Dendritic Cells

So named for their many branching processes, Dendritic cells (DCs) are professional antigen presenting cells, they process antigens from pathogens and present these peptide fragments to T cells, activating the T cell. In this fashion, dendritic cells act as a messenger between the innate and adaptive arms of the mammalian immune system.

At a certain stage in their development, immature dendritic cells grow the many branching processes for which they are named, giving the cell a branched or tree-like appearance. This gives the cell a very high surface area to volume ratio, which some argue allow the DC to more efficiently survey their surrounding for pathogens.

Dendritic cells are present in those tissues that are in contact with the external environment, such as the skin and the mucosal membranes lining of the nose, lungs, stomach and intestines. Here, they act as the sentinels of the immune system, sampling their surroundings for pathogenic organisms. This is done through pattern recognition receptors such as the toll-like receptors. Toll like receptors recognize specific chemical signatures found on subsets of pathogens. Once they have encountered a presentable antigen, DCs become activated and begin to migrate to the local lymph node.

Immature dendritic cells phagocytose pathogens and degrade their proteins into small pieces and upon maturation present those fragments at their cell surface using MHC molecules. Simultaneously, they upregulate cell-surface receptors that act as co-receptors in T-cell activation such as CD80, CD86, and CD40. This greatly enhances their ability to activate T-cells. They also upregulate CCR7, a chemotactic receptor that induces the dendritic cell to travel through the blood stream to the spleen or through the lymphatic system to a lymph node. At the lymph node, they act as antigen-presenting cells: they activate helper T-cells and killer T-cells as well as B-cells by presenting them with antigens derived from the pathogen, alongside non-antigen specific costimulatory signals.

The use of Dendritic cells in cancer immunotherapy is an active and ongoing area of research. DCs could be loaded with tumour specific antigens in vitro and then infused back into the patient, where it is hoped they will activate tumour specific T cells

Mouse Dendritic Cell Differentiation Kit New!
Differentiates mouse bone marrow cells into dendritic cells.

Resources for in vitro Differentiation and Expansion: