Causal Relationship Between Anti-TPO IgE and Chronic Urticaria by In Vitro and In Vivo Tests

PURPOSE: Immunoglobulin (Ig) E autoantibodies against thyroid antigens such as thyroid peroxidase (TPO) have been demonstrated in chronic spontaneous urticaria (CSU) patients in higher frequency than healthy subjects. However, if these IgE autoantibodies can trigger urticaria is still a matter of study. The aim of this study was to investigate the relationship between concomitant IgE autoantibodies against thyroid antigens in CSU. METHODS: Patients with CSU, healthy subjects and patients with autoimmune thyroid disease (ATD) were recruited. Total IgE and specific anti-TPO IgE and IgG were assessed in all subjects. The basophil activation test and skin tests with TPO were performed to demonstrate whether this antigen could selectively induce urticaria reaction in subjects with positive anti-TPO IgE. RESULTS: Anti-TPO IgE was present in all 3 groups (CSU: 34.0%, ATD: 16.6%, healthy subjects: 8.1%). Anti-TPO IgE levels were higher in CSU patients, whereas anti-TPO IgG were higher in ATD patients. After exposure to TPO, CD203c expression from patients with CSU and anti-TPO IgE significantly increased in comparison to the other groups; 33.0% vs. 14.0% in ATD patients and 9.0% in control subjects (P < 0.05). Skin reactions with TPO were higher in patients with CSU according to the intradermal (CSU: 18.0%, ATD: 3.3%, control: 8.0%) and skin prick tests (12.0%, 0%, 0%, respectively). Passive transfer of anti-TPO IgE from a CSU patient to the skin of control subjects without anti-TPO IgE induced a positive skin reaction. CONCLUSIONS: Anti-TPO IgE is not a specific biomarker for CSU. However, IgE against TPO plays a pathogenic role in inducing effector cell activation and skin exacerbation in some patients with CSU.

Research of RBP1 like protein--a novel autoantigen in RA / 中国免疫学杂志

Objective:Rheumatoid arthritis(RA) is a systemic autoimmune disease,but its etiology is unclear.Therefore,it is urgent to search antigens which is relate to induce this disease,however,there are few reports about the new self-antigens at home and abroad.In this study,we investigate new autoantigen through cloning.Methods: We used antigens in synovium of patients with rheumatoid arthritis as probe,extracted mRNA from synoviocyte,performed cDNA library immunological screening and sequence,and analyzed the conformation and performed Northern blotting.Results: We found that new autoantigen had 36.5% homology with retinoblastoma binding protein 1(RBP1)and it was found that these special protein structure such as AT-rich interaction domain,chromo domain,A+T-hook and TAF homology domain.Therefore,it will be named RBP1-like Protein(Rbik).Rbik RNA is not only expressed in the synovial membrane,but also in the heart,small intestine,muscle and other organs.Conclusion: We report that the discovery of the new autoantibodies to RBP1-like Protein(Rbik)may provide a new possible index and target in diagnosis and therapy.

Chaperonin containing T-complex protein 1 subunit epsilon (CCT5) serves as γδT cell-related autoantigen / 基础医学与临床

Objective To examine the relationship between CCT 5 ,γδ T cell and autoimmune diseases .Methods Recombinant CCT5 protein was cloned , expressed and purified in E.coli.Three peptides of CCT5 protein were used to prepare for anti-CCT5 monoclonal antibodies .Purified CCT5 protein was used to expand γδT cells from pe-ripheral blood mononuclear cells (PBMC).Plasma level of CCT5 in healthy donors, patients with rheumatoid arthritis (RA) and systemic lupus erythematosus (SLE) were detected by ELISA assays .The correlation analysis between plasma CCT5 concentration and the percentage of different subtypes of γδT cells measured by flow cytometry was made . Results The CCT5 gene was amplified by PCR and the length of the target fragment was 1 750 bp.The expressed 65 ku CCT5 protein was purified and validated by SDS-PAGE.Two paired monoclonal anti-CCT5 antibodies were screened to detect CCT5 protein in plasma.Immobilized recombinant CCT5 protein was able to induce specific sig-nificant amplification of peripheral γδT cells.Correlation analysis of 10 healthy donors indicated significant corre-lation between the plasma CCT 5 concentration and the proportion of Vγ9 and Vδ2 γδ T cells.The plasma CCT5 concentration significantly decreased in autoimmune diseases patients , including RA and SLE .Conclusions These data suggest that CCT 5 could be a novel Vγ9δ2 γδT cell-related factor in autoimmune diseases , which deepen the understanding of Vγ9δ2 γδT cell function in autoimmune diseases .

Rheumatic heart disease patients with valvular tissue autoantigen change and IL-10,TGF-β1 relationship between serum concentration changes / 中国免疫学杂志

Objective:Through the ale tissue in patients with rheumatic heart disease ( RHD) autoantigen cells change and pe-ripheral blood indicators of detection and IL-10,TGF-beta 1 discusses the relationship between serum concentration.Methods:cases of RHD patients and 63 healthy volunteers in the morning on an empty stomach acquisition anticoagulation peripheral venous blood,used flow cytometry assay of CD4+CD25+,signature molecules of regulatory T cells ( Foxp3 Treg) for testing,the proportion of the ELISA de-tection of IL-10,concentration of TGF-beta 1;Corresponding antigen gene expression library construction of rheumatic heart disease screening.Results:The autoantigen RHDAG1 has obvious differences with the control,RHD patients serum Treg ratio is lower than the control group in the sample data,IL-l0,TGF-beta 1 has the difference between the concentration of serum,compared the statistically difference between groups.Conclusion:Autoantigen RHDAG1 have certain effect on the development of the expression of RHD, the concentration and Treg cells on peripheral blood related indexes change detection has a certain clinical significance to the diagnosis of RHD.

Detection of antibodies against melanocytes in serum samples from patients with vitiligo and identifi-cation of the associated melanocyte membrane antigens / 中华微生物学和免疫学杂志

Objective To detect the autoantibodies against melanocytes in serum samples from pa-tients with vitiligo and to identify the associated membrane antigens .To detect heat shock protein 70 (HSP70) and anti-tyrosinase related protein 1 (TRP-1) antibody in serum samples and to further analyze their correlations .Methods Normal human melanocytes were cultured in vitro.Indirect immunofluorescent assay was used to locate associated antigens .Western blot assay was performed to detect autoantibodies against membrane and cytoplasmic proteins of melanocytes in 50 cases of patients with vitiligo ( including 4 cases with HBV infection ) .Membrane antigens with higher frequencies were identified with protein mass spectrometry analysis .ELISA assay was performed to detect the HSP 70 and anti-TRP-1 antibody in serum samples from 70 patients with vitiligo ( including 10 cases with HBV infection ) .Results The specific anti-gens were detected in the cytoplasm and on the membrane of melanocytes .The membrane antigens were de-tected in 40 out of 50 (80%) randomly selected serum samples as indicated by Western blot assay .The au-toantibodies could react to several membrane antigens with approximate molecular weights (Mr) of 86×103, 75×103, 60×103, 52×103 and 44×103, showing strip positive rates of 36%, 58%, 22%, 2%and 2%re-spectively.The cytoplasmic antigens with Mr of 110×103, 90×103, 75×103, 50×103 and 40×103 were ac-count for 30%of the 50 tested serum samples , showing strip positive rates of 12%, 4%, 12%, 10% and 2% respectively .The positive rates of membrane and cytoplasmic antigens were 15% and 5% respectively for health subjects.Results of protein mass spectrometry analysis indicated that membrane Mr of 86×103 and 75×103 might be Lamin A/C and the membrane protein at a Mr of 60×103 was predicted as Vimentin X1. High titers of anti-TRP-1 antibody in serum samples were detected in patients with vitiligo in combination with HBV infection, which was confirmed to have a positive correlation with HSP 70 (r=0.927, P<0.01). Conclusion A membrane antigen associated with vitiligo was newly identified which might provide evidence for the investigation on the autoimmune pathogenesis of vitiligo and the formation of autoantibodies .A prelim-inary study on the relationship between HBV infection and vitiligo was conducted through detecting the HSP70 and anti-TRP-1 antibody in serum samples .

Immunization and glaucoma / 中华实验眼科杂志

Glaucoma,the major cause of global irreversible blindness,is a chronic neurodegenerative disease of the optic nerve.Apoptosis of retinal ganglion cells (RGCs) and progressive loss of optic nerve axons results in structural and functional deficits in glaucoma patients.Growing evidence obtained from clinical and experimental studies over the last decade strongly suggests the involvement of the immune system in the neurodegenerative process of glaucoma.This review aims to provide a perspective on the complex interplay of cellular events during glaucomatous neurodegeneration that involves aberrances or dysfunctions of immune system,such as ocular immune privilege,glial activation response,T cell-mediated immune responses,autoantibody-mediated immune responses,complement fixation reaction and aging,oxidative stress.The complex interplay of cellular events amplify the primary injury process and contribute to disease progression by oxidative stress and immune response,ultimately lead to cell death with loss of RGCs.

Gastric Autoantigenic Proteins in Helicobacter Pylori Infection

PURPOSE: This study tried to identify novel gastric autoimmune antigens that might be involved in aggravating the atrophic gastritis among patients with Helicobacter pylori infection using two-dimensional immunoblotting analysis. MATERIALS AND METHODS: Proteins from gastric mucosal antrectomy specimens and AGS cells (gastric adenocarcinoma cell lines derived from a Caucasian patient who had received no prior therapy) were 2-dimensionally immunoblotted separately with a pool of 300 sera from H. pylroi-infected patients at Gyeongsang National University Hospital. RESULTS: Thirty-eight autoantigenic proteins including alcohol dehydrogenase [NADP+], alpha enolase, gastrokine-1, gastric triacylglycerol lipase, heat shock 70 kDa protein 1, and peroxiredoxin-2 were identified in the gastric mucosal tissue. Fourteen autoantigenic proteins including programmed cell death 6-interacting protein, serum albumin and T-complex protein 1 subunit gamma were identified in the AGS cells. Albumin, alpha-enolase, annexin A3, cytoplasmic actin 1, heat shock cognate 71 kDa protein and leukocyte elastase inhibitor were commonly observed autoantigenic proteins in both gastric mucosal tissue and AGS cells. Alpha-enolase, glutathione S-transferase P, heat shock cognate 71 kDa protein, heat shock 70 kDa protein 1, human mitochondrial adenosine triphosphate synthase (ATP) subunit beta, mitochondrial 60 kDa heat shock protein, peroxiredoxin-2, 78 kDa glucose-regulated protein precursor, tyrosine-protein phosphatase non-receptor type 11 and Tryptophan-Aspartic acid (WD) repeat-containing protein 1 showed 60% or higher amino acid positivity. CONCLUSION: These newly identified gastric autoimmune antigens might be useful in the control and prevention of gastroduodenal disorders, and might be valuable in breaking the vicious circle that exists in gastroduodenal disorders if their pathophysiological roles could be understood in the progress of chronic atrophic gastritis, gastroduodenal ulcers, intestinal metaplasia, and gastric carcinogenesis.

Anti-UACA autoantibody in thyroid-associated ophthalmopathy / 中华内分泌代谢杂志

Serum anti-uveal autoantigen with coiled coil domains and ankyrin repeats (UACA) antibody titer was measured using ELISA in 32 patients with thyroid-associated ophthalmopathy ( TAO ) and 20 patients with Graves' disease (GD) without ophthalmopathy.The level of anti-UACA antibody in TAO group was higher than that in GD group [ (225.91 ± 144.21 vs 187.42 ± 46.77 ) pg/ml,P＜0.05 ],and especially higher in patients with ocular myopathy [ (254.35 ± 168.29 ) pg/ml ].It seems that anti-UACA antibody is the sensitive clinical marker of ocular myopathy in TAO patients.

Most Highly Cytokinergic IgEs Have Polyreactivity to Autoantigens

PURPOSE: Monomeric IgE molecules, when bound to the high-affinity receptor, exhibit a vast heterogeneity in their ability to induce survival promotion and cytokine production in mast cells. At one end of this spectrum, highly cytokinergic (HC) IgEs can induce potent survival promotion, degranulation, cytokine production, migration, etc., whereas at the other end, poorly cytokinergic (PC) IgEs can do so inefficiently. In this study, we investigated whether IgEs recognize autoantigens and whether IgEs' binding of autoantigens correlates with difference s in HC versus PC properties. METHODS: Enzyme-linked immunosorbent assays were performed to test whether IgEs bind antigens. Histamine-releasing factor in human sera was quantified by western blotting. Cultured mast cells derived from human cord blood were used to test the effects of human sera on cytokine production. RESULTS: Most (7/8) of mouse monoclonal HC IgEs exhibited polyreactivity to double-stranded DNA (dsDNA), single-stranded DNA (ssDNA), beta-galactosidase, thyroglobulin and/or histamine-releasing factor. By contrast, mouse PC IgEs failed to react with these antigens. A human monoclonal HC IgE also showed polyreactivity to histamine-releasing factor, dsDNA and ssDNA. Interestingly, sera from atopic dermatitis patients showed increased reactivity to ssDNA and beta-galactosidase and increased levels of histamine-releasing factor. Some atopic dermatitis patients, but not healthy individuals, had substantial serum levels of HRF-reactive IgE. Sera from atopic dermatitis patients with high titers of DNA-reactive IgE could induce several fold more IL-8 secretion in human mast cells than sera from healthy individuals. CONCLUSIONS: The results show that most HC, but not PC, IgEs exhibit polyreactivity to autoantigens, supporting the autoimmune mechanism in the pathogenesis of atopic dermatitis.

SIRT1 promotes DNA repair activity and deacetylation of Ku70

Human SIRT1 controls various physiological responses including cell fate, stress, and aging, through deacetylation of its specific substrate protein. In processing DNA damage signaling, SIRT1 attenuates a cellular apoptotic response by deacetylation of p53 tumor suppressor. The present study shows that, upon exposure to radiation, SIRT1 could enhance DNA repair capacity and deacetylation of repair protein Ku70. Ectopically over-expressed SIRT1 resulted in the increase of repair of DNA strand breakages produced by radiation. On the other hand, repression of endogenous SIRT1 expression by SIRT1 siRNA led to the decrease of this repair activity, indicating that SIRT1 can regulate DNA repair capacity of cells with DNA strand breaks. In addition, we found that SIRT1 physically complexed with repair protein Ku70, leading to subsequent deacetylation. The dominant-negative SIRT1, a catalytically inactive form, did not induce deacetylation of Ku70 protein as well as increase of DNA repair capacity. These observations suggest that SIRT1 modulates DNA repair activity, which could be regulated by the acetylation status of repair protein Ku70 following DNA damage.

Cloning and characterization of promoter region of cell division autoantigen 1 / 吉林大学学报(医学版)

Objective To clone different lengths cell division autoantigen1(CDA1) promoters(CDA1P) and measure their activities in order to provide basis for fumctional study of CDA1P.Methods Different lengths CDA1P were amplified by PCR using mouse liver genomic as template and cloned into BglⅡ digested pGL3-basic plasmid to produce recombinant plasmid pGL3-basicmCDA1P,then they were transfected into Lewis lung cell line(LLC) and RAW 264.7 cells differently,these cells were collected after transfected for 48 h,finally luciferase activities of pGL3-basic-mCDA1P were measured.Results ①Different lengths CDA1P were cloned and characterized by restriction enzymes.②Different lengths CDA1P were ligated into pGL3basic vector,and were proved with PCR and DNA sequencing .③Activities of pGL3-basic-mCDA1A were different in the two kinds of Leuwis and mononuclear macrophage cells(RAW264.7 cells).Conclusion The different activities of CDA1P may be related with different cellular types.

Crucial Role of Tissue-specific Apoptosis on the Development of Primary Sjögren's Syndrome / Oral Science International

Primary Sjögren's syndrome is an autoimmune disorder characterized by lymphocytic infiltrates and destruction of the salivary and lacrimal glands, and systemic production of autoantibodies to the ribonucleoprotein (RNP) particles SS-A/Ro and SS-B/La, leading to clinical symptoms of dryness of the mouth and eyes (sicca syndrome). Autoreactive T cells bearing the CD4 molecule may recognize an unknown self antigen, triggering autoimmunity in the salivary and lacrimal glands. Although several candidate autoantigens including α-fodrin have been reported in Sjögren's syndrome, the pathogenic roles of the autoantigens in initiation and progression of SS are still unclear. It is possible that individual T cells activated by an appropriate self antigen can proliferate and form a restricted clone. Recent evidence suggests that the apoptotic pathway plays a central role in making T cells tolerant to tissue-specific self antigen, and may drive the autoimmune phenomenon. We recently reported that tissue-specific apoptosis in estrogen-deficient mice may contribute to autoantigen cleavage, leading to the development of autoimmune exocrinopathy. The studies reviewed imply that tissue-specific apoptosis and caspase-mediated α-fodrin proteolysis are involved in the progression of autoimmune lesions in Sjögren's syndrome. Moreover, Fas ligand (FasL) and its receptor Fas are essential in the homeostasis of the peripheral immune system. It is considered that a defect in activation-induced cell death (AICD) of effector T cells may result in the development of autoimmune exocrinopathy in Sjögren's syndrome.

The Effects of Iodide on the Cellular Functions and Expression of Thyroid Autoantigens in Thyroid Cells / 대한내분비학회지

BACKGROUND: Iodide has been known to control the function and the growth of the thyroid gland, and to be used as a substrate of thyroid hormone. Moreover, it has been suggested that excessive iodide stimulates the thyroid autoimmune responses. To evaluate the effects of iodide on thyrocytes, we investigated cell function and proliferation, or thyroid autoantigen expression after administering iodide to rats or FRTL-5 cells. MEHTODS AND RESULTS: Ten-weeks-old Sprague-Dawley rats were sacrificed after 7 days of NaI treatment. The expressions of thyroid autoantigens were examined by northern blot analysis. Chronic administration of iodide resulted in no effect on TSH receptor (TSHR) and thyroperoxidase (TPO) mRNA expression, while it increased thyroglobulin (TG) and diminished sodium-iodide symporter (NIS) mRNA expression. FRTL-5 cells were also treated with various concentrations of NaI. The generation of cAMP or iodide uptake was decreased, and the cellular growth was also inhibited by iodide. However, the expressions of all thyroid autoantigens (TSHR, TG, TPO, MHC class I and class II) except NIS were unchanged for 72 hours after iodide administration. The expression of NIS was mildly increased after 24 hours. CONCLUSION: Iodide resulted in decreased cell proliferation and cellular function of cAMP generation and iodide uptake. Chronic administration of iodide increased TG and diminished NIS mRNA expression in vivo but not in vitro

Cloning, expression and identification of M2 autoantigen and its trimer / 中华消化杂志

Objective To express the immunodominant epitopes of the branched chain 2 oxo acid dehydrogenase complex (BCOADC), the pyruvate dehydrogenase complex (PDC), the 2 oxo glutarate dehydrogenase complex (OGDC) and a triple hybrid clone (designated as BPO), and use BPO as a tool for the detection of M2 specific for primary biliary cirrhosis (PBC). Methods The cDNA fragments encoding the M2 reactive epitopes of BCOADC, PDC and OGDC were amplified using PCR with total RNA extracted from human peripheral mononuclear blood cell. The fragments were cloned into pQE 30 and then transformed into plasmid E.coli M15. Its products were induced by isopropylthio ? D galactoside and confirmed with SDS PAGE and Western blot. Results Four specific proteins induced from the transformants containing the fused plasmid were shown to have antigenic reactivity with PBC sera, but not with normal control sera. Conclusions We succeeded in expressing three immunodominant epitopes and a hybrid clone which can be used as a powerful and specific method for the diagnosis of PBC.

The influence of swallowing autoantigen on differentiation,development and function of the bone marrow-derived DC in vitro / 中国免疫学杂志

Objective:To observe the changes in differentiation,development and function of DCs after mouse bone marrow-derived dendritic cells devouring autoantigen in vitro,to study its impact on the immune status.Methods:Mouse bone marrow cells were cultured in GM-CSF+IL-4 to generate DCs,and the purity of DCs was detected by fluorescence microscope and flow cytometry.It was identified whether DCs could swallow autoantigen by immunohistochemistry and transmission electron microscope;and the changes in CD86,MHCⅡ on DCs after swallowing autoantigen were observed by flow cytometry.The changes in proliferation after the mouse spleen lymphocytes were cultured with the same genetic background of DCs were measured by MTT.The amounts of IL-4,IFN-? secreted by the mouse spleen lymphocytes after stimulation with DCs were measured by ELISA.Results:The purity of DCs was 90.6%.DCs could swallow autoantigen,which induced differentiation dysplasia of the DCs in vitro.Swallowing autoantigen had negative effect on the maturation as well as the potentiation to stimulate proliferation of the mouse spleen lymphocytes with the same genetic background.Secretion of IFN-? by stimulated lymphocytes decreased,but secretion of IL-4 promoted.Conclusion:The DCs that swallow autoantigen could inhibit imDCs maturation,but promote the immune tolerance and humoral immunity.

Expression of a recombinant branched chain alpha-oxo acid dehydrogenase complex E2 (BCOADC-E2) in insect cells and its immunoreactivity to autoimmune sera

Preparation of a pure autoantigen by way of recombinant DNA technology has an important value in an accurate diagnosis or prognosis of an autoimmune disease. BCOADC-E2 subunit, a mitochondrial protein, has been known to be the autoantigen of primary biliary cirrhosis (PBC), a chronic autoimmune liver disease, as well as idiopathic dilated cardiomypathy (IDCM), a chronic autoimmune heart disease. Recombinant form of this molecule had been expressed in E. coli but with low yield and severe degradation. Furthermore, sera from IDCM patients failed to recognized BCOADC-E2 molecule produced in prokaryotic expression system. In this study, a recombinant bovine BCOADC-E2 fusion protein has been expressed in insect cells using baculovirus expression system and analyzed anti-BCOADC-E2 reactivity in sera from patients with PBC or with IDCM. Optimal production of the recombinant fusion protein has been achieved at 20 multiplicity of infection (MOI), and the protein was affinity-purified using metal-binding resins. The affinity-purified BCOADC-E2 protein was successfully recognized by sera from PBC patients, but not by sera from IDCM patients suggesting that the different auto-immune response against BCOADC-E2 is needed to be elucidated in terms of epitope recognition.

Cloning of 119-264 Amino Acid Fragment of Ro52 Antigen and Analysis of Its Antigenicity / 中华皮肤科杂志

Objective To investigate the role of Ro52 antigen fragment from amino acid (AA) 119 to 264 that contains leucine zipper motif in forming the epitopes of Ro52 autoantigen. Methods cDNA encoding Ro52 antigen fragment from aa 119 to 264 was amplified by PCR from human heart cDNA first strand. The obtained cDNA fragment was inserted into vector pMTY4 and transformed into E. coli pop2136 for fusion protein expression. The recombinant fusion protein was then purified, and the antigenicity was determined by immunoblotting. Results A 28 000 Dalton fusion protein was obtained. It was highly expressed in host E. coli pop2136. 61.90% of the anti-full-length Ro52 positive sera reacted with the fusion protein in immunoblotting. Conclusion The results suggest that the antigen fragment from the 119 AA to 264 AA that contains the leucine zipper motif represents an important epitope region in Ro52 autoantigen.

Expression and specific cell response of autoantigen Dsg3 in pemphigus vulgaris / 中国免疫学杂志

Objective:In view of analysis of role of autoantigen Dsg3 in specific T cell response to understand the molecular mechanism of autoimmune diseases.Methods:Based on the sequence analysis of autoantigen Dsg3,the five fractions cDNAs of Dsg3 were cloned and Dsg3-GST fusion proteins induced by IPTG in E.coli.JM109 were purified,then mixed-cultured with T cell from PV patients.The T cell proliferation response were analyzed by MTT.Results:Dsg3 E1,E2 and E4,E5 stimulated T cell from PV patients,not controls.Conclusion:Dsg3 E1,E2 and E4,E5 contained the epitopes relevant to T-B cell interaction,which play an important role in the pathogenesis of pemphigus vulgaris.

RECOMBINANT EXPRESSION AND EPITOPE ANALYSIS OF AUTOANTIGEN Dsg3 IN PEMPHIGUS VULGARIS / 解放军医学杂志

The present study was to analyze the epitopes of autoantigen Dsg3 in pemphigus vulgaris (PV), and to elucidate the molecular mechanisms underlying autoimmune diseases. Based on the sequence analysis of autoantigen Dsg3 in Genbank five fragments of Dsg 3 cDNA (E1, E2, E3, E4, and E5) were cloned using RT PCR. Then PCR products were inserted into the expression vector pGEX 2T, and transformed into JM109 strain of E. coli. Dsg3 recombinant proteins were purified from the cell lysates. The epitopes of Dsg3 in PV patients were analyzed with five Dsg3 recombinant proteins by Western blot. The results showed that Dsg3 E1, E2 and E4 recombinant proteins reacted with PV patients′ sera, but not with control or normal sera. The dominant epitopes of Dsg3 in PV patients were different. The above data indicated that the epitopes of Dsg3 were located in E1, E2, and E4, which might play an important role in the pathogenesis of pemphigus vulgaris.