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)

The CD1 molecules have been shown to present non-protein antigens, such as complex lipids to Mycobacteria, and may be important in presenting glycolipids which are involved in inflammatory neuropathies. To study the expression of CD1 molecules in peripheral nerve, we examined nerve biopsies from two patients with acute inflammatory demyelinating polyradiculoneuropathy (AIDP), five with acute axonal neuropathy, six with chronic inflammatory demyelinating polyradiculoneuropathy (CIDP), nine with chronic axonal neuropathy, six with vasculitic neuropathy and three with no histological abnormality. Immunocytochemical studies showed strong labelling of CD1b on endoneurial macrophages (CD68+) and on myelinated nerve fibres in both AIDP patients, but it was rarely observed in the other patients. Weaker staining was seen on endoneurial macrophages and/or other endoneurial cells in some of the patients with other peripheral neuropathies, but none of the control nerves. CD1a had a weaker, but similar pattern. There was endoneurial infiltration of CD4+ and CD8+ T cells in the AIDP and CIDP nerves and sometimes in the other peripheral neuropathy nerves, but not in the normal nerves. Most T cells had alpha beta+ T cell receptors (TCR), but gamma delta+ TCR T cells were found in the nerves of both AIDP patients and sometimes in the nerves of other patients with peripheral neuropathy. Staining for mannose receptor was almost universal, being more intense in AIDP, chronic axonal neuropathy and vasculitis patients. We conclude that CD1 molecule expression is upregulated in peripheral neuropathy, especially in association with inflammation.
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PMID:The distribution of CD1 molecules in inflammatory neuropathy. 970 86

The role of tumour necrosis factor (TNF)-alpha in the mobilization and migration of human epidermal Langerhans cells (LC) has been investigated. Intradermal injection of normal human volunteers with homologous recombinant TNF-alpha was found to cause a dose-dependent reduction in the frequency of LC within epidermal sheets 2 h later. Equivalent results were obtained when epidermal LC were identified on the basis of either CD1a or HLA-DR expression. At the dose of TNF-alpha used routinely (500 U), treatment resulted in an average reduction in LC density of approximately 24%. Treatment with TNF-alpha was associated with a perivascular polymorphonuclear infiltration at 2 h, but the epidermis appeared normal with neither fibrinoid necrosis nor vasculitis, and LC morphology was not affected significantly. These results demonstrate that TNF-alpha provides an important signal for LC migration in humans and is likely therefore to play a crucial part in the induction of cutaneous immune responses.
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PMID:Tumour necrosis factor-alpha induces Langerhans cell migration in humans. 1046 87

Vasculitic neuropathy and chronic inflammatory demyelinating polyneuropathy (CIDP) are neuropathies characterized by a T-lymphocyte infiltrate in the peripheral nerves. The microenvironment in which these T cells become activated, and the molecules and cells that play a role in this process are incompletely understood. Using immunohistochemical analysis, we studied the effect of the presence of adhesion, costimulatory and antigen-presenting molecules on different cell types as a precondition for local T-cell activation in human sural nerve biopsies of seven patients with CIDP, three patients with vasculitic neuropathy and three healthy controls. In biopsies from CIDP and vasculitic neuropathy patients, but not in those from healthy controls, Schwann cells expressed the adhesion/T-cell stimulatory molecule CD58 (LFA-3). The CD58 molecule was also present on endothelial cells of all vasculitic neuropathy patients and one CIDP patient. In biopsies from normal controls and patients, CD54 (ICAM-1) expression was detectable on microvascular endothelial cells. In addition, expression of the costimulatory molecule CD86 was detected on vascular tissue in patients with vasculitic neuropathy. Although macrophages were always present in all subjects, expression of the major histocompatibility complex (MHC)-like molecule CD1a by macrophages was restricted to biopsies from two CIDP patients and one vasculitic neuropathy patient. Unexpectedly, Schwann cells of a single vasculitis patient strongly expressed CD1b, a molecule involved in the presentation of self-glycolipids to T cells. Schwann cells in biopsies from patients and normal controls expressed high levels of the invariant chain, CD74, a molecule involved in the intracellular sorting of MHC class II molecules. There was no evidence for the presence of dendritic cells in sural nerve biopsies. These findings support a model in which T-cell activation can be initiated and/or perpetuated locally in sural nerve biopsies of patients with CIDP and vasculitic neuropathy, and predict an important role for Schwann cells and endothelial cells.
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PMID:Expression of accessory molecules for T-cell activation in peripheral nerve of patients with CIDP and vasculitic neuropathy. 1100 19

The cutaneous variant of Rosai-Dorfman disease is a rare benign lymphoproliferative disorder that occurs without lymphadenopathy or internal organ involvement. We present a 55-year-old woman with a diffuse exanthematous eruption that evolved into pruritic papulopetechial and purpuric lesions on the back and lower extremities, diagnosed clinically as a vasculitis. The patient's lesions cleared spontaneously with no recurrence. Histopathologic examination showed a dense dermal nodular lymphohistiocytic infiltrate with occasional eosinophils, plasma cells, and neutrophils and with numerous extravasated red blood cells. The large, foamy histiocytes exhibited abundant pale cytoplasm, feathery cytoplasmic borders, and emperipolesis. A few histiocytes had longitudinal nuclear grooves resembling Langerhans cells; however, these cells were positive for S-100 protein and negative for CD1a. The clinical presentation of the cutaneous variant of Rosai-Dorfman disease is generally nonspecific. We present this case because of the unusual clinical presentation mimicking a vasculitis.
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PMID:Cutaneous sinus histiocytosis (Rosai-Dorfman disease) presenting clinically as vasculitis. 1200 23

A 50-year-old man presented with an asymptomatic, 1.5 x 1.5 cm, dark-brown noduloplaque with a rubbery consistency (Fig. 1) on the lateral aspect of the left lower leg of uncertain duration. His general condition was healthy, and he did not recall any trauma or insect bite at this site. No similar skin lesions were found elsewhere and no lymphadenopathy was observed. The lesion revealed a nonencapsulated, but well-circumscribed, deep dermal nodule with several lymphoid aggregates and germinal center-like structures within the tumor and also at the periphery, when examined microscopically at scanning power (Fig. 2a). The epidermis showed no remarkable changes, except for basal hyperpigmentation. At higher power, a mixed inflammatory infiltrate composed of histiocytes, foamy histiocytes (Fig. 2b), lymphocytes, and abundant plasma cells (Fig. 2c) with Russell bodies was revealed. The stroma contained mainly hyalinized and sclerotic collagen fibers (Fig. 2d). Prominent venules were noted, especially in the sclerotic areas, and some were surrounded by dense collagen fibers. No vasculitis or emperipolesis was found. No foreign materials were observed by polarization microscopy, and no organisms could be identified by periodic acid-Schiff (PAS), Grocott methenamine silver (GMS), Giemsa, Gram, acid-fast, or fite stains. The results of testing for infection by Epstein-Barr virus (EBV) (latent membrane protein 1, LMP-1) were negative. No spindle cells were found in the lesion. Immunohistochemical studies demonstrated mature plasma cells stained with CD138, and polyclonality was confirmed by the expression of both kappa and lambda light chains. The germinal center-like lymphoid aggregates were found to be B cells, which reacted positively with CD20. Scarce S100-positive cells and even rarer CD1a-positive cells were detected. Test results for smooth muscle actin (SMA) and anaplastic lymphoma kinase (ALK) were negative. Abundant CD68+ macrophages were observed within the lesion (Fig. 3a), and about 50-75% of the inflammatory cells were found to express cyclooxygenase-2 (COX-2) (Fig. 3b). The patient's condition was diagnosed as cutaneous plasma cell granuloma (CPCG). One year after excision, no evidence of recurrence was observed.
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PMID:Cutaneous plasma cell granuloma: report of a case with novel histologic and immunohistochemical findings. 1933 29

Scrub typhus is a common and underdiagnosed cause of febrile illness in Southeast Asia, caused by infection with Orientia tsutsugamushi. Inoculation of the organism at a cutaneous mite bite site commonly results in formation of a localized pathological skin reaction termed an eschar. The site of development of the obligate intracellular bacteria within the eschar and the mechanisms of dissemination to cause systemic infection are unclear. Previous postmortem and in vitro reports demonstrated infection of endothelial cells, but recent pathophysiological investigations of typhus patients using surrogate markers of endothelial cell and leucocyte activation indicated a more prevalent host leucocyte than endothelial cell response in vivo. We therefore examined eschar skin biopsies from patients with scrub typhus to determine and characterize the phenotypes of host cells in vivo with intracellular infection by O. tsutsugamushi, using histology, immunohistochemistry, double immunofluorescence confocal laser scanning microscopy and electron microscopy. Immunophenotyping of host leucocytes infected with O. tsutsugamushi showed a tropism for host monocytes and dendritic cells, which were spatially related to different histological zones of the eschar. Infected leucocyte subsets were characterized by expression of HLADR+, with an "inflammatory" monocyte phenotype of CD14/LSP-1/CD68 positive or dendritic cell phenotype of CD1a/DCSIGN/S100/FXIIIa and CD163 positive staining, or occasional CD3 positive T-cells. Endothelial cell infection was rare, and histology did not indicate a widespread inflammatory vasculitis as the cause of the eschar. Infection of dendritic cells and activated inflammatory monocytes offers a potential route for dissemination of O. tsutsugamushi from the initial eschar site. This newly described cellular tropism for O. tsutsugamushi may influence its interaction with local host immune responses.
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PMID:Orientia tsutsugamushi in human scrub typhus eschars shows tropism for dendritic cells and monocytes rather than endothelium. 2225 38

Granuloma faciale (GF) is a rare chronic inflammatory skin disease characterized by single or multiple reddish-brown cutaneous plaques or nodules. Although this condition is benign, its clinical course is extremely chronic with poor response to therapy. The typical histopathological features of GF include vasculitis with mixed cellular infiltration; however, its etiopathogenesis remains unknown. Here, we describe the case of a 76-year-old man with GF resistant to topical steroids. Biopsy of the lesion revealed i) dense mixed inflammatory cellular infiltrates of lymphocytes, histiocytes, neutrophils, and eosinophils, ii) mild perivascular nuclear dust and swollen endothelium of blood vessels, and iii) a narrow Grenz zone beneath the epidermis. Immunohistochemical staining demonstrated mixed cellular infiltrates intermixed with CD1a(+) dendritic cells, CD68(+) histiocytes, and CD4(+) and CD8(+) T cells.
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PMID:The interaction of inflammatory cells in granuloma faciale. 2538 52