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:3.4.24.3 (collagenase)
18,340 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Cell surface markers of mouse thymic dendritic cells have been studied by flow cytometry after isolation by collagenase digestion, separation of the low-density cell fraction and differential adherence. The dendritic cell preparation had a purity of greater than 90%, the contaminating population being essentially composed of thymocytes, macrophages constituting less than 1%. Dendritic cells displayed high forward and low-intermediate side angle scatter, and expressed high levels of major histocompatibility complex (MHC) class I and class II molecules, the heat-stable antigen (HSA), the adhesion molecules Pgp-1 (CD44), LFA-1, ICAM-1 and low levels of Mac-1 and the leukocyte common antigen CD45. Thymic dendritic cells are negative for the stem cell antigen-2 (Sca-2), the B cell-specific form of CD45 (B220), the mouse macrophage markers Fc receptor and F4/80, and the granulocyte marker Gr-1. However, although they do not express the T cell markers Thy-1, CD2, CD3, CD4 and CD5, 20%-30% of dendritic cells are positive for the interleukin 2 receptor alpha chain (CD25), and about 30% express intermediate levels of CD8. These results are discussed with regard to the functional significance of the expression of CD8 by thymic dendritic cells, and the existence of different dendritic cell subpopulations in the murine thymus.
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PMID:Cell surface marker analysis of mouse thymic dendritic cells. 134 47

A new procedure for rapid isolation of dendritic cells (DC) was devised, involving collagenase digestion of tissues, dissociation of lymphoid-DC complexes, selection of light-density cells, then depletion of lymphocytes and other non-DC by treatment with a mixture of lineage-specific monoclonal antibodies (mAbs) and removal with anti-immunoglobulin-coupled magnetic beads. This enriched population (approximately 80% DC) was further purified when required by fluorescence-activated cell sorting for cells expressing high levels of class II major histocompatibility complex (MHC). The isolated DC were characterized by immunofluorescent staining using a panel of 30 mAbs. Thymic DC were surface positive for a number of markers characteristic of T cells, but they were distinct from T-lineage cells in expressing high levels of class II MHC, in lacking expression of the T cell receptor (TCR)-CD3 complex, and having TCR beta and gamma genes in germline state. Splenic DC shared many markers with thymic DC, but were negative for most T cell markers, with the exception of CD8. A substantial proportion of DC from both thymus and spleen expressed CD8 at high levels, comparable with that on T cells. This appeared to be authentic CD8, and was produced by the DC themselves, since they contained CD8 alpha mRNA. Thymic DC presented both the CD8 alpha and beta chains on the cell surface (Ly-2+3+), although the alpha chain was in excess; the splenic DC expressed only the CD8 alpha chain (Ly-2+3-). It is suggested that the expression of CD8 could endow certain antigen-presenting DC with a veto function.
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PMID:The surface phenotype of dendritic cells purified from mouse thymus and spleen: investigation of the CD8 expression by a subpopulation of dendritic cells. 161 65

The localization of surface antigens and the binding activity of two monoclonal antibodies, HAM2 and HAM4, which recognize the rat major histocompatibility complex (MHC) antigen class I and the rat hepato-renal antigen respectively, on dissociated (free) hepatocytes was examined by light (LM) and electron microscopy (EM), and by radioimmunoassay (RIA). Fixed hepatocytes, fixed before dissociation, and fresh hepatocytes, dissociated by collagenase, were treated by direct staining with HAM2- or HAM4-immunogold complexes (HAM2-gold and HAM4-gold). Some of the directly stained hepatocytes were further mixed with antimouse IgG-gold complex (IgG-gold) to supplement the direct staining. The polarity of the sinusoidal and contiguous faces and the bile canaliculus, i.e. the in situ morphology, was well preserved in the fixed hepatocytes, while the fresh cells had lost the polarity and were round. On the fixed hepatocytes HAM2-gold particles were distributed predominantly on the sinusoidal face, while HAM4-gold particles were localized on both the bile canalicular and sinusoidal faces. No different antigen distribution on the fresh cells was detected with the two antibodies. Supplementation by IgG-gold was noticeable in most cases. The extent of binding activity in both the immunogold and RIA experiments was lower in the fixed cells than in fresh cells. These results suggest that HAM2 and HAM4 are useful monoclonal antibodies for detecting the localization of the MHC class I antigen and the hepato-renal antigen on the hepatocytes, respectively.
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PMID:Immunoelectron microscopic localization of cell surface antigens on rat hepatocytes detected with monoclonal antibodies (HAM2 and HAM4). 178 68

Methodological differences in major histocompatibility complex (MHC) antigen detection were investigated on isolated, viable hepatocytes and cryostat hepatic sections from 27 children with liver disorders, six of whom had normal histology. Class I antigens were constantly found on sections using a three step immunoperoxidase technique after acetone/chloroform fixation, other techniques being less sensitive, or on isolated hepatocytes by indirect immunofluorescence alone. With mechanical isolation the percentage of positivity ranged from 85 to 100%, while with collagenase isolation it ranged from 22 to 49% on immediate testing, and from 53 to 80% after 24 hour incubation. Class II antigens were only detected in one patient with autoimmune chronic active hepatitis and two with primary sclerosing cholangitis. Flow cytofluorimetric analysis in 11 cases confirmed class II or class I positivity, or both, on isolated hepatocytes, allowing MHC antigen expression on hepatocytes to be measured. Class I and II antigen detection on hepatocytes is influenced by the technique used. Although class I antigens are invariably expressed on hepatocytes, class II antigens are only found on hepatocytes from patients with immune mediated liver disorders.
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PMID:Class I and class II major histocompatibility complex antigens on hepatocytes: importance of the method of detection and expression in histologically normal and diseased livers. 186 83

Endothelial cells play a fundamental role in the pathogenesis of chronic inflammatory arthritis in humans such as rheumatoid arthritis (RA), as well as experimental animal models such as streptococcal cell wall (SCW) arthritis in Lewis (LEW/N) rats. This review summarizes data in support of this concept. The earliest apparent abnormalities in synovial tissues of patients with RA and Lewis rats with SCW arthritis appear to reflect microvascular endothelial cell activation or injury. At the molecular level, the abnormalities include enhanced expression by endothelial cells of activation markers such as class II major histocompatibility complex antigens, phosphotyrosine, leukocyte adhesion molecules, oncoproteins such as c-Fos and c-Myc, and metalloproteinases such as collagenase and transin/stromelysin. The development of severe, chronic, destructive arthritis is dependent upon thymic-derived lymphocytes and is accompanied by tumorlike proliferation of cells in the synovial connective tissue stroma (blood vessels and fibroblastlike cells), which results in resorptive destruction of bone and cartilage. Multiple criteria support the analogy to a neoplastic process. Paracrine and autocrine factors such as interleukin-1 (IL-1), platelet-derived growth factor (PDGF), transforming growth factor-beta (TGF-beta), and heparin-binding fibroblast growth factors (HBGF, FGF) appear to play important roles in the generation of these lesions. Finally, in addition to the autocrine and paracrine regulatory factors, neuroendocrine factors, particularly the hypothalamic-pituitary-adrenal axis, appear to be involved in the counterregulation of the inflammatory process. The counterregulatory effects are mediated, in part, by inhibition of endothelial cell activation by corticosteroids.
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PMID:Endothelial cells and the pathogenesis of rheumatoid arthritis in humans and streptococcal cell wall arthritis in Lewis rats. 205 44

Class II major histocompatibility complex (MHC) antigens have been demonstrated on the surface of thyroid epithelial cells (thyrocytes) from patients with autoimmune thyroid disease. The present study was designed to investigate how the expression of class II MHC antigens is involved in autoimmune processes in Graves' disease by studying cellular interactions among thyrocytes, lymphocytes within thyroid glands (TG), and peripheral blood (PB) lymphocytes. Thyrocytes were prepared by collagenase digestion, and T or non-T cells were separated by E-rosette formation. Thyrocytes were cocultured in the presence or absence of interferon-gamma, and the expression of HLA-DR antigens on cultured thyrocytes was examined by an indirect immunofluorescence method using monoclonal anti-HLA-DR antibody and monoclonal anti-HLA-DQ antibody. The cellular interactions were assessed as the proliferative response of T cells to autologous stimulators, such as thyrocytes or lymphocytes. Expression of HLA-DR antigens on thyrocytes after culture for 18 h in the absence of interferon-gamma was found in two thirds of the patients with Graves' disease studied (n = 18). Interferon-gamma induced and maintained the expression of HLA-DR antigens on thyrocytes. The percentages of HLA-DR+T cells were significantly higher among TG-T cells than among PB-T cells [32.6 +/- 12.4% (+/- SD) vs. 12.2 +/-5.0%; n = 18; P less than 0.01]. Thyrocytes from Graves' patients induced proliferation of both autologous PB-T cells and TG-T cells, and TG-T cells stimulated proliferation of autologous PB-T cells. In conclusion, interferon-gamma induces HLA-DR antigen expression on thyrocytes from patients with Graves' disease, and these cells induce proliferation of autologous T cells, which may, in turn, act on thyrocytes to perpetuate the process.
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PMID:Class II major histocompatibility complex antigen expression and cellular interactions in thyroid glands of Graves' disease. 308 70

Proximal tubular epithelial cells from mice which develop autoimmune interstitial nephritis were found to express the nephritogenic target antigen, 3M-1. Anti-3M-1 mAbs (alpha 3M-1-Ab) were used to positively select for 3M-1-secreting tubular epithelium and, after stabilization in culture, this new cell line (MCT) was examined for the production of several moieties important to either immune interactions or to the development of extracellular matrix. Alkaline phosphatase-staining MCT cells also express epithelial growth factor receptors with a Kd of 0.87 nM and an epithelial growth factor receptor constant (Ro) of 2.1 X 10(4) receptors/cell. MCT culture supernatants contain greater amounts of laminin, and types IV and V procollagens compared to types I and III procollagens, and growing MCT cells on type I collagen matrix causes them to preferentially secrete even more type IV and V procollagen. The 30,000-Mr 3M-1 antigen could be immunoprecipitated from biosynthetically labeled MCT cell supernatants with alpha 3M-1-Ab. An identical-sized moiety was isolated by immunoaffinity chromatography from collagenase-solubilized mouse kidney tubular basement membranes. The 3M-1 antigen can be found on the MCT cell surface by radioimmunoassay, or deposited in a linear array in the extracellular matrix surrounding the MCT cells in culture by immunofluorescence. Mature messenger RNA species for both class I and class II major histocompatibility complex (MHC) molecules were detected by Northern hybridization, and their corresponding cell surface gene products were detected by cytofluorography of MCT cells stained with haplotype-specific antibodies. Both the cell surface 3M-1 and the small amounts of detected class II MHC molecules appear to be biologically functional, as MCT cells can support the proliferation of 3M-1-specific, class II MHC-restricted helper T cells in culture. These findings suggest that MCT cells provide all the necessary biological parameters for interfacing both as the target of a nephritogenic immune response, and as a potential source for new extracellular matrix which develops as a fibrogenic response to interstitial nephritis.
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PMID:Characterization of a renal tubular epithelial cell line which secretes the autologous target antigen of autoimmune experimental interstitial nephritis. 317 Jun 33

The properties of rat liver dendritic cells (DC) were analyzed after collagenase digestion of the tissue and enrichment with density gradient centrifugation. The liver macrophages (Kupffer cells) were eliminated by adherence before the gradient centrifugation. The morphology of isolated DC in May-Grunwald-Giemsa (MGG) stained cytocentrifuge preparations resembled that of monocytes with certain dissimilarities. The expression of major histocompatibility complex (MHC) class II antigens (Ia) on DC was analyzed with the Staphylococcus aureus rosette method using a monoclonal antibody. The binding of anti-Ia antibody to rat liver DC was 3 times stronger than to passenger lymphocytes and 10 times stronger than to hepatocytes. All DC were Ia-positive tested with indirect immunofluorescence technique, and none of them were able to phagocytize antibody-coated human red cells. The DC did not express intracytoplasmic lysozyme, or surface Fc-receptors, and they all were negative in alpha-naphtylacetate esterase (ANAE) staining. Thus, although the dendritic cells of rat liver seem to belong to the monocytic series according to morphologic criteria, they were all negative when tested for typical monocyte/macrophage markers. The immunocenic potential of DC was analyzed by testing their ability to prime a naive recipient for graft rejection. The number DC needed for the priming was comparable with the number of spleen lymphocytes needed for an equivalent effect, indicating that the DC were highly immunogenic. The hepatocytes showed practically no immunogenic effect. Thus the immunogenic potential of the tested cells, i.e. their ability to induce accelerated transplant rejection, carries a good correlation with the expression of Ia-antigens on the cell surface.
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PMID:Characteristics of dendritic cells in rat liver. 328 40

Cultures of synovial cells from normal CBA mice were established after collagenase treatment of synovial tissue collected from the knee joint. Morphological studies using light and electron microscopy have shown that confluent monolayers are composed of 90% triangular or stellate dendritic cells with numerous microvilli and 5% secreting cells containing many dense granules. Less than 5% contaminating cells, such as fibroblasts or macrophages, are present. The class I and class II antigens of the major histocompatibility complex, detected by indirect immunofluorescence or complement-dependent cytotoxicity, are expressed on the cell surface of normal CBA synovial monolayers. Functional Ia antigens borne by synoviocytes are evidenced by the proliferative responses they elicit from syngeneic (or allogeneic) spleen cells after a 3-day co-culture. Similarly, monolayers of Ia+ synovial cells were obtained from both MRL/lpr mice, which spontaneously develop an autoimmune syndrome, and the control MRL/n mice. Spleen cells from young MRL/lpr exhibited significantly higher levels of blastogenesis in syngeneic co-cultures than those from MRL/n mice. Conversely, with advancing age the syngeneic proliferative responses declined minimally for MRL/lpr mice and were unchanged for MRL/n mice. These findings suggest that Ia+ synovial cells can effectively interact with syngeneic lymphocytes and may initiate autoimmune reactivity.
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PMID:Functional role in self reactivity for Ia antigens on murine synovial cells. 349 45

beta 2-Microglobulin (beta 2m) expression on the cell surface of the naturally occurring, allotransplantable canine transmissible venereal tumor (TVT) was investigated by use of indirect membrane immunofluorescence and radioimmunoassay. Two cell populations were identified in animal-derived, collagenase-disaggregated TVT cell suspensions. About 80% of the cells lacked surface beta 2m expression, whereas about 20% of the cells strongly reacted with anti-dog beta 2m serum. With the use of a cell separation technique, beta 2m-negative cells were demonstrated to carry TVT markers on their surface, whereas the beta 2m-positive cells did not express the tumor markers. The beta 2m-positive cells seemed, therefore, to be tumor-infiltrating host cells. These findings were supported by fluorescence staining studies of frozen sections of the TVT. The lack of beta 2m expression on the surface of TVT cells might explain the allotransplantability of this neoplasm, since beta 2m expression on the cell surface appeared to be obligatory for the expression of class I major histocompatibility complex antigens.
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PMID:Lack of beta 2-microglobulin on the surface of canine transmissible venereal tumor cells. 636 91


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