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Viral infections
Published in Phillip D. Smith, Richard S. Blumberg, Thomas T. MacDonald, Principles of Mucosal Immunology, 2020
Sarah Elizabeth Blutt, Mary K. Estes, Satya Dandekar, Phillip D. Smith
The ability of Langerhans cells in the vaginal epithelium to capture and internalize HIV-1 has been conclusively demonstrated by electron microscopy. Langerhans cells are present in the upper layers of the epithelium and may extend processes between epithelial cells into the apical surface of the epithelium, positioning the cells to capture and internalize HIV-1 inoculated onto the mucosal surface (Figure 28.5). Langerhans cells express CD207 (langerin, a C-type lectin) and CD4 and CC-chemokine 5 (CCR5), the HIV-1 primary receptor and coreceptor, but blocking studies suggest that only CD4 and CCR5 are involved in HIV-1 endocytosis. Once captured, HIV-1-containing Langerhans cells can exit the upper epithelium in an ex vivo tissue system in which the underlying stroma has been removed. However, Langerhans cells do not migrate through explanted vaginal mucosa in which the subjacent stroma remains attached to the epithelium, and Langerhans cells have not been identified in the draining lymph nodes. Moreover, langerin, at least on skin Langerhans cells, mediates the binding and internalization of HIV-1 into Birbeck granules, which degrade the virus. Thus, dermal Langerhans cells inhibit T-cell infection by viral clearance through langerin-mediated internalization, but whether vaginal Langerhans cells also serve as a barrier to HIV-1 infection is unclear.
Lymphangioleiomyomatosis and other cystic interstitial lung diseases
Published in Muhunthan Thillai, David R Moller, Keith C Meyer, Clinical Handbook of Interstitial Lung Disease, 2017
Amanda T Goodwin, William YC Chang
In PLCH, large numbers of LCs around the distal airways alongside variable numbers of eosinophils, lymphocytes and alveolar macrophages are seen histologically (18) (Table 21.5). LCs have pale, eosinophilic cytoplasm, indistinct cell borders and grooved nuclei with small nucleoli (1,26). Immunostaining for CD1a and CD207 and the presence of Birbeck granules on electron microscopy confirm the presence of LCs (26,71–73). PLCH lesions evolve from highly cellular nodules to paucicellular fibrotic areas (1). Venous and arterial structures often appear abnormal (74).
Immunology
Published in M. Alan Menter, Caitriona Ryan, Psoriasis, 2017
Langerhans cells are a type of immature conventional DC that reside in the epidermis.7 They are actively phagocytic and contain large granules known as Birbeck granules. CD1a and langerin (CD207) are used as specific markers to distinguish Langerhans cells from other DC subsets. The main role of Langerhans cells is to take up and process antigens and migrate to local skin-draining lymph nodes where they present to antigen-specific T cells.2 However, the role of Langerhans cells in psoriasis immunopathogenesis is still unclear.3 Recently, attention has focused on the potential importance of Langerhans cells in uninvolved skin sites of psoriasis patients, and it has been demonstrated that Langerhans cell migration is impaired in early onset psoriasis (onset before 40 years of age).31,32 Also, the treatment with TNF-α inhibitors (adalimumab, etanercept) and anti-IL-12p40 antibody (ustekinumab) significantly restored epidermal Langerhans cell migration in uninvolved skin.33 Although the influence of impaired Langerhans cell mobilization on the pathogenesis of psoriasis is uncertain, the loss of Langerhans cell motility may have an impact on the ability of these cells to sense the local antigenic microenvironment and regulate cutaneous immune responses.
Immunosafety evaluation in Juvenile Göttingen Minipigs
Published in Journal of Immunotoxicology, 2022
Linda Allais, Alicia Perbet, Fabienne Condevaux, Jean-Paul Briffaux, Marc Pallardy
Among the MHCII+CD172a+ population, two other subsets were analyzed using CADM1 and CD207 surface markers (Figure 7) and CD163 (Figure 8). CADM1 (SynCAM: Synaptic Cell Adhesion Molecule) has been proven to be highly expressed by both human and porcine cDC1 cells, especially by DC residing in tissues. In the current study, > 60% of MHCII+CD172a+ cells in both the blood and lymph nodes were found to co-express CADM1 in the 6-mo-old minipigs whereas < 10% of the same population was found to be CADM1+ in 4-wk-old piglets (Figure 7). CD207, also called langerin, a c-type lectin receptor expressed mainly by Langerhans cells and dermal cDC2 DC, was also included in the labeling procedure of blood and lymph node cell suspensions collected in the present study. Surprisingly, a large portion of the MHCII+CD172a+ subset was also found to be CD207+; however, there were no relevant differences for this cell type among the age groups.
Epicutaneous Administration of 17β-Estradiol Induces Langerhans Cells Depletion
Published in Immunological Investigations, 2022
Katia Jarquín-Yáñez, Miguel Ángel Herrera-Enriquez, Cristina Lemini, Edith Melendez-Moreno, Paulina Villena-López, Maria Estela Ávila, Beatriz Hernández-Téllez, Gabriela Piñón-Zárate, Enrique Agustin Sampedro-Carrillo, Andrés Eliú Castell-Rodríguez
On the other hand, dermatological responses are affected by the menstrual cycle phase in some patients, and estrogens and progesterone affect the skin and immunological function, particularly estrogens, which are considered suppressors of cellular immunity (Farage et al. 2010). In addition, LC migration might result from E2 functioning as a migration promoter, which would induce epidermal LC migration to the regional lymph nodes, similar to other molecules (Cumberbatch et al. 2003). When TUNEL/CD207 double staining was performed on histological sections of skin from mice that received a topical dose of E2, we only observed CD207 expression. Apoptosis was not observed in any cells. However, the CD207+ epidermal cell population decreased significantly, and the CD207+ cell population increased in the dermis. Two possible explanations for this phenomenon are proposed. First, the increase in CD207+ cells in the dermis might represent the migration of cells to the lymph nodes. The observation that the few CD207+ epidermal cells were always in a basal position supports this possibility (Figure 4). Second, CD207+ epidermal cells might be nonmigratory LC. The migration of maturing LC is associated with an increase in CXCR4/CXCL12 expression mediated by fibroblasts in the dermis (Gibbs et al. 2013), and E2 might directly cause the migration of LC, since E2 induces the migration of bone marrow-derived cells via CXCL12-CXCR4 signaling (Wang et al. 2015).
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).