. Polyinosinic-polycytidylic acid (poly I:C), which does not signal through MyD88, also induced cell surface CD11c down-regulation. Notably, CD11c down-regulation was not observed upon activation of human DC, either through TLR-dependent or -independent cell activation. Thus, activated mouse DC may be transiently CD11c-negative in vivo, hampering the identification of those cells. On the other hand, cell surface CD11c down-regulation may serve as a new activation marker for mouse DC.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Biomarkers / metabolism*
  • CD11c Antigen / genetics
  • CD11c Antigen / metabolism*
  • CD40 Antigens / genetics
  • CD40 Antigens / metabolism
  • Cell Differentiation / drug effects
  • Cell Differentiation / immunology
  • Cells, Cultured
  • Dendritic Cells / drug effects
  • Dendritic Cells / immunology*
  • Down-Regulation / drug effects
  • Histocompatibility Antigens Class II / genetics
  • Histocompatibility Antigens Class II / metabolism
  • Humans
  • Mice
  • Mice, Inbred C57BL
  • Mice, Knockout
  • Myeloid Differentiation Factor 88 / genetics
  • Myeloid Differentiation Factor 88 / metabolism*
  • Signal Transduction / genetics
  • Signal Transduction / immunology
  • Toll-Like Receptors / agonists
  • Toll-Like Receptors / immunology*


  • Biomarkers
  • CD11c Antigen
  • CD40 Antigens
  • Histocompatibility Antigens Class II
  • Myeloid Differentiation Factor 88
  • Toll-Like Receptors