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Peutz-Kootstra CJ, de Heer E, Hoedemaeker PJ, Abrass CK, Bruijn JA. Lupus nephritis: lessons from experimental animal models. THE JOURNAL OF LABORATORY AND CLINICAL MEDICINE 2001; 137:244-60. [PMID: 11283519 DOI: 10.1067/mlc.2001.113755] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Lupus nephritis is a frequent and severe complication of SLE. In the last decades, animal models for SLE have been studied widely to investigate the immunopathology of this autoimmune disease because abnormalities can be studied and manipulated before clinical signs of the disease become apparent. In this review an overview is given of our current knowledge on the development of lupus nephritis, as derived from animal models, and a hypothetical pathway for the development of lupus nephritis is postulated. The relevance of the studies in experimental models in relationship with our knowledge of human SLE is discussed.
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Affiliation(s)
- C J Peutz-Kootstra
- Department of Pathology, Utrecht University Medical Center, Utrecht, The Netherlands
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52
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Khalil M, Inaba K, Steinman R, Ravetch J, Diamond B. T cell studies in a peptide-induced model of systemic lupus erythematosus. JOURNAL OF IMMUNOLOGY (BALTIMORE, MD. : 1950) 2001; 166:1667-74. [PMID: 11160209 DOI: 10.4049/jimmunol.166.3.1667] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
We have previously reported that immunization with a peptide mimetope of dsDNA on a branched polylysine backbone (DWEYSVWLSN-MAP) induces a systemic lupus erythematosus-like syndrome in the nonautoimmune BALB/c mouse strain. To understand the mechanism underlying this breakdown in self tolerance, we examined the role of T cells in the response. Our results show that the anti-foreign and anti-self response induced by immunization is T cell dependent and is mediated by I-E(d)-restricted CD4(+) T cells of the Th1 subset. In addition, generation of the critical T cell epitope requires processing by APCs and depends on the presence of both DWEYSVWLSN and the MAP backbone. The breakdown in self tolerance does not occur through cross-reactivity between the T cell epitope of DWEYSVWLSN-MAP and epitopes derived from nuclear Ags. In this induced-model of SLE, therefore, autoreactivity results from the activation of T cells specific for foreign Ag and of cross-reactive anti-foreign, anti-self B cells. Despite the fact that tissue injury is mediated by Ab, the critical initiating T cell response is Th1.
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Affiliation(s)
- M Khalil
- Department of Microbiology and Immunology, Albert Einstein College of Medicine, Bronx, NY 10461, USA
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53
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Gensler TJ, Hottelet M, Zhang C, Schlossman S, Anderson P, Utz PJ. Monoclonal antibodies derived from BALB/c mice immunized with apoptotic Jurkat T cells recognize known autoantigens. J Autoimmun 2001; 16:59-69. [PMID: 11221997 DOI: 10.1006/jaut.2000.0464] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
It has been postulated that post-translational modifications and relocalization of proteins during apoptosis may lead to presentation of these molecules to the immune system in such a way that normal mechanisms of tolerance are bypassed. In the present study, Jurkat cells were induced to undergo apoptosis by treatment with the chemotherapeutic agent Ara-C. BALB/c mice were then immunized with the apoptotic cells and hybridomas were generated. Using an indirect immunofluorescence assay, the monoclonal antibodies produced were screened by flow cytometry for those monoclonal antibodies demonstrating reactivity with permeabilized apoptotic Jurkat cells but not with non-permeabilized normal or apoptotic Jurkat cells. Of 281 monoclonal antibodies, 20 monoclonal antibodies with these properties were selected for further analysis. Using 32P- or 35S-metabolically labelled Jurkat cells, these selected monoclonal antibodies were screened for their ability to recognize autoantigens by immunoprecipitation and Western blotting. Well characterized autoimmune sera were then used to confirm the identity of autoantigens by immunoblotting. We demonstrate that immunization of normal mice with apoptotic Jurkat cells results in the formation of antibodies targeting multiple autoantigens or autoantigen complexes, including Ku, rRNPs, snRNPs and vimentin. These findings are consistent with the hypothesis that apoptosis can contribute to the development of autoimmunity.
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Affiliation(s)
- T J Gensler
- The Department of Medicine, Division of Rheumatology, Immunology and Allergy, Brigham & Women's Hospital, Boston, MA 02115, USA
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54
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Kato T, Kurokawa M, Sasakawa H, Masuko-Hongo K, Matsui T, Sekine T, Tanaka C, Yamamoto K, Nishioka K. Analysis of accumulated T cell clonotypes in patients with systemic lupus erythematosus. ARTHRITIS AND RHEUMATISM 2000; 43:2712-21. [PMID: 11145029 DOI: 10.1002/1529-0131(200012)43:12<2712::aid-anr11>3.0.co;2-t] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
OBJECTIVE To compare the accumulated T cell clonotypes in peripheral blood (PB) samples obtained at various times, and the accumulated T cell clonotypes in a PB sample and in an affected kidney, from patients with systemic lupus erythematosus (SLE). METHODS Peripheral blood mononuclear cells (PBMC) were obtained at 2-4 different times from each of 5 SLE patients, with or without flare-up of the disease; in addition, a biopsied kidney tissue sample was obtained from 1 of the patients. RNA was extracted from each sample and complementary DNA was prepared. Genes that encode the variable region of T cell receptor (TCR) B chains (BV) of 3 BV families, 5S1, 8, and 14, were amplified by reverse transcription-polymerase chain reaction (PCR), and the PCR products were cloned for sequencing. RESULTS A total of 877 cloned TCR genes was detected in the PBMC samples and the kidney sample. Oligoclonal T cell expansion was detected in 34 of the 36 PCR-amplified BV samples from PBMC (amplification of 3 BV families in 2-4 samples from 5 patients). The composition of clonally expanded T cell clonotypes was relatively stable in the patients with inactive SLE. In contrast, the composition of clonotypes in the PB changed drastically after the patient experienced the active phase of the disease. T cell clonotypes that had accumulated in the kidney appeared to be restricted and distinct from those that had accumulated in the PB of the same patient. CONCLUSION Different T cell clonotypes expand at different times and at different sites in patients with active SLE. The sensitizing antigens may change over the course of the disease and may be different at each site.
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Affiliation(s)
- T Kato
- Rheumatology, Immunology, and Genetics Program, Institute of Medical Science, St Marianna University School of Medicine, Kanagawa, Japan
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55
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Affiliation(s)
- M Solimena
- Department of Internal Medicine, Yale University School of Medicine, New Haven, Connecticut 06510, USA
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56
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Peutz-Kootstra CJ, Hansen K, De Heer E, Abrass CK, Bruijn JA. Differential expression of laminin chains and anti-laminin autoantibodies in experimental lupus nephritis. J Pathol 2000; 192:404-12. [PMID: 11054725 DOI: 10.1002/1096-9896(2000)9999:9999<::aid-path707>3.0.co;2-l] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
Mice with chronic graft-versus-host disease (GvHD) develop a lupus-like disease with severe immune complex glomerulonephritis. Previous studies with this model have shown that anti-laminin autoantibodies are involved in immune complex formation and that glomerular laminin expression alters qualitatively. The present study investigated glomerular laminin chain expression and autoantibody reactivity with matrix antigens during disease development in mice with chronic GvHD, killed before and 6, 8, 10, and 11 weeks after disease induction, using antibodies raised against laminin chain peptides, in immunofluorescence and western blotting studies. Decreased glomerular expression of the laminin beta1 chain, unaltered expression of the laminin beta2 and gamma1 chains, and increased expression of the laminin alpha1 chain and filamin/actin-binding protein 280 (ABP 280) were found during disease progression. Furthermore, 4 weeks after disease induction, autoantibodies appeared which were reactive with laminin alpha1, beta1, beta2, and gamma1 chains, and filamin in rat mesangial cell matrix. Ten weeks after disease induction, autoantibodies reacted with filamin, and beta2 and gamma1 laminin chains. Autoantibodies reacted with laminin chains only and not with other proteins in matrices extracted from glomeruli of normal and diseased mice. Staining with H50, an anti-laminin alpha1 chain/anti-filamin monoclonal autoantibody derived from an MRL/lpr mouse with spontaneous lupus nephritis, confirmed these observations and showed identical anti-laminin/anti-filamin autoantibody reactivity in two different models for lupus nephritis. In summary, differential glomerular expression of laminin chains was found during the development of chronic GvHD. Concomitantly with expression of the laminin alpha1 chain and/or filamin in the glomerulus, anti-laminin alpha1 and/or anti-filamin reactivity was present, pointing towards a role for (neo) antigen expression in the epitope spreading of the immune response. Furthermore, glomerular expression of laminin beta1 decreased in conjunction with decreased presence of anti-laminin beta1 reactivity, presumably due to antigen masking or shedding of immune complexes into the urine. These changes in anti-laminin chain autoantibodies, with concomitant alterations in the glomerular expression of laminin chains, may aggravate progressive immune injury in this model for lupus nephritis.
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Affiliation(s)
- C J Peutz-Kootstra
- Department of Pathology, Leiden University Medical Center, Leiden, The Netherlands.
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57
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Abstract
Studies in humans and mice with systemic lupus erythematosus (SLE) suggest that the development of autoantibodies and disease is dependent on T helper (Th) cells. This review highlights recent efforts to identify the antigens that activate such autoreactive Th cells. Various laboratories are using different approaches to identify the autoantigenic epitopes, which appear to be derived from diverse sources such as nucleosome core histones, ribonucleoproteins, and immunoglobulin variable regions. Identification of the putative autoantigenic epitopes has raised the possibility of peptide-specific vaccination as therapy for SLE. Indeed, vaccination of prenephritic lupus-susceptible mice with such peptides delays the development of autoantibodies and nephritis, and prolongs survival. Recent data suggest that peptide treatment can also influence established disease in older lupus mice. These studies offer new hope for a similar treatment approach in patients with SLE. Studies have begun to identify T cell epitopes in human disease.
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MESH Headings
- Amino Acid Sequence
- Animals
- Autoantibodies/biosynthesis
- Autoantigens/chemistry
- Autoantigens/immunology
- Disease Models, Animal
- Epitope Mapping
- Epitopes, T-Lymphocyte/chemistry
- Epitopes, T-Lymphocyte/immunology
- Humans
- Lupus Erythematosus, Systemic/drug therapy
- Lupus Erythematosus, Systemic/immunology
- Lymphocyte Activation
- Mice
- Molecular Sequence Data
- Nuclear Proteins/immunology
- Peptides/chemistry
- Peptides/immunology
- T-Lymphocytes, Helper-Inducer/immunology
- T-Lymphocytes, Helper-Inducer/metabolism
- Vaccination
- Vaccines, Subunit/chemistry
- Vaccines, Subunit/immunology
- Vaccines, Subunit/therapeutic use
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Affiliation(s)
- R R Singh
- Department of Internal Medicine, Universisty of Cincinnati College of Medicine and Veterans Affairs Medical Center, Ohio 45267-0563, USA.
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58
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Yiannaki E, Vlachoyiannopoulos PG, Manoussakis MN, Sakarellos C, Sakarellos-Daitsiotis M, Moutsopoulos HM, Tzioufas AG. Study of antibody and T cell responses in rabbits immunized with synthetic human B cell epitope analogues of La (SSB) autoantigen. Clin Exp Immunol 2000; 121:551-6. [PMID: 10971524 PMCID: PMC1905730 DOI: 10.1046/j.1365-2249.2000.01326.x] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/22/2000] [Indexed: 11/20/2022] Open
Abstract
The aim of this study was to investigate the immunogenicity of four synthetic peptides, representing linear B cell epitopes of the human La/SSB autoantigen: 145-164 aa (p1), 289-308 aa (p2), 301-318 aa (p3) and 349-364 aa (p4), in rabbits. New Zealand White rabbits were immunized with each of the above peptides attached in four copies on tetrameric sequential oligopeptide carriers (SOC) in duplicate. Control immunizations were also performed (one rabbit each, immunized with Freud's complete adjuvant alone or with the SOC carrier alone). Animals were bled at regular intervals and sera were analysed for anti-La/SSB activity by ELISA assays using as antigen the various synthetic peptides, as well as the whole La/SSB protein. Four months after the last immunization, the animals were killed and peripheral blood mononuclear and spleen cells were co-cultured with either the peptides, the SOC carrier, or 27 peptides, covering the entire length of the human La/SSB molecule (23 amino acids long, overlapping by eight residues to each other). A specific, IgG, anti-peptide antibody response was detected, initially directed against the priming peptide, and subsequently expanded to the other La/SSB synthetic peptides. The antibody titres remained high, even 4 months after the last immunization. Sera from rabbits immunized with either p2 or p3 reacted also with the whole La/SSB protein, as was demonstrated by ELISA and immunoblot assays. No reactivities against either Ro60 or Ro52 autoantigen were found. Rabbit spleen cell reacted not only with the epitope used for the immunization but also with other La/SSB peptides. Immunization of rabbits with the major human La/SSB B cell antigenic determinants, linked to SOC carrier, induces strong and sustained antibody and T cell responses against multiple epitopes of the human La/SSB protein. Thus, La/SSB B cell linear epitopes are probably capable also of functioning as T cell epitopes, in this experimental animal.
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Affiliation(s)
- E Yiannaki
- Department of Pathophysiology, School of Medicine, National University of Athens, Athens, Greece
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59
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Degen WG, Pruijn GJ, Raats JM, van Venrooij WJ. Caspase-dependent cleavage of nucleic acids. Cell Death Differ 2000; 7:616-27. [PMID: 10889506 DOI: 10.1038/sj.cdd.4400672] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Abstract
Autoimmune diseases are frequently characterized by the presence of autoantibodies directed against nucleic acid-protein complexes present in the nucleus of the cell. The mechanisms by which these autoantigenic molecules escape immunological tolerance are largely unknown, although a number of recent observations suggest that modified self-proteins generated during apoptosis may play an important role in the development of autoimmunity. It has been hypothesized that the recognition of these modified self-proteins by the immune system may promote autoantibody production. While apoptosis is specifically characterized by posttranslational modification of proteins, recent findings also show that nucleic acids are modified. This review summarizes the specific cleavages of some of these key nucleic acids, i.e. chromosomal DNA, ribosomal RNA and small structural RNAs (U1 snRNA, Y RNA), in apoptotic cells.
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Affiliation(s)
- W G Degen
- Department of Biochemistry, University of Nijmegen, P.O. Box 9101, NL-6500 HB Nijmegen, The Netherlands
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60
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Deshmukh US, Lewis JE, Gaskin F, Dhakephalkar PK, Kannapell CC, Waters ST, Fu SM. Ro60 peptides induce antibodies to similar epitopes shared among lupus-related autoantigens. JOURNAL OF IMMUNOLOGY (BALTIMORE, MD. : 1950) 2000; 164:6655-61. [PMID: 10843726 DOI: 10.4049/jimmunol.164.12.6655] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
The coexistence of autoantibodies to ribonucleoproteins (RNP) in sera of patients with systemic lupus erythematosus has been attributed to intermolecular determinant spreading among physically associated proteins. Recently, we showed that murine Ab responses to rRo60 or Ro60 peptides were diversified unexpectedly to small nuclear RNP. In this investigation, the mechanisms for this autoantibody diversification were examined. Intramolecular determinant spreading was demonstrated in mice immunized with human or mouse Ro60316-335. Immune sera depleted of anti-peptide Ab immunoprecipitated Ro60-associated mY1 and mY3 RNA and remained reactive to a determinant on Ro60128-285. Absorption with the immunogen depleted the immune sera completely of anti-Golgi complex Ab (inducible only with human Ro60316-335) and anti-La Ab, and reduced substantially Ab to SmD and 70-kDa U1RNP. Mouse rRo60 completely inhibited the immune sera reactivity to La, SmD, and 70-kDa U1RNP. However, La, SmD, and 70-kDa U1RNP preferentially inhibited the antiserum reactivities to these Ags, respectively. Affinity-purified anti-La Ab were reactive with Ro60, La, SmD, and 70-kDa U1RNP. These results provide evidence that a population of the induced autoantibodies recognized determinants shared by these autoantigens. Lack of sequence homology between Ro60316-335 and La, SmD, or 70-kDa U1RNP suggests that these determinants are conformational. Interestingly, similar cross-reactive autoantibodies were found in NZB/NZW F1 sera. Thus, a single molecular mimic may generate Ab to multiple RNP Ags. Furthermore, cross-reactive determinants shared between antigenic systems that are not associated physically (Ro/La RNP and small nuclear RNP) may be important in the generation of autoantibody diversity in systemic lupus erythematosus.
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MESH Headings
- Absorption
- Amino Acid Sequence
- Animals
- Antigens, Heterophile/administration & dosage
- Antigens, Heterophile/immunology
- Antigens, Heterophile/metabolism
- Autoantibodies/biosynthesis
- Autoantibodies/metabolism
- Autoantigens/administration & dosage
- Autoantigens/immunology
- Autoantigens/metabolism
- Cross Reactions
- Crosses, Genetic
- Epitopes, B-Lymphocyte/immunology
- Epitopes, B-Lymphocyte/metabolism
- Female
- Humans
- Lupus Erythematosus, Systemic/immunology
- Mice
- Mice, Inbred A
- Mice, Inbred BALB C
- Mice, Inbred NZB
- Molecular Sequence Data
- Peptide Fragments/administration & dosage
- Peptide Fragments/immunology
- Peptide Fragments/metabolism
- RNA, Small Cytoplasmic
- Ribonucleoproteins/administration & dosage
- Ribonucleoproteins/immunology
- Ribonucleoproteins/metabolism
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Affiliation(s)
- U S Deshmukh
- Department of Internal Medicine, University of Virginia Specialized Center of Research on Systemic Lupus Erythematosus, Charlottesville 22908, USA
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61
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Fabini G, Rutjes SA, Zimmermann C, Pruijn GJ, Steiner G. Analysis of the molecular composition of Ro ribonucleoprotein complexes. Identification of novel Y RNA-binding proteins. EUROPEAN JOURNAL OF BIOCHEMISTRY 2000; 267:2778-89. [PMID: 10785401 DOI: 10.1046/j.1432-1327.2000.01298.x] [Citation(s) in RCA: 46] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Human Ro ribonucleoproteins (RNPs) are composed of one of the four small Y RNAs and at least two proteins, Ro60 and La; association of additional proteins including the Ro52 protein and calreticulin has been suggested, but clear-cut evidence is still lacking. Partial purification of Ro RNPs from HeLa S100 extracts allowed characterization of several subpopulations of Ro RNPs with estimated molecular masses of between 150 and 550 kDa. The majority of these complexes contained Ro60 and La, whereas only a small proportion of Ro52 appeared to be associated with Ro RNPs. To identify novel Y RNA-associated proteins in vitro, binding of cytoplasmic proteins to biotinylated Y RNAs was investigated. In these reconstitution experiments, several proteins with estimated molecular masses of 80, 68, 65, 62, 60 and 53 kDa, the latter two being immunologically distinct from Ro60 and Ro52, respectively, appeared to bind specifically to Y RNAs. Furthermore, autoantibodies to these proteins were found in sera from patients with systemic lupus erythematosus. The proteins bound preferentially to Y1 and Y3 RNA but, with the exception of the 53-kDa protein, only weakly to Y4 RNA and not at all to Y5 RNA. Coprecipitation of the 80, 68, 65, and 53-kDa proteins by antibodies to Ro60 and La was observed, suggesting that at least a proportion of the novel proteins may reside on the same particles as La and/or Ro60. Finally, the binding sites for these proteins on Y1 RNA were clearly distinct from the Ro60-binding site involving a portion of the large central loop 2, which was found to be indispensable for binding of the 80, 68, 65 and 53-kDa proteins, as well as the stem 3-loop 3 and stem 2-loop 1 regions. Interestingly, truncation of the La-binding site resulted in decreased binding of the novel proteins (but not of Ro60), indicating La to be required for efficient association. Taken together, these results suggest the existence of further subpopulations of Ro RNPs or Y RNPs, consistent with the heterogeneous characteristics observed for these particles in the biochemical fractionation experiments.
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Affiliation(s)
- G Fabini
- Institute of Biochemistry, University of Vienna, Austria
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62
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Author's reply:. Am J Kidney Dis 2000. [DOI: 10.1016/s0272-6386(00)70278-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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63
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Steinbach F, Henke F, Krause B, Thiele B, Burmester GR, Hiepe F. Monocytes from systemic lupus erythematous patients are severely altered in phenotype and lineage flexibility. Ann Rheum Dis 2000; 59:283-8. [PMID: 10733475 PMCID: PMC1753112 DOI: 10.1136/ard.59.4.283] [Citation(s) in RCA: 67] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
OBJECTIVE Cells of the myeloid lineage comprise a very heterogeneous population with many phenotypes and functional activities including macrophages and dendritic cells. To investigate the status, differentiative potential and lineage commitment of monocytic cells in systemic lupus erythematosus (SLE) patients, this study isolated and cultured peripheral blood monocytes from patients and healthy donors. METHODS Monocytes were isolated by gradient centrifugation and adherence to plastic dishes. The cells were then cultured for three days, partially supplemented with GM-CSF and interleukin 4 (IL4) to obtain dendritic cells. The differentiation status was monitored by the expression of surface markers using flow cytometry and cytokine secretion. RESULTS Monocytes from SLE patients expressed significantly lower numbers of the monocytic marker CD14 and HLA-DR while secreting significantly more tumour necrosis factor alpha (TNFalpha) than monocytes from healthy donors. The addition of GM-CSF and IL4 resulted in an inhibition of TNFalpha secretion, but was not sufficient to generate monocytederived dendritic cells. CONCLUSION Monocytes from SLE patients are severely altered in phenotype and function and have a limited differentiation flexibility towards the accessory type of monocytic cells.
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Affiliation(s)
- F Steinbach
- Institute of Virology, FU Berlin, Königin-Luise-Str 49, 14 195 Berlin, Germany
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64
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Utz PJ, Gensler TJ, Anderson P. Death, autoantigen modifications, and tolerance. ARTHRITIS RESEARCH 2000; 2:101-14. [PMID: 11094420 PMCID: PMC129993 DOI: 10.1186/ar75] [Citation(s) in RCA: 117] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Received: 01/04/2000] [Revised: 01/17/2000] [Accepted: 01/20/2000] [Indexed: 12/18/2022]
Abstract
Autoantibodies present in the serum of patients with a variety of inflammatory diseases have proven useful as diagnostic markers and as probes with which to elucidate biochemical and signaling pathways. The mechanisms governing the generation of autoantibodies remain elusive, constituting a critical missing link in our understanding of rheumatologic illnesses. Several lines of experimentation in recent years have strongly implicated events surrounding cell death in this process. This review will address the potential role played by death-specific modifications of autoantigens in bypassing tolerance to highly conserved autoantigens, including nucleic acids, lipids, and proteins.
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Affiliation(s)
- P J Utz
- Department of Medicine, Stanford University School of Medicine, Stanford, California 94305, USA.
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65
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Hattori N, Kuwana M, Kaburaki J, Mimori T, Ikeda Y, Kawakami Y. T cells that are autoreactive to beta2-glycoprotein I in patients with antiphospholipid syndrome and healthy individuals. ARTHRITIS AND RHEUMATISM 2000; 43:65-75. [PMID: 10643701 DOI: 10.1002/1529-0131(200001)43:1<65::aid-anr9>3.0.co;2-i] [Citation(s) in RCA: 59] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
OBJECTIVE To identify the T cells responsive to beta2-glycoprotein I (beta2GPI) that mediate antiphospholipid antibody production in patients with antiphospholipid syndrome (APS). METHODS In vitro proliferative responses and anti-beta2GPI antibody production induced by beta2GPI were examined in peripheral blood mononuclear cell (PBMC) cultures from 12 APS patients, 13 systemic lupus erythematosus patients without APS, and 12 healthy donors. RESULTS Peripheral blood T cells from all subjects failed to respond to beta2GPI in its native form. In contrast, reduced beta2GPI was able to stimulate T cells not only from all 12 patients with anti-beta2GPI antibodies, but also from 10 of 25 individuals without anti-beta2GPI antibodies. The specificity of the responses to beta2GPI was confirmed by activation of the reduced beta2GPI-primed T cells by recombinant beta2GPI in secondary cultures. Characterization of the T cell response induced by beta2GPI revealed that the response was associated with the presence of the DR53-associated alleles, the responding T cells were CD4+ and restricted by HLA class II, and antigenic peptides were located in domains IV and/or V. Anti-beta2GPI antibody production was induced specifically in anti-beta2GPI antibody-positive patients, in PBMC cultures with reduced beta2GPI. Anti-beta2GPI antibodies produced in vitro recognized beta2GPI immobilized with cardiolipin or beta2GPI coated on "high-binding" polystyrene plates. CONCLUSION These results strongly suggest that CD4+ and HLA class II-restricted T cells responsive to beta2GPI are involved in the production of antiphospholipid antibodies in APS patients.
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Affiliation(s)
- N Hattori
- Keio University School of Medicine, Tokyo, Japan
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66
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Abstract
Some severe auto-immune diseases, including rheumatoid arthritis, require immunosuppression to save life or vital organ function. One major limiting factor in such immunosuppression is the unwanted and dangerous haematoablation occurring at the same time. It is now possible to give supralethal doses of haematoimmunoablative drugs, and to 'rescue' the patient with haematopoietic stem cell transplantation. There are case reports of patients with rheumatoid arthritis who have received bone marrow transplantation, now called haematopoietic stem cell transplantation (HSCT), for a conventional indication such as aplastic anaemia or malignancy, in whom a long lasting improvement of the arthritis was observed. However, not all cases have responded, and there are still many open questions concerning optimal treatment regimens. In addition, some animal model research has supported the concept of HSCT as a permanent treatment of auto-immune disease including arthritis. In the past three years, HSCT has been applied to treat auto-immune disease alone in around 180 patients, 20 of whom having had rheumatoid arthritis and 13 juvenile arthritis. Early results are encouraging, but many issues require further clarification through co-ordinated clinical trials. The evolution of this project, details of the early results, the remaining open questions and possible strategies to resolve these are the subject of this chapter.
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Affiliation(s)
- A Tyndall
- University Department of Rheumatology, Felix Platter Spital, Basel, Switzerland
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67
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Craft J, Peng S, Fujii T, Okada M, Fatenejad S. Autoreactive T cells in murine lupus: origins and roles in autoantibody production. Immunol Res 1999; 19:245-57. [PMID: 10493178 DOI: 10.1007/bf02786492] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
The conventional paradigm to explain systemic lupus erythematosus (SLE) is that disease results from tissue deposition of pathogenic autoantibodies and immune complexes, secondary to activation of autoreactive B cells in the context of help from alphabeta T cells. Recent work in murine lupus has confirmed this notion and demonstrated that autoantigen-specific alphabeta T cells are absolutely required for full penetrance of disease, with such autoreactive alphabeta T cells, even in Fas-intact mice, likely arising from defects in peripheral tolerance. These studies have also revealed a network of regulation that also involves nonclassical pathogenic and downregulatory alphabeta and gammadelta T cells, suggesting that the lupus immune system involves more complex interactions than the conventional paradigm suggests.
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Affiliation(s)
- J Craft
- Department of Medicine, Yale University School of Medicine, New Haven, CT 06520-8031, USA.
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Lu L, Kaliyaperumal A, Boumpas DT, Datta SK. Major peptide autoepitopes for nucleosome-specific T cells of human lupus. J Clin Invest 1999; 104:345-55. [PMID: 10430616 PMCID: PMC408421 DOI: 10.1172/jci6801] [Citation(s) in RCA: 123] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
We tested 154 peptides spanning the entire length of core histones of nucleosomes for the ability to stimulate an anti-DNA autoantibody-inducing T helper (Th) clone, as well as CD4(+) T-cell lines and T cells, in fresh PBMCs from 23 patients with lupus erythematosus. In contrast to normal T cells, lupus T cells responded strongly to certain histone peptides, irrespective of the patient's disease status. Nucleosomal peptides in histone regions H2B(10-33), H4(16-39) (and overlapping H4(14-28)), H4(71-94), and H3(91-105) (and overlapping H3(100-114)) were recurrently recognized by CD4 T cells from the patients with lupus. Remarkably, these same peptides overlap with major epitopes for the Th cells that induce anti-DNA autoantibodies and nephritis in lupus-prone mice. We localized 2 other recurrent epitopes for human lupus T cells in H2A(34-48) and H4(49-63). All the T-cell autoepitopes have multiple HLA-DR binding motifs, and the epitopes are located in histone regions recognized by lupus autoantibodies, suggesting a basis for their immunodominance. Native nucleosomes and their peptides H4(16-39), H4(71-94), and H3(91-105) induced a stronger IFN-gamma response, whereas others, particularly, H2A(34-48), favored an IL-10- and/or IL-4-positive T-cell response. The major autoepitopes may reveal the mechanism of autoimmune T-cell expansion and lead to antigen-specific therapy of human lupus.
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Affiliation(s)
- L Lu
- Department of Medicine, Northwestern University Medical School, Chicago, Illinois 60611, USA
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69
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Kaliyaperumal A, Michaels MA, Datta SK. Antigen-Specific Therapy of Murine Lupus Nephritis Using Nucleosomal Peptides: Tolerance Spreading Impairs Pathogenic Function of Autoimmune T and B Cells. THE JOURNAL OF IMMUNOLOGY 1999. [DOI: 10.4049/jimmunol.162.10.5775] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Abstract
In the (SWR × NZB)F1 mouse model of lupus, we previously localized the critical autoepitopes for nephritogenic autoantibody-inducing Th cells in the core histones of nucleosomes at aa positions 10–33 of H2B and 16–39 and 71–94 of H4. A brief therapy with the peptides administered i.v. to 3-mo-old prenephritic (SWR × NZB)F1 mice that were already producing pathogenic autoantibodies markedly delayed the onset of severe lupus nephritis. Strikingly, chronic therapy with the peptides injected into 18-mo-old (SWR × NZB)F1 mice with established glomerulonephritis prolonged survival and even halted the progression of renal disease. Remarkably, tolerization with any one of the nucleosomal peptides impaired autoimmune T cell help, inhibiting the production of multiple pathogenic autoantibodies. However, cytokine production or proliferative responses to the peptides were not grossly changed by the therapy. Moreover, suppressor T cells were not detected in the treated mice. Most interestingly, the best therapeutic effect was obtained with nucleosomal peptide H416–39, which had a tolerogenic effect not only on autoimmune Th cells, but autoimmune B cells as well, because this peptide contained both T and B cell autoepitopes. These studies show that the pathogenic T and B cells of lupus, despite intrinsic defects in activation thresholds, are still susceptible to autoantigen-specific tolerogens.
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Affiliation(s)
- Arunan Kaliyaperumal
- Departments of Medicine and Microbiology-Immunology and Multipurpose Arthritis Center, Northwestern University Medical School, Chicago, IL 60611
| | - Marissa A. Michaels
- Departments of Medicine and Microbiology-Immunology and Multipurpose Arthritis Center, Northwestern University Medical School, Chicago, IL 60611
| | - Syamal K. Datta
- Departments of Medicine and Microbiology-Immunology and Multipurpose Arthritis Center, Northwestern University Medical School, Chicago, IL 60611
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Mason LJ, Timothy LM, Isenberg DA, Kalsi JK. Immunization with a Peptide of Sm B/B′ Results in Limited Epitope Spreading But Not Autoimmune Disease. THE JOURNAL OF IMMUNOLOGY 1999. [DOI: 10.4049/jimmunol.162.9.5099] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Abstract
An experimental model of systemic lupus erythematosus has recently been described in normal animals. We sought to confirm and extend this model, which involved immunization of normal rabbits and mice with a peptide of Sm B/B′, PPPGMRPP. This peptide is an early target of the immune response in anti-Sm-positive patients with lupus. The peptide was used in a multiple Ag peptide format, with multiple copies of PPPGMRPP bound to an inert lysine backbone. New Zealand White rabbits and A/J and C57BL/10ScSn mouse strains were immunized with PPPGMRPP-MAP. Pepscan assays were used to determine the epitope spreading of the anti-PPPGMRPP-MAP response to other octamers of SmB/B′ following immunization. We obtained high titer anti-PPPGMRPP-MAP IgG responses in the New Zealand White rabbits and A/J mice. The rabbits immunized with PPPGMRPP-MAP showed varying degrees of epitope spreading, while the A/J mice showed no spreading. We observed no autoantibodies to dsDNA or other anti-nuclear autoantibodies in our animals by ELISA or immunofluorescence, although anti-nuclear autoantibodies were found by Western blotting in some of the rabbits. No evidence of clinical disease was seen in our normal animals. These data underline the difficulties often associated with the reproduction of animal models in different laboratories.
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Affiliation(s)
- Lesley J. Mason
- Center for Rheumatology/Bloomsbury Rheumatology Unit, Department of Medicine, University College London, London, United Kingdom
| | - Linda M. Timothy
- Center for Rheumatology/Bloomsbury Rheumatology Unit, Department of Medicine, University College London, London, United Kingdom
| | - David A. Isenberg
- Center for Rheumatology/Bloomsbury Rheumatology Unit, Department of Medicine, University College London, London, United Kingdom
| | - Jatinderpal K. Kalsi
- Center for Rheumatology/Bloomsbury Rheumatology Unit, Department of Medicine, University College London, London, United Kingdom
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71
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Scofield RH, Kaufman KM, Baber U, James JA, Harley JB, Kurien BT. Immunization of mice with human 60-kd Ro peptides results in epitope spreading if the peptides are highly homologous between human and mouse. ARTHRITIS AND RHEUMATISM 1999; 42:1017-24. [PMID: 10323459 DOI: 10.1002/1529-0131(199905)42:5<1017::aid-anr22>3.0.co;2-7] [Citation(s) in RCA: 52] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
OBJECTIVE Immunization with peptide fragments of autoantigens may lead to an immune response at both the T and B cell level that is directed not only at the immunogen, but also at the autoantigen from which the peptide came. In addition, a complex multicomponent particle may become the target of this expanded immune response. The purpose of this study was to determine the ability of several different peptides from 60-kd Ro to induce expansion of the immune response to the Ro/La RNP particle. METHODS We immunized BALB/c mice with 3 different oligopeptides from human 60-kd Ro (or, SSA). RESULTS Animals immunized with peptides either identical to or differing by only 1 amino acid developed autoimmunity to the entire Ro RNP particle. Animals immunized with a human peptide highly divergent from the corresponding mouse sequence developed an immune response to the immunogen only and showed little evidence of epitope spreading. Furthermore, these mice did not have antibodies that bound the poorly conserved mouse homolog peptide, and the antibody response to this peptide did not include IgG1. CONCLUSION These data indicate that B lymphocytes specific for the self-peptide that is homologous to the immunogen are a critical determinant for spreading of the immune response to other components of self.
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Affiliation(s)
- R H Scofield
- Oklahoma Medical Research Foundation, University of Oklahoma Health Sciences Center, Department of Veterans Affairs Medical Center, and WK Warren Medical Research Institute, Oklahoma City 73104, USA
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Shanklin DR, Smalley DL. The immunopathology of siliconosis. History, clinical presentation, and relation to silicosis and the chemistry of silicon and silicone. Immunol Res 1999; 18:125-73. [PMID: 9951648 DOI: 10.1007/bf02788777] [Citation(s) in RCA: 40] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
Abstract
Recent evidence confirms the fundamental involvement of the human immune system in the reaction to implantation of silicone-based medical devices. An as yet-to-be particularized epitope of many complex substances sharing siloxane structures is presented through the MHC-II apparatus with development and retention of T cell memory. This memory can be tested for in practical terms using one or more forms of silica, which links the immuno-histopathology and autoimmune attributes of "silicosis" with those of "siliconosis." The lesions of siliconosis are typical of those for persistent antigens and delayed, cell mediated hypersensitivity. The basic descriptive pathology of the reaction to silicone has been known since soon after introduction of silicones in medical procedures, with the exception of some details related to the more recent discoveries on the role of cytokines in the immunopathic process. The clinical consequences of siliconosis are common and can be severe in some individuals implanted with silicone devices.
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Affiliation(s)
- D R Shanklin
- Department of Pathology, University of Tennessee, Memphis 38163, USA
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74
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Deshmukh US, Lewis JE, Gaskin F, Kannapell CC, Waters ST, Lou YH, Tung KS, Fu SM. Immune responses to Ro60 and its peptides in mice. I. The nature of the immunogen and endogenous autoantigen determine the specificities of the induced autoantibodies. J Exp Med 1999; 189:531-40. [PMID: 9927515 PMCID: PMC2192918 DOI: 10.1084/jem.189.3.531] [Citation(s) in RCA: 68] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/1998] [Revised: 11/29/1998] [Indexed: 11/30/2022] Open
Abstract
Anti-Ro60 autoantibodies are found in a variety of autoimmune disorders including systemic lupus erythematosus (SLE), Sjögren's syndrome, primary biliary cirrhosis, and active hepatitis. They are the most prevalent autoantibodies in normal individuals and in asymptomatic mothers of infants afflicted with neonatal lupus. In the present study, immune responses to recombinant human Ro60 (rhRo60) and recombinant mouse Ro60 (rmRo60) and selected Ro60 peptides in non-SLE-prone mice were investigated. Multiple T and B cell epitopes were identified in Ro60. Immunizations with either xenogeneic or autologous Ro60 induced autoantibodies to a diverse group of autoantigens. In addition to La and Ro52, proteins in the small nuclear ribonucleoprotein (snRNP) particles such as SmA, SmB, SmD, and 70-kD U1-RNP were unexpectedly identified as targeted antigens. In the studies involving synthetic Ro60 peptides, both human and mouse Ro60316-335 peptides, which differ in three amino acids, were found to contain dominant cross-reactive T cell determinants. Immunizations with these peptides induced autoantibodies to Ro60, La, SmD, and 70-kD U1-RNP without autoantibodies to Ro52, SmA, or SmB. With human Ro60316-335 as the immunogen, additional autoantibodies reactive with the Golgi complex were found. In contrast to the immunodominance of both human and mouse Ro60316-335 peptides, the T cell determinant in human Ro60441-465 was dominant, whereas that in the mouse peptide was cryptic. Immunization with human Ro60441-465 induced primarily anti-peptide Abs. Mouse Ro60441-465 failed to induce an antibody response. These results show that both the nature of the immunogen and the immunogenicity of the related endogenous antigen are important in determining the specificities of the autoantibodies generated. They have significant implications for proposed mechanisms on the generation of complex patterns of autoantibodies to a diverse group of autoantigens in SLE patients.
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Affiliation(s)
- U S Deshmukh
- Division of Rheumatology, Department of Internal Medicine, University of Virginia School of Medicine, Charlottesville, VA 22908, USA
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75
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Kinoshita G, Purcell AW, Keech CL, Farris AD, McCluskey J, Gordon TP. Molecular chaperones are targets of autoimmunity in Ro(SS-A) immune mice. Clin Exp Immunol 1999; 115:268-74. [PMID: 9933452 PMCID: PMC1905168 DOI: 10.1046/j.1365-2249.1999.00794.x] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/13/1998] [Indexed: 11/20/2022] Open
Abstract
We have used a murine model of experimental anti-Ro(SS-A) autoimmunity to dissect additional intermolecular interactions between the 52-kD Ro (Ro52) and 60-kD Ro (Ro60) autoantigens and molecular chaperones. Immune responses to members of the heat shock protein hsp70 and hsp90 families were measured by immunoblotting and ELISA in sera from mice immunized and boosted with purified recombinant Ro52, Ro60 and La (SS-B). All Ro52 and Ro60 immune sera immunoblotted the inducible glucose-regulated protein grp78 and hsp70 species but not constitutive hsc70 or hsp90. The kinetics of antibody production and reciprocal affinity purification experiments indicated that the grp78 and hsp70 responses were cross-reactive but distinct from immune responses to the primary Ro52 and Ro60 immunogens and the endoplasmic reticulum (ER)-resident chaperone calreticulin. No responses to molecular chaperones were detected in the La-immunized mice. Control immunizations indicated that the recruited grp78 and hsp70 responses were specific for the Ro proteins and not due to immunization with denatured protein. The rapid spreading of immunity to the inducible grp78 and hsp70 in Ro52- and Ro60-immunized mice suggests that these components may co-localize and physically associate under certain physiological conditions which may promote autoimmunization. The potential importance of the ER-resident chaperones grp78 and calreticulin is further supported by their co-localization with Ro in small apoptotic membrane blebs and the finding of a novel putative grp78 binding motif in the carboxyl-terminal region of Ro52.
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Affiliation(s)
- G Kinoshita
- Department of Immunology, Allergy & Arthritis, Flinders Medical Centre and Flinders University, Adelaide, South Australia
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76
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Abstract
A select population of autoimmune T-helper (T(H)) cells drive the production of pathogenic anti-DNA autoantibodies in SLE. These T(H) cells recognize nucleosomal peptides that are processed and presented by the anti-DNA B cells that they help. The critical peptide epitopes for the T(H) cells reside in the core histones of the nucleosome particle. Remarkably, the nucleosomal peptide epitopes do not obey the rule of MHC-restriction; they can be promiscuously presented and recognized in the context of diverse MHC alleles. Such promiscuous antigens, called pantigens, are also recognized by autoimmune T cells, in a degenerate fashion, and this promiscuous recognition is conferred by the lupus TCR alpha chains. High-affinity interactions between the lupus TCRs and MHC-nucleosomal peptide complex due to reciprocally charged residues probably overcome the requirement for MHC restriction. These studies open up the possibility of developing 'universally' tolerogenic epitopes for therapy of lupus in humans despite their diversity of HLA alleles. The results also have profound implications regarding the selection of autoimmune T cells in the lupus-prone thymus and their expansion in the periphery. Furthermore, the T(H) cells, as well as B cells of lupus, have a regulatory defect causing markedly increased and prolonged expression of CD40 ligand (CD40L), which mediates abnormal co-stimulatory signals to autoimmune B cells, sustaining the production of pathogenic autoantibodies. These observations suggest a new paradigm for B cell hyperactivity in lupus and provide alternative targets for immunotherapy. Indeed, giving only three injections of anti-CD40L antibody in a one-week period to mice with manifest lupus selectively blocks the pathogenic autoimmune response and delays the development of lupus nephritis by one year (equivalent to three decades in humans). Thus, possession of promiscuous, high-affinity receptors and prolonged expression of CD40L by lupus T cells probably lowers activation threshold, leading to an autoimmune response against nucleosomes derived from apoptotic cells that are normally ignored by the immune system.
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Affiliation(s)
- S K Datta
- The Department of Medicine, Multipurpose Arthritis Center, Northwestern University Medical School, Chicago, Illinois 60611, USA
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78
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von Mühlen CA, Chan EK, Anglés-Cano E, Mamula MJ, Garcia-De La Torre I, Fritzler MJ. Advances in autoantibodies in SLE. Lupus 1998; 7:507-14. [PMID: 9863891 DOI: 10.1191/096120398678920613] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
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81
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Abstract
This article discusses the use and interpretation of antinuclear antibody (ANA) testing in connective tissue diseases. Methods of ANA detection are discussed and analyzed in detail as is the role of ANAs in systemic lupus, scleroderma, and polymyositis, connective tissue diseases with prominent pulmonary involvement.
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Affiliation(s)
- J Evans
- Department of Medicine, Yale University School of Medicine, New Haven, Connecticut, USA
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82
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Singh RR, Hahn BH, Tsao BP, Ebling FM. Evidence for multiple mechanisms of polyclonal T cell activation in murine lupus. J Clin Invest 1998; 102:1841-9. [PMID: 9819370 PMCID: PMC509134 DOI: 10.1172/jci3872] [Citation(s) in RCA: 51] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
Individuals with systemic autoantibody-mediated diseases such as lupus have polyclonal T and B cell activation. Yet, autoantibody production is restricted to certain autoantigens. The mechanisms underlying this phenomenon remain unclear. We propose three potential mechanisms by which autoreactive helper T cell responses diversify to become polyclonal, yet are restricted to certain antigens. First, using a model where self-Ig peptides spontaneously activate T cells and modulate disease in lupus mice, we demonstrate that the numbers of autoantibody-augmenting T helper peptides increased across the Ig molecule as mice aged ("intramolecular determinant spreading"). Secondly, a single T cell hybridoma established from a (NZB x NZW)F1 mouse immunized with one self-Ig peptide recognized several Ig-derived determinants, which had little sequence homology with the immunizing peptide. Such determinant degeneracy can lead to polyclonality. To explore a mechanism for restriction to certain autoantigens, a protein database search was done for homologies with sequences of selected stimulatory Ig peptides. Identical sequences of such determinants were not found in murine proteins other than Ig. These occurred infrequently in nonautoantibody Ig, but quite commonly in lupus-related autoantibodies such as antibodies to DNA, cardiolipin, and erythrocytes. Thus, determinant spreading and degenerate recognition in T cells coupled with recurring use of T cell determinant sequences among autoantibodies result in polyclonality that is restricted to certain autoantigens.
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Affiliation(s)
- R R Singh
- Autoimmunity and Tolerance Laboratory, Department of Medicine, UCLA, Los Angeles, California 90095, USA.
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83
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Takeda Y, Wise KS, Wang G, Grady G, Hess EV, Sharp GC, Dynan WS, Hardin JA. Human autoantibodies recognizing a native macromolecular structure composed of Sm core proteins in U small nuclear RNP particles. ARTHRITIS AND RHEUMATISM 1998; 41:2059-67. [PMID: 9811062 DOI: 10.1002/1529-0131(199811)41:11<2059::aid-art22>3.0.co;2-q] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
OBJECTIVE Monoclonal antibody (mAb) F78 recognizes a heat-labile particle composed of Sm core proteins designated F78P. The objective of this study was to identify human autoantibodies recognizing the conformational structure of F78P. METHODS Immunoblots using HeLa cell extracts without heating prior to sodium dodecyl sulfate-polyacrylamide gel electrophoresis were used to identify autoantibodies recognizing F78P. To confirm reactivities with F78P, immunoprecipitates of mAb F78 were used as a substrate for immunoblots. To identify reactivities against the F78P structure in classic anti-Sm-positive sera, autoantibodies to individual Sm core proteins were absorbed with purified U1 small nuclear RNP before immunoblotting. RESULTS We identified 2 sera that, like F78, recognized only F78P and not its component polypeptides. When classic anti-Sm antibodies were preabsorbed, the presence of F78-like, particle-specific antibodies was revealed in all of the anti-Sm-positive sera tested. CONCLUSION Autoantibodies against the F78P structure were commonly present in sera from patients with systemic rheumatic diseases, often in combination with4=1998 M autoantibodies.
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Affiliation(s)
- Y Takeda
- Medical College of Georgia Institute of Molecular Medicine and Genetics, Augusta 30912, USA
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84
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Kuwana M, Kaburaki J, Ikeda Y. Autoreactive T cells to platelet GPIIb-IIIa in immune thrombocytopenic purpura. Role in production of anti-platelet autoantibody. J Clin Invest 1998; 102:1393-402. [PMID: 9769332 PMCID: PMC508987 DOI: 10.1172/jci4238] [Citation(s) in RCA: 163] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
T cell proliferative responses to platelet membrane GPIIb-IIIa were examined in 14 patients with chronic immune thrombocytopenic purpura (ITP), 7 systemic lupus erythematosus (SLE) patients with or without thrombocytopenia, and 10 healthy donors. Although peripheral blood T cells from all subjects failed to respond to the protein complex in its native state, reduced GPIIb-IIIa stimulated T cells from three ITP patients and one SLE patient with thrombocytopenia, and tryptic peptides of GPIIb-IIIa stimulated T cells from nearly all subjects. The specificity of the responses for GPIIb-IIIa was confirmed by activation of GPIIb-IIIa-primed T cells by a recombinant GPIIbalpha fragment in secondary cultures. Characterization of T cell response induced by modified GPIIb-IIIa showed that the response was restricted by HLA-DR, the responding T cells had a CD4(+) phenotype, and the proliferation was accelerated only in ITP patients, suggesting in vivo activation of these T cells. In vitro IgG anti-GPIIb-IIIa synthesis in PBMC cultures was induced by modified GPIIb-IIIa specifically in ITP patients with platelet-associated anti-GPIIb-IIIa antibody. Anti-GPIIb-IIIa antibody produced in supernatants was absorbed by incubation with normal platelets. In summary, CD4(+) and HLA-DR-restricted T cells to GPIIb-IIIa are involved in production of anti-platelet autoantibody in ITP patients and are related to the pathogenic process in chronic ITP.
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Affiliation(s)
- M Kuwana
- Department of Internal Medicine, Keio University School of Medicine, Tokyo 160-8582, Japan.
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85
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Singh RR, Hahn BH. Reciprocal T-B determinant spreading develops spontaneously in murine lupus: implications for pathogenesis. Immunol Rev 1998; 164:201-8. [PMID: 9795777 DOI: 10.1111/j.1600-065x.1998.tb01221.x] [Citation(s) in RCA: 44] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Recent work from several laboratories has shown that, in contrast to the widely held notion that one autoimmune disease is caused by one or a few related autoantigenic determinants, autoimmunity is fundamentally a continuously evolving process. The autoimmune responses shift, drift and diversify with time not only to other determinants in the original antigen but also to other antigens. We have described a form of determinant spreading--reciprocal T-B determinant spreading--where the induction of first T cells by peptides from an autoantibody molecule could lead to help provided to a variety of B cells displaying a cross-reactive version of the original determinant. The response spreads in this way by reciprocal T-B stimulation until large cohorts of T and B cells have expanded. Such spontaneous expansion must be important in clinical disease, since tolerance induction to a limited set of T-cell determinant peptides derived from an anti-DNA antibody VH region delayed the appearance of IgG anti-dsDNA antibodies and onset of lupus nephritis in the NZB/NZW F1 mouse model of systemic lupus erythematosus. Understanding the diversification patterns in autoimmune responses has enormous implications in developing peptide-targeted therapies.
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Affiliation(s)
- R R Singh
- Department of Medicine, University of California, Los Angeles 90095-1670, USA.
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86
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Abstract
Systemic lupus erythematosus (SLE) is an autoimmune rheumatic disease characterized by the deposition of autoantibodies and immune complexes, leading to tissue damage. The immunopathogenesis of SLE is like a jigsaw puzzle, some pieces of which are missing or have not fallen into place. In predisposed individuals, the initial stimulus is likely to be one or more of the environmental agents interacting with susceptibility genes. Once the critical threshold is breached there is a failure of the immune system to downregulate the ensuing abnormal immune response, involving polyclonal B cell activation and hyperactive T cell help. Key questions include, what are the processes behind the availability of autoantigens and the breakdown of tolerance that give rise to the pathogenic autoantibodies? Current areas of research also involve the roles played by cytokines, adhesion molecules, co-stimulatory molecules and apoptosis.
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Affiliation(s)
- L J Mason
- Bloomsbury Rheumatology Unit, Department of Medicine, University College London, UK
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87
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Utz PJ, Anderson P. Posttranslational protein modifications, apoptosis, and the bypass of tolerance to autoantigens. ARTHRITIS AND RHEUMATISM 1998; 41:1152-60. [PMID: 9663470 DOI: 10.1002/1529-0131(199807)41:7<1152::aid-art3>3.0.co;2-l] [Citation(s) in RCA: 156] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Affiliation(s)
- P J Utz
- Brigham and Women's Hospital, Boston, Massachusetts 02115, USA
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88
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Affiliation(s)
- J S Smolen
- Ludwig Boltzmann-Institute for Rheumatology, and University of Vienna, Austria
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89
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Fatenejad S, Bennett M, Moslehi J, Craft J. Influence of antigen organization on the development of lupus autoantibodies. ARTHRITIS AND RHEUMATISM 1998; 41:603-12. [PMID: 9550469 DOI: 10.1002/1529-0131(199804)41:4<603::aid-art7>3.0.co;2-e] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
OBJECTIVE To investigate the reason for grouping of antibodies against small nuclear RNP (snRNP) particles, which are major autoantigens in systemic lupus erythematosus (SLE). METHODS Mice were immunized with biochemically purified native snRNP particles or recombinant proteins, followed by assessment of antibody and T cell responses. Since mouse (self) snRNPs are not immunogenic in mice, a eukaryotic expression vector was constructed to induce high-level expression of the human U1 snRNP-associated A protein in murine cells. Native chimeric (mouse/human) snRNP particles were used to immunize normal mice of both H-2k and H-2b backgrounds. We also disrupted the native snRNPs by digestion with ribonuclease and used this mixture of proteins to immunize mice. RESULTS Immunization with native chimeric snRNPs resulted in the development of antibodies against a set of snRNP-associated proteins, a response which was accompanied by breakdown in T cell tolerance to mouse snRNPs in mice immunized with chimeric snRNPs. We also demonstrated that the ordered production of these antibodies was due to the fact that snRNP-associated proteins are grouped together in snRNP particles, since disruption of the particles resulted in development of antibodies in a random order, distinct from antibodies seen with intact particles. CONCLUSION Our findings directly demonstrate that the pattern of development of antibodies to native snRNPs is similar to that which is commonly observed in SLE, and that disruption of the particles results in disappearance of this ordered pattern. These results suggest that the autoimmune response to snRNPs, and possibly to other autoantigens, in lupus is a specific reaction similar to that seen in a typical immune response to foreign immunogens.
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Affiliation(s)
- S Fatenejad
- Yale University School of Medicine, New Haven, Connecticut 06520-8031, USA
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90
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Utz PJ, Hottelet M, van Venrooij WJ, Anderson P. Association of phosphorylated serine/arginine (SR) splicing factors with the U1-small ribonucleoprotein (snRNP) autoantigen complex accompanies apoptotic cell death. J Exp Med 1998; 187:547-60. [PMID: 9463405 PMCID: PMC2212144 DOI: 10.1084/jem.187.4.547] [Citation(s) in RCA: 67] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/1997] [Revised: 11/21/1997] [Indexed: 02/06/2023] Open
Abstract
Proteins subject to proteolysis or phosphorylation during apoptosis are commonly precipitated by autoantibodies found in the serum of patients with systemic lupus erythematosus (SLE). We screened a panel of murine monoclonal and human monospecific sera reactive with known autoantigens for their ability to selectively precipitate phosphoproteins from apoptotic Jurkat T cell lysates. Sera known to recognize the U1-small nuclear ribonucleoprotein (snRNP) complex (confirmed by their ability to precipitate U1-snRNA) selectively precipitated a phosphoprotein complex (pp54, pp42, pp34, and pp23) from apoptotic lysates. Monoclonal antibodies reactive with U1-snRNP proteins precipitated the same phosphoprotein complex from apoptotic lysates. The phosphorylation and/or recruitment of these proteins to the U1-snRNP complex is induced by multiple apoptotic stimuli (e.g., Fas ligation, gamma irradiation, or UV irradiation), and is blocked by overexpression of bcl-2. The U1-snRNP-associated phosphoprotein complex is immunoprecipitated by monoclonal antibodies reactive with serine/arginine (SR) proteins that comprise a structurally related family of splicing factors. The association of phosphorylated SR proteins with the U1-snRNP complex in cells undergoing apoptosis suggests a mechanism for regulation of alternative splicing of apoptotic effector molecules.
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Affiliation(s)
- P J Utz
- Department of Medicine, Division of Rheumatology, Immunology, and Allergy, Brigham & Women's Hospital, Boston, Massachusetts 02115, USA
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