Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:3.4.24.11 (CD10)
 9,792 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

In the present study the capacity of early fetal B cells to produce Ig was investigated. It is shown that B cells from fetal liver, spleen, and bone marrow (BM) can be induced to produce IgM, IgG, IgG4, and IgE, but not IgA, in response to IL-4 in the presence of anti-CD40 mAb or cloned CD4+ T cells. Even splenic B cells from a human fetus of only 12 wk of gestation produced these Ig isotypes. IFN-alpha, IFN-gamma, and transforming growth factor-beta inhibited IL-4-induced IgE production in fetal B cells, as described for mature B cells. The majority of B cells in fetal spleen expressed CD5 and CD10 and greater than 99% of B cells in fetal BM were CD10+. Highly purified CD10+, CD19+ immature B cells and CD5+, CD19+ B cells could be induced to produce Ig, including IgG4 and IgE, in similar amounts as unseparated CD19+ B cells. Virtually all CD19+ cells still expressed CD10 after 12 days of culture. However, the IgE-producing cells at the end of the culture period were found in the CD19-,CD10- cell population, suggesting differentiation of CD19+,CD10+ B cells into CD19-,CD10- plasma cells. Pre-B cells are characterized by their lack of expression of surface IgM (sIgM). Only 30 to 40% of BM B cells expressed sIgM. However, in contrast to sIgM+,CD10+,CD19+ immature B cells, sorted sIgM-,CD10+,CD19+ pre-B cells failed to differentiate into Ig-secreting cells under the present culture conditions. Addition of IL-6 to these cultures was ineffective. Taken together, these results indicate that fetal CD5+ and CD10+ B cells are mature in their capacity to be induced to Ig isotype switching in vitro as soon as they express sIgM.
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PMID:Induction of isotype switching and Ig production by CD5+ and CD10+ human fetal B cells. 137 43

The low frequency of plasma cells and the lack of specific cell surface markers has been a major obstacle for a detailed characterization of plasma cells in normal human bone marrow. Multiparameter flow cytometry enabled the identification of plasma cells in normal bone marrow aspirates. The plasma cells were located in a unique position in the correlation of forward light scattering, orthogonal light scattering, and immunofluorescent-labeled CD38. The identity of the sorted cell populations was confirmed by microscopic examination of Wright's stained slides and slides stained for cytoplasmic immunoglobulin using polyclonal antibodies reactive with light chains; ie, anti-kappa fluorescein isothiocyanate and anti lambda phycoerythrin (PE). The purity of the sorted plasma cells was greater than 97% (n = 4). The average frequency of plasma cells in normal bone marrow aspirates was low--0.25% of the nucleated cells (n = 7)--but surprisingly consistent between individuals (SD = .05; range 0.14% to 0.30%). A detailed analysis showed two distinct populations of plasma cells: (1) A population relatively smaller by forward light scattering expressed CD22, CD35, and sigE and was identified as early plasma cells (ie, lymphoplasmacytoid), and (2) a population larger by forward light scattering lacked these markers and was identified as mature plasma cells. The antigenic profile of the normal plasma cells was determined in two-color immunofluorescence studies. The expression of cell surface immunoglobulin G (IgG), IgA, IgE, IgD, IgM, and the cell surface antigens CD10, CD11b, CD13, CD11c, CD14, CD15, CD16, CD19, CD22, CD20, CD33, CD35, CD45, and HLA-DR was determined on the plasma cells. A significant heterogeneity in cell surface antigen expression was observed within the plasma cell population. Unexpectedly, myeloid-specific cell surface antigens such as CD33 and CD13 and the early B-cell antigen identified by CD10 were expressed on a proportion of plasma cells. These observations imply that the association of myeloid and early B-cell markers described in multiple myeloma may not be associated with the neoplasia but is a normal phenomenon.
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PMID:Identification and characterization of plasma cells in normal human bone marrow by high-resolution flow cytometry. 222 23

Immunophenotypic analyses of immature stage (day 19-23), intermediate stage (day 28-32), mature stage (day 34-37), and older stage (day 42-44) human hemopoietic mast cells from colonies grown in semi-solid agar cultures were performed to study the ontogeny and identity of this cell type and its relationship to other leukocytes. Intermediate to mature stage mast cells were positive with the YB5.B8 mouse monoclonal antibody, (McAb) specific for human mast cells, whereas the reactivity of immature mast cells with this McAb was inconsistent and older cells were generally negative. Mast cells at all stages of maturation were strongly positive for IgE receptor sites and negative with the Bsp-1 McAb, specific for human basophils. Mast cells at all stages of maturation were also strongly positive with the monocyte McAbs RPA-M1 (CD11), positive with the monocyte McAb OKM5 and the monocyte/granulocyte McAbs BMA-210 and MY7 (CD13), strongly positive with the B-cell markers J5 (CD10) and anti-IgM, and positive with the plasma cell marker PCA-1 and to a lesser extent with the activated B-cell marker CD23. The mast cells were also strongly positive with anti-CD45 to the common leukocyte antigen and positive with an antibody to HLA-DR and an antibody to FVIIIC. They were negative for specific T-cell markers. The diversity of this phenotype supports the current concept that mast cells originate from the pluripotential progenitor cells in the bone marrow.
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PMID:Immunophenotypic analyses of cultured hemopoietic mast cells. 239 49

The EBV-transformed B cell line JR-2 proliferates in response to partially purified preparations of low m.w. B cell growth factor (LMW-BCGF). Two clones of JR-2 were generated that retained this LMW-BCGF responsiveness, exhibiting similar dose/response characteristics but differing phenotypically. The B10 clone grows as single, discrete, small round cells, whereas D3 grows in aggregates. The clones also differ in the expression of cell surface Ag, D3 being weakly DR+ and strongly CD23+, whereas B10 lacks these Ag. The CD23 on D3 cells binds IgE. Both clones are T9+, 4F2+, B1-, B2- and CALLA-. D3 expresses surface IgG and differentiates in the presence of LMW-BCGF, to secrete IgG. B10 lacks surface and cytoplasmic Ig and fails to differentiate in response to LMW-BCGF. CD23 cannot be induced on B10 by incubation with either LMW-BCGF or IL-4. B10 does not shed CD23 and shed CD23 is not a growth factor for either cloned line. Expression of CD23 on D3 cells is not affected by preincubation with LMW-BCGF. Neither B10 or D3 cells respond to rIL-1, rIL-2, rIL-4, rIL-6, rTNF-alpha/beta, rIFN-gamma, or to high m.w. BCGF (Namalwa), alone or in combination. Both clones absorb BCGF activity and crossover absorptions indicate that the clones remove growth factors required by each other. D3 and B10 both appear therefore to respond selectively to LMW-BCGF. These data suggest that the loss of CD23 from a cloned derivative of the cell line JR-2, although accompanied by considerable phenotypic change, is not associated with the disappearance of LMW-BCGF responsiveness, indicating that CD23 is not the essential receptor for LMW-BCGF.
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PMID:Low molecular weight B cell growth factor-responsive cloned human B cell lines. I. Phenotypic differences and lack of requirement for CD23 (Fc epsilon RII). 252 11

The effect of rIL-4 on the expression of low affinity receptor for the Fc part of IgE (Fc epsilon R2/CD23) and class II MHC antigens on Burkitt's lymphoma (BL) cell lines was investigated. Some of the BL lines contained low percentages of CD23 and HLA-DQ-positive cells, but virtually all cells expressed HLA-DR. IL-4 induced CD23 and class II MHC Ag expression on 7 of 9 BL. Optimal CD23 and class II MHC expression was observed after 48-72 h of incubation. Induction of CD23 and class II MHC Ag in the BL cell line BL2 by IL-4 was confirmed at the specific mRNA level. Significant activation of HLA-DQ mRNA was obtained after 6 h of incubation with IL-4 and gradually increased during prolonged incubation. Maximal induction of mRNA transcription occurred after 48 to 72 h. Optimal induction of HLA-DR and CD23 transcription in BL2 was also observed after 48 to 72 h. The induction of CD23 and class II MHC Ag seems to be specific for IL-4, because rIL-1, rIL-2, rIFN-gamma, recombinant granulocyte-macrophage-CSF, and a commercial source of low m.w. B cell growth factor were ineffective. In addition, the expression of class I MHC Ag, the transferrin receptor, CD38, CD25, CD10, CD20, and CD21 were not affected by IL-4. Interestingly, IFN-gamma and PGE2 suppressed the IL-4-induced membrane expression of CD23 and class II MHC Ag in a dose-dependent way. IFN-gamma also blocked IL-4-induced CD23 mRNA transcription in BL2 completely, whereas PGE2 (10(-7) M) was partially inhibitory. The induction of CD23 and class II MHC Ag by IL-4 required intact protein synthesis as shown by its inhibition by cycloheximide. These results indicate that the induction of CD23 and class II MHC Ag by IL-4 is regulated in a coordinated way.
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PMID:Regulation of Fc receptor for IgE (CD23) and class II MHC antigen expression on Burkitt's lymphoma cell lines by human IL-4 and IFN-gamma. 296 26

Biochemical studies of pollen proteins have been focused, primarily, in investigating their roles as allergens. These molecules, some of which have enzymatic activity, act as antigens and initiate the production of IgE antibodies, leading to allergic and/or asthmatic responses. Included in this mixture of proteins are proteinases which, although they may or may not be allergenic, could still be involved in airway dysfunction. We have isolated an arginine-specific endopeptidase to homogeneity from mesquite (Prosopis velutina) pollen, a known wind-borne allergen, which has a molecular mass near 84 kDa by NaDodSO4-gel electrophoresis, a pH optimum in the neutral to alkaline range, and a requirement for Ca2+ for stabilization. The enzyme is inhibited by diisopropyl fluorophosphate (DFP) and N-p-tosyl-L-lysine chloromethylketone but not by N-p-tosyl-L-phenylalanine chloromethylketone, EDTA, or iodoacetamide. It was also not inhibited by human plasma proteinase inhibitors nor several other naturally occurring plant and animal inhibitors. Cleavage by the endopeptidase was primarily on the carboxy-terminal side of arginine residues in peptides, whereas proteins such as kallikrein and prothrombin were only activated and/or degraded extremely slowly. Several bioactive peptides that may be involved in maintaining normal lung function were readily fragmented, including angiotensin II, a vasoconstrictor, and atrial natriuretic peptide, a modulator of vascular permeability, both of which were rapidly cleaved at low enzyme:substrate molar ratios. Thus, the pollen endopeptidase could be involved in exacerbating the development of asthma by inactivating bioactive peptides that have ameliorating effects in maintaining lung airway homeostasis.
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PMID:Isolation and properties of an angiotensin II-cleaving peptidase from mesquite pollen. 769 24

Severe combined immunodeficient (SCID) mice were transplanted with different human fetal organs (SCID-hu mice), including thymus, liver, spleen, and omentum, and the serum levels of human IgM, IgG, IgE, and IgA were measured. In all SCID-hu mice significant levels (up to 590 ng/ml) of IgM were detected, irrespective of the organs transplanted. In contrast, IgG was present (up to 530 ng/ml) only when the fetal thymus was transplanted together with the fetal liver, indicating that the presence of human T cell is a prerequisite for in vivo isotypes switching by human B cells in SCID-hu mice. Additional transplantation of fetal spleen did not significantly increase IgG levels. was observed 4 months after transplantation. At that time, analysis by IEF showed that human IgG present in SCID-hu serum was at least oligoclonal. Furthermore, all IgG subclasses were represented in the human IgG pool. Human B cells were undetectable in the peripheral blood, spleen, and bone marrow of these SCID-hu mice; in contrast, B cells expressing CD19 could be isolated from the SCID-hu thymus. Considerable proportions of the CD19+ B cells coexpressed CD5, CD7, CD10, CD40, and CD2. These B cells spontaneously produced IgM and IgG in vitro and could be induced to switch to IgE-producing cells when cocultured with cloned activated CD4+ T cells in the presence of IL-4. Collectively, these data demonstrate that functionally mature B cells able to produce IgM and IgG in vivo, and IgE in vitro, are present in the SCID-hu human thymus.
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PMID:Human Ig production and isotype switching in severe combined immunodeficient-human mice. 832 22

Bermuda grass pollen (BGP) contains a very complex mixture of allergens, but only a few have been characterized. One of the allergens, with an apparent molecular mass of 21 kDa, has been shown to bind serum IgE from 29% of patients with BGP allergy. A combination of chromatographic techniques (ion exchange and reverse phase HPLC) was used to purify the 21 kDa allergen. Immunoblotting was performed to investigate its IgE binding and lectin-binding activities, and the Lysyl-C endopeptidase digested peptides were determined by N-terminal sequencing. The cDNA sequence was analyzed by RACE PCR-based cloning. The protein mass and the putative glycan structure were further elucidated using MALDI-TOF mass spectrometry. The purified 21 kDa allergen was designated Cyn d 24 according to the protocol of International Union of Immunological Societies (IUIS). It has a molecular mass of 18,411 Da by MALDI-TOF analysis and a pI of 5.9. The cDNA encoding Cyn d 24 was predicted to produce a 153 amino acid mature protein containing tow conserved sequences seen in the pathogen-related protein family. Carbohydrate analysis showed that the most abundant N-linked glycan is a alpha(3)-fucosylated pauci-mannose (Man3GlcNAc2) structure, without a Xyl beta-(1,2)-linked to the branching beta-Man. Thus, Cyn d 24 is a glycoprotein and the results of the sequence alignment indicate that this novel allergen is a pathogenesis-related protein 1. To the best of our knowledge, this is the first study to identify any grass pollen allergen as a pathogenesis-related protein 1.
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PMID:Purification and structural analysis of the novel glycoprotein allergen Cyn d 24, a pathogenesis-related protein PR-1, from Bermuda grass pollen. 1633 60

It has been suggested that the recent increase in inflammatory diseases is related to an increase in environmental chemicals and psychiatric stress. To investigate the effect of chronic topical exposure to chemicals and isolation stress, low-dose formalin (a mild contact sensitizer and an irritant), 2,4,6-trinitrochlorobenzene (TNCB; a potent contact sensitizer) and sodium lauryl sulphate (SLS; an irritant) were applied to mouse ears at 7-d intervals under no-stress or stress conditions. Skin reactions (ear swelling) elicited by formalin and TNCB increased time dependently. At the chronic stage, a significant skin reaction peaking at 1 h after application was elicited on the formalin-treated sites, while a shift from a delayed-type hypersensitivity to an immediate-type response was observed on the TNCB-treated sites. At the formalin-treated sites, genes related to neurogenic inflammation, i.e., bradykinin (BK) B2 receptor, IL-6, and membrane metallo endopeptidase (NEP) mRNA were upregulated. In the TNCB-treated sites, marked upregulation of IFN-gamma, IL-1beta, IL-4, and IL-6 mRNA was observed in addition to B2 receptor mRNA. Pretreatment with HOE140, the B2 receptor antagonist suppressed these skin reactions. Increased skin sensitivity to an unrelated chemical, ethanol, and thermal stimuli were elicited in formalin and TNCB-treated mice. Cortisol levels in formalin-treated mice and IgE levels in TNCB-treated mice were elevated respectively. Stress markedly amplified the skin reactions and gene expression related to neurogenic inflammation. SLS did not induce any changes. It was concluded that chronic topical exposure to low-dose noxious chemicals and stress could easily induce skin sensitivity relating to the BK-B2 pathway and nociceptive sensitization reflecting neural sensitization.
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PMID:Effect of chronic topical exposure to low-dose noxious chemicals and stress on skin sensitivity in mice. 1807 3

Airborne fungal spores bearing allergens are the causative agent for inducing immediate hypersensitive reaction in sensitive individuals. In this study the potential aeroallergens have been reported for the first time from Rhizopus oryzae a common airborne mold. Clinical data based on SPT was further confirmed by ELISA. IgE reactive bands were revealed by one-dimensional immunoblotting. A 44 kDa major reactive band was found in all immunoblots. For precise identification of allergens, an immuno-proteomic approach was taken with a combination of 2-Dimensional gel electrophoresis and Mass-spectrometry. 2D map of spore-mycelial protein was confronted with pooled sera and several IgE reactive spots were detected, most of which were glycoproteins and except for one, which has no antigenic determinacy after metaperiodate modification. Each of those spots was identified by MALDI-TOF-TOF. Some bioinformatic approaches were taken to predict the signal peptide and subcellular localization of each protein. Major 44 kDa allergen was identified as Aspartyl endopeptidase. Sequence information was extracted from MS/MS spectra of two tryptic peptides generated from the 44 kDa endopeptidase. Multiple alignments with other reported aspartyl protease allergens showed significant homology. Allergenicity assessment of this protein was performed in silico and identified as a potential putative allergen.
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PMID:Identification of aero-allergens from Rhizopus oryzae: an immunoproteomic approach. 2304 Nov 33


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