Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound   Target Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound

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Query: EC:3.4.21.4 (trypsin)
42,187 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The adhesion molecule L-selectin is proteolytically cleaved from the surface of lymphocytes and neutrophils within minutes after stimulation by phorbol ester or calcium ionophores. In contrast to neutrophils, soluble factors have not been shown to induce down-regulation of L-selectin on lymphocytes. We therefore examined whether signals generated by interaction with cell surface receptors could deliver physiological stimuli inducing this regulatory mechanism. While cross-linking of several adhesion molecules (CD2, CD44, alpha 4-integrin, LFA-1) by antibody did not result in a significant reduction of the expression of L-selectin, antibodies against CD45 and Thy-1.2, both involved in the regulation of lymphocyte activation, induced loss of cell surface L-selectin within minutes, even at 4 degrees C, by shedding into the supernatant. Cross-linking of these molecules was shown to be essential, but Fc interactions or adherent cells were not required. A similar response, albeit less effective, was found after cross-linking of CD3. Interestingly, initiation of shedding only occurred in the presence of cell-cell contact, pointing to a second, as yet unknown, signal required. Loss of L-selectin induced by CD45 cross-linking is followed by a rapid re-expression of the molecule upon incubation at 37 degrees C. This reaction is also dependent on specific triggering signals as rapid re-expression was not observed after removal of L-selectin by trypsin. The data indicate that the protein phosphatase CD45 as well as the TCR complex itself in combination with a further, as yet unknown, cell-cell contact-dependent stimulus have a regulatory role in the dynamic control of L-selectin expression in lymphocytes.
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PMID:CD45-mediated signals can trigger shedding of lymphocyte L-selectin. 913 16

The case of a 62-year-old man who presented with acute abdominal pain and a widespread tumor involving the retroperitoneum is described. Three weeks after initial presentation, the patient died suddenly of acute cardiac failure with signs of arrhythmia. Autopsy revealed a disseminated tumor with infiltration of the retroperitoneal fat, as well as nodules in the left testis and the right atrium. The tumor cells were reactive for CD45, vimentin, and chloroacetate esterase, but were unreactive with a broad spectrum of antibodies against myelomonocytic and lymphocytic antigens and with antibodies against tryptase and c-kit (CD117), which are characteristic markers for mast cells. However, the bone marrow exhibited the typical picture of mastocytosis, with disseminated clusters of differentiated spindle-shaped cells that stained strongly for tryptase, c-kit, and chloroacetate esterase. No infiltrates of well-differentiated mastocytosis could be detected in any of the extramedullary tissues investigated. A diagnosis of bone marrow mastocytosis with an associated undifferentiated extramedullary tumor of hemopoietic origin was established. By definition, the extramedullary tumor could not be diagnosed as a granulocytic sarcoma or (differentiated) mastocytoma, but the possibility that a mast cell progenitor could be involved in the evolution of both tumors cannot be ruled out.
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PMID:Bone marrow mastocytosis associated with an undifferentiated extramedullary tumor of hemopoietic origin. 914 Mar 15

We have shown that oestrogen has a central integrative role in regulating key components of the progesterone biosynthetic and corticosteroid metabolic pathways within syncytiotrophoblasts that govern placental function and maturation of the fetal pituitary-adrenocortical axis. Studies utilizing classic binding procedures and RNAse protection have demonstrated that human placental villous tissue exhibits specific high affinity oestrogen binding and expresses the mRNA for the oestrogen receptor. However, it is not known whether the oestrogen receptor is expressed specifically in syncytiotrophoblasts. Therefore, the present study determined whether the oestrogen receptor protein was detectable by immunocytochemistry in cultured human syncytiotrophoblast maintained in a low oestrogen/progestin environment. Cytotrophoblasts were isolated from human term placentae by trypsin dispersion and Percoll gradient centrifugation and cultured for 5, 7 or 10 days. Incubation of syncytiotrophoblast with 5-10 micrograms/ml of the anti-oestrogen receptor rat monoclonal antibody D-75, which is specific for the primate oestrogen receptor, resulted in identification of the oestrogen receptor in the nuclei of these cells. In contrast, there was no reactivity of the trophoblasts to either rat IgG or an irrelevant rat monoclonal antibody IgG2a against mouse common leukocyte antigen T200. Collectively, these findings indicate that oestrogen receptor is expressed in the nuclei of human placental syncytiotrophoblasts and support the suggestion that the syncytiotrophoblast is an oestrogen-responsive tissue.
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PMID:Immunocytochemical identification of the oestrogen receptor in the nuclei of cultured human placental syncytiotrophoblasts. 917 30

The case of a 63-year-old man with a widespread retroperitoneal tumor and two tumor nodules in the left testis is described. Histopathological and cytopathological examination of tissue from the retroperitoneal tumor led to a diagnosis of lymphoreticular neoplasia. The patient died in acute cardiac failure, five weeks after initial presentation. Autopsy revealed another tumor nodule in the right atrium. Macroscopically, the bone marrow appeared normal. The tumor cells were reactive for CD45, vimentin and chloroacetate esterase, but were uncreative with a broad spectrum of antibodies against myelomonocytic and lymphocytic antigens and antibodies against tryptase and c-kit (CD117), characteristic markers for mast cells. However, the bone marrow exhibited the typical picture of mastocytosis. A diagnosis of bone marrow mastocytosis with an associated secondary extramedullary mast cell sarcoma was established. The cause of death was heart failure due to arrhythmia caused by an exophytic atrioseptal tumor nodule.
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PMID:[Association of bone marrow mastocytosis with extremely immature extramedullary mast cell sarcoma]. 927 45

CD45 is a transmembrane two-domain tyrosine phosphatase required for efficient signal transduction initiated by lymphocyte antigen receptors. As with most transmembrane two-domain phosphatases, the role of the second phosphatase domain is unclear. In this study, recombinant CD45 cytoplasmic domain proteins purified from bacteria were used to evaluate the function of the individual phosphatase domains. A recombinant protein expressing the membrane-proximal region, first phosphatase domain, and spacer region of CD45 (rD1) was catalytically active and found to exist primarily as a dimer. In contrast to this, a recombinant protein expressing the spacer region, the second phosphatase domain and the carboxy tail of CD45 (rD2) existed as a monomer and had no catalytic activity against any of the substrates tested. Comparison of rD1 with the recombinant protein expressing the entire cytoplasmic domain of CD45 (rD1/D2) indicated that rD1/D2 was 2-3-fold more catalytically active, was more thermostable, and existed primarily as a monomer. Limited trypsin digestion of rD1/D2 provided evidence for a noncovalent association between an N-terminal 27-kDa fragment and a C-terminal 53-kDa fragment, suggesting an intramolecular interaction. Furthermore, rD1 was found to specifically associate with rD2 in an in vitro binding assay. Taken together, these data provide evidence for an intramolecular interaction occurring in the cytoplasmic domain of CD45. In the absence of the C-terminal region containing the second phosphatase domain, intermolecular interactions occur, resulting in dimer formation.
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PMID:Characterization of recombinant CD45 cytoplasmic domain proteins. Evidence for intramolecular and intermolecular interactions. 965 87

The microenvironment of secondary lymphoid organs consists of two major populations of cells, the lymphoid cells and a population of stromal cells that contribute to both tissue architecture and function. Interactions of both populations are essential for the development and control of humoral immune responses. In this study, stromal-cell preparations were obtained by a multistage process. This involved culturing 300-400-microm slices of human tonsil for 6-8 days at 25 degrees C, trypsin digestion of the residual explant, followed by CD45-positive-cell depletion using magnetic beads, and a final period of culture for 4 days to remove remaining nonadherent cells. Phenotyping with a panel of monoclonal antibodies revealed that the cells express HLA-DR, CD54 (ICAM-1), CD44, but no CD45 nor a range of other markers for epithelial and endothelial cells. Immunoassays of supernatants from stromal cells revealed that IL-6 was produced constitutively, and its production was increased by treatment with TNF-alpha and IFN-gamma. In contrast IL-1, IL-2, IL-4, IL-7, IL-8, IL-10, IL-12, TNF-alpha, and IFNgamma were not produced. Functional tests showed that these cells express follicular dendritic cell-like properties. Coculturing of tonsilar B cells with stromal cells resulted in enhanced proliferation and also led to increased production of immunoglobulins and IL-6, suggesting crucial signaling between these populations.
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PMID:Tonsil stromal-cell lines expressing FDC-like properties: isolation, characterization, and interaction with B lymphocytes. 981 1

To identify chymase- and tryptase-positive mast cells in the human uvea, and to study their associations with different types of resident uveal cells, uveal specimens from 24 human donor eyes were cryosectioned in sagittal and tangential planes. Enzyme histochemical staining of chymase was combined with immunohistochemical staining for tryptase, detected with the APAAP method. Fluorescence immunohistochemistry was performed with antibodies against c-kit, alpha smooth muscle actin, protein gene product (PGP) 9.5, CD45, and HLA-DR. In different uveal compartments, the total amounts of mast cells were calculated and the distributions of chymase and tryptase were quantified. All uveal mast cells were c-kit and CD45 positive and HLA-DR negative. No association existed between mast cells and actin-containing cells. Only a few mast cells were in close association with PGP 9.5-labeled nerve fibers. In the choroid, most mast cells were located in the inner central part (mean density = 48.9/mm(2)), and contained both chymase and tryptase (96%). The ciliary muscle contained numerous mast cells (mean density = 33.7/mm(2)), many of them tryptase positive but chymase negative (63%). In the pars plana, a high number of chymase-positive, tryptase-negative mast cells were found (20%). In the iris only a few mast cells were present. Although the choroid contains the most common subtype of mast cells, a unique situation concerning the distribution of chymase and tryptase is present in the anterior uveal tissues. A possible role for these cells in the special immunological situation of the anterior eye chamber merits further investigation.
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PMID:Mast cell heterogeneity in the human uvea. 1060 78

The polymerase chain reaction (PCR) analysis of DNA extracted from tissue sections can be applied to a variety of research and diagnostic protocols. To analyze selectively the specific areas of tissue, a direct microdissection of histochemically or immunohistochemically stained sections, if satisfactory for PCR, is helpful. However, the influence of various staining methods on PCR has been poorly investigated. In this study, paraffin sections of formalin-fixed lymph node samples were histochemically stained with Mayer's hematoxylin, eosin Y, methyl green, or May-Grunwald solution and immunostained for CD45 using 3,3'-diaminobenzidine (DAB), DAB with cobalt ion (DAB-Co), or new fuchsin as the chromogen. In addition, unstained sections were treated with trypsin, microwave, or pressure cooker, the techniques frequently used in immunostains for antigen unmasking. DNA was extracted from each section, and the PCR efficiency in amplifying a 110 bp portion of the beta-globin gene was evaluated by two parameters: the cycle count in which the first visible band was obtained (CYCLE(min)) and the maximum amount of PCR products (CONC(max)). The hematoxylin stain showed a significantly prolonged CYCLE(min) (P < .01) and lower CONC(max) (P < .05) in comparison with unstained and untreated control sections. The May-Grunwald stain showed a prolonged CYCLE(min) (P < .01), although the CONC(max) was not significantly different from that of the control (P = .051). The eosin and methyl green stains showed no effects against PCR. In immunostains, the DAB-Co method showed a lower CONC(max) (P < .05), whereas the CYCLE(min) was not prolonged. The DAB and new fuchsin methods had no untoward effects. Antigen-unmasking treatments showed deteriorating effects on PCR. The trypsin treatment significantly prolonged the CYCLE(min) (P < .01), and the PCR amplification did not reach the "plateau" level with a maximum of 60 cycles. The PCR efficiency was worse in microwave or pressure cooker treatment, with neither CYCLE(min) nor CONC(max) being obtained. When target areas from sections for subsequent PCR amplification are microdissected, methyl green is most suitable as a dye for nuclear staining. The immunohistochemical visualization with DAB or new fuchsin yields no unfavorable effects. A successful PCR amplification may not be expected in sections that are pretreated in a microwave oven or pressure cooker.
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PMID:Influence of histochemical and immunohistochemical stains on polymerase chain reaction. 1069 71

Renal interstitial fibrosis is the final common pathway leading to end-stage renal disease in various nephropathies including renal amyloidosis. However, the role of mast cells (MCs) in the fibrotic process of renal amyloidosis is not fully understood. We compared the distribution of MCs in renal biopsies from 30 patients with AA type renal amyloidosis and 20 control cases. Immunoreactivity of renal MCs to anti-tryptase and anti-chymase was studied. Interstitial myofibroblasts were stained with anti-alpha-smooth muscle actin (alpha-SMA) antibody, and inflammatory cells were identified by anti-CD45, -CD20, and -CD68 mAbs. Positively stained cells were counted, and the relative interstitial and fractional areas of anti-alpha-SMA stained cells were measured. Anti-CD29 mAb was used to detect beta1 integrin and anti-basic fibroblast growth factor (bFGF) mAb for the growth factor on MCs. MCs were rarely found in control samples. In contrast, samples showing amyloid deposition contained numerous tryptase-positive (MCT) (940.17 +/- 5.4 versus 6.74 +/- 1.1/mm2) but fewer chymase-positive (MCTC) cells (20.7 +/- 2.86 versus 1.7 +/- 0.76/mm2) in the renal interstitium. There was a significant relationship between interstitial MCT and creatinine clearance (r = -0.72), and between interstitial MCT and glomerular amyloid-index (GAI) (r = 0.723) and interstitial amyloid area (r = 0.824). Accumulation of MCs correlated significantly with the number of T lymphocytes (MCT: r = 0.694). There was also a significant relationship between mast cell (MC) number and the fractional area of alpha-SMA positive interstitium (r = 0.733) and interstitial fibrotic area (r = 0.6). Double immunostaining demonstrated intracytoplasmic presence of beta1 integrin on 87% of MCT and correlated significantly with the interstitial amyloid area (r = 0.818, P = .001) and T-cell number (r = 0.639, P = .002). bFGF was also detected on 85.5% of MCTC correlating well with the interstitial alpha-SMA-area (r = 0.789). Our results indicate that MCs constitute an integral part of the overall inflammatory process and play a crucial role in interstitial fibrosis in renal amyloidosis.
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PMID:Increased density of interstitial mast cells in amyloid A renal amyloidosis. 1100 43

In an attempt to identify novel diagnostic markers for mast cell (MC)-proliferative disorders, serial bone marrow (bm) sections of 22 patients with mastocytosis (systemic indolent mastocytosis, n = 19; mast cell leukemia [MCL], n = 1; isolated bm mastocytosis, n = 2) were analyzed by immunohistochemistry using antibodies against CD2, CD15, CD29, CD30, CD31, CD34, CD45, CD51, CD56, CD68R, CD117, HLA-DR, bcl-2, bcl-x(L), myeloperoxidase (MPO), and tryptase. Staining results revealed expression of bcl-x(L), CD68R, and tryptase in neoplastic MCs (focal dense infiltrates) in all patients. Mastocytosis infiltrates were also immunoreactive for CD45, CD117 (Kit), and HLA-DR. In most cases, the CD2 antibody produced reactivity with bm MCs in mastocytosis, whereas in control cases (reactive bm, immunocytoma, myelodysplastic syndrome), MCs were consistently CD2 negative. Expression of bcl-2 was detectable in a subset of MCs in the patient with MCL, whereas no reactivity was seen in patients with SIM or bm mastocytosis. Mastocytosis infiltrates did not react with antibodies against CD15, CD30, CD31, CD34, or MPO. In summary, our data confirm the diagnostic value of staining for tryptase, Kit, and CD68R in mastocytosis. Apart from these, CD2 may be a novel useful marker because MCs in mastocytosis frequently express this antigen, whereas MCs in other pathologic conditions are CD2 negative.
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PMID:Immunohistochemical properties of bone marrow mast cells in systemic mastocytosis: evidence for expression of CD2, CD117/Kit, and bcl-x(L). 1138 74


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