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

Pathological skin reactions were induced with both UVA and UVB in 12 patients with lupus erythematosus (LE) and with UVA in 7 with polymorphous light eruption (PMLE) but in none of the controls. Biopsy specimens taken from UV-induced lesions showed that in dermal infiltrates of LE cases CD4-positive cells predominated, whereas in the majority of PMLE cases CD8-positive cells predominated. Keratinocytes expressed intercellular adhesion molecule-1 (ICAM-1) in 7 of the 12 UVA- and in eight of the ten UVB-induced LE lesions, and in three of the UVA-induced lesions of PMLE patients. Three different staining patterns were found. In subacute cutaneous LE (SCLE) cases staining throughout the epidermis resembled that seen in genuine SCLE lesions. In discoid LE (DLE) lesions, the staining was most prominent in and near the basal cell layer. In the one systemic LE case and in the PMLE cases, ICAM-1 expression was seen only in association with epidermal spongiosis and T-cell infiltration. Keratinocytes did not express ICAM-1 in the controls or in the non-irradiated skin of the LE patients. In five on the UVA-induced lesions, in eight of the UVB-induced LE lesions and in one of the PMLE cases, keratinocytes expressed CD36. In four of the six LE lesions with fewer CD1a-positive cells, dendritic CD36-positive cells were seen in the epidermis. In conclusion, the pattern of activated keratinocytes and immunocompetent cells in the dermis was similar to that seen in genuine LE and PMLE lesions, but dissimilar to each other and to the controls.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Expression of intercellular adhesion molecule-1 (ICAM-1) and OKM5 in UVA- and UVB-induced lesions in patients with lupus erythematosus and polymorphous light eruption. 769 27

Using immunohistochemical techniques, we mapped and quantified the distribution of Langerhans cells (LCs) within the follicular epithelium of normal human skin in serial horizontal sections. Ten skin biopsies from disparate, disease-free sites from individuals of various skin types were stained with antibody to CD1a. LCs concentrated in the infundibular epithelium (x=16.16 cells), including the follicular bulge, and extended into the germinative sebaceous epithelium (x=8.84). In contrast, rare LCs (x=1.06) were observed in the follicular epithelium below the entry of sebaceous glands into the follicle. LCs were absent in bulbar epithelium. This infundibulocentric distribution of LCs corresponds to the pattern of follicular inflammation in the scarring folliculitides of lupus erythematosus and lichen planopilaris, as well as allogeneic graft versus host reaction and infundibulofolliculitis of atopy. Follicular LCs may act as the trigger and/or target for these T cell-mediated inflammatory processes.
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PMID:Distribution of Langerhans cells in human hair follicle. 944 91

Chemerin is a chemotactic agent that was recently identified as the ligand of ChemR23, a serpentine receptor expressed by activated macrophages and monocyte-derived dendritic cells (DCs). This paper shows that blood plasmacytoid and myeloid DCs express functional ChemR23. Recombinant chemerin induced the transmigration of plasmacytoid and myeloid DCs across an endothelial cell monolayer. In secondary lymphoid organs (lymph nodes and tonsils), ChemR23 is expressed by CD123(+) plasmacytoid DCs and by CD1a(+) DC-SIGN(+) DCs in the interfollicular T cell area. ChemR23(+) DCs were also observed in dermis from normal skin, whereas Langerhans cells were negative. Chemerin expression was selectively detected on the luminal side of high endothelial venules in secondary lymphoid organs and in dermal endothelial vessels of lupus erythematosus skin lesions. Chemerin(+) endothelial cells were surrounded by ChemR23(+) plasmacytoid DCs. Thus, ChemR23 is expressed and functional in plasmacytoid DCs, a property shared only by CXCR4 among chemotactic receptors. This finding, together with the selective expression of the cognate ligand on the luminal side of high endothelial venules and inflamed endothelium, suggests a key role of the ChemR23/chemerin axis in directing plasmacytoid DC trafficking.
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PMID:Role of ChemR23 in directing the migration of myeloid and plasmacytoid dendritic cells to lymphoid organs and inflamed skin. 1572 34

Systemic lupus erythematosus (SLE) is characterized by a systemic autoimmune response with profound and diverse T cell changes. Dendritic cells (DCs) are important orchestrators of immune responses and have an important role in the regulation of T cell function. The objective of this study was to determine whether myeloid DCs from individuals with SLE display abnormalities in phenotype and promote abnormal T cell function. Monocyte-derived DCs and freshly isolated peripheral blood myeloid DCs from lupus patients displayed an abnormal phenotype characterized by accelerated differentiation, maturation, and secretion of proinflammatory cytokines. These abnormalities were characterized by higher expression of the DC differentiation marker CD1a, the maturation markers CD86, CD80, and HLA-DR, and the proinflammatory cytokine IL-8. In addition, SLE patients displayed selective down-regulation of the maturation marker CD83 and had abnormal responses to maturation stimuli. These abnormalities have functional relevance, as SLE DCs were able to significantly increase proliferation and activation of allogeneic T cells when compared with control DCs. We conclude that myeloid DCs from SLE patients display significant changes in phenotype which promote aberrant T cell function and could contribute to the pathogenesis of SLE and organ damage.
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PMID:Aberrant phenotype and function of myeloid dendritic cells in systemic lupus erythematosus. 1705 12

Dendritic cells (DCs) are antigen-presenting cells with an important role in the innate and adaptive immune system. In skin lesions, cutaneous DCs (Langerhans cells, dermal DCs and plasmacytoid DCs) are involved in immune activation in inflammatory benign lesions, as well as in malignant lymphoid proliferations. Density and distribution of DCs in the dermal infiltrate can be helpful to differentiate benign, reactive infiltrate from malignant nature of the lymphoid population. We performed a retrospective study including 149 patients: 35 with mycosis fungoides, 35 with spongiotic dermatitis, 35 with psoriasis, 35 with lupus and 9 with cutaneous T-cell lymphomas (other than mycosis fungoides), diagnosed using histopathological and immunohistochemical stains. Density and distribution of DCs were evaluated using specific markers (CD1a, CD11c and langerin). In all cases, numerous DCs were identified in the dermal infiltrate. Their number was significantly increased in mycosis fungoides and T-cell lymphomas and moderately increased in inflammatory lesions. Variable patterns of distribution were identified such as clusters of DCs with arachnoid extension in mycosis fungoides, nodular pattern in inflammatory lesions and dispersed distribution with peripheric accumulation in T-skin lymphomas. Therefore, immunohistochemical characterization of DC distribution can be an adjuvant tool in differential diagnosis in inflammatory dermatosis and skin lymphomas.
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PMID:Dendritic cell distribution in mycosis fungoides vs. inflammatory dermatosis and other T-cell skin lymphoma. 3094 98

Indeterminate cell histiocytosis (ICH) is an extremely rare clonal proliferative disorder of dendritic cells which presents with skin lesions in the majority of cases. Although extra-cutaneous manifestations are very rare, ICH may involve the mucosa, cornea, and conjunctiva as well as the visceral organs. Since the clinical appearance of cutaneous lesions of ICH is not distinctive, it is diagnosed with histopathological and immunohistochemical findings after clinical suspicion. Herein, we report a 27-year-old man with a two-year history of asymptomatic reddish papules and papulonecrotic lesions on his face, arms and buttocks. He was previously diagnosed with systemic lupus erythematosus (SLE) and antiphospholipid antibody syndrome (APS), and he had been treated with hydroxychloroquine and low-dose aspirin. Diffuse dermal infiltration of a mixture of histiocytes and lymphocytes accompanied with multinuclear giant cells, the positive CD68 and Factor XIIIa and negative Langerin immunoreactions, along with the positive staining with CD1a and S100, led us to the diagnosis of ICH. To the best of our knowledge, this is the first case of ICH associated with SLE and APS.
Lupus 2020 Jan
PMID:Indeterminate cell histiocytosis in a patient with systemic lupus erythematosus and antiphospholipid antibody syndrome: an unusual association. 3178 27