China
Africa
Explore chapters and articles related to this topic
Pathology and Epidemiology
Published in John T. Kemshead, Pediatric Tumors: Immunological and Molecular Markers, 2020
A diagnostic finding of great value in histiocytosis X however are the trilaminar and racquet-shaped Birbeck granules; indeed most would agree that the ultrastructural presence of these granules is pathognomonic of this group of disorders. Attempts have been made24 to correlate the presence of these structures with a histological subtype of the disease bearing a particularly good prognosis, and characterized by a mixed population of cells in the tumor infiltrate, including a high proportion of multinucleate giant cells. It is also probable that the identification of Birbeck granules ultrastructurally is at least as reliable, and probably more so, than the use of such immunohistological techniques as S-100 protein or histochemical methods as α-1 mannosidase.
Oncology
Published in Rachel U Sidwell, Mike A Thomson, Concise Paediatrics, 2020
Rachel U Sidwell, Mike A Thomson
Langerhans’ cells are skin histiocytes with antigen-presenting function (part of the antigen-specific immune response). They are CD1a positive. Identified on EM with the cytoplasmic organelles Birbeck granules, which look like tennis rackets.
Tumours
Published in Ashley W. Blom, David Warwick, Michael R. Whitehouse, Apley and Solomon’s System of Orthopaedics and Trauma, 2017
Jonathan Stevenson, Michael Parry
Histologically, LCH is characterized by the appearance of intermediate-sized Langerhans cells with indistinct cytoplasm intermixed with inflammatory cells. Langerhans cells contain distinctive ‘tennis-racket’ intracytoplasmic inclusion bodies, Birbeck granules, which have arisen from the cell membrane.
Dendritic Cells Currently under the Spotlight; Classification and Subset Based upon New Markers
Published in Immunological Investigations, 2021
Samaneh Soltani, Mahdi Mahmoudi, Elham Farhadi
Professional APCs in the skin include DCs, monocytes, and macrophages. LCs are antigen-presenting DCs that populates in basal/suprabasal layers of stratified epithelial tissues such as epidermis, urogenital/oral mucosae, and cornea (Strobl et al. 2019). LCs are stable self-renewing cells that are not dependent on CD34+ precursors in the absence of inflammation (Chopin et al. 2013). LCs are considered as the first immunological barrier in the epidermis, which perpetually arises from resident radioresistant precursor cells in steady-state and comprises about 1–3% of all nucleated cells in the human epidermis (Said and Weindl 2015). LCs present a range of TLRs, including TLR 1, 2, 3, 6, 10 (Sehgal et al. 2014), high amount of the CLR, CD207, CD1a, and the invariant MHC class I molecule. In addition, they express HLA-DR, ATPase (CD39), FcεR1 (The high-affinity IgE receptor), and EpCAM (Collin and Bigley 2018; Sparber 2014). E-Cadherin, EpCAM (TROP1), TROP2, AXL, and tight junction proteins, including claudin, occluding, and ZO-1, are involved in tight accretion of LCs in the epithelium (Bauer et al. 2012; Hieronymus et al. 2015). ID2 and Runt-related transcription factor 3 (RUNX3) are the differential TFs, which recognized in LC cells (Collin and Bigley 2018). The expression of CD207 is associated with intra-cytoplasmic vesicles and Birbeck granules (BG) that are two features by which LCs readily distinguished from other DCs (Valladeau et al. 2000). In the human epidermis LCs are the main hematopoietic cells while γδ T cells are central in the murine epidermis (Merad et al. 2013).
The potential role of using vaccine patches to induce immunity: platform and pathways to innovation and commercialization
Published in Expert Review of Vaccines, 2020
Kamran Badizadegan, James L. Goodson, Paul A. Rota, Kimberly M. Thompson
As suggested in Figure 3, normal human skin harbors a variety of APCs, the majority of which belong to the general category of conventional dendritic cells (DCs). Skin DCs show extensive immunophenotypic diversity relevant to both health and disease, but their subclassification into epidermal DCs, also known as LCs, and dermal DCs (DDC) serves as a useful high-level subdivision [149]. LCs, reviewed in detail by others [150,151], are resident epidermal APCs responsible for T-cell priming to antigens encountered in the epidermis. The ability of LCs to migrate to regional lymph nodes where classical T-cell priming takes place facilitates their significant immunological function. Although LCs and DDCs share many morphological and functional similarities, LCs also share many similarities with macrophages, and may behave as resident tissue macrophages with the ability for local self-renewal, as opposed to conventional DCs that derive from hematopoietic stem cells [150]. Immunophenotypically, human LCs express high levels of CD1a, which is an MHC-related membrane protein involved in the presentation of lipid antigens [151]. An endosomal protein called CD207/Langerin also expresses at high levels in humans and is a constituent of Birbeck granules, which may play a role in the internalization of viruses [152].
A case of multisystem Langerhans cell histiocytosis presenting as central diabetes insipidus
Published in Journal of Community Hospital Internal Medicine Perspectives, 2019
P. Daniel Nicholas, Ian Garrahy
The label Langerhans cell histiocytosis (LCH) derived from histologic studies of biopsied lesions. It was noted that the malignant histiocytes contain Birbeck granules and the protein langerin (CD207), both associated with Langerhans cells (LC), and it was postulated that the epidermal LC underwent a malignant transformation in LCH. However, a subsequent cytologic study illustrated that the dendritic cells that form LCH lesions are actually precursors from the bone marrow that travel to lesion sites and differentiate into langerin+ cells, a theory termed the ‘Misguided Myeloid Dendritic Cell Precursor’ model [1]. Animal studies confirmed the identity of LCH as a myeloid neoplasia by demonstrating that inducing a point mutation implicated in the disease’s pathogenesis, BRAF-V600E, in bone marrow dendritic cell progenitors resulted in a phenotype mimicking high-risk LCH in humans, while inducing the same mutation in differentiated dendritic cells resulted in a low-risk LCH phenotype [6].