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)

Colonies of CD1a+ HLA-DR+/DQ+ CD4+ cells with the functional and some of the structural attributes of Langerhans cells are observed in human bone marrow cultures in semi-solid media and are assumed to be the progeny of an early progenitor, the dendritic/Langerhans cell CFU (CFU-DL). The cytokine-regulated growth of these cells has been studied using a chemically defined serum-free system to culture both unfractionated and highly enriched bone marrow progenitor cell populations. Although unfractionated cell growth was optimal in serum replete cultures with PHA-stimulated leukocyte-conditioned medium (PHA-LCM) suboptimal proliferation of CFU-DL was observed in serum even in the absence of PHA-LCM. No colonies were observed under serum-free conditions when granulocyte-macrophage CSF (GM-CSF), IL-3, granulocyte CSF (G-CSF), and macrophage CSF (M-CSF) were present at levels optimal for granulocyte colony-forming unit (CFU-G) and macrophage colony-forming unit (CFU-M) growth. Addition of IL-1 alpha to these cytokines stimulated a small number of CFU-DL. However, in the presence of GM-CSF and IL-3, TNF-alpha or TNF-beta (5 U/ml) were both highly effective in promoting growth up to 82% of optimal and CFU-G growth was also enhanced at these concentrations. TNF was only active during the first 3 days of culture and higher concentrations of TNF-alpha but not TNF-beta were inhibitory for both CFU-DL and CFU-G. CD34+ cell-enriched populations were also enriched for both myeloid progenitors (CFU-G + CFU-M) and CFU-DL to 36- and 48-fold, respectively, and single cell cultures of CD34+ cells yielded single colonies containing both CD1a+ dendritic cells and CD1a- macrophages. Thus dendritic/Langerhans progenitors in the bone marrow expresses CD34, have a capacity for both macrophage and dendritic cell differentiation, and depend on hemopoietic growth factors and TNF for their further development in vitro.
 ...
PMID:Interactions of tumor necrosis factor with granulocyte-macrophage colony-stimulating factor and other cytokines in the regulation of dendritic cell growth in vitro from early bipotent CD34+ progenitors in human bone marrow. 138 22

The possibility that production of some cytokines in the carcinoma microenvironment is associated with the presence and differentiation of cells belonging to the dendritic cell (DC)/Langerhans' cell (LC) lineage was investigated. Immunohistochemical examination showed the presence of intraepithelial LCs (CD1a- and S100-positive cells) in 6 of 10 squamous cell carcinomas and in 8 of 10 adenocarcinomas. Langerhans' cells were mainly located close to lymphoid aggregates. In situ hybridization performed in four cases (three LC positive and one LC negative) of squamous cell carcinoma and in five cases (four LC positive and one LC negative) of adenocarcinoma showed that some mononuclear cells in the interstitium displayed hybridization with granulocyte macrophage-colony stimulating factor (GM-CSF), tumor necrosis factor-alpha (TNF alpha), and interleukin 1-beta (IL1 beta) cDNA probes. Only in LC-positive carcinomas did epithelial cells close to lymphoid aggregates display small amounts of GM-CSF and TNF alpha mRNA expression. Immunohistochemical analysis performed in the 20 cases of lung carcinoma showed that epithelial cells in tumors with lymphoid aggregates and LCs were immunoreactive with antihuman GM-CSF monoclonal antibody. Specimens negative for GM-CSF contained very few LCs. Northern blot analysis was used to investigate GM-CSF, TNF alpha, IL1 alpha, and IL1 beta mRNA expression in six human lung carcinoma cell lines. A constitutive expression of TNF alpha mRNA was found in all of them, whereas only three showed a low constitutive expression of GM-CSF mRNA. In the latter three cell lines treatment with phytohemagglutinin (PHA)-stimulated peripheral blood lymphocyte (PBL) supernatant (PHA-SUP) upregulated GM-CSF mRNA expression and induced that of IL1 alpha mRNA. Carcinomatous epithelial cells producing small amounts of cytokines could promote the recruitment of cells of DC/LC lineage. Subcellular factors produced by reactive lymphocytes and/or macrophages may influence the production of GM-CSF and IL1 alpha by various epithelia. Up-regulation of this production could favor the arrival and differentiation of DCs and activate LC functions.
 ...
PMID:Role of cytokines in distribution and differentiation of dendritic cell/Langerhans' cell lineage in human primary carcinomas of the lung. 763 48

The expression of the alpha 6 beta 4 and alpha 6 beta 1 integrins on epidermal Langerhans cells (LC) before and after mast cell degranulation was studied in cultured human neonatal foreskin by immunohistochemistry. Twenty-four hours after addition of mast cell secretagogues, morphine sulfate, or substance P, solitary mid-epidermal cells showed staining for the integrin subunits alpha 6, beta 4, and beta 1. This expression was not observed in cultured control explants, and immunostained cells were confirmed to be non-epithelial, dendritic cells by immuno-electron microscopy. The identity of these cells as LC was further established by coincident staining for alpha 6 and CD1a using double immunofluorescence labeling. Addition of tumor necrosis factor-alpha (TNF alpha), the predominant cytokine in mast cell granules, also induced LC to express alpha 6 integrins. Furthermore, preincubation of skin organ cultures with anti-TNF alpha antibodies or the mast cell inhibitor cromolyn sodium abrogated the ability to induce alpha 6 integrins on LC consequent to experimental mast cell degranulation by substance P. These data implicate a role for mast cell-derived TNF alpha in the regulation of the integrins alpha 6 beta 4 and alpha 6 beta 1 on LC. These findings may have important implications relevant to mechanisms for spatial localization of LC within the cutaneous compartments during immune responses.
 ...
PMID:Mast cell degranulation upregulates alpha 6 integrins on epidermal Langerhans cells. 834 16

Recently, we described the isolation through fluorescent-activated cell sorting (FACS) of low autofluorescent (LAF) cells from human bronchoalveolar lavage (BAL). These LAF cells displayed an immunophenotype comparable with that of dendritic cells (DC), and showed a high potency to stimulate naive T cells. In the study reported here we investigated the capability of LAF cells to produce interleukin-1 (IL-1), IL-6, and tumor necrosis factor alpha (TNF-alpha), and the role of these cytokines in allogeneic T-cell stimulation by LAF cells. Lipopolysaccharide (LPS)-stimulated LAF cells released biologically active IL-1, IL-6, and TNF, and also showed intracellular immunoreactivity for IL-1, IL-6, and TNF-alpha. A neutralizing antibody against IL-1 slightly but statistically significantly (P < 0.05, Wilcoxon's test) inhibited the ability of the LAF cells to stimulate allogeneic T-cell proliferation (89% of stimulation in the absence of the antibody). Neutralizing antibodies against IL-6 and TNF-alpha had no effect. An antibody to granulocyte-macrophage colony-stimulating factor (GM-CSF) also interfered with the accessory function of the LAF cells (79% of stimulation in the absence of the antibody, P < 0.05). We also investigated whether subsets of LAF cells (i.e., positive or negative for CD1a and purified by FACS sorting) differed in T-cell stimulatory capacity and in the ability to produce IL-1, IL-6, TNF-alpha, and S100. CD1a+ LAF cells were positive for and produced S100, CD1a- LAF cells were negative in this respect. The CD1a+ subset exhibited a clearly higher and very strong accessory capability as compared with the CD1a- subset. Despite this, CD1a+ LAF cells were poor producers of IL-1, IL-6, and TNF-alpha. The neutralizing antibody to IL-1, however, inhibited the ability of CD1a+ cells to stimulate allogeneic T-cell proliferation (43% of stimulation in the absence of the antibody, P < 0.01). Anti-IL-6 and alpha-GM-CSF had no effects. CD1a- LAF cells were potent producers of IL-1, IL-6, and TNF-alpha, and antibodies to IL-1, IL-6, and GM-CSF strongly interfered with their weaker accessory capability. In conclusion, two different subsets of LAF cells could be identified on the basis of accessory capability and cytokine profile. CD1a+ LAF cells (S100+; very potent T-cell stimulators, poor cytokine producers) are the "Langerhans cells" of the lung. CD1a- LAF cells (S100-; lower T-cell stimulatory capability, potent producers of IL-1, IL-6, and TNF-alpha) displayed a marker pattern intermediate between that of monocytes and monocyte-derived DC.
 ...
PMID:CD1a+ and CD1a- accessory cells from human bronchoalveolar lavage differ in allostimulatory potential and cytokine production. 896 70

The potent calciotropic hormone calcitriol (1,25-dihydroxyvitamin D3, 1,25(OH)2D3) has been shown to be very effective and safe in the topical treatment of psoriasis. In vitro, 1,25(OH)2D3 inhibits proliferation and stimulates differentiation of human keratinocytes. Increasing evidence suggests an immunoregulatory function of this potent steroid hormone. To further characterize the biological effects of topical calcitriol treatment in psoriasis, we have analyzed immunohistochemically the expression of markers for epidermal proliferation (proliferating cell nuclear antigen=PCNA) and differentiation (transglutaminase K, involucrin, cytokeratin 16), as well as inflammation (CD1a, 55 kDa TNF-receptor, NAP-1/IL-8) in calcitriol-treated psoriatic skin in situ. Our findings strongly support the hypothesis that calcitriol modulates keratinocyte proliferation/differentiation as well as inflammation in human skin in vivo. The immunoreactivity of markers for epidermal proliferation and differentiation, as well as of CD1a and NAP-1/IL-8, changed after 8 weeks of calcitriol treatment almost completely to the pattern characteristic for non-lesional psoriatic skin, while a large number of 55 kDa TNF-receptor positive cells could be found in the dermal compartment.
 ...
PMID:Topical calcitriol (1,25-dihydroxyvitamin D3) treatment of psoriasis: an immunohistological evaluation. 922 16

Dendritic cells (DCs), which are antigen presenting cells of potential use in human antitumor vaccination trials, are presently the subject of intense investigation. Many recent studies have reported the possibility of generating ex vivo large numbers of DCs with high antigen presenting capacity by the culture of bone marrow or blood progenitors. In this study, we examined the differentiation into DCs of CD34+ progenitors isolated from the G-CSF mobilized blood of 3 healthy donors and 5 patients with breast cancer and cultured in the presence of GM-CSF + IL-13. The characteristics of the cells were compared to those of cells obtained in the presence of GM-CSF + TNF alpha. By day 15, one third of the bulk cells cultured with IL-13 were CD1a+/CD14- and strongly expressed CD1c, CD40, CD80 and HLA-DR. In contrast, cells obtained with TNF alpha expressed CD1a on one in three cells but with a considerably lower fluorescence intensity than on IL-13-cultured cells and strongly expressed CD14 on more than 50% of cells. CD1a+/CD14- cells emerged in IL-13 cultures at day 5, while in TNF alpha cultures CD14+ cells appeared before CD1a+ cells. Cells grown in the presence of IL-13 had an increased capacity to present antigens to autologous lymphocytes and to stimulate allogeneic T-lymphocytes. This effect was greater than that of cells grown in the presence of TNF alpha. These cells should therefore have greater effector potential in any therapeutic applications in humans.
 ...
PMID:IL-13 induces CD34+ cells isolated from G-CSF mobilized blood to differentiate in vitro into potent antigen presenting cells. 943 67

Dendritic cells (DC) are the most effective cells for antigen presentation in primary immune responses. Human cord blood CD34+ progenitors cultured in the presence of GM-CSF and TNF alpha generate a heterogeneous population of DC including Langerhans-like DC (LLDC) and monocytes. We describe here that IL-4 exerts different effecs in such culture according to the cells considered. Thus, IL-4 favors DC components at the expense of monocytic development, and permits long-time persistence of DC which can be maintained up to one month in culture. These results show an IL-4-dependent inhibition of proliferation and emergence of CD14+ cells. Notably, however, IL-4 also acts on the DC precursors. Thus, IL-4 enhances survival and delays maturation of LLDC from CD1a+ CD14- precursors. In addition, IL-4 also favors orientation of CD14+ CD1a- DC/monocyte precursors towards dermal-type CD1a+ DC. DC recovered from IL-4 treated cultures display reduced allostimulatory capacity, but this function is restored upon IL-4 weaning. Finally, a short (48h) IL-4 pulse is sufficient to favor DC development. The present study demonstrates that IL-4 positively regulates DC development at several levels on distinct precursor cells.
 ...
PMID:IL-4 addition during differentiation of CD34 progenitors delays maturation of dendritic cells while promoting their survival. 958 60

The ability to generate dendritic cells (DCs) in sizeable numbers has enormous implications for the development of clinically-effective antigen presentation procedures for cancer immunotherapy. We evaluated the generation of immunostimulatory DCs from peripheral blood CD34+ cells collected from healthy donors. CD34+ cells purified from leukapheresis product were seeded at 1 x 10(4) cells/mL in complete medium supplemented with GM-CSF, TNF alpha, IL-4, c-kit ligand, and flt3 ligand (FL). By day 14 of culture in the presence of GM-CSF + TNF alpha, the total cell number increased by 23.4 +/- 5.4-fold compared to the starting number of CD34+ cells. When the c-kit and FL were added to GM-CSF and TNF alpha, the cell number increased by 109.8 +/- 11.2-fold without affecting the immunophenotype of recovered cells. Flow cytometric analysis indicated that cells with the markers of mature dendritic cells, i.e., CD1a +CD14 -HLA-DR+, and CD80+CD86+HLA-DR+, constituted 49.0% +/- 7.5%, and 38.9% +/- 6.5%, respectively. This pattern of expression of surface antigen was unchanged whether the c-kit ligand and/or FL was added. The irradiated CD1a+HLA-DR+ cells recovered from in vitro cultures elicit a vigorous proliferation of allogeneic peripheral blood T-cells, irrespective of cytokine combinations. These findings provide advantageous tools for the large-scale generation of DCs that are potentially usable for clinical protocols of immunotherapy or vaccination in patients undergoing cancer treatment.
 ...
PMID:Ex vivo generation of functional dendritic cells from mobilized CD34+ hematopoietic stem cells. 975 99

Dendritic cells (DC), the most potent antigen-presenting cells found to date, can be generated from the adherent fraction of peripheral blood mononuclear cells (PBMC) by culture with granulocyte-macrophage colony-stimulating factor (GM-CSF) and IL-4. When interferon gamma (IFN-gamma) was added to the culture medium, the expression of CD1a, CD4 and CD80 markers were significantly reduced, while that of HLA-A, B, C, MHC II (MHC-DR), CD11a and CD54 were increased. T cell proliferation analysis showed that the DC derived from monocytes cultured with GM-CSF, IL-4 and IFN-gamma only induced weak responses in both activated and naive allogenic CD4(+) and CD8(+) T cells when compared to the reaction elicited by DC cultured without IFN-gamma. Furthermore, the DC derived from cultures with IFN-gamma, loaded with an immunogenic peptide derived from the HER2/neu protein [HER2 (9466)], only induced low levels of TNF release and weak proliferative responses in a specific cytotoxic CD8(+) T lymphocyte clone. Therefore, our results indicate that IFN-gamma negatively influences the differentiation and function of monocyte-derived DC by affecting the expression of surface molecules involved in their antigen-presenting function. This supports the general hypothesis that there exists a feedback immune regulatory mechanism between T cells and monocytes/DC.
 ...
PMID:Interferon gamma impairs the ability of monocyte-derived dendritic cells to present tumour-specific and allo-specific antigens and reduces their expression of CD1A, CD80 AND CD4. 981 27

Chemokines are involved in the control of dendritic cell (DC) trafficking, which is critical for the immune response. We have generated DC from human umbilical cord blood CD34+ progenitors cultured with granulocyte-macrophage colony-stimulating factor, tumor necrosis factor alpha (TNF-alpha), and stem cell factor. Using an anti-CCR6 monoclonal antibody, we observed that these cells showed maximum expression of this beta-chemokine receptor when they were immature, as determined by their relatively low expression of several DC maturation markers such as CD1a, CD11c, CD14, CD40, CD80, and CD83. Immature DC responded strongly to macrophage inflammatory protein-3alpha (MIP-3alpha), the CCR6 ligand, in migration and calcium mobilization assays. CCR6 expression decreased in parallel with the DC maturation induced by prolonged TNF-alphaq treatments. Interleukin-4 was also able to decrease CCR6 protein levels. Our findings suggest that the MIP-3alpha/CCR6 interaction plays an important role in the trafficking of immature DC to chemokine production sites such as injured or inflamed peripheral tissues, where DC undergo maturation on contact with antigens.
 ...
PMID:Down-regulation of the beta-chemokine receptor CCR6 in dendritic cells mediated by TNF-alpha and IL-4. 1057 17


1 2 3 4 5 Next >>