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E De Heer

Publications and source records attributed to E De Heer.

34 records · Page 2Linked to original sources
PubMed1996

Isolation of cDNAs encoding immunogenic regions of gp330, the autoantigen involved in Heymann nephritis.

Active Heymann nephritis is an organ-specific autoimmune disease of the rat kidney, characterized by the formation of immune complexes located subepithelially in the glomerulus. The T cell-mediated humoral immune response is directed to gp330, a large renal epithelial glycoprotein which is expressed both in the proximal tubule and on glomerular podocytes. In this study polyclonal rabbit antibodies raised against affinity-purified rat gp330 were used to screen a lambda-gt11 expression library of the rat kidney. One cDNA clone that was recognized by the antibodies coded for a 2.7-kb protein that is not described in the sequence database of GenBank/EMBL. Two other groups of cDNA clones were identified that displayed similarity with several members of the low-density lipoprotein (LDL)-receptor gene family to which gp330 belongs. By comparison with the gp330-cDNA sequence, these two clones could be mapped to two remote areas on the extracellular domain of gp330. The antigenicity of these two areas is in accordance with their location in highly hydrophilic regions on the extracellular domain of gp330. The cDNA clones described in this study may represent two main immunodominant regions on rat gp330.

Animals↗
PubMed1996

Non-MHC genes determine the development of lupus nephritis in H-2 identical mouse strains.

Susceptibility to systemic lupus erythematosus (SLE) and, in particular, lupus nephritis is strongly influenced by genetic factors. Previous studies have shown that MHC-related antigens influence the development of SLE. In the current study, we set out to investigate how non-MHC genes influence the pathogenesis of glomerulonephritis in chronic graft-versus-host disease (GVHD) in mice, a model for lupus nephritis. For the induction of GVHD we used parent-to-F1 hybrid mouse strain combinations. DBA/2, BALB/c, BALB.D2 and C57B1/10.D2 (BL10.D2) donor lymphocytes carrying an H-2d haplotype were injected into H-2b/d F1 hybrids of BL10 mice, which differed only at non-MHC loci. Within these hybrid strains the development of immune complex glomerulonephritis was investigated by monitoring the occurrence of autoantibodies in the circulation, deposition of immunoglobulins in the glomeruli, development of albuminuria, and glomerulosclerosis. In diseased DBA/2 mice albuminuria developed 6 weeks after induction of the disease. Mice with a BALB background developed a lupus-like syndrome characterized by albuminuria starting 8 weeks after induction of the GVHD. During the development of the GVHD, polyclonal B cell activation occurred in both the DBA/2 and BALB/c strains, resulting in the formation of autoantibodies. Only the strain combination using DBA/2 mice developed anti-GBM antibodies. In DBA/2 and BALB strain combinations immune complexes were detected in a granular pattern along the glomerular capillary walls. In the DBA/2 recipients a linear pattern of immunoglobulin depositions preceded the granular phase. This study demonstrates that: (i) non-MHC genes govern the pathogenesis of immune complex nephritis in this model by influencing the autoantibody profile; and (ii) the presence of anti-GBM antibodies in the early stages of the disease is a conditio sine qua non for the development of full-blown glomerulonephritis and glomerulosclerosis in this model.

Albuminuria↗
PubMed1995

Specific accumulation of exogenous fibronectin in experimental glomerulosclerosis.

The prognosis of patients showing glomerulosclerosis as a complication of an immunologically mediated kidney disease is poor. To improve the diagnosis and treatment of these patients, it is important to understand the processes involved in the development of glomerulosclerosis. In this study, we investigated the molecular composition of experimental end-stage glomerular sclerotic lesions and their pathogenesis in chronic graft-versus-host disease (GvHD) in the mouse and chronic serum sickness in the rat. Accumulation studies were performed to determine the degree of specific trapping of constituents from the circulation. Two different models were investigated to determine whether differences in disease initiation resulted in different compositions of the glomerulosclerotic lesions. In both models, glomerulosclerosis was preceded by expansion of the mesangial matrix and thickening of the glomerular basement membrane (GBM). The end-stage sclerotic lesions consisted mainly of fibronectin, which appeared to displace the other extracellular matrix (ECM) components peripherally in the mesangial matrix and GBM. The abundance of fibronectin in the lesions was not reflected in the mRNA levels for this component. Indeed, antibodies directed against the cellular form of fibronectin did not stain positive in the end-stage lesions. These findings, together with accumulation studies, suggest that specific accumulation rather than de novo synthesis of fibronectin plays a major role in the development of experimental glomerulosclerosis, which appears to be independent of the pathway of induction.

Animals↗
PubMed1993

Gender-related influences on the development of chronic graft-versus-host disease-induced experimental lupus nephritis.

Autoimmune diseases are far more common in women than in men. In the incidence of systemic lupus erythematosus (SLE), the female-to-male ratio is as high as 10:1. This suggests that sex hormones may play a fundamental role in determining the susceptibility to these diseases. In order to investigate the sex-related differences in the inducibility of chronic graft-versus-host disease-related experimental lupus nephritis, lymphocytes from female DBA/2 donor mice were administered to either male or female (C57BL10 x DBA/2)F1 recipients. An additional group of male recipients received lymphocytes from male DBA/2 donors. After four cell transfers, female recipients developed a significantly higher albuminuria than both male groups. Serum concentrations of autoantibodies against glomerular basement membrane (GBM), collagen IV, and laminin were significantly higher in females 2-4 weeks after induction. Levels of circulating autoantibodies against renal tubular epithelial antigens (RTE) and nuclear antigens were not different between the sexes. In transfer studies, the necessity of the presence of anti-GBM and anti-RTE autoantibodies for the development of glomerulonephritis was confirmed. These findings indicate that: (i) in this model of lupus nephritis, susceptibility to glomerulonephritis is strongly influenced by sex-related genes; and (ii) among the variety of autoantibodies occurring in this model of SLE, both anti-GBM and anti-RTE autoantibodies play a key role in the pathogenesis of glomerulonephritis.

Albuminuria↗
PubMed1993

Epitope specificity of anti-gp330 autoantibodies determines the development of proteinuria in active Heymann nephritis.

In active Heymann nephritis, an experimental autoimmune disease in the rat, gp330 is regarded as the main antigenic target. Immunization with detergent-solubilized renal tubular epithelium (RTE-DOC) has been shown to be less nephritogenic than immunization with crude RTE. In this study immunization with either crude RTE or affinity-purified gp330 did, but immunization with RTE-DOC did not induce proteinuria. Both a possible aberrant subclass distribution of anti-gp330 autoantibodies and the involvement of additional nephritogenic autoantigens such as DPP IV (gp90) or laminin could be excluded. Circulating anti-gp330 autoantibody titers were significantly higher in RTE-DOC-immunized rats than in RTE-immunized animals. In contrast, significantly more antibodies were shown to bind in the glomeruli in the latter group. The time of onset of abnormal proteinuria was shown to be related to the recognition of a particular V8 protease-induced 250 kD fragment of gp330 in Western blots. This study shows that a particular fragment-specific subset of autoantibodies against gp330 is involved in the glomerular damage in Heymann nephritis.

Animals↗
PubMed1991

Susceptibility to the induction of either autoimmunity or immunosuppression by mercuric chloride is related to the major histocompatibility complex class II haplotype.

Mercuric chloride (HgCl2) induces in Brown Norway rats a CD4+ T lymphocyte-dependent systemic autoimmune syndrome, involving synthesis of anti-glomerular basement membrane autoantibodies and development of proteinuria. Lewis rats are resistant to HgCl2-induced autoantibody production and, in contrast, develop immunosuppression, mediated by CD8+ T lymphocytes. In the present study, genetic requirements governing autoreactivity or immunosuppression in response to HgCl2 were further explored. Both major histocompatibility complex (MHC) and non-MHC genes are involved in determining susceptibility to HgCl2-induced autoimmunity. Both AO (RT1u) and DZB (RT1u) rats were found to develop a membranous autoimmune glomerulopathy upon exposure to HgCl2. Only the DZB strain, which differs in part of the non-MHC background from AO, developed proteinuria. AO.1P (RT1.AuB1D1Eu) rats, which are genetically identical to AO except for the Lewis haplotype at the MHC class II loci, appeared to develop immunosuppression upon exposure to HgCl2. It is concluded that autoreactivity and immunosuppression, induced by HgCl2, are both dependent on the MHC class II haplotype. In autoimmune responder strains the type of autoimmune glomerulopathy is influenced by non-MHC genes.

Animals↗
PubMed1990

Specificity and cross-reactive idiotypes of anti-glomerular basement membrane autoantibodies in HgCl2-induced autoimmune glomerulonephritis.

Mercury-induced autoimmune glomerulonephritis in the Brown-Norway (BN) rat is characterized by the successive appearance of linear and granular glomerular IgG deposits. Anti-laminin autoantibodies represent the major part of the anti-glomerular basement membrane (GBM) antibodies produced in this model. Fusions were performed in this model and four anti-GBM monoclonal antibodies (mAb) were obtained. Three of them were laminin specific. Using rabbit anti-idiotype antibodies, cross-reactive idiotypes (CRId) were characterized on anti-laminin antibodies. They were expressed on the three anti-laminin mAb, on kidney-eluted and circulating anti-laminin antibodies. CRId-bearing immunoglobulins were detected transiently in the circulation and paralleled the anti-laminin antibody activity. By immunofluorescence studies on kidney cryostat sections two different CRId were defined. One was localized close to the antigen-combining site since it was not revealed on kidney-bound antibodies, in contrast with the second CRId. This latter CRId was also found deposited in a typical linear pattern in the early phase of the disease and in a granular pattern in the late phase, demonstrating that these CRId are components of immune deposits. Taken together, these results suggest that in this model of T-dependent polyclonal B cell activation, restricted sets of V genes encode for at least a part of the anti-GBM autoantibodies.

Animals↗
PubMed1990

Specificity and cross-reactive idiotypes of anti-gp330 autoantibodies in active Heymann nephritis.

The aim of this study was to characterize the epitope specificity and the idiotype(s) of gp330-specific autoantibodies in active Heymann nephritis (HN). To study this, two monoclonal autoantibodies (mAb), 3D9B and 5B8C, derived from Lewis rats with HN, were generated. These antibodies bound to different epitopes on the autoantigen gp330, as shown by in vitro studies. In order to characterize the idiotype(s) of the mAb, rabbit anti-idiotypic antisera were prepared. It was shown that the rabbit antisera directed against the 3D9B as well as the 5B8C idiotype were able to inhibit the binding of nephritic eluate to gp330. This indicated that the idiotypes recognized on 3D9B and 5B8C were relevant to the spectrum of idiotypes involved in HN. In order to investigate the nature of the two idiotypes of these mAb, cross-absorption and binding studies were performed. The rabbit antisera raised against one of the two idiotypes bound in a direct binding ELISA to both idiotypes. Since the observed cross-reactivity of the antisera suggested that the idiotypes of 3D9B and 5B8C were at least partly cross-reactive, homologous polyclonal and monoclonal anti-idiotypic antibodies were prepared by immunizing rats with 3D9B or 5B8C. The results from the binding and inhibition experiments strongly suggest that the idiotypes of 3D9B and 5B8C contain cross-reactive or public idiotopes.

Animals↗
PubMed1988

Cyclosporin A induces long-term unresponsiveness in mercuric chloride-induced autoimmune glomerulonephritis.

Mercuric chloride induces a transient systemic T-lymphocyte dependent autoimmune syndrome in Brown Norway rats. Two weeks after the first HgCl2 injection maximum serum levels of anti-GBM antibodies and nephrotic range proteinuria are detected. CyA treatment during HgCl2 administration completely prevented these autoimmune phenomena. Moreover, a prolonged unresponsiveness to HgCl2 was induced, lasting for at least 5 weeks after combined pretreatment with CyA and HgCl2. This unresponsiveness could not be adoptively transferred with peripheral lymphoid cells. Suppression of development of HgCl2-induced proteinuria was adoptively transferred with lymphoid cells from HgCl2-treated donors in remission phase. Unresponsiveness to HgCl2, induced by CyA plus HgCl2 pretreatment, could be broken by reconstitution with naive lymphoid cells. These results suggest that the tolerogenic effect of CyA in HgCl2-induced autoimmunity is not mediated by active suppression; instead, the observed unresponsiveness might be due to direct functional deletion of autoreactive T-lymphocytes. A serendipitous finding was the dissociation in time between synthesis of anti-GBM antibodies and development of proteinuria, suggesting a role for cellular effector mechanisms in the induction of proteinuria.

Animals↗
PubMed1988

Antibodies to purified renal tubular epithelial antigens contain activity against laminin, fibronectin, and type IV collagen.

Antibodies directed against tubular brush border antigens (RTE) are used to induce heterologous immune-complex nephritis. Among these antigens a glycoprotein with a molecular weight of 330 kilodaltons (gp330) has been shown to be of pathogenetic significance. We investigated whether antibodies other than those directed against gp330 are present in anti-RTE and whether they play a pathogenetic role. By using enzyme-linked immunosorbent assay techniques and Western blotting, we investigated polyclonal antibodies directed not only against crude RTE but also against RTEgp, a purified glycoprotein fraction of RTE, with respect to activity against glomerular basement membrane (GBM) components laminin, fibronectin, and type IV collagen. Both antibody preparations showed reactivity predominantly to the 220 kilodaltons subunit of laminin. Lower but nevertheless distinct reactivity to fibronectin and type IV collagen was also found. The antibody fraction directed against components of the GBM, which was isolated from anti-RTE IgG by affinity chromatography, showed linear binding to the GBM in indirect immunofluorescence studies. Injection of these antibodies into the renal artery also led to linear binding to the GBM with linear deposition of complement factors 3 and 9 and induced a weak and transient proteinuria. Immunoelectron microscopy revealed binding of the antibodies to glomerular epithelial and endothelial cell surfaces adjacent to the GBM. Injection of anti-RTE antibody absorbed to GBM components resulted in binding of antibodies and complement factors 3 and 9 in a fine granular pattern along the GBM, whereas injection of unabsorbed anti-RTE led to a course granular pattern. We conclude that the presence of antibodies (cross-)reacting with laminin, fibronectin, and type IV collagen in anti-RTE antibody has pathogenetic effects and could explain differences in pathogenicity between monospecific anti-gp330 antibody and polyclonal anti-RTE antibody.

Animals↗
PubMed1982

Cell surface antigen phenotypes and enzyme expression patterns of two murine T-cell lymphomas derived from early and/or mature thymus cells.

A number of cell surface markers (T200, ThB, Thy1, Lyt1 and Lyt2 and a glycolipid) and enzymes (ATP-ase, acid phosphatase, beta-glucuronidase, 5'-nucleotidase, non-specific esterase, ANAE and chloroacetate esterase) were determined for two murine T-cell lymphomas: the DBA/2-strain-derived SL2 with a phenotype close to that of a mature thymocyte and the GRS-strain-derived GSRL13 with a phenotype of a more primitive thymocyte. While the pattern of expression of the enzymes was similar for SL2 and GRSL13 and as such indistinguishable from that of the majority of thymus cells, the pattern of cell surface antigen expression was clearly different. GRSL12 cells express the ThB antigen and a glycolipid antigen detectable with monoclonal antibody 30-H11, but not Lyt1 and Lyt2 antigens. SL2 cells, however, do not express ThB and the glycolipid antigen, but do express Lyt1 and Lyt2.

Animals↗
PubMed1982

Staging, growth properties and metastatic behaviour of a transplantable murine T-cell lymphoma.

Cell surface markers, enzymatic patterns, proliferation characteristics and metastatic behaviour of the DSA/2 derived SL2 lymphoma were determined. SL2 cells are sensitive to a heterologous antiserum to murine T-cells and to allo-antisera for Thy 1.2 and TL 1.2.3. They show acid-phosphatase, betaglucuronidase, acid-alpha-naphthytesterase and non-specific esterase staining. The reactions for ATP-ase, and 5'nucleotidase were negative. The SL2 tumour cells can be transplanted in vivo, growing rapidly both as an ascites or a solid tumour, and can be grown in vitro as a suspension culture (doubling time about 18 hours). One hundred cells kill an animal after i.p. transplantation, while 1,000 cells kill an animal after s.c. transplantation. Histopathological examination combined with TEM shows that SL2 metastasizes rapidly, especially after i.p. injection. The metastasizing cells reach the blood vessels in the lung septa and extravascular positions in the liver.

Animals↗
PubMed1982

Peritoneal cell populations during tumour injection.

The response of peritoneal cells to the SL2 lymphoma was studied in immunized and non-immunized mice to elucidate further the cellular events that lead to tumour rejection in an allogeneic and a syngeneic tumour system. Anti-tumor immunity was induced by intraperitoneal injection of normal, irradiated or mitomycin-C treated tumour cells. Four different immunization schedules were tested. The response of the peritoneal cells was investigated by studying the peritoneal cell population kinetics (appearance and/or disappearance of various cell types e.g. mononuclear phagocytes, lymphocytes, PMNS and mast cells). Total cell counts were done using phase contrast microscopy, differential cell counts were done on cytocentrifuge slides, stained with May Grünwald-Giemsa. The activity of the lysosomal enzyme beta-glucuronidase present in mononuclear phagocytes was also studied. The results indicated that the composition and morphology of the cellular fraction of the peritoneal exudate changes quite dramatically during tumour rejection. Especially the beta-glucuronidase activity of the mononuclear phagocytes line varies significantly. The observed changes in the cellular population depended upon the dose of tumour cells injected i.p. No significant differences were observed between the peritoneal cell populations of mice grafted i.p. with irradiated or with mitomycin-C treated tumour cells. On the other hand when mice previously immunized with three injections with 10 irradiated or mitomycin-C treated tumour cells were challenged i.p. with various doses of tumour cells, the immune potency against the tumour is greater after previous immunization with irradiated SL2 cells than after immunization with mitomycin-C treated tumour cells.

Animals↗
PubMed1980

Electron microscopic observations on the interaction of Listeria monocytogenes and peritoneal macrophages of normal mice.

Acid phosphatase histochemistry was performed to study ultrastructurally the intracellular survival and digestion of Listeria monocytogenes in normal mouse peritoneal macrophages. Acid phosphatase activity proved to be a useful marker for digestive processes of the macrophages, as this activity could be seen in the cytoplasm of killed listeria before disintegration, but not in viable listeria. Almost all killed listeria and the majority of the viable listeria were found in phagosomes of the loosely fitting type. The fusion of lysosomes and phagosomes containing killed bacteria was completed very quickly; the fusion involving phagosomes containing viable listeria was delayed. This delay was abolished by opsonization of bacteria. Disintegration of killed listeria in macrophages could be seen. No such effects were observed when viable listeria were used. Increased numbers of listeria within the phagosomes upon longer incubation suggest multiplication within macrophages.

Acid Phosphatase↗