• International Journal of Oral Biology
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• v.45 no.4
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• pp.211-217
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• 2020

Molecular mimicry is the most common mechanism that breaches self-tolerance. We previously identified autoantibodies to aquaporin-5 (AQP5) in the sera of patients with Sjögren's syndrome and found that the aquaporin of Prevotella melaninogenica (PmAqp), an oral commensal, is highly homologous to human AQP5. This study aimed to test whether PmAqp can induce anti-AQP5 autoantibodies via molecular mimicry. From the amino acid sequence of PmAqp, an immunizing peptide; i.e., PmE-L, was designed, which contained both the B cell epitope "E" and T cell epitope. C57BL/6 and BALB/c mice were subcutaneously immunized with linear or cyclic forms of PmE-L emulsified in incomplete Freund's adjuvant. The concentrations of the antibodies in sera were measured using enzyme-linked immunosorbent assays. Both linear and cyclic PmE-L induced high levels of antibodies against not only the immunized peptides but also autoantibodies against AQP5E and antibodies against PmE, a Pm homolog of AQP5E. In C57BL/6 mice; however, the cyclic form of PmE-L was more efficient than the linear form in inducing autoantibodies against AQP5E that contained a cyclic epitope. The levels of anti-PmE antibodies and anti-AQP5E autoantibodies showed a strong positive correlation (r = 0.95, p < 0.0005), suggesting molecular mimicry. Collectively, the mice produced anti-AQP5E autoantibodies in response to a PmAqp-derived peptide. This model proved to be useful for studying the mechanisms of autoantibody production by molecular mimicry.

• Asian Pacific Journal of Cancer Prevention
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• v.17 no.11
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• pp.4977-4982
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• 2016

Introduction: Elevated serum interleukin (IL) 6 has been reported in patients infected with the hepatitis C virus (HCV), but it remains debatable whether this influences the production of autoantibodies and the biochemical profile of HCV disease. Therefore, this current study was conducted to evaluate the relationship between IL-6 and circulating autoantibody levels in HCV positive patients. Methods: Levels of IL-6 in serum samples from 102 patients with HCV and 103 normal controls were determined by enzyme linked immunosorbent assay (ELISA). Autoantibodies were detected by immunofluorescence. Results: Levels of IL-6 were significantly higher (p=0.028) in patients infected with (HCV) compared with normal group. Autoantibodies were noted in in 43.1% of the patients; of these, 23.5% featured anti-nuclear antibodies (ANA+), 16.7% anti-smooth muscle antibodies (ASMA+), 7.8% anti-mitochondrial antibodies (AMA+), 17.6% anti-parietal cell antibodies (APCA+), 7.8% anti canalicular antibodies, and 2.9% anti reticulin antibodies (ARA+). No patients were found to be positive for anti-brush border antibodies (ABBA) or anti-ribosomal antibodies. (ARiA). No links with IL-6 levels were apparent. Conclusions: IL-6 levels are increased in patients infected with HCV disease and could influence the production of autoantibodies. However, this study did not provide evidence of a specific relationship between IL6 and circulating autoantibodies in such cases.

• Proceedings of the Korean Society of Applied Pharmacology
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• 2006.04a
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• pp.139-149
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• 2006

Amyloid beta (A$\beta$) is believed one of the major pathogens of Alzheimer's disease (AD), and the reduction of A$\beta$ is considered a primary therapeutic target. Immunization with A$\beta$ can reduce A$\beta$ burden and pathological features in transgenic AD model mouse. This means anti-A$\beta$ autoantibodies may have a role in AD pathology. Recent findings suggest anti-A$\beta$ autoantibodies level decrease in AD patients. The early detection of AD is important for treatment of this disease. However, diagnosis on AD has only been possible through limited methods such as neuropsychological examination or MRI. To investigate whether it was possible to detect the presence and different levels of naturally occurring anti-A$\beta$ autoantibodies in the plasma of patients with AD and age-matched controls. An advanced ELISA was performed to detect levels of naturally occurring anti-A$\beta$ autoantibodies in the plasma. The level of anti-A$\beta$ auto-antibodies from patients with idiopathic Parkinson's disease or stroke and from normal controls were compared to that of AD patients. Our results showed a significantly lower anti-A$\beta$ autoantibodies level in AD compared to those with other neurological diseases or control. The level of anti-A$\beta$ autoantibodies in the serum may be used to diagnose the presence of AD.

• 한국약용작물학회:학술대회논문집
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• 2006.04a
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• pp.137-149
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• 2006

Amyloid beta ($A{\beta}$) is believed one of the major pathogens of Alzheimer's disease (AD), and the reduction of $A{\beta}$ is considered a primary therapeutic target. Immunization with $A{\beta}$ can reduce $A{\beta}$ burden and pathological features in transgenic AD model mouse. This means $anti-A{\beta}$ autoantibodies may have a role in AD pathology. Recent findings suggest $anti-A{\beta}$ autoantibodies level decrease in AD patients. The early detection of AD is important for treatment of this disease. However, diagnosis on AD has only been possible through limited methods such as neuropsychological examination or MRI. To investigate whether it was possible to detect the presence and different levels of naturally occurring $anti-A{\beta}$ autoantibodies in the plasma of patients with AD and age-matched controls. An advanced ELISA was performed to detect levels of naturally occurring $anti-A{\beta}$ autoantibodies in the plasma. The level of $anti-A{\beta}$ auto-antibodies from patients with idiopathic Parkinson's disease or stroke and from normal controls were compared to that of AD patients. Our results showed a significantly lower $anti-A{\beta}$ autoantibodies level in AD compared to those with other neurological diseases or control. The level of $anti-A{\beta}$ autoantibodies in the serum may be used to diagnose the presence of AD.

• Journal of Veterinary Science
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• v.22 no.3
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• pp.38.1-38.17
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• 2021

Background: The feline viral rhinotracheitis, calicivirus, and panleukopenia (FVRCP) vaccine, prepared from viruses grown in the Crandell-Rees feline kidney cell line, can induce antibodies to cross-react with feline kidney tissues. Objectives: This study surveyed the prevalence of autoantibodies to feline kidney tissues and their association with the frequency of FVRCP vaccination. Methods: Serum samples and kidneys were collected from 156 live and 26 cadaveric cats. Antibodies that bind to kidney tissues and antibodies to the FVRCP antigen were determined by enzyme-linked immunosorbent assay (ELISA), and kidney-bound antibody patterns were investigated by examining immunofluorescence. Proteins recognized by antibodies were identified by Western blot analysis. Results: The prevalences of autoantibodies that bind to kidney tissues in cats were 41% and 13% by ELISA and immunofluorescence, respectively. Kidney-bound antibodies were observed at interstitial cells, apical border, and cytoplasm of proximal and distal tubules; the antibodies were bound to proteins with molecular weights of 40, 47, 38, and 20 kDa. There was no direct link between vaccination and anti-kidney antibodies, but positive antibodies to kidney tissues were significantly associated with the anti-FVRCP antibody. The odds ratio or association in finding the autoantibody in cats with the antibody to FVRCP was 2.8 times higher than that in cats without the antibody to FVRCP. Conclusions: These preliminary results demonstrate an association between anti-FVRCP and anti-cat kidney tissues. However, an increase in the risk of inducing kidney-bound antibodies by repeat vaccinations could not be shown directly. It will be interesting to expand the sample size and follow-up on whether these autoantibodies can lead to kidney function impairment.

• Childhood Kidney Diseases
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• v.25 no.1
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• pp.29-34
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• 2021

C3 glomerulonephritis (C3GN), a rare condition associated with dysregulation of the alternative pathway of the complement system, is histopathologically characterized by isolated or dominant C3 deposition in the renal glomeruli. We report a case of C3GN associated with anti-complement factor H (CFH) autoantibodies and CHF-related protein deficiency in an adolescent male. A 16-year-old adolescent male was admitted to a hospital with a 1-month history of generalized edema prior to presentation. Persistent microscopic hematuria and low serum C3 levels were incidentally detected at 7 and 10 years of age, respectively. Laboratory test results revealed hypoalbuminemia, nephrotic-range proteinuria, microscopic hematuria, and normal serum creatinine levels. The serum C3 and C4 levels were 17 mg/dL (normal 80-150 mg/dL) and 22 mg/mL (17-40 mg/mL), respectively. Renal biopsy showed typical features of C3GN. Further investigations revealed positive results on plasma anti-CFH autoantibody testing and a homozygous deletion of CFHR1 and CFHR3, which encode CFH-related proteins 1 and 3, respectively. Proteinuria persisted despite treatment with intravenous methylprednisolone, mycophenolate mofetil, and angiotensin-receptor blocker; however, his renal function remained stable. In conclusion, anti-CFH autoantibodies serve as important contributors to C3GN. This is the first case report that describes C3GN in an adolescent Korean male with anti-CFH autoantibodies and homozygous CFHR1 and CFHR3 deletion.

• The Korean Journal of Nuclear Medicine
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• v.18 no.1
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• pp.19-24
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• 1984

Clinical measurement of thyroid autoantibodies in sera of some thyroid disorders have been widely applied since about twenty years ago. We investigated the incidence and titers of both anti microsomal and antithyroglobulin antibodies in forty eight cases with controls and one hundred and thirty three patients with some form of thyroid disorders. The results were as follows; 1) In controls, antimicrosomal antibodies were positive in 2% but anti thyroglobulin antibodies were all negative. 2) In a series of one hundred and thirty three patients with thyroid disease, anti microsomal antibodies were positive in 44% but antithyroglobulin antibodies were positive in only 15%. 3) The rate disclosing the positive results of antimicrosomal antibodies were 71 % in Hashmoto's disease, 60% in Graves' disease, and 38% in primary hypothroidism, respectively. On the other hand, the positive results of antithyroglobulin antibodies showed 21 % in Graves' disease, 19% in primary hypothyroidism, and 18% in Hashmoto's disease, respectively. Though there were relatively high rate of both antimicrosomal and anti thyroglobulin antibodies in patients with nodular goiter, they were only seven cases in our series. 4) The rate with the extremely high titers of antimicrosomal and antithyroglobulin antibodies$(>1:160^2)$ was 83% and 67% in Hashmoto's disease, 50% and 67% in primary hypothyroidism, and 41% and 18% in Graves' disease. Accordingly, the thyroid autoantibodies were commonly found higher positive rate in patients with Hashmoto's disease, primary hypothyroidism, and Graves' disease. Among these disorders, the extremely high positive rate of the thyroid autoantibodies was found in patients with Hashmoto's disease.

• Asian Pacific Journal of Cancer Prevention
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• v.17 no.1
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• pp.335-339
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• 2016

Background: The aim of this work was to investigate if serum and salivary auto-antibodies, isotypes IgG and IgM, against HER2 and MUC1 tandem repeat fragments could play a role in breast cancer screening. Materials and Methods: Our case-control study was conducted in breast cancer patients, in early stages (n=29), at the gynecology service, Maternity Souissi Hospital, Rabat, Morocco and healthy woman (n=31). Salivary and serum auto-antibodies against HER2 and MUC1 (tandem repeat) were assessed by enzyme-linked immunosorbent assay (ELISA) and compared between patients and healthy women using the Mann-Whitney U test. A P-value <0.05 was considered to be statistically significant. Results: Our data showed higher expression of all serum and salivary autoantibodies in patients as compared to healthy women p<0.05. However, serum IgM anti-MUC1 expression did not show a significant difference between cases and controls (p=0.79). Similarly, salivary IgG anti-HER2 expression did not differ (p=0.15). The correlation between the different isotypes of antibodies revealed that the highest correlation was between salivary IgG anti-HER2 and salivary IgG anti-MUC1(r=0.65). In fact, we have found in saliva the correlation between autoantibodies anti-MUC1 and anti-HER2 more important than in serum (r=0.59 and r=0. 55). However, the correlation between serum and saliva values for all antibodies was weak. Conclusions: Autoantibodies against HER2 and MUC1 may provide a useful approach in breast cancer screening when using both serum and saliva values.

• Journal of Microbiology and Biotechnology
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• v.10 no.5
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• pp.707-713
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• 2000

Myasthenia gravis (MG) is caused mainly by autoantibodies directed against acetylcholine receptors located in the postsynaptic muscle cell membrane. Using in vitro selection techniques, we isolated an RNA containing 2'-fluoro pyrimidines that can specifically and avidly ($K_d$ ~25 nM) bind rat monoclonal antibody called mAb198, which recognizes the main immunogenic region on the acetylcholine receptors. This RNA can act as a very effective decoy and block mAb198 binding to the receptors in vitro. Furthermore, this RNA decoy can prevent the antigenic modulation of the acetylcholine receptor caused by mAb198 in human muscle cell cultures with and $IC_{50} $of approximately $2.4{\mu}M$. These results indicate that the RNA selected in this study is a more potent decly inhibitor of myashthenic antibodies than the previously identified RNA with 2'-amino pyrimidines [11]. Moreover, this RNA cross-reacts with autoantibodies from patients with MG and can protect human cells from the effects of these antibodies. These observations have important implications for developing an antigen-specific treatment of autoimmune diseases including MG, which is based on decoy RNAs selected in vitro.

• BMB Reports
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• v.45 no.12
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• pp.677-685
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• 2012

In the process of tumorigenesis, normal cells are remodeled to cancer cells and protein expression patterns are changed to those of tumor cells. A newly formed tumor microenvironment elicits the immune system and, as a result, a humoral immune response takes place. Although the tumor antigens are undetectable in sera at the early stage of tumorigenesis, the nature of an antibody amplification response to antigens makes tumor-associated autoantibodies as promising early biomarkers in cancer diagnosis. Moreover, the recent development of proteomic techniques that make neo-epitopes of tumor-associated autoantigens discovered concomitantly has opened a new area of 'immuno-proteomics', which presents tumor-associated autoantibody signatures and confers information to redefine the process of tumorigenesis. In this article, the strategies recently used to identify and validate serum autoantibodies are outlined and tumor-associated antigens suggested until now as diagnostic/prognostic biomarkers in various tumor types are reviewed. Also, the meaning of autoantibody signatures and their clinical utility in personalized medicine are discussed.