Dendritic Cell Products

Dendritic cells (DCs) are antigen-presenting cells that are beneficial in defending against invading infections whilst strengthening tolerance to self and innocuous environmental antigens. The infections they acquire and the signals they get from those pathogens shape the immune response they elicit. Based on these signals, DCs direct the differentiation and silence of antigen-specific T cells. Additionally, tissues near the boundary between the body and its external environment are rich in DCs and foreign proteins and pathogens are continually present around these tissues. The blood also contains immature DCs. After activation, DCs migrate to lymph tissue where they engage in interactions with T and B cells, ultimately leading to the development of the adaptive immune response. Nowadays, particular DCs have been attracting a large amount of interest in utilizing DCs to develop immunotherapies for various conditions such as cancer and infections.

Fig.1 Dual tolerogenic and immunogenic T cell responses induced by activated pDCs.¹

Dendritic Cells Subsets

Various subgroups and populations of DCs have evolved in each organ. The location, surface marker expression, and function of these subsets are distinct.

• Plasmacytoid DCs (pDCs): They express marker B220 and PDCA1 on their surface. They resemble plasma cells in morphology and can numerously generate type I interferons (IFNs). Thus, pDCs play a vital role in anti-viral immunity.
• Conventional DCs (cDCs): CD8α⁺ and CD11b⁺ cDCs are two major members of cDCs. Both of them can be implicated in overlapping functions, including antigen presentation to T cells and cytokine secretion. Yet, they have distinct functions and can be found in different locations in vivo, respectively.
• Migratory DCs (mDCs): They are distributed in non-lymphoid tissues. CD103⁺ and CD103^- DCs are two subtypes of mDCs. They are named mDCs as they can be transmitted from non-lymphoid tissues to lymphoid organs.
• Monocyte-derived DC (Mo-DCs): Mo-DCs are derived from monocytes when inflammation occurs. Mo-DCs release TNF-a and iNOS after they get into infection sites, providing inherent defense.

DCs Serve as the Bridge Between Innate and Adaptive Immunity

Many cytoplasmic processes on DCs provide them with a huge surface area, allowing them to make close contact with many different types of neighboring cells (T cells, NK cells, neutrophils, epithelial cells, etc.). DCs in mucosal membranes, for example, are in a phenotypically stable condition in which they are ready for antigen absorption but are incapable of transmitting these antigens to T cells. The absorption of soluble antigen particles is mediated by either micropinocytosis or macropinocytosis, depending on their size. Notably, receptor-mediated endocytosis is a more effective method of antigen absorption.

After the uptake of antigens, the morphology and expression of cell surface markers change, triggering the process of maturation and migration to the lymph nodes. In the lymph nodes, the antigens bind to various histocompatibility complex (MHC) molecules and are delivered to T lymphocytes, which initiate immune response depending on the types and functions of DCs.

Dendritic Cells at Creative Biolabs

Currently, a growing understanding of dendritic cell biology has shed light on promising new treatment avenues. In response to global customers' feedback as well as facilitate the conversion of dendritic cell research into clinical settings, Creative Biolabs provides several available for immediate use dendritic cell products with strict quality control. Please feel free to contact us or inquire about an appropriate product.

Reference

1. Guéry, Leslie, and Stéphanie Hugues. "Tolerogenic and activatory plasmacytoid dendritic cells in autoimmunity." Frontiers in Immunology 4 (2013): 59.