GLOSSARY

D

• DC-SIGN (CD209/CD209a) #

  Alternative names: CLEC4L, CDSIGN, CIRE

  In humans and in mice, DC-SIGN can be found on the surface of: dendritic cells, macrophages/monocytes, endothelial cells

  Ligands and associated molecules: CD102 (ICAM-2), CD50 (ICAM-3), mannose glycoproteins on pathogens including HIV gp120

  Function: antigen endocytosis and degradation, dendritic cell migration, T cell activation, HIV receptor, pathogen receptor

  Additional information: Dendritic cell-specific ICAM-3-grabbing non-integrin (DC-SIGN) is also known as CD209. CD209 binds to CD50 to stimulate T cell proliferation. CD209 expression is upregulated by IL-4 during monocyte-to-dendritic cell differentiation. By interacting with CD102, CD209 facilitates dendritic cell migration into tissues. Furthermore, CD209 binds mannose glycoproteins found on the surface of bacterial and viral pathogens, initiating antigen endocytosis and degradation. By binding to CD209 on mucosal dendritic cells, HIV is transported to secondary lymphoid organs, where it can efficiently infect CD4⁺ T cells. CD209 similarly facilitates hepatitis C virus dissemination.

  Further reading:

  • DC-SIGN (CD209) Expression Is IL-4 Dependent and Is Negatively Regulated by IFN, TGF-β, and Anti-Inflammatory Agents. Miguel Relloso M, et al. Journal of Immunology (2002)
  • DC-SIGN, a Dendritic Cell-specific HIV-1-Binding Protein that Enhances trans-Infection of T cells. Geijtenbeek TBH, et al. Cell (2000)

• Dendritic Cell (DC) #

  A family of bone-marrow-derived cells that are central to initiating, developing, and regulating innate and adaptive immune responses. Dendritic cells (DCs) are sentinel cells located throughout the body that capture antigens and carry them to lymphoid organs to initiate T and B cell responses. DCs are also critical in educating thymocytes and eliminating self-reactive thymocytes, inducing peripheral and central tolerance. DCs are a complex set of cells employing a wide range of mechanisms in their different roles. Recent improved classification methods employing surface markers, expression profiling,functional assays, and more, have clarified the ontogeny of DCs derived from haematopoietic stem cells (HSC). DCs can be divided into three major subsets:

  • plasmacytoid DC (pDC)
  • myeloid/conventional DC1 (cDC1), and
  • myeloid/conventional DC2 (cDC2).

  These subsets can themselves diverge to have different functionalities. In addition, HSC-derived monocytes can differentiate into subgroups of monocyte-derived DC (moDC) and monocyte-derived macrophages.