Langerhans cells
2001; Elsevier BV; Linguagem: Inglês
10.1016/b978-012455851-9/50044-4
Autores Tópico(s)Immune Cell Function and Interaction
ResumoThis chapter describes the characteristics of human epidermal Langerhans cells (LCs). Resident LCs display nonspecific esterase and ATPase activity, and are the only cells within the normal epidermis to express CD1a, Fc-IgG receptors type II (FcRγII, CD32), Fc-IgE receptors type I (FcɛRI), C3bi receptors (CD11b–CD18), and major histocompatibility complex (MHC)-encoded class II antigens. LCs in situ have only a limited potency for stimulating naive resting T cells but are quite efficient in antigen capture. They are capable of engulfing large particles beads but lack classical antigen uptake receptors such as the mannose receptor. The mAb DCGM4 reacts selectively with LCs staining both the cell surface and the cytoplasm. By immunoprecipitation, DCGM4 identifies a 40 kDa molecule, termed Langerin—a type II Ca-dependent lectin displaying mannose-binding specificity. While sparing MHC class II cytoplasmic compartments, Langerin co-localizes with Birbeck granules. When incubated with freshly isolated LCs, the anti-Langerin mAb is internalized into Birbeck granules.
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