The novel endocytic and phagocytic C-Type lectin receptor DCL-1/CD302 on macrophages is colocalized with F-actin, suggesting a role in cell adhesion and migration

J Immunol. 2007 Nov 1;179(9):6052-63. doi: 10.4049/jimmunol.179.9.6052.


C-type lectin receptors play important roles in mononuclear phagocytes, which link innate and adaptive immunity. In this study we describe characterization of the novel type I transmembrane C-type lectin DCL-1/CD302 at the molecular and cellular levels. DCL-1 protein was highly conserved among the human, mouse, and rat orthologs. The human DCL-1 (hDCl-1) gene, composed of six exons, was located in a cluster of type I transmembrane C-type lectin genes on chromosomal band 2q24. Multiple tissue expression array, RT-PCR, and FACS analysis using new anti-hDCL-1 mAbs established that DCL-1 expression in leukocytes was restricted to monocytes, macrophages, granulocytes, and dendritic cells, although DCL-1 mRNA was present in many tissues. Stable hDCL-1 Chinese hamster ovary cell transfectants endocytosed FITC-conjugated anti-hDCL-1 mAb rapidly (t(1/2) = 20 min) and phagocytosed anti-hDCL-1 mAb-coated microbeads, indicating that DCL-1 may act as an Ag uptake receptor. However, anti-DCL-1 mAb-coated microbead binding and subsequent phagocytic uptake by macrophages was approximately 8-fold less efficient than that of anti-macrophage mannose receptor (MMR/CD206) or anti-DEC-205/CD205 mAb-coated microbeads. Confocal studies showed that DCL-1 colocalized with F-actin in filopodia, lamellipodia, and podosomes in macrophages and that this was unaffected by cytochalasin D, whereas the MMR/CD206 and DEC-205/CD205 did not colocalize with F-actin. Furthermore, when transiently expressed in COS-1 cells, DCL-1-EGFP colocalized with F-actin at the cellular cortex and microvilli. These data suggest that hDCL-1 is an unconventional lectin receptor that plays roles not only in endocytosis/phagocytosis but also in cell adhesion and migration and thus may become a target for therapeutic manipulation.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Actins / metabolism*
  • Amino Acid Sequence
  • Animals
  • Antibodies, Monoclonal / immunology
  • Cell Adhesion
  • Cell Line
  • Cell Movement*
  • Conserved Sequence
  • Cricetinae
  • Dendritic Cells / metabolism
  • Endocytosis*
  • Humans
  • Lectins, C-Type / chemistry
  • Lectins, C-Type / genetics
  • Lectins, C-Type / immunology
  • Lectins, C-Type / metabolism*
  • Macrophages / cytology*
  • Macrophages / metabolism*
  • Membrane Proteins / chemistry
  • Membrane Proteins / genetics
  • Membrane Proteins / metabolism
  • Mice
  • Mice, Inbred BALB C
  • Molecular Sequence Data
  • Phagocytosis*
  • Receptors, Cell Surface / chemistry
  • Receptors, Cell Surface / genetics
  • Receptors, Cell Surface / immunology
  • Receptors, Cell Surface / metabolism
  • Sequence Alignment


  • Actins
  • Antibodies, Monoclonal
  • CD302 protein, human
  • Cd302 protein, rat
  • Dcl1 protein, mouse
  • Lectins, C-Type
  • Membrane Proteins
  • Receptors, Cell Surface