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Yang Z, Wang H, Liu Y, Feng Y, Xiang Y, Li J, Shan Z, Teng W. The expression of anti-protein disulfide isomerase A3 autoantibody is associated with the increased risk of miscarriage in euthyroid women with thyroid autoimmunity. Int Immunopharmacol 2022; 104:108507. [PMID: 34996009 DOI: 10.1016/j.intimp.2021.108507] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2021] [Revised: 11/30/2021] [Accepted: 12/28/2021] [Indexed: 02/07/2023]
Abstract
Miscarriage frequently occurs in euthyroid women with thyroid autoimmunity (TAI), but its mechanisms remain unclear. Our previous study has found that the serum level of anti-protein disulfide isomerase A3 autoantibody (PDIA3Ab) was significantly increased in mice with TAI. This study was aimed to explore whether there could be an association between the expression of PDIA3Ab and the occurrence of miscarriage in euthyroid TAI women. It was found that the serum level of PDIA3Ab was significantly increased in euthyroid TAI women as compared with that of non-TAI controls. Especially, serum PDIA3Ab level was markedly higher in euthyroid TAI women with miscarriage than the ones without miscarriage. Furthermore, binary logistic regression analysis showed that the serum PDIA3Ab level was an independent risk factor for spontaneous abortion in euthyroid TAI women with an odds ratio of 13.457 (95% CI, 2.965-61.078). The receiver operating characteristic (ROC) analysis of serum PDIA3Ab expression for predicting the miscarriage in euthyroid TAI women showed that the area under the curve was 0.707 ± 0.05 (P < 0.001). The optimal cut-off OD450 value of serum PDIA3Ab was 0.7129 with a sensitivity of 52.5% and specificity of 86.3% in euthyroid TAI women. Trend test showed that the prevalence of spontaneous abortion was markedly increased with the rise of serum PDIA3Ab level among TAI women in a titer-dependent manner. In conclusion, serum PDIA3Ab expression may imply an increased risk of spontaneous abortion in euthyroid TAI women, and it can be used as a new predictive bio-marker.
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Affiliation(s)
- Zheng Yang
- Department of Endocrinology and Metabolism, Institute of Endocrinology, NHC Key Laboratory of Diagnosis and Treatment of Thyroid Diseases, The First Affiliated Hospital of China Medical University, Shenyang 110001, PR China
| | - Haoyu Wang
- Department of Endocrinology and Metabolism, Institute of Endocrinology, NHC Key Laboratory of Diagnosis and Treatment of Thyroid Diseases, The First Affiliated Hospital of China Medical University, Shenyang 110001, PR China
| | - Yifu Liu
- Department of Endocrinology and Metabolism, Institute of Endocrinology, NHC Key Laboratory of Diagnosis and Treatment of Thyroid Diseases, The First Affiliated Hospital of China Medical University, Shenyang 110001, PR China
| | - Yan Feng
- Department of Endocrinology and Metabolism, Institute of Endocrinology, NHC Key Laboratory of Diagnosis and Treatment of Thyroid Diseases, The First Affiliated Hospital of China Medical University, Shenyang 110001, PR China; Gastroenterology Tumor and Microenvironment Laboratory, Department of Gastroenterology, The First Affiliated Hospital of Chengdu Medical College, Chengdu 610000, PR China
| | - Yang Xiang
- Department of Endocrinology and Metabolism, Institute of Endocrinology, NHC Key Laboratory of Diagnosis and Treatment of Thyroid Diseases, The First Affiliated Hospital of China Medical University, Shenyang 110001, PR China; Department of Endocrinology, The First Affiliated Hospital of Zhejiang University, Hangzhou 310003, PR China
| | - Jing Li
- Department of Endocrinology and Metabolism, Institute of Endocrinology, NHC Key Laboratory of Diagnosis and Treatment of Thyroid Diseases, The First Affiliated Hospital of China Medical University, Shenyang 110001, PR China.
| | - Zhongyan Shan
- Department of Endocrinology and Metabolism, Institute of Endocrinology, NHC Key Laboratory of Diagnosis and Treatment of Thyroid Diseases, The First Affiliated Hospital of China Medical University, Shenyang 110001, PR China
| | - Weiping Teng
- Department of Endocrinology and Metabolism, Institute of Endocrinology, NHC Key Laboratory of Diagnosis and Treatment of Thyroid Diseases, The First Affiliated Hospital of China Medical University, Shenyang 110001, PR China
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Experimental evidence for alpha enolase as one potential autoantigen in the pathogenesis of both autoimmune thyroiditis and its related encephalopathy. Int Immunopharmacol 2020; 85:106563. [PMID: 32442899 DOI: 10.1016/j.intimp.2020.106563] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2020] [Revised: 04/26/2020] [Accepted: 05/03/2020] [Indexed: 11/24/2022]
Abstract
Alpha-enolase (ENO1) is a ubiquitous protein. Patients with autoimmune thyroiditis-associated encephalopathy have high serum ENO1Ab titers. We aimed to explore whether ENO1Ab was the pathogenic antibody in the thyroid and brain. The serum ENO1Ab titers were significantly increased in the mice immunized with Thyroglobulin (Tg). And in the mice immunized with ENO1, serum levels of both TgAb and thyroid-stimulating hormone (TSH) were significantly increased. Obvious CD16+ cell infiltration, IgG deposit and cleaved caspase-3 were observed in the thyroid of ENO1-immunized mice. Spatial learning and memory abilities and synaptic functions were impaired in ENO1-immunized mice. Furthermore, the expression levels of Iba-1, GFAP, interlukin-6, CDK5, and phosphorylated tau were increased, and endothelial tight junction proteins were decreased in the brain of ENO1-immunized mice. These results suggest that ENO1Ab can cause thyrocyte damage via ADCC effect and impair cerebral function by disrupting the blood-brain barrier.
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3
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Yang W, Xiang Y, Zhang H, Shan Z, Li J, Teng W. The role of protein disulphide-isomerase A3 as autoantigen in the pathogenesis of autoimmune thyroiditis and related brain damage in adult mice. Clin Immunol 2020; 212:108350. [PMID: 31982645 DOI: 10.1016/j.clim.2020.108350] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2019] [Revised: 01/17/2020] [Accepted: 01/23/2020] [Indexed: 01/26/2023]
Abstract
Autoimmune thyroiditis (AIT)-related brain damage is one of most severe extrathyroidal manifestations of AIT, but the mechanism remains unclear. In this study, we confirmed that protein disulfide-isomerase A3 (PDIA3) is expressed in both thyroid and brain tissues of mouse, and found the significantly increased serum levels of anti-PDIA3 antibody (PDIA3Ab) in classical mouse models of thyroiditis. In addition, we investigated the PDIA3-specific autoimmune reaction in thyroid and brain tissues in a mouse model with high-serum PDIA3Ab induced by immunization with recombinant PDIA3 protein. PDIA3-immunized mice had elevated serum thyrotropin and impaired learning and memory. PDIA3-expressing cells had IgG deposition, and IgG colocalized with C3 in the thyroid and brain tissues of PDIA3-immunized mice, resulting in membrane attack complex formation. Our results suggest that PDIA3 protein may be a common autoantigen shared by the thyroid and brain tissues and involve in the thyroidal and intracerebral damage through activating complement system.
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Affiliation(s)
- Wenqing Yang
- Department of Endocrinology and Metabolism, Institute of Endocrinology, Liaoning Provincial Key Laboratory of Endocrine Diseases, The First Affiliated Hospital of China Medical University, Shenyang 110001, PR China
| | - Yang Xiang
- Department of Endocrinology and Metabolism, Institute of Endocrinology, Liaoning Provincial Key Laboratory of Endocrine Diseases, The First Affiliated Hospital of China Medical University, Shenyang 110001, PR China
| | - Hongmei Zhang
- Department of Endocrinology and Metabolism, Institute of Endocrinology, Liaoning Provincial Key Laboratory of Endocrine Diseases, The First Affiliated Hospital of China Medical University, Shenyang 110001, PR China
| | - Zhongyan Shan
- Department of Endocrinology and Metabolism, Institute of Endocrinology, Liaoning Provincial Key Laboratory of Endocrine Diseases, The First Affiliated Hospital of China Medical University, Shenyang 110001, PR China
| | - Jing Li
- Department of Endocrinology and Metabolism, Institute of Endocrinology, Liaoning Provincial Key Laboratory of Endocrine Diseases, The First Affiliated Hospital of China Medical University, Shenyang 110001, PR China.
| | - Weiping Teng
- Department of Endocrinology and Metabolism, Institute of Endocrinology, Liaoning Provincial Key Laboratory of Endocrine Diseases, The First Affiliated Hospital of China Medical University, Shenyang 110001, PR China.
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4
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Kiseleva EP, Mikhailopulo KI, Zdorovenko EL, Knirel YA, Novik GI. Linear α-(1 → 6)-d-glucan from Bifidobacterium bifidum BIM В-733D is low molecular mass biopolymer with unique immunochemical properties. Carbohydr Res 2017; 466:39-50. [PMID: 29422338 DOI: 10.1016/j.carres.2017.12.008] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2017] [Revised: 12/02/2017] [Accepted: 12/19/2017] [Indexed: 11/24/2022]
Abstract
Role of microorganisms in induction of/protection from autoimmune diseases is proven though molecular mechanisms and bacterial/viral/yeast biopolymers responsible for these effects are in the research stage. Autoantobodies (AAbs) to thyroid peroxidase (anti-TPO) and thyroglobulin (anti-Tg) as well as AAbs to transglutaminase 2 (anti-TG2) and antibodies to gliadins (anti-gliadins) are serological markers of autoimmune thyroid disease and celiac disease, respectively, and players in pathogenesis of these autoimmune diseases. In current study, biopolymer of Bifidobacterium bifidum BIM В-733D that interacts selectively with anti-gliadins (Bb-Ganti-gliadins) was isolated by affinity chromatography with anti-gliadins, purified by size exclusion chromatography on TSK 40 gel and identified by NMR as linear α-(1 → 6)-d-glucan with molecular mass about 5000 Da. It was proven that compounds Bb-Ganti-gliadins and Bb-Ganti-TPO/Bb-Ganti-Tg isolated early from the same strain [Kiseleva, E. P. et al., Benef Microbes.2013, 4, 375 -391] are the same substance designated GBb. Its unique immunochemical property is the ability to interact selectively with anti-TPO, anti-Tg, anti-TG2 and anti-gliadins in presence of no less than 10-fold excess of total immunoglobulins of class G (tIgG), as it was proven by ELISA. Synthesis of GBb-bovine serum albumin (GBb-BSA) conjugate is an example of increasing the reliability and reproducibility of ELISA results by mediated immobilization of a polysaccharide covalently attached to a well-adsorbed protein. Taking into account that there are population of bispecific anti-gliadins (anti-gliadins and anti-TG2 simultaneously) we regard our data as first argument in favor of hypothesis that GBb differentiates between human AAbs per se and other human Ig (e.g. antibodies to antigens of infectious agents) due to its binding with a yet unidentified site which is present in the molecules of all AAbs (independently on their specificity) and absent in other human Igs.
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Affiliation(s)
- Elena P Kiseleva
- Institute of Bioorganic Chemistry, National Academy of Sciences of Belarus, Minsk, Belarus.
| | | | - Evelina L Zdorovenko
- N.D. Zelinsky Institute of Organic Chemistry, Russian Academy of Sciences, Moscow, Russia
| | - Yuriy A Knirel
- N.D. Zelinsky Institute of Organic Chemistry, Russian Academy of Sciences, Moscow, Russia
| | - Galina I Novik
- Institute of Microbiology, National Academy of Sciences of Belarus, Minsk, Belarus
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McLachlan SM, Rapoport B. Thyroid Autoantibodies Display both "Original Antigenic Sin" and Epitope Spreading. Front Immunol 2017; 8:1845. [PMID: 29326719 PMCID: PMC5742354 DOI: 10.3389/fimmu.2017.01845] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2017] [Accepted: 12/06/2017] [Indexed: 11/13/2022] Open
Abstract
Evidence for original antigenic sin in spontaneous thyroid autoimmunity is revealed by autoantibody interactions with immunodominant regions on thyroid autoantigens, thyroglobulin (Tg), thyroid peroxidase (TPO), and the thyrotropin receptor (TSHR) A-subunit. In contrast, antibodies induced by immunization of rabbits or mice recognize diverse epitopes. Recognition of immunodominant regions persists despite fluctuations in autoantibody levels following treatment or over time. The enhancement of spontaneously arising pathogenic TSHR antibodies in transgenic human thyrotropin receptor/NOD.H2h4 mice by injecting a non-pathogenic form of TSHR A-subunit protein also provides evidence for original antigenic sin. From other studies, antigen presentation by B cells, not dendritic cells, is likely responsible for original antigenic sin. Recognition of restricted epitopes on the large glycosylated thyroid autoantigens (60-kDa A-subunit, 100-kDa TPO, and 600-kDa Tg) facilitates exploring the amino acid locations in the immunodominant regions. Epitope spreading has also been revealed by autoantibodies in thyroid autoimmunity. In humans, and in mice that spontaneously develop autoimmunity to all three thyroid autoantigens, autoantibodies develop first to Tg and later to TPO and the TSHR A-subunit. The pattern of intermolecular epitope spreading is related in part to the thyroidal content of Tg, TPO and TSHR A-subunit and to the molecular sizes of these proteins. Importantly, the epitope spreading pattern provides a rationale for future antigen-specific manipulation to block the development of all thyroid autoantibodies by inducing tolerance to Tg, first in the autoantigen cascade. Because of its abundance, Tg may be the autoantigen of choice to explore antigen-specific treatment, preventing the development of pathogenic TSHR antibodies.
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Affiliation(s)
- Sandra M McLachlan
- Thyroid Autoimmune Disease Unit, Cedars-Sinai Medical Center, UCLA School of Medicine, Los Angeles, CA, United States
| | - Basil Rapoport
- Thyroid Autoimmune Disease Unit, Cedars-Sinai Medical Center, UCLA School of Medicine, Los Angeles, CA, United States
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6
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Kiseleva EP, Mikhailopulo KI, Novik GI, Szwajcer Dey E, Zdorovenko EL, Shashkov AS, Knirel YA. Isolation and structural identification of glycopolymers of Bifidobacterium bifidum BIM B-733D as putative players in pathogenesis of autoimmune thyroid diseases. Benef Microbes 2013; 4:375-391. [PMID: 24311320 DOI: 10.3920/bm2013.0015] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/15/2024]
Abstract
Bifidobacterium bifidum 791 (commercially available as B. bifidum BIM B-733D) cell-surface biopolymers (BPs) interact selectively with human serum thyroid peroxidase (TPO) and thyroglobulin (Tg) autoantibodies (anti TPO and anti Tg, respectively). BPanti-TPO and BPanti-Tg were isolated from the soluble fraction of B. bifidum BIM B-733D by affinity chromatography with anti-TPO or anti-Tg, respectively. Homogeneity of affinity eluates (AEanti-TPO and AEanti-Tg) was tested by size exclusion chromatography. For each AE, the elution profiles generated on the basis of absorbance at 280 nm do not conform to ELISA data for functional activity characteristic of BPs. Moreover, high functional activity was detected in chromatographic fractions that had significantly different molecular weights and no absorbance at 280 nm, which suggests a non-protein (carbohydrate) nature of BPanti-TPO and BPanti-Tg. The semi-preparative size exclusion chromatography of AEanti-TPO and AEanti-Tg with detection by refractometer gave 5,000-7,000 Da fractions containing substances that interact selectively with either anti TPO (BPanti-TPO) or anti-Tg (BPanti-Tg) according to ELISA data. Analysis by two-dimensional NMR spectroscopy including a 1H, 13C-heteronuclear single-quantum coherence experiment indicated that both substances are linear α-1,6-glucans. For the first time, an immunological similarity (molecular mimicry) of glycopolymers of B. bifidum BIM B-733D and human thyroid proteins, TPO and Tg, was shown. On the whole, our data point to a possible role of bifidobacteria in the pathogenesis of autoimmune thyroid diseases (ATD). The main requirements for triggering/acceleration or prevention/abrogation of ATD by bifidobacteria through molecular mimicry mechanism are hypothesised to be (1) genetic predisposition to ATD and (2) intestinal epithelium penetration by α-1,6-glucan.
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MESH Headings
- Antigens, Bacterial/chemistry
- Antigens, Bacterial/immunology
- Antigens, Bacterial/isolation & purification
- Antigens, Bacterial/metabolism
- Autoantibodies/metabolism
- Autoimmune Diseases/etiology
- Autoimmune Diseases/microbiology
- Bifidobacterium/chemistry
- Bifidobacterium/immunology
- Chromatography, Affinity
- Chromatography, Gel
- Humans
- Iodide Peroxidase/immunology
- Magnetic Resonance Spectroscopy
- Molecular Weight
- Polysaccharides, Bacterial/chemistry
- Polysaccharides, Bacterial/immunology
- Polysaccharides, Bacterial/isolation & purification
- Polysaccharides, Bacterial/metabolism
- Protein Binding
- Thyroglobulin/immunology
- Thyroid Diseases/etiology
- Thyroid Diseases/microbiology
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Affiliation(s)
- E P Kiseleva
- The Institute of Bioorganic Chemistry, National Academy of Sciences of Belaru, Acad. Kuprevicha 5/2, 220141 Minsk, Republic of Belarus
| | - K I Mikhailopulo
- The Institute of Bioorganic Chemistry, National Academy of Sciences of Belaru, Acad. Kuprevicha 5/2, 220141 Minsk, Republic of Belarus
| | - G I Novik
- The Institute of Microbiology, National Academy of Sciences of Belarus, Acad. Kuprevicha 5/2, 220141 Minsk, Republic of Belarus
| | - E Szwajcer Dey
- Division of Pure and Applied Biochemistry, Lund University, P.O. Box 124, 22100 Lund, Sweden
| | - E L Zdorovenko
- N.D. Zelinsky Institute of Organic Chemistry, Russian Academy of Sciences, Leninsky prospekt 47, 119991 Moscow, Russia
| | - A S Shashkov
- N.D. Zelinsky Institute of Organic Chemistry, Russian Academy of Sciences, Leninsky prospekt 47, 119991 Moscow, Russia
| | - Y A Knirel
- N.D. Zelinsky Institute of Organic Chemistry, Russian Academy of Sciences, Leninsky prospekt 47, 119991 Moscow, Russia
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7
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Hayward SL, Suzuki K, Elliott JF. A radioligand binding assay to measure anti-thyroperoxidase autoantibodies in mice. J Immunol Methods 2007; 323:114-22. [PMID: 17482640 DOI: 10.1016/j.jim.2007.04.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2006] [Revised: 03/06/2007] [Accepted: 04/02/2007] [Indexed: 10/23/2022]
Abstract
Autoimmune (Hashimoto's) thyroiditis is a chronic inflammatory disease which affects >3% of the population and shows an increasing prevalence with increasing age. Anti-thyroid autoantibodies, particularly against thyroperoxidase (also known as thyroid peroxidase or TPO), occur commonly in humans with autoimmune thyroid disease, and assays for anti-TPO autoantibodies are used in clinical diagnosis. In contrast anti-TPO autoantibodies have not been observed in classical mouse models of autoimmune thyroiditis, except in cases where mice were deliberately immunized with TPO. In the past, detection of anti-TPO autoantibodies in mice has relied on an indirect immunofluorescence assay (iIFA) which screens for thyroid follicle membrane staining in frozen sections of mouse thyroid glands. Since recent transgenic mouse models of autoimmune thyroiditis spontaneously develop anti-TPO autoantibodies, an assay other than serial dilution and iIFA would be useful to detect and quantify these autoantibodies. In this paper we describe such an assay, based on the capacity of autoimmune mouse sera to bind to the extracellular domain of mouse TPO which was produced in a radioactively labeled form using a coupled in vitro transcription/translation system. The same approach, using human TPO, could provide a highly sensitive method to detect anti-TPO autoantibodies in humans.
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Affiliation(s)
- Sarah L Hayward
- Department of Medical Microbiology and Immunology, University of Alberta, Edmonton, Alberta, Canada
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Thrasyvoulides A, Liakata E, Lymberi P. Spreading of antibody reactivity to non-thyroid antigens during experimental immunization with human thyroglobulin. Clin Exp Immunol 2006; 147:120-7. [PMID: 17177971 PMCID: PMC1810443 DOI: 10.1111/j.1365-2249.2006.03246.x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022] Open
Abstract
Intermolecular spreading of antibody reactivity has been implicated in the evolution of autoimmune disease. In this study, spreading of antibody reactivity to non-thyroid autoantigens after experimental immunization with thyroglobulin (Tg) was investigated. For this purpose, two rabbits were injected with human Tg six times (stages 1-6) every 3 weeks. Animals were also bled before priming. Antisera were tested by enzyme-linked immunosorbent assay (ELISA) for reactivity to several non-thyroid antigens: bovine serum albumin (BSA), native DNA (nDNA), human myosin, human globular (G) and filamentous (F) actin and porcine tubulin. Tg-immunized animals developed the following serological reactivity pattern: (a) high reactivity to myosin from stage 2 onward, (b) significant reactivity to F-actin, remaining high up to stage 6, (c) reactivity to BSA with a peak at stage 3, (d) a small increase of reactivity to G-actin at stage 3 and (e) no increase of reactivity to nDNA and tubulin. The study of affinity-purified anti-Tg antibodies and the use of competitive assays revealed that reactivity to F-actin was not due to cross-reaction with Tg. On the contrary, reactivity to myosin during the first stages of immunization was due to cross-reaction with Tg, while at stage 6 it became myosin-specific. Reactivity to BSA at stage 3 was also due to cross-reaction with Tg. We conclude that at least part of the induced anti-Tg antibodies may result from the expansion of B cell clones producing polyreactive natural autoantibodies, and polyreactivity of anti-Tg antibodies during the first stages of Tg-immunization may be responsible for the intermolecular spreading of antibody response.
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Affiliation(s)
- A Thrasyvoulides
- Laboratory of Immunology, Department of Biochemistry, Hellenic Pasteur Institute, Athens, Greece
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Klitgaard JL, Coljee VW, Andersen PS, Rasmussen LK, Nielsen LS, Haurum JS, Bregenholt S. Reduced Susceptibility of Recombinant Polyclonal Antibodies to Inhibitory Anti-Variable Domain Antibody Responses. THE JOURNAL OF IMMUNOLOGY 2006; 177:3782-90. [PMID: 16951339 DOI: 10.4049/jimmunol.177.6.3782] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
The immunogenicity of therapeutic Abs is a concern as anti-drug Abs may impact negatively on the pharmacodynamics and safety profile of Ab drugs. The factors governing induction of anti-drug Abs are not fully understood. In this study, we describe a model based on mouse-human chimeric Abs for the study of Ab immunogenicity in vivo. Six chimeric Abs containing human V regions and mouse C regions were generated from six human anti-Rhesus D Abs and the Ag-binding characteristics of the parental human Abs were retained. Analysis of the immune response toward the individual chimeric Abs revealed the induction of anti-variable domain Abs including anti-idiotypic Abs against some of these, thereby demonstrating the applicability of the model for studying anti-drug Ab responses in vivo. Immunization of BALB/c, C57, and outbred NMRI mice with a polyclonal composition consisting of all six chimeric Abs demonstrated that the immunogenicity of the individual Abs was haplotype dependent. Chimeric Abs, which were nonimmunogenic when administered individually, did not become immunogenic as part of the polyclonal composition, implying the absence of epitope spreading. Ex vivo Ab-binding studies established a clear correlation between the level of immunogenicity of the Abs comprised in the composition and the impact on the pharmacology of the Abs. These analyses demonstrate that under these conditions this polyclonal Ab composition was generally less susceptible to blocking Abs than the respective mAbs.
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MESH Headings
- Amino Acid Sequence
- Animals
- Antibodies, Anti-Idiotypic/administration & dosage
- Antibodies, Anti-Idiotypic/biosynthesis
- Antibodies, Anti-Idiotypic/metabolism
- Antibodies, Blocking/pharmacology
- Antibodies, Monoclonal/administration & dosage
- Antibodies, Monoclonal/metabolism
- Binding Sites, Antibody/genetics
- Female
- Humans
- Immune Sera/metabolism
- Immunoglobulin G/metabolism
- Immunoglobulin Variable Region/administration & dosage
- Immunoglobulin Variable Region/genetics
- Immunoglobulin Variable Region/immunology
- Immunoglobulin Variable Region/metabolism
- Mice
- Mice, Inbred BALB C
- Mice, Inbred C57BL
- Molecular Sequence Data
- Protein Structure, Tertiary/genetics
- Recombinant Fusion Proteins/administration & dosage
- Recombinant Fusion Proteins/immunology
- Recombinant Fusion Proteins/metabolism
- Rh-Hr Blood-Group System/immunology
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Ruf J, Carayon P. Structural and functional aspects of thyroid peroxidase. Arch Biochem Biophys 2005; 445:269-77. [PMID: 16098474 DOI: 10.1016/j.abb.2005.06.023] [Citation(s) in RCA: 123] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2005] [Revised: 06/16/2005] [Accepted: 06/20/2005] [Indexed: 10/25/2022]
Abstract
Thyroperoxidase (TPO) is the enzyme involved in thyroid hormone synthesis. Although many studies have been carried out on TPO since it was first identified as being the thyroid microsomal antigen involved in autoimmune thyroid disease, previous authors have focused more on the immunological than on the biochemical aspects of TPO during the last few years. Here, we review the latest contributions in the field of TPO research and provide a large reference list of original publications. Given this promising background, scientists and clinicians will certainly continue in the future to investigate the mechanisms whereby TPO contributes to hormone synthesis and constitutes an important autoantigen involved in autoimmune thyroid disease, and the circumstances under which the normal physiological function of this enzyme takes on a pathological role.
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Affiliation(s)
- Jean Ruf
- INSERM Unit U555, Faculté de Médecine Timone, Université de la Méditerranée, Marseille, France.
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