Adaptive Tumor Suppression
John Melford in Pocket Guide to Cancer, 2017
Dendritic cells get their name from their surface projections that resemble the dendrites of neurons, a type of cell used to relay messages in the nervous system. Immature dendritic cells are produced in the bone marrow from where they migrate throughout the body. They remain dormant until they encounter invading pathogens or molecules of foreign origin, which they engulf, process, and present. Dendritic cells are found in most tissues of the body and are particularly abundant in areas where they are more likely to encounter antigens such as the skin, lungs, and gastrointestinal tract. Although macrophages also present antigens, dendritic cells are better at it, and often are described as professional antigen‑presenting cells. For this function, dendritic cells have an enhanced capability to uptake antigens and process them for presentation on their outer cell membrane. Macrophages and dendritic cells use both MHC Class I and MHC Class II molecules to present antigens. Other cells of the body use just MHC Class I molecules. Dendritic cells also help to control the function of T-cells and other types of lymphocytes.
Polyphenols and Cancer Immunology
Spyridon E. Kintzios, Maria G. Barberaki, Evangelia A. Flampouri in Plants That Fight Cancer, 2019
Dendritic cells belong to the group of immune cells which are most highly specialized in the presentation of antigens. They can be found in peripheral tissues or immunological organs and are considered to provide a link between innate and adaptive immunity. Activated by chemotactic factors (chemokines CXCL12 or CCL20) produced by the tumor microenvironment, DCs migrate to the pathological tissue, contributing to the reactive stroma. They mainly function as antigen presenting cells (APC), presenting antigens to T-cells in the context of MHC I and II. As a consequence, cytotoxic T-cells infiltrate the tumor mass and destroy it as well as stimulating B lymphocytes, which also limit tumor growth by producing antibodies. Cells of the CD11c+CD8a+ DR+ dendritic cell subpopulation directly kill tumor cells and may exert a cytotoxic effect on transformed cells through perforin and granzyme expression. Other types of DCs found in the tumor microenvironment include myeloid dendritic cells (mDCs) CD11c+ with an antitumor activity (which act mainly by inducing cytotoxic T lymphocytes), plasmacytoid dendritic cells (pDCs) CD123+, and so-called immunotolerant dendritic cells (itDCs), which may exert an immunosuppressive activity promoting tumor growth through CD4+ Th2 and Treg cells. Generally, immature DCs (iDCs), which are precursors of mDCs, are also recruited into the tumor. They are inhibited in maturation and stimulated to promote angiogenesis and trans differentiation into endothelial progenitors. Endothelization is characterized by a loss of CD14/45 and appearance of typical markers such as CD31, CD34, von Willebrand Factor (vWF), VE-cadherin, and VEGF receptors. Tumor-Associated Dendritic Cells (TA-DCs) exert an immunosuppressive activity and significantly promote the angiogenic process in the tumor stroma by producing matrix metalloproteinases (MMPs), VEGF, angiogenin, basic Fibroblast Growth Factor (bFGF), and heparanase (Benencia et al. 2012, Francisco et al. 2014, Li et al. 2015, del Cornò et al. 2016).
Applications of Antiviral Nanoparticles in Cancer Therapy
Devarajan Thangadurai, Saher Islam, Charles Oluwaseun Adetunji in Viral and Antiviral Nanomaterials, 2022
To overcome tumour tolerance, vaccination can be used to enhance antitumour responses. Immunotherapy could be a potential approach in targeting the specific antigens of the tumours and can be sensitised to the host immune system (Jonuleit et al. 2016). Dendritic cells are well known for triggering naive T-cells and the adaptive immune responses (Schuler et al. 2003). This generally results in the reduction of cancer progression.
The screening of a microRNA expression during development of human macrophages and mouse dendritic cells
Published in Cancer Biology & Therapy, 2017
Eui Young So, Trisha Winchester, Toru Ouchi
There is increasing evidence showing specific roles of microRNA in cell differentiation and cancer progression. Here we examine miRNA profiles during maturation of monocytes and bone marrow-derived dendritic cells (BMDCs) in human and mouse, respectively. We have identified significant changes of various miRNA expression during monocyte and BMDC monocyte development via miRNA microarrays, confirmed by quantitative PCR. Increases in miR155 expression positively correlated with increasing maturity of monocyte and BMDC in both mouse and human microarrays, indicating its importance in development. We describe a requirement of miR155 for MHCII expression during GM-CSF-induced development and LPS-induced maturation of DCs, suggesting reduced immune function of DC when miR155 is absent. Our study suggests that miRNAs might have an important role in differentiation of myeloid cell such as dendritic cells and macrophages.
The Role of Dendritic Cells in the Pathogenesis of COPD: Liaison Officers in the Front Line
Published in COPD: Journal of Chronic Obstructive Pulmonary Disease, 2009
Geert R. Van Pottelberge, Ken R. Bracke, Guy F. Joos, Guy G. Brusselle
Dendritic cells are professional antigen presenting cells linking innate and adaptive immune responses. Different dendritic cell subsets were identified in human lung, each with their own functional characteristics. As innate and adaptive immune responses are activated in Chronic Obstructive Pulmonary Disease (COPD), dendritic cells could play a role in the pathogenesis of this disease. Indeed, cigarette smoke appears to modulate dendritic cell function in vitro and alters dendritic cell numbers and function in cigarette smoke exposed mice. The number of pulmonary dendritic cells differs between COPD patients, smokers and non-smokers. Moreover, the number of Langerhans-type dendritic cells increases with the severity of the disease. In this review we will discuss the scientific evidence regarding the role of dendritic cells in COPD and we will put forward the concept of modulation of dendritic cell differentiation and function as a crucial step in the pathogenesis of COPD.
Morphologic Characteristics of Blastic Plasmacytoid Dendritic Cell Neoplasm: A Case Report
Published in Ultrastructural Pathology, 2014
Yongxin Ru, Peihong Zhang, Shuxu Dong, Huijun Wang, Shixuan Zhao, Yingchang Mi, Brian Eyden
Blastic plasmacytoid dendritic cell neoplasm (BPDCN) is a rare aggressive lymphoma derived from plasmacytoid dendritic cells or precursor dendritic cells. Despite some 240 reported cases, its morphology and especially ultrastructure has not been satisfactorily studied. A case is reported of a 13 year old boy, who, despite chemotherapy, died within a 12-month period. The electron microscopy findings – microvillous processes, nuclei with slight irregularities, a moderate amount of heterochromatin, and rough endoplasmic reticulum in the form of long, narrow profiles, often in parallel arrangements – taken together, serve to distinguish BPDCN from other neoplastic cells, such as monocytes, plasma cells and the cells of chronic lymphocyte leukemia.