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)

The immunophenotype and proliferation fraction have been investigated in 26 cases of Langerhans' cell histiocytosis (LCH). In all cases LCH cells were positive for S-100 protein, CD1a, or both. In most cases LCH cells expressed the macrophage-associated marker CD68 and in two cases they contained lysozyme. Expression of both cytoplasmic CD2 and CD3 was observed in cryostat sections. An unexpected finding was the presence of placental alkaline phosphatase in LCH cells. Langerhans' cells in normal skin were negative for both CD2 and CD3, but a proportion contained placental alkaline phosphatase. In four cases of Rosai-Dorfman disease the histiocytic cells, which share certain immunophenotypic properties with Langerhans' cells, also were positive for placental alkaline phosphatase. A significant proportion of LCH cells stained positively with the antibody to proliferating cell nuclear antigen and also with the proliferation marker Ki-S1. A good correlation between the percentage of Ki-67-positive and proliferating cell nuclear antigen- and Ki-S1-positive cells, respectively, was observed. Thus, in comparison with their putative precursors, LCH cells have an aberrant phenotype and are proliferating locally. This might suggest that LCH is a neoplastic rather than a reactive process.
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PMID:Langerhans' cell histiocytosis (histiocytosis X): immunophenotype and growth fraction. 769 Jul 35

To determine events that transpire during the earliest stages of human T cell development, we have studied fetal tissues before (7 wk), during (8.2 wk), and after (9.5 wk to birth) colonization of the fetal thymic rudiment with hematopoietic stem cells. Calculation of the approximate volumes of the 7- and 8.2-wk thymuses revealed a 35-fold increase in thymic volumes during this time, with 7-wk thymus height of 160 microM and volume of 0.008 mm3, and 8.2-wk thymus height of 1044 microM and volume of 0.296 mm3. Human thymocytes in the 8.2-wk thymus were CD4+ CD8 alpha+ and cytoplasmic CD3 epsilon+ cCD3 delta+ CD8 beta- and CD3 zetta-. Only 5% of 8-wk thymocytes were T cell receptor (TCR)-beta+, < 0.1% were TCR-gamma+, and none reacted with monoclonal antibodies against TCR-delta. During the first 16 wk of gestation, we observed developmentally regulated expression of CD2 and CD8 beta (appearing at 9.5 wk), CD1a,b, and c molecules (CD1b, then CD1c, then CD1a), TCR molecules (TCR-beta, then TCR-delta), CD45RA and CD45RO isoforms, CD28 (10 wk), CD3 zeta (12-13 wk), and CD6 (12,75 wk). Whereas CD2 was not expressed at the time of initiation of thymic lymphopoiesis, a second CD58 ligand, CD48, was expressed at 8.2 wk, suggesting a role for CD48 early in thymic development. Taken together, these data define sequential phenotypic and morphologic changes that occur in human thymus coincident with thymus colonization by hematopoietic stem cells and provide insight into the molecules that are involved in the earliest stages of human T cell development.
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PMID:Early human T cell development: analysis of the human thymus at the time of initial entry of hematopoietic stem cells into the fetal thymic microenvironment. 769 29

To date no hematopoietic progenitors of dendritic Langerhans' cells (DLC), which represent an highly efficient class of antigen presenting cells, have been identified or the cytokines they elaborate have been defined. Here we describe an acute leukemia patient whose blasts (90-96% in peripheral blood and bone marrow) had a phenotype consistent with putative progenitors of DLC. The patient was treated with ara-C and VP-16 but did not achieve remission. The blasts had lobulated nuclei, no cytoplasmic vacuolation or Auer rods and were weakly positive for acid phosphatase and non-specific esterase and negative for PAS, granzyme A, dipeptidyl aminopeptidase IV, ATPase/ADPase and lysozyme production. The blasts were positive for CD1a, CD4, CD16, CD35, HLADR, HLADQ, CD11b, CD11c, CD14, CD33, CD34, CD11a, CD71, CD19, CD25, IL-2R beta and negative for CD2, CD7, CD8, CD10, CD22, CD56, CD57, surface or cytoplasmic CD3, TCR delta and TCR beta, HTLV-1p19 and P-glycoprotein. On liquid culture with or without 5 x 10(-9) M 12-O-tetradecanoylphorbol-13-acetate (TPA) for 3 days, the blasts formed aggregates of proliferating and elongating cells on the wall of the flasks with a decline in CD34, numerous dendritic processes appeared on the cells and there was strong positivity for ATPase/ADPase, but no other changes in phenotype. No macrophages were observed, indicating derivation from separate DLCs. Cytogenetic analysis showed chromosomal abnormalities and electron microscopy showed Birbeck granules. Southern blotting of DNA showed rearrangement of one allele for both JH and TCR beta but no HTLV-1 related sequences. Culture supernatants from blasts cultured with or without TPA showed the production of large amounts of IL-8, IL-6, TNF-alpha, MIP-1 alpha, IL-10 and interferon gamma and modest amounts of IL-1 alpha, GM-CSF and stem cell factor. The presence not only of CD1a, HLADR, HLADQ and many other characteristics including Birbeck granules, but also differentiation along the lines of DLC with appearance of dendritic processes on the cells and expression of ATPase/ADPase activity, indicate that the leukemic blasts in our patient represented a leukemic counterpart of normal progenitors of DLC and the leukemia a new entity which could possibly be classified as AML-M8. Lastly, many pro-inflammatory cytokines produced by DLC could contribute to inflammation and IL-10 to immunosuppression.
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PMID:Phenotype, genotype and cytokine production in acute leukemia involving progenitors of dendritic Langerhans' cells. 791 55

We describe the case of a patient with peripheral gamma/delta T-cell lymphoma (T-ML) with hepatosplenomegaly, generalized lymphadenopathy, and bone marrow involvement. A 44-year-old man had lymphoma, which became clinically apparent 2 months after the onset of myositis and insulin-dependent diabetes mellitus. A cervical lymph node biopsy specimen showed diffuse infiltration by large neoplastic cells with vascular proliferation. The neoplastic cells expressed the T-cell receptor (TCR)delta chain detected by TCR delta 1 and delta-TCS1, CD3, CD30, CD45RO, and epithelial membrane antigen, but not the TCR beta chain detected by beta F1, CD1a, CD2, CD4, CD5, CD7, CD8, CD25, HLA-DR, and terminal deoxynucleotidyl transferase. The cells had a clonal rearrangement of TCR gamma chain gene and a germ-line configuration of immunoglobulin heavy chain gene and TCR beta chain gene. Despite chemotherapy, the patient died of refractory lymphoma 4 months after diagnosis. Examination at autopsy revealed that the main hepatic and splenic neoplastic infiltration sites were the portal area and white pulp, respectively. Our patient differed from those with gamma/delta T-ML with hepatosplenic involvement reported previously with respect to the hepatic and splenic neoplastic infiltration patterns and the presence of lymphadenopathy.
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PMID:Gamma/delta T-cell lymphoma with hepatosplenomegaly: report of a case. 836 90

Two different subsets of CD4+,CD8+ T lymphocytes have been identified in peripheral blood collected from normal subjects and from patients with different diseases. The subpopulations differed in the degree of CD4 and CD8 antigen expression. Hence, it was possible to distinguish by cytofluorimetric analysis cells with a low (dim) or with a high (bright) fluorescence intensity after the staining with anti-CD4 or anti-CD8 mAbs. CD4+dim,CD8+bright lymphocytes were found in patients with EBV-infectious mononucleosis and were present for less than a month. CD4+bright,CD8+dim T cells were observed in neoplastic patients as well as in healthy subjects and were continuously present in similar percentages over a long period of time (at the moment, about 3 years). Both the subpopulations expressed CD2, CD3, CD5 antigens and had an alpha beta-TCR, but did not express CD1a or CD7. Only CD4+dim,CD8+bright cells expressed HLA-DR antigen and the activation marker CD38, while only CD4+bright,CD8+dim lymphocytes expressed CD56 and CD57 molecules. The hypothesis may be put forward that these two subsets represent an effort of the immune system to cope with different requirements, i.e., of viral or neoplastic origin, while it is not clear the meaning of these cells in healthy subjects.
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PMID:Cytofluorimetric identification of two populations of double positive (CD4+,CD8+) T lymphocytes in human peripheral blood. 846 Oct 16

The immunophenotype of 304 adult lymphoblastic leukemias (> 18 years) diagnosed on the basis of the FAB criteria was determined at the time of diagnosis using a panel of monoclonal antibodies. The series comprised cases diagnosed and immunophenotyped in 43 Italian centers (GIMEMA Cooperative Group) between April 1988 and June 1991. The immunophenotypic characterization consisted of two consecutive steps. The initial screening was based on the reactivity for TdT, HLA-Dr, CD7, CD10, CD13, CD19, CD24, CD33 and CD41. According to the results obtained, the second level of investigation assessed the positivity for intra cytoplasmic (Cy) Ig, CD1a, CD2, CD3, CD4, CD5, CD8 and CD20. Based on the hierarchical expression of the different B- and T-cell related antigens, each case was assigned to a given differentiation stage. B-lineage ALL were classified in five subgroups (B0-B4) and T-lineage ALL in four subgroups (T0-T3). Cases in which the blasts were lymphoid according to the FAB criteria, but expressed myeloid antigens in association with B- and T-lymphoid markers were defined as hybrid leukemias. As expected, CD10+ cases (B2-B3) were the most frequent within the B-lineage ALL (83.2% of cases). CyIg+ (B3) accounted for about 20% of CD10+ ALL. Twenty eight cases (13.4%) were at a pre-cALL stage (B0-B1) and of these, 8 (3.8% of the total series) were positive only for TdT and HLA-Dr (B0). Intermediate and mature thymic phenotypes (T2-T3) were predominant within the T-ALL (67.2%) groups. Five cases, were positive only for TdT and CD7 (CD5+), and classified as T0. 9.2% of cases fulfilled the definition of hybrid leukemia, largely in view of the co-expression of B-lymphoid and myeloid markers.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Immunophenotype of acute lymphoblastic leukemia cells: the experience of the Italian Cooperative Group (Gimema). 847 81

Evidence for the involvement of cellular immunity in the etiopathogenesis of the hypopigmentary disorder vitiligo is provided by rare cases of inflammatory vitiligo. Nonlesional, perilesional, and lesional skin biopsies from three inflammatory vitiligo patients were immunohistochemically analyzed. The composition of inflammatory infiltrates present in perilesional skin was analyzed by antibodies to T cells (CD2, CD3, CD4, and CD8), Langerhans cells (CD1a), and macrophages (CD36 and CD68). The presence of activation markers on inflammatory cells was evaluated by analysis of HLA-DR, interleukin-2 receptor, and HECA452 expression. The presence or absence of melanocytes was determined by the antibody NKI-beteb. Moreover, the abundance of matrix molecule tenascin was semi-quantified using T2H5. Results indicate that within perilesional skin, epidermis-infiltrating T cells exhibit an increased CD8/CD4 ratio and increased cutaneous lymphocyte antigen and interleukin-2 receptor expression. These cells are frequently juxtapositionally apposed to remaining melanocytes. In perilesional dermis, CD68+OKM5- macrophages were more numerous than in lesional or nonlesional skin. Keratinocytes as well as melanocytes consistently express major histocompatibility complex class II antigens along stretches of basal and suprabasal layers in perilesional epidermis. Moreover, inflammation is accompanied by increased tenascin content. Although these observations do not permit differentiation between the immune infiltrates being a result as opposed to the cause of the disease process, results presented in this study are very suggestive of involvement of local immune reactivity in melanocyte destruction.
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PMID:Presence of T cells and macrophages in inflammatory vitiligo skin parallels melanocyte disappearance. 864 62

Human dendritic cells (DC) can now be generated in vitro in large numbers by culturing CD34+ hematopoietic progenitors in presence of GM-CSF+TNF alpha for 12 d. The present study demonstrates that cord blood CD34+ HPC indeed differentiate along two independent DC pathways. At early time points (day 5-7) during the culture, two subsets of DC precursors identified by the exclusive expression of CD1a and CD14 emerge independently. Both precursor subsets mature at day 12-14 into DC with typical morphology and phenotype (CD80, CD83, CD86, CD58, high HLA class II). CD1a+ precursors give rise to cells characterized by the expression of Birbeck granules, the Lag antigen and E-cadherin, three markers specifically expressed on Langerhans cells in the epidermis. In contrast, the CD14+ progenitors mature into CD1a+ DC lacking Birbeck granules, E-cadherin, and Lag antigen but expressing CD2, CD9, CD68, and the coagulation factor XIIIa described in dermal dendritic cells. The two mature DC were equally potent in stimulating allogeneic CD45RA+ naive T cells. Interestingly, the CD14+ precursors, but not the CD1a+ precursors, represent bipotent cells that can be induced to differentiate, in response to M-CSF, into macrophage-like cells, lacking accessory function for T cells. Altogether, these results demonstrate that different pathways of DC development exist: the Langerhans cells and the CD14(+)-derived DC related to dermal DC or circulating blood DC. The physiological relevance of these two pathways of DC development is discussed with regard to their potential in vivo counterparts.
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PMID:CD34+ hematopoietic progenitors from human cord blood differentiate along two independent dendritic cell pathways in response to GM-CSF+TNF alpha. 876 Aug 23

The Rel/NF-kappa B proteins, p50, p52, p65, c-Rel, and RelB, constitute a family of transcription factors involved in the positive regulation of a variety of genes during the immune response. Recently, it has been shown that RelB knockout mice have no dendritic cells (DC). An overexpression of p50 has been described in follicular dendritic cells (FDC). A constitutive NF-kappa B activity has been reported in mature macrophages. This led to the hypothesis that some of the Rel/NF-kappa B proteins were key nuclear factors in functions of accessory cells of the immune response. Therefore, we investigated in situ the nuclear localization of Rel/NF-kappa B proteins in accessory cells of the immune system by immunohistochemistry and double labeling by immunofluorescence from five normal human tonsils and five lymph nodes with follicular hyperplasia. Nuclear p65 and c-Rel proteins were found in all cell types including lymphocytes. In germinal centers GC, p50, p52, and RelB were found in the nuclei of FDC only and were not detected in the nuclei of CD68+ cells. In T cell areas, p50, p52, and RelB were found in the nuclei of HLA-DR+ cells with an antigen-presenting cell (APC) morphology. p52 and RelB were detected in the nuclei in both CD1a+ and CD68+ cells from the T cell area, whereas p50 was found only in CD68- and CD1a- cells. Cells with nuclear p50 were negative for the CD38, CD20 and CD2 markers. These results show that, physiologically, high levels of nuclear of p50, p52 and RelB are restricted to accessory cells of the immune system, which include FDC in GC, and DC and macrophages in the T cell zone, that specialized scavenger macrophages from GC do not have detectable levels of p52 and RelB, whereas macrophages from the T cell area, known to present the antigen to T cells, do have both nuclear p52 and RelB, and that in the T cell zone, p52 and RelB are located in nuclei of both CD1a+, CD68+ or both, cells APC, whereas p50 is restricted to CD1a- and CD68- APC. The different patterns of p50, p52 and RelB protein nuclear localization may provide insight into their different roles during the immune response in vivo.
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PMID:Differential nuclear localization of p50, p52, and RelB proteins in human accessory cells of the immune response in situ. 892 37

In response to granulocyte-macrophage colony-stimulating factor plus tumor necrosis factor alpha, cord blood CD34+ hematopoietic progenitor cells differentiate along two unrelated dendritic cell (DC) pathways: (1) the Langerhans cells (LCs), which are characterized by the expression of CD1a, Birbeck granules, the Lag antigen, and E cadherin; and (2) CD14+ cell-derived DCs, characterized by the expression of CD1a, CD9, CD68, CD2, and factor XIIIa (Caux et al, J Exp Med 184:695, 1996). The present study investigates the functions of each population. Although the two populations are equally potent in stimulating naive CD45RA cord blood T cells through apparently identical mechanisms, each also displays specific activities. In particular CD14-derived DCs show a potent and long-lasting (from day 8 to day 13) antigen uptake activity (fluorescein isothiocyanate dextran or peroxidase) that is about 10-fold higher than that of CD1a+ cells, which is restricted to the immature stage (day 6). The antigen capture is exclusively mediated by receptors for mannose polymers. The high efficiency of antigen capture of CD14-derived cells is coregulated with the expression of nonspecific esterase activity, a tracer of lysosomial compartment. In contrast, the CD1a+ population never expresses nonspecific esterase activity. The most striking difference is the unique capacity of CD14-derived DCs to induce naive B cells to differentiate into IgM-secreting cells, in response to CD40 triggering and interleukin-2. Thus, although the two populations can allow T-cell priming, initiation of humoral responses might be preferentially regulated by the CD14-derived DCs. Altogether, those results show that different pathways of DC development might exist in vivo: (1) the LC type, which might be mainly involved in cellular immune responses, and (2) the CD14-derived DC related to dermal DCs or circulating blood DCs, which could be involved in humoral immune responses.
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PMID:CD34+ hematopoietic progenitors from human cord blood differentiate along two independent dendritic cell pathways in response to granulocyte-macrophage colony-stimulating factor plus tumor necrosis factor alpha: II. Functional analysis. 926 63


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