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M R Daha

Publications and source records attributed to M R Daha.

At least 181 records · Page 10Linked to original sources
PubMed1995

Monocyte chemoattractant protein-1 in normal and diseased human kidneys: an immunohistochemical analysis.

We conducted an immunohistochemical analysis to investigate the presence of monocyte chemoattractant protein-1 (MCP-1) in normal and diseased human kidneys and the correlation with infiltration of macrophages. A total of 50 renal biopsies were classified according to pathologic diagnosis. The distribution as well as the intensity of MCP-1 staining, and infiltration by CD68+ macrophages were evaluated in diseased versus normal kidneys. Weak staining of MCP-1 was detected in normal renal tissue, especially in tubular epithelial cells. Significant alterations in MCP-1 staining were observed in a number of diseases, in which the intensity of MCP-1 staining rather than the distribution of MCP-1-positive cells was higher. In membranous nephropathy, IgA nephropathy, and glomerulosclerosis, an association was found between the intensity of MCP-1 staining in tubular epithelial cells and interstitial infiltration of macrophages. The glomeruli in membranous nephropathy showed a stronger intensity of MCP-1 staining particularly in the glomerular visceral epithelial cells. The glomerular MCP-1 staining did not correlate significantly with the number of macrophages in the glomeruli. In conclusion, we describe increased cellular staining for MCP-1 in diseased human renal tissue, especially by tubular epithelial cells. Our observations suggest, complementary to in vitro and in vivo observations made by us and others, that specific roles may be played by MCP-1 in physiological and inflammatory processes in the kidney.

Biopsy↗
PubMed1995

Progression of chronic renal disease in humans is associated with the deposition of basement membrane components and decorin in the interstitial extracellular matrix.

The degree of impairment of renal function in patients with chronic renal failure correlates closely with the extent of fibrosis in the tubulointerstitium, i.e. of interstitial extracellular matrix (ECM) accumulation. The composition of this pathological extracellular matrix and the relation between the ECM composition on the one hand and the severity of histological changes and renal function on the other has not been investigated. This prompted us to perform the present study. The severity of histological abnormalities and the composition of the interstitial ECM were assessed using a semiquantitative scoring technique in 57 biopsies from patients with kidney disease of diverse etiology and variable degrees of renal failure and were contrasted with the results of 9 control biopsies. Tissue sections were stained with an indirect immunoperoxidase technique using antibodies against collagen I, III, IV, V, VI, laminin, fibronectin, decorin and heparansulphate proteoglycan core protein (HSPG). Collagen IV, laminin and HSPG were virtually absent from the interstitium in controls. These components were more widely distributed in patients and the extent of their deposition correlated with the severity of interstitial histological abnormalities. In patients with severe interstitial damage the deposition became diffuse. Collagen type I and III were already diffusely distributed in the interstitium of controls and did not increase significantly as interstitial damage became more severe. However, the extent of collagen III staining in patients was significantly higher than in controls. Decorin staining showed a patchy distribution both in patients and controls. The overall distribution was significantly increased in patients. The extent of the deposition of both collagen V and VI was significantly increased in patients when compared with controls. Only the distribution of collagen V correlated with the severity of histological abnormalities. Our findings suggest that an increased interstitial deposition of extracellular matrix substances which are generally regarded as basement membrane components contributes more to the development of interstitial fibrosis and renal failure than the deposition of the fiber forming interstitial collagens type I and III, which are prominent in controls and in patients irrespective of the severity of histological abnormalities. Decorin staining was significantly enhanced in patients and was found to be the best predictor both of the severity of interstitial fibrosis and of renal failure. This could mean that decorin is important in human renal pathology. Collagen V and VI staining was significantly increased in patients when compared with controls. To our knowledge this is the first study in which this is demonstrated.

Adult↗
PubMed1995

Tissue antigens in tubulointerstitial and vascular rejection.

We propose that tissue-specific alloantigens are of importance in interstitial and vascular rejection. To study this hypothesis we took the following approaches: multivariate analysis on our database (N = 482) was performed, the specificity of T cells cultured from kidneys with rejection was analyzed, and non-anti-HLA antibodies reactive with endothelium were studied. First we observed that in a cohort study of 482 patients receiving a cadaveric renal allograft 76 (15.8%) patients developed vascular rejection and 115 (23.9%) developed interstitial rejection. The incidence of vascular rejection was increased in patients with delayed graft function, HLA-DR mismatches, a prolonged cold ischemia period, and previous transplantations. Next we examined 40 graft infiltrating cell (GIC) lines cultured from renal biopsies taken during rejection episodes. Thirteen GIC lines reacted in a donor-specific fashion to proximal tubular cells (PTEC) but not to donor splenocytes. These GIC recognize polymorphic tissue-specific peptides in the context of allo-MHC Class I. Finally, we studied if non-conventional allo-antigen systems on endothelial cells could be the target of the humoral immune response during vascular rejection. We found the endothelial monocyte (EM) system, and another system that is present on endothelial cells and platelets, which can be tested in an antibody-dependent cellular cytotoxicity assay (ADCC).

Graft Rejection↗
PubMed1994

Antibody-dependent cell-mediated cytotoxicity against porcine endothelium induced by a majority of human sera.

Preformed natural antibodies seem to play a predominant role in hyperacute xenograft rejection. The potential of these antibodies in antibody-dependent cell-mediated rejection has not been elucidated, yet. This study was performed to assess a possible role of human antibodies in antibody-dependent cell-mediated cytotoxicity (ADCC) in pig to human transplantation using cultured porcine endothelial cells (PEC). Sera from 100 healthy blood donors were used to determine their ability to lyse PEC in a 51Cr release assay using human PBMC as effector cells. To reveal the underlying mechanism of the observed lysis, binding of human IgM, IgA, and IgG (IgG1, IgG2, IgG3, and IgG4) antibodies and F(ab')2 fragments to PEC was studied. Sixty-four percent of the sera showed a positive ADCC with 12-56% specific lysis of PEC using 1/16 diluted serum. Blocking of FcRIII (CD16) on effector cells did prevent PEC lysis. Most sera contained IgM, IgG, and IgA antibodies to PEC. IgG F(ab')2 fragments isolated from these sera specifically recognized PEC antigens without displaying ADCC activity. With regard to IgG subclass distribution of these antibodies, all sera contained IgG antibodies reacting with PEC, whereas most sera showed binding of IgG1 or IgG3 antibodies to PEC. No binding of IgG4 antibodies to PEC was found. Binding of total IgG, IgG1, IgG2, or IgG3 antibodies to PEC was not directly correlated with serum cytotoxicity. In conclusion, most human sera have the ability to lyse PEC through non-complement-fixing IgG antibodies via binding to FcRIII (CD16) on killer cells. Thus, human IgG antibodies may contribute to porcine xenograft rejection. The in vivo consequences of the predominant recognition of PEC antigens by IgG2 and IgA antibodies remain to be studied.

Adult↗
PubMed1994

Granzyme-positive cytotoxic cells are specifically increased in early rheumatoid synovial tissue.

OBJECTIVE: To define the expression and the phenotype of granzyme (Gran) A and B positive cytotoxic cells in synovial tissue (ST) from patients with rheumatoid arthritis (RA) with respect to disease duration and activity. METHODS: Using antibodies against GranA and GranB, which serve as markers of activated natural killer (NK) cells and cytotoxic T lymphocytes, ST sections from 10 patients with early RA, 10 patients with longstanding RA, and 10 patients with osteoarthritis were examined. The phenotype of Gran+ cells was determined with double-labeling techniques. RESULTS: Gran+ cells, the majority of which were NK cells, were found in ST from patients in all groups. Several of these cells did not express the surface markers CD16, CD56, and CD57. The highest ST expression of GranB was found in patients with early RA. In RA patients, there was a positive correlation of GranB expression with serum levels of acute-phase reactants, but not with histologic scores for inflammation. CONCLUSION: Gran+ cells are mainly NK cells, a substantial proportion of which do not express conventional NK cell surface markers. GranB expression is specifically increased in the synovial tissues of patients with RA of short duration.

Aged↗
PubMed1994

Detachment and cytolysis of human endothelial cells by proteinase 3.

Activation and degranulation of polymorphonuclear leukocytes (PMN) with release of proteolytic enzymes, such as proteinase 3 (PR3) and elastase, in the vessels of patients with Wegener's granulomatosis (WG) is thought to play an important role in the vascular endothelial cell damage. We have investigated the detachment and cytolysis of 51Cr-labeled umbilical vein endothelial cells (HUVEC) induced by highly purified, enzymatically active, PR3 and elastase. Incubation of confluent monolayers of HUVEC with 100 mU/ml of PR3 for 3 h at 37 degrees C generally resulted in 20% detachment and 30% cytolysis. Elastase (350 mU/ml) induced approximately 40% detachment and 15% cytolysis. Both PR3-mediated and elastase-mediated detachment and cytolysis were fully inhibited by alpha-1-proteinase inhibitor (alpha 1 PI), while anti-leukoprotease (ALP) only inhibited elastase-mediated endothelial damage. By selective inhibition of an azurophilic granule extract with either alpha 1PI or ALP we calculated that PR3 is responsible for 23% of the total detachment and cytolysis induced by the extract. Elastase was responsible for 60% of the detachment and 19% of the cytolysis. Detachment induced by PR3 was inhibited by three out of five IgG preparations purified from c-ANCA-positive sera of WG patients. PR3-mediated cytolysis was inhibited by each of the c-ANCA+IgG preparations and also to a limited extent by control IgG, suggesting a partial nonspecific stabilization of the endothelial cells. These studies provide evidence that besides elastase, PR3 also plays an important role in the PMN-mediated endothelial cell damage.

Antibodies, Antineutrophil Cytoplasmic↗
PubMed1994

Expression of granzymes A and B in synovial tissue from patients with rheumatoid arthritis and osteoarthritis.

Granzymes A and B are serine proteinases which are stored in the granules of activated cytotoxic T cells and NK cells. Expression of these granzymes by cytotoxic cells in tissues can be used as an activation marker for these cells. To investigate a possible role of cytotoxic lymphocytes in rheumatoid arthritis (RA) and osteoarthritis (OA), we assessed the expression of granzymes A and B by cytotoxic lymphocytes in synovial biopsies from five RA and five OA patients using mAb specific for these serine proteinases. In three of the five RA patients but also in two of the five OA patients granzyme A- and B-expressing lymphocytes were observed in the synovium. Double-labeling immunohistochemical techniques revealed that up to 75% of the granzyme-positive synovial lymphocytes had the CD16+ or CD56+ natural killer cell phenotype. Less than 5% were CD3+, CD8+ cytotoxic T cells, whereas in some patients the phenotype of up to 50% of these cells could not be identified. The presence of granzymes A and B in the synovium of both RA as well as OA patients was confirmed on the molecular level in a second group of 11 RA and 5 OA patients using the polymerase chain reaction. Thus, expression of granzymes A and B occurs in the synovium in patients with RA as well as those with OA. These proteins are mainly expressed by NK cells that may therefore play a role in the pathogenesis of these diseases.

Aged↗
PubMed1994

Inflamed joints of patients with rheumatoid arthritis contain T cells that display in vitro proliferation to antigens present in autologous synovial fluid. Functional analysis on the basis of synovial-fluid-reactive T-cell clones and lines.

The immunopathology of inflamed joints in patients with RA is thought to result from an antigen-driven T-cell response. The antigen(s) responsible for the activation of synovial T cells, however, are as yet unidentified. In this study, we tested SF as a potential source of (auto)antigen(s). Five of 15 IL-2-expanded T-cell lines generated from SF cells of RA patients displayed a proliferative response to autologous SF. Five CD4+CD8-alpha beta TCR+SF-reactive T-cell clones obtained from responder T-cell lines were studied in more detail. Three T-cell clones from one RA patient were found to recognize epitopes in autologous SF in the context of DR4(Dw4), and two T-cell clones of another RA patient responded to autologous SF in the context of the HLA-DPB1*0401 gene product. The two DP-restricted clones and one of the DR-restricted clones did not proliferate to 50 SF samples of other RA patients, whereas the remaining DR-restricted clones responded to one allogeneic sample. Sequence analysis demonstrated that the latter clones expressed identical V beta 6.9 + TCR beta chains. This was also found for the (V beta 19+) DP-restricted clones. Proliferation of SF-reactive T cells was not only obtained with SF of the joint that had contained the T cells, but also with autologous SF of other affected joints. Together, these findings indicate that epitopes able to stimulate synovial T cells differ among RA patients, but may be similar within multiple joints of an individual patient. The presence of T cells able to respond to SF antigens in inflamed joints suggests that these T cells play an active role in the pathogenesis of RA.

Amino Acid Sequence↗
PubMed1994

Tumor necrosis factor alpha-308 gene variants in relation to major histocompatibility complex alleles and Felty's syndrome.

The location of the human TNF genes within the MHC complex has prompted much speculation about the role of TNF alleles in the etiology of MHC-associated autoimmune diseases. On sequencing the 5' regulatory region of the human TNFA gene a G (TNFA-308G) to A (TNFA-308A) transition polymorphism at position -308 was discovered. We have developed a simple PCR assay to facilitate the screening of the -308 polymorphism at the DNA level. In view of the possible linkage between the TNFA-308A allele and a certain MHC type, TNFA-308 genotypes in HLA-typed healthy individuals (n = 88) were determined. A statistically significant association between the TNFA-308A allele and HLA-DR3, DQB1*0201, DQA1*0501, A1, B8, and the NcoI 5.5-kb RFLP of the TNFB gene was observed. In addition, we determined the frequency of the TNFA-308A allele in patients with FS (n = 13), an HLA-DR4-associated disease. In this study, no association was found of Felty's syndrome with the TNFA-308A allele, indicating that this allele does not appear to be a susceptibility factor for FS.

Alleles↗
PubMed1994

The role of unconventional alloantigens in interstitial and vascular rejection after renal transplantation.

Lymphocytes have been used as the classic target cells to measure donor specific alloreactivity before and after renal transplantation. This was based on the concept that during rejection after kidney transplantation graft cells were recognized only because of sharing of alloantigens with lymphoid cells. There is, however, sufficient evidence to suggest that tissue specific recognition of proximal tubular cells and graft endothelial cells can occur by allospecific T cells and IgG antibodies, respectively. The antigens involved have not yet been well characterized, but seem to be of relevance in the pathogenesis of both interstitial and vascular rejection. Identification of the antigens involved may lead to more appropriate matching strategies.

Animals↗
PubMed1994

Binding of dimeric and polymeric IgA to rat renal mesangial cells enhances the release of interleukin 6.

The mesangium plays a crucial role in processes of inflammation in the kidney. Since deposits of IgA in the mesangium in patients with IgA nephropathy suggest a role for IgA in the inflammatory process, we investigated whether IgA is able to bind to cultured rat mesangial cells (MC) in vitro and induce activation of MC. As a source of IgA, monomeric (mIgA), dimeric (dIgA) and polymeric IgA-alpha-DNP (pIgA) rat monoclonal antibodies were used. FACS analysis indicated binding of dIgA and pIgA to MC while only a small percentage of the cells exhibited binding of mIgA. Additional experiments employing radiolabeled IgA revealed a time- and dose-dependent binding of 125I-dIgA and 125I-pIgA with 6 x 10(6) binding sites for dIgA with an affinity of 5.5 x 10(6) M-1 and 7.2 X 10(6) binding sites/cell for pIgA with an affinity of 1.2 x 10(6) M-1. As compared to 125I-dIgA and 125I-pIgA, little binding of 125I-mIgA to MC occurred; the binding of dIgA and pIgA was not influenced by excess cold BSA, IgG or asialofetuin. Since some studies have suggested that fibronectin might interact with IgA, the binding of IgA to MC in the presence or absence of fibronectin or the RGD fragment was also analyzed. However no influence of fibronectin or the RGD fragment on binding of dIgA and pIgA to MC was observed. As a measure for activation of MC by IgA, the production of IL-6 by MC was analyzed. Dimeric IgA and pIgA both induced a dose-dependent increase of IL-6 production by MC.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1994

Complement deficiency predisposes for meningitis due to nongroupable meningococci and Neisseria-related bacteria.

Nongroupable meningococci or bacteria related to the genus Neisseria rarely cause meningitis. Complement deficiency has been identified as a major predisposing factor for meningococcal disease. To assess whether patients with meningitis due to such strains have a complement deficiency, we studied 12 persons. Six patients had meningitis due to nongroupable strains of meningococci, and six patients had meningitis due to Moraxella species or Acinetobacter species. Inherited complement component C7 or C8 deficiency was found in two persons who had had meningitis due to nongroupable meningococci, and one C8-deficient person had had meningitis caused by Moraxella osloensis. Hypocomplementemia resulting from CSF drain-associated shunt nephritis was found in one person with meningitis due to Moraxella nonliquefaciens and in one person with meningitis due to Acinetobacter lwoffi. This rather high frequency of inherited or acquired complement deficiencies among patients with meningitis due to nongroupable meningococci, Moraxella species, and Acinetobacter species justifies the recommendation that such patients must be studied for complement deficiency.

Acinetobacter Infections↗
PubMed1994

Interleukin 6 production by human proximal tubular epithelial cells in vitro: analysis of the effects of interleukin-1 alpha (IL-1 alpha) and other cytokines.

Proximal tubular epithelial cells (PTEC) from human renal tissue obtained from biopsy or nephrectomy were grown in monoculture and evaluated in vitro at passage 2-4 for interleukin 6 (IL-6) production in response to medium alone or to interleukin 1 alpha (IL-1 alpha), tumour necrosis factor alpha (TNF alpha), interleukin 2 (IL-2), interferon gamma (INF gamma) or lipopolysaccharide (LPS). IL-6 bioactivity was quantitated using the IL-6-dependent murine hybridoma cell line (B9) and expressed as IL-6 units/ml/10(5) PTEC. PTEC cell lines exposed to medium alone produced intermediate amounts of IL-6 with substantial variability between cell lines. Introduction of IL-1 alpha resulted in a dose- and time-dependent increase in IL-6 production by PTEC that was maximal at 1 ng/ml IL-1 alpha at 24 h. All PTEC cell lines showed an increased IL-6 production on exposure to IL-1 alpha varying from 1.3- to 24-fold increase over baseline production. This response was completely blocked by anti-rIL-1 alpha. No significant IL-6 production by PTEC could be induced by TNF alpha, IL-2, IFN gamma, or LPS over a broad dosage range. Cycloheximide inhibited IL-6 production without irreversible cell toxicity, indicating de-novo synthesis. IL-6 produced by PTEC had a molecular weight of 26-29 kDa as demonstrated by Western blot analysis. Using PCR analysis we could demonstrate upregulation by IL-1 alpha of IL-6 mRNA in a dose-response fashion, indicating that IL-1 alpha regulates IL-6 production at a pretranslational value of protein synthesis.(ABSTRACT TRUNCATED AT 250 WORDS)

Actins↗
PubMed1994

Uveitis and anti-neutrophil cytoplasmic antibodies.

Serum samples of 485 uveitis patients were screened for the presence of anti-neutrophil cytoplasmic antibodies using a standardized immunofluorescence test (IIF) on neutrophil granulocytes. Seventeen of these sera contained cytoplasmic (C)-ANCA antibodies, while two of the sera contained perinuclear (P)-ANCA antibodies (both antinuclear antibody (ANA)-positive, one anti-myeloperoxidase (MPO)-positive). None of the C-ANCA-positive sera reacted with proteinase-3 in ELISA using a highly purified proteinase-3 preparation. Four C-ANCA and one P-ANCA-positive serum reacted with MPO. The majority of the sera did react with azurophilic granules in ELISA. The implication of these results is that in patients with uveitis a positive C-ANCA test is not diagnostic for Wegener's granulomatosis, but is most probably caused by the presence of autoantibodies against as yet unknown constituents of azurophilic granules.

Adolescent↗
PubMed1994

Regulation of C3 and factor H synthesis of human glomerular mesangial cells by IL-1 and interferon-gamma.

Previous reports have shown production of complement components C4, C2 and factor B by renal tissue. We have shown recently that human proximal tubular epithelial cells (PTEC) synthesize C3 in vitro, and that IL-2 enhances this production. In the present study we demonstrate that human mesangial cells (MC) in culture produce factor H and that supernatants of activated peripheral blood mononuclear cells (T cell growth factor (TCGF)) induce C3 production and enhance factor H synthesis in both a time- and dose-dependent manner. To investigate whether certain defined cytokines from TCGF were responsible for the observed effect, we tested various cytokines for their effect on complement production by MC. It is shown that IL-1 induces C3 synthesis whereas factor H production is up-regulated by IFN-gamma, in both a dose- and time-dependent manner. Antibody blocking experiments revealed that C3 synthesis induced by both TCGF and IL-1 could be blocked with antibodies specific for IL-1, and also that TCGF and IFN-gamma enhanced factor H synthesis could both be blocked with antibodies specific for IFN-gamma. Cycloheximide was able to inhibit C3 and factor H production, suggesting de novo synthesis of the proteins. mRNA-polymerase chain reaction (PCR) analysis revealed mRNA encoding for C3 after stimulation with TCGF and IL-1. Factor H genes are constitutively expressed in cultured mesangial cells and its expression is up-regulated by TCGF and IFN-gamma. Northern blot analysis with specific probes for C3 and factor H revealed bands which support the results obtained by PCR analysis.

Base Sequence↗
PubMed1994

Hereditary C6 deficiency in a strain of PVG/c rats.

A chance observation has led to the discovery of a strain of PVG rats (PVG/c-) which are deficient in complement (C) component C6. Analysis of total haemolytic activity (CH50) of PVG/c- serum revealed an absent CH50 activity compared with serum of other rat strains and of a PVG/c rat (PVG/c+) that showed normal C activity. Thus, the PVG/c- rat was unable to activate the C5b-9 membrane attack complex. To gain insight into the complement abnormalities, analysis of individual C components was performed. Testing the PVG/c- serum in a C6 haemolytic assay and using deficient human sera showed a deficiency of C6 in the PVG/c- rat. Highly purified human C6 and human sera deficient in other components were able to reconstitute the CH50 activity of the PVG/c- rat. The possibility that an inactivator of C was present in PVG/c- serum was excluded. The deficiency was found to be inheritable and under the control of an autosomal recessive gene. Furthermore, tissue antigens and immunity of the PVG/c- rat were found to be identical to those determined in the PVG/c+ rat. With regard to their health status, the PVG/c- animals seem to have no disadvantages compared with PVG/c+ rats when held under the same conditions within the protected environment of animal facilities. Taken together, both rat strains provide an unique animal model for studying the biological role of C, particularly the C5b-9 membrane attack complex in experimental medicine.

Animals↗
PubMed1994

Binding of proteinase 3 and myeloperoxidase to endothelial cells: ANCA-mediated endothelial damage through ADCC?

Binding of both proteinase 3 (PR3) and myeloperoxidase (MPO) to endothelial cells (EC) has been suggested to be involved in the vascular damage seen in patients with Wegener's granulomatosis or microscopic polyangiitis. In the present study we investigated in detail the interaction of MPO and PR3 with cultured human umbilical vein endothelial cells (HUVEC) and its matrix products. In addition, we investigated whether interaction of PR3 or MPO with HUVEC monolayers also resulted in antibody-dependent cell-mediated cytotoxicity (ADCC) mediated by anti-neutrophil cytoplasmic antibody (ANCA)-positive patient sera or rabbit IgG anti-PR3 or anti-MPO. Preincubation of HUVEC monolayers with PR3 or MPO resulted in a dose-dependent binding of both PR3 and MPO. However, HUVEC, preincubated with PR3 or MPO, followed by ANCA or by rabbit anti-PR3 or anti-MPO, were not susceptible to ADCC. Detailed analysis of the binding of PR3 to HUVEC monolayers showed that PR3 binds primarily to the extracellular matrix of endothelial cells, and to a very limited extent to the cells themselves. For MPO it was shown that it binds both to the extracellular matrix and to the endothelial cells themselves. However, after binding to HUVEC cultures, MPO was not detectable by polyclonal rabbit or human antibodies specific for MPO, probably because MPO is bound to sites not accessible for immunoglobulins. Binding of PR3 to HUVEC cultures (cells + matrix) was inhibited by fetal calf serum and by alpha 1-antitrypsin, but inactivation of enzymatic activity of PR3 by PMSF did not influence binding of PR3 to HUVEC cultures. Binding of MPO to HUVEC cultures was not influenced by fetal calf serum.

Animals↗