Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P06126 (CD1a)
 2,221 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

We have performed double immunolabelings for cytofluorometric analysis and electron microscopy to investigate the coexpression of the CD1a (OKT6 and DMC1 monoclonal antibodies) antigen and the promonocyte/monocyte differentiation antigens CD14 (My4) or CD33 (My9) on putative bone marrow and umbilical cord blood precursors of the Langerhans cells (LC) and the epidermal LC. By cytofluorometric analysis, the percentage of CD1a+ cells which coexpressed the CD33 antigen was different from the bone marrow (5% of CD33+ cells are CD1a+), to the cord blood (3% of the CD33+ are CD1a+) and to the epidermis (the whole population of CD33+ LC are CD1a+). The ultrastructural morphology of the CD1a-expressing bone marrow, cord blood cells closely approximated that of a promonocyte/monocyte. Only LC epidermal were specifically recognized by the intracytoplasmic Birbeck granules. These CD1a+/CD33+ or CD14+ subpopulations found in three different locations (epidermis, bone marrow, cord blood) display a similar quantitative expression of the CD14 and CD33 antigens.
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PMID:Ontogeny of Langerhans cells: phenotypic differentiation from the bone marrow to the skin. 169 67

The structural similarities of CD1a molecules to major histocompatibility complex (MHC) class I antigens, as well as their expression on epidermal antigen-presenting cells suggest that CD1a molecules might be involved in the cutaneous immune response. In the present study, we investigated the effect of different anti-CD1a monoclonal antibodies (BL6, DMC1, and Na1/34) on T cell proliferation induced by allogeneic epidermal cells in vitro. A significant inhibition of the mixed skin cell-lymphocyte reaction was obtained with BL6 and DMC1 monoclonal antibodies (MoAb), which recognize the same epitope on CD1a molecule. The observed inhibition could not be related to a steric hindrance of MHC class II molecules, because Na1/34 MoAb, which reacts with another epitope on CD1a molecule, had no significant effect. BL6 and DMC1 MoAb interfered with an early event of T-cell activation, as shown by a time-course study. In the presence of these MoAb, the addition of exogenous interleukin 2 did not restore T-cell proliferation. Furthermore, the inhibitory effect of anti-CD1a MoAb was not mediated by a suppressor factor released by Langerhans cells (LC). These present data suggest that CD1a molecule may have an important function in self peptide presentation by human Langerhans cells.
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PMID:A potential role for CD1a molecules on human epidermal Langerhans cells in allogeneic T-cell activation. 171 29

Human epidermal Langerhans cells express two (CD1a and CD1c) of the three human thymic cell surface differentiation antigens (CD1a, CD1b, and CD1c). The first cluster of differentiation antigens (CD1) is defined by a group of monoclonal antibodies (MCA). All these MCA were obtained after immunization of mice or rats with human cortical thymocytes. OKT6 MCA (a CD1a MCA) was the first to be described as reactive with human epidermal Langerhans cells. We produced a murine MCA, called DMC1, after immunization with proliferating Langerhans cells of Eosinophilic Granuloma of the bone (Histiocytosis X). In tissues DMC1 MCA reacted with epidermal dendritic cells (Langerhans cells) in the skin and cortical thymocytes in the thymus as observed on indirect immunofluorescence. At the ultrastructural level, DMC1 MCA was specific for Birbeck granule-containing Langerhans cells and did not react with melanocyte and keratinocyte populations. The quantitative analysis of immunoelectron labeling and the cytofluorometric study showed that the intensity of labeling was inversely correlated with the concentration of trypsin used in the preparation of epidermal cell from skin samples. DMC1 MCA precipitated a protein with a relative mass of 49,000 (CD1a molecule) from lysates of iodinated epidermal Langerhans cells under reducing conditions. It recognized the original CD1a molecule (Mr 49,000) but not the membrane breakdown product of CD1a (Mr 27,000) brought about by trypsin.
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PMID:DMC1: a monoclonal antibody produced from histiocytosis X cells which reacts with the native CD1a molecule of human epidermal Langerhans cells. 246 37