Defining dendritic cells

Abstract

Dendritic cells (DCs) are versatile controllers of the immune system, best known for their potent ability to initiate adaptive immunity. Traditionally, DCs have been defined on the basis of cell morphology, expression of specific markers and select functional attributes such as the ability to migrate to T cell areas of secondary lymphoid organs and activate T lymphocytes. However, such properties are not qualitative and often change in conditions of inflammation or infection. Phenotypic-based and function-based definitions can therefore lead to difficulties in cell identification. Here we review other approaches to try and solve questions of DC lineage attribution with an emphasis on recent insights arising from our increased understanding of DC ontogeny and differentiation.

Dendritic Cells in Atherosclerosis

“…[6][7][8][9][10] On the basis of these considerations, DCs in mice were proposed to be classified as a separate lineage of mononuclear phagocytes that arises from progenitors that are distinct from precursors of monocytes/macrophages. In the bone marrow common monocyte-DC precursors (MDPs) either give rise to monocyte progenitors restricted to monocytes and their descendants or commit toward DC precursors.…”

“…33 Given recent advances in defining bone fide DCs, an in-depth characterization of the ontogeny of vascular and adventitial DCs in healthy and atherosclerotic arteries is now warranted. For example, fate mapping studies will bring clarity to the origin of vascular DCs versus macrophages, such as the one exploiting DNGR-1 expression 6 to trace cDC precursors. Subsequently, their transcriptional profiling could help identifying genes specifically regulated during disease development.…”

“…[6][7][8][9][10][11][12] Both cDCs and pDCs depend on the growth factor fms-like tyrosine kinase 3 ligand (Flt3L), and Flt3L-dependence can serve as a surrogate marker for common DC precursor origin. 6,10 In contrast, macrophage colony-stimulating factor 1 receptor + monocytes that circulate in blood and enter tissues under inflammatory conditions, give rise to macrophages and monocyte-derived DCs. It is currently unclear if monocyte-derived DCs and macrophages constitute two distinct lineages, or if they are instead highly plastic cells that acquire different functional modules in response to microenvironmental cues 10 (Table 1 14 Similar to mice, DCs can be detected in the arterial intima of healthy young individuals, 32 and increased numbers of DCs are found in atherosclerotic lesions 29 using unspecific markers, such as S100, CD1a, or fascin.…”

Enhanced Influenza Virus-Like Particle Vaccination with a Structurally Optimized RIG-I Agonist as Adjuvant

“…The most efficient antigen-presenting cells are mature, immunologically competent dendritic cells (DC) (32), and it is now accepted that the adjuvant component of vaccines contributes to vaccine efficacy by triggering DC maturation and antigen presentation (33). To determine whether selected 5=pppRNA sequences differ in their ability to induce DC maturation ex vivo, we first examined the mRNA levels of selected genes involved in DC maturation and activation.…”

Optimization of Ex Vivo Murine Bone Marrow Derived Immature Dendritic Cells: A Comparative Analysis of Flask Culture Method and Mouse CD11c Positive Selection Kit Method

“…DCs, macrophages, and B cells are professional Antigen Presenting Cells (APC) whereas basophils, mast cells, eosinophils, and innate lymphoid cells are atypical APCs [1]. DCs stimulate both naïve and memory T cells [2, 3]. They capture and present foreign material on their surface and promote their differentiation into cytotoxic T lymphocytes (CTLs)/CD8 + and helper T cells (Th)/CD4 + cells [4].…”