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)

We have studied the effects of phorbol-dibutyrate (PBu2), a protein kinase C (PKC) activator, on the proliferation of peripheral human T cells and thymocyte subpopulations selected by treatment with monoclonal antibodies and complement: pre-thymocytes (CD1a-CD3-CD4-CD8-), cortical thymocytes (CD3-, class I- antigens) and medullary thymocytes (enriched as CD1a- cells). PBu2 induces a dose-dependent proliferative response in human peripheral blood T cells at concentrations greater than 6 ng/ml, this proliferation being mediated by the autocrine interleukin 2 (IL2)/IL2 receptor (IL2R) pathway. Pre-thymocytes respond to PBu2 in a way similar to T cells, being able to secrete IL2 in significant amounts and express the p55 chain of IL2R. On the other hand, cortical thymocytes are not induced to proliferate after PKC activation and neither expression of the p55 chain of IL2R nor IL2 secretion is observed. Human medullary thymocytes, phenotypically identical to peripheral blood T cells, show no proliferation in response to PBu2 at any concentration tested unless IL2 is supplied to the cultures. The activation of PKC induces the expression of IL2R in these cells, but not IL2 secretion. The implications of PKC activation in thymic maturation, the role of IL2 and the relevance of the differences between medullary thymocytes and peripheral blood T cells are discussed.
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PMID:Proliferative responses induced by the activation of protein kinase C during the development of human T lymphocytes. 199 83

Dendritic cells are attractive candidates for vaccine-based immunotherapy because of their potential to function as natural adjuvants for poorly immunogenic proteins derived from tumors or microbes. In this study, we evaluated the feasibility and consequences of introducing foreign genetic material by retroviral vectors into dendritic cell progenitors. Proliferating human bone marrow and cord blood CD34+ cells were infected by retroviral vectors encoding the murine CD2 surface antigen. Mean transduction efficiency in dendritic cells was 11.5% from bone marrow and 21.2% from cord blood progenitors. Transduced or untransduced dendritic cell progeny expressed comparable levels of HLA-DR, CD83, CD1a, CD80, CD86, S100, and p55 antigens. Granulocytes, macrophages, and dendritic cells were equally represented among the transduced and mock-transduced cells, thus showing no apparent alteration in the differentiation of transduced CD34+ precursors. The T-cell stimulatory capacity of retrovirally modified and purified mCD2-positive allogeneic or nominal antigen-pulsed autologous dendritic cells was comparable with that of untransduced dendritic cells. Human CD34+ dendritic cell progenitors can therefore be efficiently transduced using retroviral vectors and can differentiate into potent immunostimulatory dendritic cells without compromising their T-cell stimulatory capacity or the expression of critical costimulatory molecules and phenotypic markers. These results support ongoing efforts to develop genetically modified dendritic cells for immunotherapy.
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PMID:Retrovirally transduced human dendritic cells express a normal phenotype and potent T-cell stimulatory capacity. 931 Apr 66

Corticosteroids are used therapeutically as potent immunosuppressive and antiinflammatory drugs for a broad spectrum of diseases. Although corticosteroids are known to inhibit the production of many cytokines in activated T cells, there is also evidence for increases in IL-4 and in some cases IFNgamma production. These conflicting results may be caused by contrary effects of corticosteroids on different cell types involved in immune regulation, for instance antigen presenting cells (APC) versus T cells. In the present study we simultaneously investigated the effect of local as well as systemic application of glucocorticoids (GCC) on the phenotype of APC in the skin as well as the lymph nodes in a model primate species, the rhesus macaque. Using a range of APC markers, including CD68, HAM56, HLA-DR, CD1a, p55, RFD-1, and costimulatory molecules CD40, CD80, and CD86 we document the close phenotypic resemblance of rhesus and human APC. We noted that topical GCC treatment specifically lead to a marked decrease in the number of CD1a expressing cells in the draining lymph nodes. However, the number of CD1a positive cells in peripheral lymph nodes was not affected by systemic GCC treatment. Importantly, by performing double staining of CD1a with RFD-1 we observed a shift in the expression pattern of these dendritic cell markers in the lymph nodes, with an increase in the number of RFD-1 single positive cells relative to CD1a single positive and CD1a/RFD-1 double positive cells. These findings suggest that GCC treatment results in the presence of phenotypically more mature APC.
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PMID:Changes in dendritic cell subsets in the lymph nodes of rhesus macaques after application of glucocorticoids. 1125 38

The local cytokine environment and the presence of stimulatory signals determine whether circulating monocytes will finally acquire characteristics of dendritic cells (DCs) or macrophages. Because FcepsilonRI expressed on professional APCs, e.g., monocytes and DCs, has been suggested to play a key role in the pathophysiology of atopic diseases, we evaluated the effect of receptor ligation on the generation of monocyte-derived DCs (MoDCs). Aggregation of FcepsilonRI at the initiation of the IL-4-GM-CSF-driven differentiation resulted in the emergence of macrophage-like cells with a strong expression of the mannose receptor and a low level of CD1a and the DC-specific markers CD83 and the actin-bundling protein (p55). These cells sustained the ability to take up FITC-labeled Escherichia coli by phagocytosis and were significantly less efficient in stimulating purified allogeneic T cells. In addition, receptor ligation of FcepsilonRI at the beginning of the culture prevented the generation of MoDCs, mainly due to a dramatic increase in the IL-10 production. These results suggest that FcepsilonRI aggregation prevents the generation of CD1a(+) MoDCs and imply a novel pivotal function of this receptor in modulating the differentiation of monocytes.
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PMID:Engagement of Fc epsilon RI on human monocytes induces the production of IL-10 and prevents their differentiation in dendritic cells. 1144 Oct 85

In Thailand, the predominant HIV subtype is E, rather than Subtype B as in North America and Europe, and the predominant mode of transmission is heterosexual contact. Subtype E has the ability to replicate in vitro in Langerhans cells. We hypothesized that this cell type might constitute a reservoir for the HIV virus in vaginal mucosa of asymptomatic carriers. To examine this hypothesis, we compared vaginal tissue histology in HIV-1-seropositive cases with seronegative cases and determined the immunophenotype of HIV-1-infected cells, their numbers, and their distribution in vaginal mucosa. Vaginal biopsies were performed at four different sites from six asymptomatic HIV-1 Subtype E-infected persons and from six seronegative cases at necropsy and examined histologically. Immunophenotyping was performed using immunoperoxidase for Gag p24 HIV, CD3, CD20, CD68, CD1a, S-100 and p55 antigens and by double labeling, combining immunoperoxidase with alkaline phosphatase using pairs of the above antigens. Twenty of twenty-four vaginal biopsies (83.3%) from HIV-seropositive cases showed definite inflammation compared to five of twenty-four vaginal necropsies (20.8%) from HIV-seronegative cases. One third of HIV-seropositive biopsies (8/24) demonstrated p24-positive cells in the epithelium, whereas three-fourths (18/24) of the biopsies revealed p24-positive cells in the lamina propria. All seropositive patients showed positive cells in at least one biopsy, but not all biopsies contained positive cells. Infected cells were more frequently observed at sites of greater inflammation. The dendritic cell count in HIV-seropositive vaginal epithelium was significantly higher than that observed in the seronegative cases (P =.004). The majority of p24-positive cells in the vaginal epithelium were Langerhans cells (CD1a+/S-100+), whereas in the lamina propria, about half of p24-positive cells were Langerhans-related dendritic cells (p55+ and S-100+) and half were T lymphocytes. In conclusion, the increased propensity for heterosexual transmission of Subtype E may be related to vaginal inflammation, leading to the accumulation of Langerhans cells and related dendritic cells which, once infected with HIV, can act as a reservoir for further virus transmission.
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PMID:In vivo identification of Langerhans and related dendritic cells infected with HIV-1 subtype E in vaginal mucosa of asymptomatic patients. 1174 49

Dendritic cells (DC) are the most potent antigen-presenting cells of the organism. They are specialized to capture, process, and present antigen via the MHC class II as well as the MHC class I pathways to CD4+ and CD8+ T cells, respectively. This results in T cell-mediated immune responses that are likely to counteract the generation and propagation of tumors in vivo. Therefore, we studied the distribution of dendritic cells in mammary Paget's disease. Paraffin-embedded samples of Paget's disease of the breast (n=27) and of disease-free epidermis of the nipple (n=10) were investigated immunohistochemically for the presence of dendritic cells, in particular of Langerhans cells, using antibodies against S-100, CD1a, and HLA-DR, as well as novel reagents against Langerin/CD207, DC-LAMP/CD208 and p55 (Fascin), the latter two being specific for mature dendritic cells. Paget samples presented a decrease of CD1a+, S-100+, and Langerin+ intraepidermal Langerhans cells in almost all cases. This was paralleled by a concentration of immature dendritic cells in the tumor-infiltrated tissue itself. Similar to infiltrating breast carcinoma we observed a marked increase of DC-LAMP+ and p55+ mature dendritic cells in the corial tissue beneath the tumor. These cells were almost always found in ribbon-like or nodular lymphocytic infiltrates. Moreover, rare mature dendritic cells were also found in the Paget cell-infiltrated epidermis of the nipple, i.e. in the tumorous lesion itself. These findings may indicate an effective ongoing anti-tumor immune response in this part of spreading breast cancer.
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PMID:Immunohistochemical tracking of an immune response in mammary Paget's disease. 1884 36