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)

The changes in the number of Langerhans cells within the gingiva during a 21 day experimental gingivitis episode were investigated immunohistochemically. Monoclonal antibodies to CD1a (specific for Langerhans cells and thymocytes) and HLA-DR (class II major histocompatibility antigens - (MHC)) were used to identify Langerhans cells within gingival biopsies taken on days 0, 7, 14 and 21. HLA-DR antibody stained dendritic cells within the oral epithelium which were morphologically identical to the CD1a+ Langerhans cells. Class II MHC LC numbers rose and plateaued between day 7 and 14 then decreased to baseline by day 21. As plaque accumulated and initial inflammation developed there was an increase in the number of CD1a+ Langerhans cells which peaked at day 7 and stayed high (day 14). As inflammation developed there was a statistically significant decrease in the number of CD1a+ Langerhans cells by day 21 (p = 0.028). The initial increase, followed by a decrease in CD1a+ Langerhans cells as inflammation developed, suggests that migration of Langerhans cells occurs within the gingival epithelium and this may represent an important early event in the gingival immune response to plaque.
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PMID:Langerhans cell dynamics in human gingiva during experimentally induced inflammation. 128 8

Histochemical and immunohistochemical studies performed in only a few cases of sinus histiocytosis with massive lymphoadenopathy (SHML) indicated that SHML cells belong to the macrophage--histiocyte system, though their exact origin is still uncertain. We analyzed the morphological, antigenic and enzymatic characteristics of the histiocyte-like cells in one paediatric case of SHML (also named Rosai-Dorfman disease). The SHML cells expressed the S-100 protein, lectins concanavalin A, peanut agglutinin and monocyte-macrophage related antigens CD 11c, CD 14, CD 33, CD 68 and LN 5. Reactivity with other anti-macrophage antibodies (MAC387, lysozyme, alpha-1 anti-chymotrypsin) was variable. The CD1a antigen was present only in scattered cells, whereas HLA-DR and the HLA-DR associated invariant chain were absent. Cytochemistry demonstrated an intense activity of acid phosphatase and non specific esterase of SHML cells. A large amount of medium sized mononuclear cells were located in the sinuses and intersinusoidal tissue. Our findings suggest that SHML cells have intermediate features between phagocytes and Langerhans cells/interdigitating reticulum cells. The heterogeneity of marker expression on SHML cells might be related to the local content of factors (e.g., cytokines), capable of modulating the phenotype of monocyted and derived cells.
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PMID:Sinus histiocytosis with massive lymphoadenopathy (Rosai-Dorfman disease). Clinico-pathological analysis of a paediatric case. 840 78

Langerhans cells originate in bone marrow and probably belong to the monocyte-macrophage lineage. CD1 is a specific marker of Langerhans cells. By immunofluorescence and immunoelectron microscopy, CD1a antigen and myeloid markers (CD11, CD13, CD14, CD15, CD33, HLA-DR) were studied in 53 cases of acute myeloid leukemias (AML) and 3 acute lymphoblastic leukemias (ALL). The 11 ANLL without monocytic component were CD1a negative. 2/5 of acute myelomonocytic leukemias (AML4) and 9/37 of acute monocytic leukemias (AML5) were positive. All 3 ALL were negative. No correlation was found between CD1a and myeloid markers. CD1a+ AML did not differ from CD1a- AML with regard to cytogenetics or response to therapy. The CD1a positive cells may originate from an abnormal proliferation of CD1a positive cells which are present in bone marrow and which may differentiate into Langerhans cell precursors.
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PMID:CD1-reactive leukemic cells in bone marrow: presence of Langerhans cell marker on leukemic monocytic cells. 137 Apr 20

Epidermal Langerhans cells (ELC) are definitively primed to differentiate into dendritic cells (DC). It is unknown at what stage of monocyte development this priming occurs. In a culture system characterized by low paracrine stimulation, i.e. Iscove's modified Dulbecco medium (IMDM) with 2% FCS, we tested the ability of peripheral blood monocytes to turn to the route of the LC-DC lineage. In this system monocytes did not develop significant yeast cell phagocytosis, although mannose receptors were available. However, they became strong stimulators of mannan specific T cell proliferation. Phenotype development was analysed by flow cytometry using the monoclonal antibodies OKT6 (CD1a), IOT2 (HLA-DR), IOM2 (CD14) and the ligand Man-BSA-FITC. CD1a was the first marker which distinguished cultured monocytes from developing macrophages, obtained by addition of 8% human serum. Like cord blood Langerhans cells (CBLC) they internalized OKT6 in deep coated pits. They maintained a phenotype of monocyte derived Langerhans cells (MoLC) during eight days of in vitro culture, expressing CD1a, mannose receptors and HLA-DR and decreasing CD14, if left in their own conditioned medium. MoLC could be converted into macrophages by addition of human serum only within the first four days in vitro. Our data suggest that monocytes acquire an LC phenotype by autocrine stimulation.
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PMID:Development of a Langerhans cell phenotype from peripheral blood monocytes. 137 Dec 67

Depletion of Langerhans cells (LC) is known to follow bone marrow transplantation (BMT) and is thought to be mainly related to pretransplant radiation and chemotherapy conditioning regimens. We studied sequential biopsies of clinically normal skin of 22 thalassemic and leukemic patients undergoing allogeneic BMT who had received only chemotherapy (busulfan and cyclophosphamide) as conditioning regimen. LC were identified immunohistochemically using antibodies against CD1a and HLA-DR antigens, and their number expressed per square mm of epidermal vertical section, the latter measured by computerized image analysis. After the preparatory regimen, the number of LC decreased progressively in both leukemic and thalassemic patients. CD1a+ and HLA-DR+ epidermal cells were reduced, respectively, to 68.5% and 64.5% of their original number around Day 2, and to 23.1% and to 18.2% around Day 17. By this time, electron microscopic examination of selected biopsies confirmed the depletion of LC. Variable repopulation was observed between Days 40 and 60. Our results indicate that a conditioning regimen based exclusively on high dose chemotherapy depletes epidermal LC early after BMT, and that such depletion is not related to the development of acute graft-versus-host disease.
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PMID:Epidermal Langerhans cells after allogeneic bone marrow transplantation: depletion by chemotherapy conditioning regimen alone. 138 97

The Langerhans cell (LC) migrates between the epidermis and the regional lymph nodes to present antigens. This migration pattern requires the expression of a changing repertoire of cell-surface molecules. In this work, we have investigated the expression of the adhesion molecules CD 11/CD 18 and CD 58 on LCs. Human epidermal cell suspensions were enriched in LCs (mean enrichment 75%) using a two-step technique including a Ficoll-Hypaque gradient followed by Fc receptor panning with IgG-coated sheep erythrocytes. The number of cells obtained per experiment was 750,000 (extremes 280,000-1,800,000), and the following antibodies were tested on fresh suspensions and/or after 48 hours in culture: BB3 (antithyroglobulin negative control IgG2a), OKT6 (anti CD1a, Ortho), anti HLA-DR (Becton-Dickinson), MHM 24 (anti CD 11a, leukocyte typing workshop n(0)3), MO1 and 44 (anti CD 11b, leukocyte typing workshop n(0)3), anti CD 11c (Immunotech), 60.3 and MHM 23 (anti CD 18, leukocyte typing workshop n(0)2), TS2/9.1.1 (anti CD 58, leukocyte typing workshop n(0)3). We found that amongst CD 11 subunits, only CD 11c was expressed in fresh suspensions, but was weaker than CD 18, and disappeared with culture. CD 58 was not detected in fresh suspensions but appeared after 2 days of culture, confirming earlier work. Thus the LC exhibits cell surface characteristics similar to tissue macrophages (CD 18 and CD 11c) prior to culture. The expression of CD 58 after culture is in accordance with the interaction of LC with CD2 bearing T-lymphocytes during antigen presentation in peripheral lymph-nodes.
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PMID:Flow cytometry analysis of adhesion molecules on human Langerhans cells. 145 12

CD36 recognizes a 88 Kd glycoprotein, found on different cell populations involved in immunoregulation and are induced on keratinocytes by in vitro treatment with gamma-interferon. Therefore, we obtained skin biopsies from 48 patients with various dermatological diseases and from 5 healthy volunteers and stained these with monoclonal antibodies OKM5 (CD36), anti-HLA-DR and OKT6 (CD1a) using a three stage immunoperoxidase method. In normal skin, CD36 expression was not observed. In contrast, keratinocytes in diseased skin were CD36+. In most cases, the staining was restricted to the stratum granulosum and the stratum spinosum, but in psoriasis, squamous cell carcinoma and lymphomatoid papulosis, more extensive staining of keratinocytes was seen. In addition, CD36+ epidermal leukocytes were found in allergic patch-test infiltrates and in mycosis fungoides. The findings of CD36 expression by epidermal cells within a broad spectrum of dermatological diseases indicate a role for these cells in the regulation of immune reactions in the skin.
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PMID:Keratinocyte and epidermal leukocyte expression of CD36 (OKM5) in benign and malignant skin diseases. 168 91

This study examined the influence of cytokines on surface antigen expression by gingival Langerhans cells (LC) in organ culture, interleukin-6 (IL-6) and tumor necrosis factor alpha (TNF-alpha) upregulated the expression of CD1a, HLA-DR and HLA-DP antigens on LC. TNF-alpha, interleukin-4 (IL-4), and transforming growth factor beta (TGF-beta) suppressed CD29 expression, while other cytokines, including interleukin-3 and granulocyte-macrophage colony stimulating factor, were without effect. No cytokines induced CD3, CD4, CD23, CD25 or CD45 RA antigen expression in organ culture. Since TNF-alpha and IL-6 can be secreted by keratinocytes, these molecules, together with interleukin-1, are likely to play a role in the local control of LC number and function within the epithelial milleu. Thus, alterations in cytokine secretion by keratinocytes may at least in part be responsible for variations in LC number and antigen expression which occur in oral mucosal disorders.
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PMID:Modulation of Langerhans cell surface antigen expression by recombinant cytokines. 170 Nov 95

Seventeen human renal graft biopsies taken 1 h to 50 days after transplantation and 3 human renal non-graft biopsies (2 minimal change and 1 non-tumour portion of angiomyolipoma) were investigated with immunoelectron microscopy in order to identify interdigitating reticulum cells (IDC) or dendritic cells (DC) in renal tissues. The antibodies used consisted of a rabbit polyclonal antibody of antihuman S100 beta protein, mouse monoclonal antibodies of antihuman HLA-DR, anti-CD3, and anti-CD1a. IDC or DC were identified in 11 renal grafts. They were found both in the glomerular and interstitial (peritubular) capillary lumens but not in the interstitium of 1 case: both were present in the interstitial capillary lumens and interstitium of another case, and in the interstitium only of 9 cases. In the remaining 6 grafts and 3 non-grafts they were not detected. These 6 grafts and 3 non-grafts did not show any pathological change except for foot process fusion of the glomerular epithelia in 2 cases of minimal change. These findings suggest that IDC or DC are not normally present in human renal tissues. The presence of the cell in the glomerular and peritubular capillary lumens of a biopsy taken after 1 h and their presence in the interstitial capillary lumens of another graft biopsy, suggest that the IDC or DC in human renal grafts are derived from recipients, not donors, and that they migrate from the circulating blood toward the interstitium.
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PMID:Interdigitating reticulum cells in human renal grafts. 170 64

The regional development of Langerhans cells (LC) and the formation of Birbeck granules (BG) were examined in human embryonic and fetal skin. Samples were obtained from multiple anatomic sites and stained with anti-CD36, anti-CD1a, and anti-HLA-DR antibody as well as Lag antibody specifically reactive to BG and some vacuoles of human LC. In the first trimester, CD36+ dendritic epidermal cells were identified before the appearance of CD1a+ cells and Lag+ cells. Some of the former co-expressed HLA-DR antigens but not CD1a antigens. In the second trimester, regional variations in LC development were observed. Epidermal LC of palms and soles reached a peak in number in the first trimester but were rarely detected after 18 weeks estimated gestation age (EGA), whereas, in other regions, their number increased with age. In the second trimester, CD1a+ cells and Lag+ cells were also identified in the epidermis, although Lag+ cells appeared later than CD1a+ cells. The Lag+ cells until 17 weeks EGA showed a variety of staining intensities and immunoelectron microscopy revealed that they contained various amounts of Lag-reactive BG. Flow cytometric analysis showed that relative amounts of Lag antigens in LC increased during the second trimester and that fetal LC of 18 weeks EGA expressed the same amounts of HLA-DR, CD1a, and Lag antigens as did adult human LC. In the dermis, in the second trimester, numerous CD36+ cells and HLA-DR+ cells were found, whereas CD1a+ cells and Lag+ cells were rarely detected. Taken together, it is suggested that HLA-DR+ dendritic cells acquire CD1a+ antigens first and then form BG after migration to the epidermis and that fetal LC are phenotypically mature in the second trimester.
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PMID:Regional development of Langerhans cells and formation of Birbeck granules in human embryonic and fetal skin. 171 49


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