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)

Herpes simplex viruses (HSV) have developed several immunoevasive strategies. Here we demonstrate a novel mechanism by which HSV type 1 may interfere with the immune response through infection of immature dendritic cells (DC) and selective downmodulation of costimulatory molecules. In our study we show productive infection of immature monocyte-derived DC, which closely resemble sessile Langerhans cells, by sequential expression of immediate-early, early, and late viral proteins and of glycoprotein D mRNA, as well as production of infectious virus of moderate titers. Infection was cytopathic, with the progressive loss of 20 to 45% of cells from 24 to 48 h after infection, with no more than 80% of DC found to be infected. These results are in contrast to those of previous findings of nonpermissive or abortive infection of monocytes and mature monocyte-derived DC. Infection of immature DC also led to selective and asynchronous downregulation of CD1a, CD40, CD54 (ICAM-1) (12 h postinfection), CD80 (24 h postinfection), and CD86 (48 h postinfection) but not of CD11c or major histocompatibility complex class I and II molecules when compared to DC exposed to UV-inactivated virus. Thus, we propose that productive infection of epidermal Langerhans cells in vivo may lead to delayed activation of T cells, allowing more time for replication of HSV type 1 in epidermal cells.
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PMID:Immature monocyte-derived dendritic cells are productively infected with herpes simplex virus type 1. 1139 May 97

Dendritic cells (DC) with potentially important clinical applications have been generated from human peripheral blood monocytes and CD34(+) cells in the presence of recombinant cytokines granulocyte-macrophage colony-stimulating factor (GM-CSF) + interleukin-4 (IL-4) and GM-CSF + tumor necrosis factor-alpha (TNF-alpha), respectively. Many of the studies generating DC have included fetal calf serum, which is not desirable due to the risk of immune reactions and infectious disease transmission. Additionally, low DC yields have been reported using serum-free media. In this study, we investigate supplementing serum-free media with autologous serum and plasma for DC generation from monocytes and CD34(+) cells. Our results show that functional DC can be reproducibly obtained in the presence of autologous serum using monocytes and CD34(+) cells as the starting populations. However, with the addition of autologous serum, a differential effect is observed in the phenotypic characterization of these culture-derived DC. Monocytes cultured for 7 days in X-VIVO 15 serum-free media in the presence of GM-CSF + IL-4 showed down-regulation of CD14 with increased expression of HLA-DR, mannose receptor, CD80, and CD86, along with highly up-regulated CD1a(+) expression. The addition of autologous serum to serum-free media in monocyte cultures resulted in a dose-dependent decrease in the CD1a(+) expression generating a distinct subset of CD1a(+/-) cells expressing HLA-DR, mannose receptor, CD80, and CD86. Upon stimulation with CD40L cells, both monocyte-derived DC subsets CD1a(+/-) and CD1a(++) were capable of maturation measured by CD83 and CD86 up-regulation. Data suggest the differences in the monocyte-derived DC in serum-free (CD1a(++)) or autologous serum (CD1a(+/-)) supplemented cultures is of a qualitative nature, rather than quantitative. CD1a(+) and CD14(+) cells expressing HLA-DR, mannose receptor, CD80, and CD86 were generated in 7 days from CD34(+) cells in serum-free media. A quantitative effect was obtained when cultures were supplemented with autologous serum, resulting in a significant enhancement of CD34-derived DC generated. These results demonstrate generation of DC from two different starting populations using serum-free media that can be enhanced with the addition of autologous serum. Interestingly, a differential effect was observed in the phenotypic characterization of these culture-derived DC.
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PMID:Differential effects of autologous serum on CD34(+) or monocyte-derived dendritic cells. 1152 39

Dendritic cells (DCs) are a heterogeneous population of antigen-presenting cells (APCs) identified in various tissues, including the skin (Langerhans cells), lymph nodes (interdigitating and follicular DCs), spleen, and thymus. Properties of DCs include the ability to (1) capture, process, and present foreign antigens; (2) migrate to lymphoid-rich tissue; and (3) stimulate innate and adaptive antigen-specific immune responses. Until recently, the ability to study DCs has been limited by their absence in most culture systems. It is now known that specific cytokines can be used to expand DCs to numbers sufficient for their in vitro evaluation and for their use in human immunotherapy trials. Human DCs can be derived from hematopoietic progenitors (CD34+-derived DCs) or from adherent peripheral blood monocytes (monocyte-derived DCs). Cultured DCs can be recognized by a typical veiled morphologic appearance and expression of surface markers that include major histocompatibility complex class II, CD86/B7.2, CD80/B7.1, CD83, and CD1a. DCs are susceptible to a variety of gene transfer protocols, which can be used to enhance biological function in vivo. Transduction of DCs with genes for defined tumor antigens results in sustained protein expression and presentation of multiple tumor peptides to host T cells. Alternatively, DCs may be transduced with genes for chemokines or immunostimulatory cytokines. Although the combination of ex vivo DC expansion and gene transfer is relatively new, preliminary studies suggest that injection of genetically modified autologous DCs may be capable of generating anti-tumor immune responses in patients with cancer. Preclinical animal studies showing potent antigen-specific tumor immunity after DC-based vaccination support this hypothesis and provide rationale to further evaluate this approach in patients. Preliminary human studies are now required to evaluate optimal DC dose, schedule of vaccination, route of delivery, and maturational state of cultured cells. Initiation of these phase I/II cell therapy-based studies will occur in collaboration with hospital-based transfusion facilities. Issues relating to cell harvesting, storage, culture methodology, and administration require the collaborative efforts of basic scientists, immunologists, clinical investigators, and transfusion medicine staff to ensure strict quality control of injected cellular products. This review is intended to provide a brief overview of clinical DC-based gene transfer.
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PMID:Genetically modified dendritic cells in cancer therapy: implications for transfusion medicine. 1166 36

We tried to efficiently generate human dendritic cells (DCs) from CD34+ peripheral blood hematopoietic progenitor cells mobilized by high-dose chemotherapy and subsequent administration of granulocyte colony-stimulating factor, using a liquid suspension culture system. Among various combinations, the combination of c-kit ligand, flt-3 ligand, c-mpl ligand (TPO), and interleukin (IL)-4 most potently generated the number of CD1a+CD14- DCs in cultures containing granulocyte-macrophage colony-stimulating factor (GM-CSF) and tumor necrosis factor alpha (TNF-alpha). The delayed addition of IL-4 on day 6 of culture gave rise to an additional increase in the yield of CD1a+CD14-DCs that were characterized by the expression of HLA-ABC, HLA-DR, CD80, CD86, and CD83. The majority of the sorted CD1a-CD14+ cells derived from 6-day culture of CD34+ cells gave rise to CD1a+CD14- DCs and CD1a-CD14+ macrophages on day 12 of culture in the presence and absence of IL-4, respectively. These findings suggest that IL-4 promotes the differentiation of CD1a- CD14+ cells derived from mobilized CD34+ peripheral blood hematopoietic progenitors to CD1a+ CD14- DCs. The majority of these DCs expressed CD68 but not the Langerhans-associated granule antigen, a finding that suggests they emerge through the monocyte differentiation pathway. The addition of TPO and IL-4 to cultures did not affect the potential of DCs to stimulate the primary allogeneic T-cell response. These findings demonstrated that the combination of c-kit ligand plus flt-3 ligand plus TPO with GM-CSF plus TNF-alpha, followed by IL-4, is useful for ex vivo generation of human DCs from mobilized CD34+ peripheral blood progenitors.
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PMID:Efficient ex vivo generation of human dendritic cells from mobilized CD34+ peripheral blood progenitors. 1172 65

Tumour-derived factors suppress differentiation and function of in vitro generated DC. Here, we investigate the effect of two melanoma clones differing in their invasive and metastatic properties on the generation and/or functional maturation of human epidermal LC. LC were generated from CD34(+) cord blood progenitors under GM-CSF/TNF-alpha/TGF-beta 1. CD34(+) cells were co-cultured with or without melanoma cells using Transwell dishes. After 11 days of co-culture, CD34(+)-derived cells display a non-adherent undifferentiated morphology, a high level of monocytic CD14 marker, a down-regulated expression of LC markers (CD1a, E-cadherin) and DC markers (CD40, CD80, CD54, CD58, CD83, CD86, HLA-DR, HLA-class I). These cells were less potent than control LC in inducing allogeneic T cell proliferation. The generation of the CD14(+) population was correlated with a decrease in the CD1a(+) population, without any statistical differences between the two clones. Melanoma cells diverted the differentiation of CD34(+) cells towards a dominant CD14(+) population only if the progenitors were in an early growth phase. IL-10, TGF-beta 1 and VEGF were not responsible for these effects, as assessed by using blocking antibodies. By contrast, co-culture of fresh epidermal LC with melanoma cells did not affect their phenotype and function. Our data demonstrate that melanoma cells inhibit the earliest steps of LC differentiation, but failed to affect the functional maturation of epidermal LC. This suggests that melanoma cells participate in their own escape from immunosurveillance by preventing LC generation in the local cutaneous microenvironment.
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PMID:Human melanoma cells inhibit the earliest differentiation steps of human Langerhans cell precursors but failed to affect the functional maturation of epidermal Langerhans cells. 1174 38

Dendritic cells (DCs) play important roles in initiation and regulation of immune responses. DCs derived from human monocytes can be classified according to presence of CD1a molecules. Although CD1a+ DCs can be prepared from monocytes in media containing GM-CSF, IL-4, and FCS, it has been reported that CD1a+ DCs could not be easily obtained from monocytes using media containing human serum or plasma. In this study, we demonstrate for the first time that heparin can reliably induce differentiation of CD1a+ DCs from monocytes with or without autologous serum or plasma. The development of CD1a+ DCs is heparin concentration dependent (0-50 U/ml). Comparing with CD1a- DCs developed without heparin, CD1a+ DCs express higher CD40 and CD80 and lower CD86. Both CD1a+ and CD1a- DCs express similar levels of HLA-DR. CD80, CD86, HLA-DR, and CD40 are proportionally up-regulated when both types of DCs are stimulated with LPS or LPS plus IFN-gamma. The effect of heparin is neutralized by heparin-binding proteins, such as protamine sulfate, platelet factor-4, and beta-thromboglobulin. Functionally, heparin-treated DCs respond to LPS or LPS plus IFN-gamma with higher IL-10 and less IL-12 production than heparin-untreated DCs. Heparin-treated DCs are more potent in priming allogeneic and autologous CD4+ T cells to proliferate and to produce both type 1 and type 2 cytokines. The results of our study show that CD1a+ DCs can be prepared from monocytes ex vivo without using xenogeneic serum and may be used for immunotherapy.
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PMID:Heparin induces differentiation of CD1a+ dendritic cells from monocytes: phenotypic and functional characterization. 1180 47

A subset of blood mononuclear cells from patients with chronic lymphocytic leukemia (CLL) can differentiate in vitro into "nurselike" cells (NLCs) that can protect CLL cells from apoptosis. NLCs express cytoplasmic vimentin and stromal-derived factor 1 (SDF-1). NLCs also express CD14, as well as CD11b, CD33, CD40, CD45RO, CD68, CD80, CD86, HLA-DQ, and HLA-DR, but not CD1a, CD2, CD3, CD11c, CD19, CD45RA, CD83, CD106, or CD154. Consistent with this phenotype, NLCs failed to differentiate from blood mononuclear cells that were depleted of CD14+ cells or from isolated CD19+ cells. CD14+ blood cells of healthy donors could differentiate into cells with the morphology and phenotype of NLCs when cultured in direct contact with CLL B cells, but not with normal B cells. Despite expressing antigens in common with blood monocytes, monocyte-derived dendritic cells, and macrophages, NLCs expressed significantly higher levels of CD68 than these other cell types. Consistent with the notion that NLCs are present in vivo, CD14+ splenocytes from CLL patients have NLC morphology and express significantly higher levels of CD68 than CD14+ splenocytes from persons without known B-cell malignancy. These findings indicate that although NLCs may differentiate from blood monocytes, they probably represent a distinctive hematopoietic cell type that exists in vivo, differentiates from hematopoietic CD14+ cells in the context of CLL, and in turn protect CLL cells from apoptosis via a mechanism that is independent of CD106 (vascular cell adhesion molecule-1). The interaction between CLL cells and NLCs may represent a novel target for therapy of patients with this disease.
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PMID:Distinctive features of "nurselike" cells that differentiate in the context of chronic lymphocytic leukemia. 1180 9

The ability of CD34+ leukemic cells to differentiate to dendritic cells (DCs) was investigated in 18 acute myeloid leukemia (AML) and 4 lymphoid leukemia (ALL) patients. The generation of DCs was determined by the expression of DC-associated CD1a or CD83 (more than 30%) with costimulatory molecules, by CD80 antigens (>20%), and by the exhibition of allostimulatory activity. In the AML patients, allostimulatory mature DCs were generated from 3 of 9 M0 or M1, 2 of 5 M2,2 of 4 M4 or M5, and 3 of 4 ALL (L2) cases. In total, DCs were more efficiently induced from cases expressing over 75% of CD34+ among whole bone marrow mononuclear cells (8 of 12), compared with those under 75% (2 of 10; P < .05). B-cell (CD19), natural killer (NK)-cell (CD56), or T-cell (CD7) lineage markers, which were aberrantly expressed on the blasts, were rarely found on leukemic DCs at the end of the culture period, and myeloid (CD13, CD33), not lymphoid (CD10), markers were shown on ALL-derived DCs. In Philadelphia chromosome-positive ALL or AML patients with t (8;21), DCs were confirmed to be of leukemic origin by fluorescence in situ hybridization analysis.
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PMID:The generation of immunocompetent dendritic cells from CD34+ acute myeloid or lymphoid leukemia cells. 1184 92

The objective of this study was to investigate CD163+ macrophages in the synovial membrane of patients with spondyloarthropathy (SpA). Immunohistochemistry was performed on synovium of 17 SpA and 18 rheumatoid arthritis (RA) patients, on colonic biopsies of 16 SpA patients and ten healthy controls, and on paired synovial biopsies of eight SpA patients, before and after anti-TNFalpha therapy. Phenotype and cytokine production were analysed by flow cytometry. CD163+ macrophages were increased in the synovial lining and sublining in SpA versus RA, as well as in colonic lamina propria in SpA versus controls. The number of CD163+ macrophages in the synovial sublining correlated with C-reactive protein levels and erythrocyte sedimentation rate. Paralleling the increase of CD163, HLA-DR was increased in the synovial lining and sublining of SpA. In contrast, the co-stimulatory molecules CD80 and CD86 and the dendritic cell markers CD1a and CD83 were scarce in SpA synovium. Flow cytometry indicated that CD163+ macrophages expressed high levels of HLA-DR and could produce in vitro tumour necrosis factor alpha (TNFalpha) but not interleukin-10 (IL-10). Finally, anti-TNFalpha therapy in vivo induced a decrease of CD163+ macrophages in the synovial lining and sublining. In conclusion, macrophages expressing the scavenger receptor CD163 are increased in synovium and in colonic mucosa in SpA, highlighting the relationship between joint and gut in this disease. The correlation with inflammatory parameters, the expression of HLA-DR, the production of TNFalpha but not IL-10, and the reduction by anti-TNFalpha therapy support a role for CD163+ macrophages in the synovial inflammation in SpA.
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PMID:Macrophages expressing the scavenger receptor CD163: a link between immune alterations of the gut and synovial inflammation in spondyloarthropathy. 1185 99

The object of this study is to explore a culture method to generate a large number of functional and mature dendritic cells (DC) from human CD34+ hematopoietic progenitor cells. In the present study, we used a two-step method combined with calcium ionophore to induce DC from cord blood (CB) or normal human bone marrow (BM) CD34+ progenitor cells. The two-step method consists of 10 days of first step culture for the expansion and proliferation of CD34+ hematopoietic progenitor cells in the presence of SCF, IL-3, IL-6, G-CSF, and 7--11 days of second step culture for the induction of DC in the presence of GM-CSF, IL-4 and TNF-alpha. By the two-step culture, total nucleated cells were increased 208+/-66 (+/-SD, n=13), or 94+/-29 (n=5)-fold in the culture of CB or BM cells, respectively, compared with the number of CD34+ cells at the time of starting culture. Out of the total nucleated cells, 23 +/-10.4% of cells in CB cell culture and 25 +/-5% of cells in the BM cell culture acquired DC characteristic phenotypes, which were marked expressions of CD1a, HLA-DR, co-stimulatory molecules such as CD80, CD40, and adhesion molecule such as CD58. In allogeneic mixed leukocyte reaction (MLR), two-step cultured cells showed potent allo-stimulatory capacity. With this two-step culture, the absolute number of CD1a+ cells that co-expressed HLA-DR, CD80, CD40 and CD58 was enhanced approximately 3 times in CB cell culture and 1.9 times in BM cell culture, compared with the commonly used one-step culture method for the generation of DC from CD34+ cells using SCF, GM-CSF and TNF-alpha. However, on these DC generated in the two-step culture, the expressions of co-stimulatory molecule CD86 and mature DC marker CD83 were not sufficient. By the treatment of two-step cultured cells with calcium ionophore agent (A23187), the expression of co-stimulatory molecules such as CD86 and CD80 (especially CD86) was up-regulated. Besides, the expression of mature DC marker CD83 was remarkably induced by treatment with A23187 for a short duration (24 h). Consistent with the up-regulation of surface molecules CD86, CD80 and CD83, the two-step cultured cells treated with A23187 also showed a stronger allo-stimulatory capacity compared with the cells without A23187 treatment. In conclusion, the present study demonstrated that the two-step culture method effectively improved the yield of CD1a+ DC generated from CD34+ cells, and the phenotypes and functions of these CD1a+ DC could be enhanced efficiently by treatment with a calcium ionophore agent.
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PMID:Generation of functional and mature dendritic cells from cord blood and bone marrow CD34+ cells by two-step culture combined with calcium ionophore treatment. 1186 Oct 65


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