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)

Dendritic cells (DCs) are bone-marrow derived 'professional' antigen presenting cells (APC). They are considered as the most potent APC able to induce primary immune responses. DC efficiently capture and process proteic and non-proteic antigens. They are widely distributed throughout the body and occupy sentinel positions such as epithelia. Establishment of an immune response against cancer may depend of the capacity of DCs to transfer (to capture, to process and to present) tumor antigens into regional lymph nodes where they can induce a specific response leading to tumor rejection. Because host 'professional' DCs are one of the most important elements in the induction of specific anti-tumor responses and lymph nodes are the places where the immune response takes place, we investigated the densities of DCs within regional metastasis-free lymph nodes from 47 patients with different malignant epithelial tumors as comparing with lymph nodes from 11 patients without malignancies using an immunohistochemistry method with anti-S100 protein, CD86 and CD1a antibodies. By means of morphometric analysis, we observed that S100+ and CD1a+ DCs densities in regional lymph nodes from cancer patients were significatively decreased as compared with control lymph nodes (P<0.0001 and 0.003, respectively). S100+ DCs and CD86+ DCs densities in lymph nodes draining cancer were similar. Taken together, these data indicated that lymph nodes draining cancer had significantly less CD1a+ DCs than S100+ and possibly CD86+ DCs. These findings may represent another mechanism by which tumors evade the immune recognition.
Immunol Lett 2002 Dec 03
PMID:Human regional lymph nodes draining cancer exhibit a profound dendritic cell depletion as comparing to those from patients without malignancies. 1241 31

Langerhans cells (LCs) are dendritic components of stratified epithelia, presenting antigens to other cells of the immune system that play a crucial role in local defense. The paucity of information about their significance in the esophageal mucosa was addressed by studying their distribution and morphology in this particular location. LCs were identified by immunohistochemical detection of CD1a, a cell-specific marker, using a monoclonal antibody, as well as by electron microscopic identification of characteristic Birbeck granules, among other typical morphological features. Cell counts carried out at 25 and 35 cm distal to the dental arch demonstrated significant differences in number and size between the two locations. The upper region contained 10.4 +/- 0.8 cells (mean +/- SEM) vs. 18.4 +/- 1.4 cells in the lower region. Also, cells in the lower region were larger and appeared to have longer dendritic processes. To our knowledge this is the first report of regional differences in number and morphology of LCs in human esophageal mucosa.
Anat Rec 2002 Dec 01
PMID:Variation in Langerhans cell number and morphology between the upper and lower regions of the human esophageal epithelium. 1242 Feb 83

The distributions of Merkel cells and Langerhans cells within human hair follicles have been reported. However, there has been no description of the relationship between Merkel cells and Langerhans cells, which were discovered by 19th century German pathologists. Merkel cells and Langerhans cells share some similar characteristics such as the localization of human hair follicles, a close association with peripheral nerves and the expression of several neuropeptides. Merkel cells were stained with CK20 or CAM5.2, while Langerhans cells were stained with CD1a or S-100 protein. We thus immunohistochemically confirmed the preferential localization of Merkel cells and Langerhans cells in normal human hair follicles. Using a double staining technique, two- and three-dimensional observations demonstrated that a small proportion of Merkel cells were closely contacted with Langerhans cells below the sebaceous gland level, presumably indicating the bulge area. Merkel cells and Langerhans cells connected directly or approached each dendrite within the basal layer of the outer root sheath. For the first time, we demonstrated a close anatomical relationship between Merkel cells and Langerhans cells within the bulge area of human hair follicles where follicular stem cells may be present. These morphological observations suggest a functional interaction between follicular Merkel cells and Langerhans cells. We herein hypothesize that Merkel cells communicate with Langerhans cells by characteristic dendrites in which some neuropeptides or cytokines may be stored.
J Dermatol Sci 2002 Dec
PMID:Spatial relationship between Merkel cells and Langerhans cells in human hair follicles. 1244 42

The orphan homeobox gene HOX11L2 was previously found to be transcriptionally activated as a result of the t(5;14)(q35;q32) translocation in three T-ALL cases. We now tested by RT-PCR Hox11L2 expression in 23 consecutive cases of T-ALL (15 children aged 0.8-14 years, eight adults aged 17-55 years) and as control 13 B-ALL patients from a single institution. Hox11L2 expression was undetectable in all patients with B-ALL, nor in adults with T-ALL. Nine children (60% of the cases), all boys, expressed Hox11L2. Blast cells from most of the latter patients carried surface CD1a, CD10 and not CD34 antigens, in contrast to the other children. FISH, M-FISH and IPM-FISH analysis failed to detect a t(5;14)(q35;q32) in one of them, which suggests a possible distinct genetic mechanism in Hox11L2 expression induction. Hence, Hox11L2 expression seems to be the most frequent abnormality in childhood T-ALL to date, comparable to the t(12;21) in child B-ALL.
Leukemia 2002 Dec
PMID:High incidence of Hox11L2 expression in children with T-ALL. 1245 47

BACKGROUND The pathogenesis of Langerhans cell histiocytosis (LCH), a disease characterized by an abnormal accumulation of the dendritic Langerhans cells, is still unknown. Based on the monoclonality of the CD1a+ cell and reports of familial clustering, it is hypothesized that a genetic alteration at a cellular level may be causative. This genetic change may have an effect on the cellular mechanisms controlling proliferation and apoptosis. MATERIALS AND METHODS LCH-lesions were studied for the expression of Ki-67, present in the nucleus of proliferating cells. Furthermore, the expression of cell cycle-related gene products TGF-beta receptor I and II, MDM2, p53, p21, p16, Rb, and Bcl2 were studied. The TGF-betaR genes play a role in tumor suppression, whereas Bcl2 inhibits apoptosis. The remaining genes are part of either the p53-p21 and/or p16-Rb pathways, which induce cell cycle arrest or apoptosis in response to DNA damage. RESULTS In 30 biopsies the diagnosis of LCH could be confirmed on the basis of CD1a positivity (27 bone and 3 skin). All cases showed scattered nuclear-positive staining for the proliferation marker Ki-67. In more than 90% (n >/=27) of these cases, expression of TGFbeta receptor I and II, MDM2, p53, p21, p16, Rb, and Bcl2 was detected in lesional LCH cells. The overexpression was in general heterogeneous, ranging from limited focal staining of scattered cells within the lesion to strong diffuse staining. CONCLUSIONS These findings suggest that the cellular mechanisms that sense and respond to DNA-damage, namely the p53-p21 pathway and the p16-Rb pathway, are activated. The expression of Ki-67 indicates that the cells in LCH are proliferating. The observed overexpression of Bcl2 may play a role in the activation of p53 and p16 and/or the arrest of apoptosis.
J Pediatr Hematol Oncol 2002 Dec
PMID:Expression of cell cycle-related gene products in Langerhans cell histiocytosis. 1246 13

Dendritic cells (DC) are potent APCs that sample Ags from the surrounding environment and present them to naive T cells using cell surface Ag-presenting molecules. The DC in both lymphoid and nonlymphoid tissues express high levels of CD1, a cell surface glycoprotein capable of presenting lipids and glycolipids to T cells. Distinct group 1 CD1 isoforms (CD1a, -b, -c) in man are known to traffic to different parts of the endocytic system where microbial Ags may be sampled. Guinea pigs are the only known rodent species that express the group 1 CD1 proteins. Therefore, we examined the expression and trafficking of guinea pig CD1 (gpCD1) isoforms on isolated DC. Confocal microscopy using mAbs specific for individual gpCD1 isoforms revealed differential trafficking of two distinct CD1b isoforms within DC. Colocalization of MHC class II was observed with the gpCD1b1 isoform, consistent with localization in the late endosomes of DC. In contrast, the gpCD1b3 isoform lacks an endosomal sorting motif and remains on the cell surface. Following incubation with Mycobacterium tuberculosis lipoarabinomannan, colocalization of endocytosed lipoarabinomannan with the gpCD1b1 isoform was observed but not with the gpCD1b3 isoform, which remained primarily on the cell surface. These data demonstrate that guinea pig DC express CD1 isoforms with unique trafficking patterns that recapitulate the patterns seen for human CD1 isoforms. This suggests evolutionary pressure for a conserved mechanism in mammals that allows CD1 to sample lipid Ags from various subcompartments of the endocytic system.
J Immunol 2002 Dec 15
PMID:Conservation of CD1 intracellular trafficking patterns between mammalian species. 1247 Nov 29

Hematopoietic neoplasm coexpressing CD4 and CD56 includes a subset of acute myeloid leukemia with myelomonocytic differentiation, plasmacytoid monocyte tumor, and other immature hematopoietic neoplasms of undefined origin. Herein, we report a CD4+CD56+CD68+ hematopoietic tumor that was thought to be a tumor of plasmacytoid monocytes. This case is unique in the absence of accompanying myelomonocytic leukemia and the faint expression of cCD3 on the tumor cells. The patient was a 22-yr old man presented with multiple lymphadenopathy and an involvement of the bone marrow. Tumor cells were large and monomorphic with an angulated eosinophilic cytoplasm of moderate amount. Nuclei of most tumor cells were eccentric and round with one or two prominent nucleoli. Rough endoplasmic reticulum was prominent in electron microscopic examination. Tumor cells expressed CD4, CD7, CD10, CD45RB, CD56, CD68, and HLA-DR and were negative for CD1a, CD2, sCD3, CD5, CD13, CD14, CD20, CD33, CD34, CD43, CD45RA, TIA-1, S-100, and TdT. cCD3 was not detected in the immunostaining using paraffin tissue, but was faintly expressed in flow cytometry and immunostaining using a touch imprint slide. T-cell receptor gene rearrangement analysis and EBV in situ hybridization showed negative results. Cytochemically, myeloperoxidase, Sudan black B, and alpha naphthyl butyrate esterase were all negative.
J Korean Med Sci 2002 Dec
PMID:CD4+CD56+CD68+hematopoietic tumor of probable plasmacytoid monocyte derivation with weak expression of cytoplasmic CD3. 1248 12

Dendritic cells are professional antigen presenting cells which are being used as adjuvants in tumor vaccination trials. Most clinical protocols currently include 4 to 10 weekly infusions of doses > 10(6) cells, each inoculum coming from a simple culture of blood monocytes. In the present study, several millions of dendritic cells from a single leukapheresis were produced; monocytes were isolated by elutriation and then cultured in Teflon bags in presence of 800 U/ml GM-CSF + 100 micro g/ml IL-13 + 10% fetal calf serum (FCS). The dendritic cells from this single batch were aliquoted in many doses for potential multiple infusions and cryopreserved in 10% DMSO + 2% human albumin in Teflon-kapton Fresenius bags either at -1 degrees C/min using a controlled rate freezer, or putting the bags directly in a -80 degrees C mechanical freezer without controlling the temperature rate. Six experiments were carried out. After one month of cryopreservation, the cells were thawed in a 40 degrees C water bath. Before and after freezing, cells were evaluated for immunophenotype (CD1a, CD14, CD40, CD80, CD83, CD86, CD54, CD58, CD16, CD32, CD64 and HLA-DR) and for their capacity to stimulate allogenic (MLR) or autologous (antigen presentation tests) lymphocytes. The results demonstrated that the mean recovery rates after freezing in liquid nitrogen or at -80 degrees C were (67 +/- 14)% and (71 +/- 13)% respectively, without any significant difference between the two techniques. The immunophenotype was not modified by the freezing-thawing procedure, as well as the lymphocyte stimulating capacities. In conclusion, our study showed that substantial numbers of functional DCs can be derived from peripheral blood monocytes using Teflon bags. DCs can be cryopreserved in a good laboratory practice setting for further clinical trials with an acceptable loss of cells and without modification of their functions.
Zhongguo Shi Yan Xue Ye Xue Za Zhi 2000 Dec
PMID:Cryopreservation of Dendritic Cells Grown in Vitro from Monocytes for Their Future Clinical Use. 1257 59

Gastrointestinal tract involvement in Langerhans'cell histiocytosis (LCH) is unusual. It is most often observed in children, is usually asymptomatic, diagnosed at post mortem examination and associated with a disseminated disease. We report 2 cases of LCH large bowel involvement occuring in a 50-year- old man and in a 71-year-old woman, who presented with digestive symptoms. Histiocytic proliferation with reniform nuclei was demonstrated in colonic biopsies it was located in the lamina propria, and dissociating the mucosa glands. Immunohistochemical study revealed a strong positivity of these cells with anti-CD1a and anti-PS100 antibodies. Ultrastructural study performed in one case showed large cells with reniform and indented nuclei, numerous tubuloreticular structures and Birbeck granules. Digestive localization of LCH is exceptional in adult, and may be underestimated.
Ann Pathol 2002 Dec
PMID:[Langerhans cell histiocytosis of the large bowel]. 1259 88

Resiquimod is a Toll-like receptor 7 (TLR7) and TLR8 agonist that is a potent inducer of alpha interferon (IFN-alpha) and other cytokines. The effects of multiple applications of resiquimod gel were assessed in a randomized, single-blind, dose-ranging, placebo-controlled study with 41 healthy subjects. Over a 3-week period, 1-g doses of resiquimod or vehicle gel (3:1 randomization) were applied to a 50-cm2 area of the upper arm according to the following regimens: 0.25% applied for 8 h two times per week, 0.05% applied for 8 h two times per week, 0.05% applied for 8 h three times per week, and 0.01% applied for 24 h three times per week. Skin biopsy specimens were obtained prior to the application of the first dose and after the completion of application of the last dose. Dosing with 0.01 and 0.05% resiquimod was well tolerated, but that with 0.25% was not; a dose-response relationship for local adverse effects was observed. The level of systemic exposure during multiple topical dosings was <1% of the applied dose. A significant increase in responders after completion of application of the last dose was observed for serum IFN and the interleukin-1 (IL-1) receptor antagonist (P<0.01, Fisher's exact test). Increased levels of mRNA for IL-6, IL-8, IFN-alpha, and Mx (an IFN-alpha-inducible protein) were seen in posttreatment biopsy specimens from the group receiving 0.25% resiquimod compared to the levels seen in specimens from the group receiving vehicle only (P<0.01, Wilcoxon rank sum test). A dose-response-related increase in CD3-positive cells consistent with T-lymphocyte infiltration and a decrease in CD1a-positive cells, consistent with emigration of Langerhans' cells, were observed in treated skin. This study suggests that resiquimod is a potent topically active immune response modifier that significantly enhances the cutaneous immune response.
Antimicrob Agents Chemother 2003 Dec
PMID:Randomized, single-blind, placebo-controlled study of topical application of the immune response modulator resiquimod in healthy adults. 1463 93


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