Advances in B-cell epitope analysis of autoantigens in connective tissue diseases

Quality of Recombinant Protein Determines the Amount of Autoreactivity Detected against the Tumor-Associated Epithelial Cell Adhesion Molecule Antigen: Low Frequency of Antibodies against the Natural Protein

“…This would rather be a possibility with Abs against naturally folded proteins, particularly if expressed on the cell surface. As reviewed recently by Mahler et al (28) for autoimmunity, disease-causing autoantibodies such as receptor-stimulating Abs against conformational epitopes of the TSH receptor are only found in Graves disease patients and not in normal individuals (38) and anti-glomerular basal membrane Abs that cause Goodpasture disease only react with three-dimensional conformational B epitopes of glomerular basal membrane protein (39). On the contrary, in cancer patients anti-p53 Abs react against a linear peptide that is cryptic in the native p53 and accessible only on the denatured or mutant protein (40).…”

“…Most autoantibodies are detected by peptide scans or Western blots that would not detect conformational epitopes and may lead to the false assumption that Abs reacting with the native Ag are also present (28).…”

Serological Aspects of Myositis

“…Initial use of the PM/Scl 100 antigen showed good sensitivity and specificity using a full length 100 kDa antigen (Hentschel et al, 2002). While a debate was going on whether the PM/Scl 75 or the PM/Scl 100 antigen should be used as the preferred antigen for IVD testing (Raijmakers et al, 2004;Mahler and Raijmakers, 2007a;Brouwer et al, 2002), a peptide sequence between amino acids 231 and 245 was found which could be proven as the main site of autoantibody binding in the PM/Scl autoantigen (Bluthner et al, 2000a;Mahler et al, 2003;Mahler and Raijmakers, 2007b). The major epitope of PM/Scl referred to as PM1 alpha, consists of a local alpha helical structure.…”

Increased non-canonical splicing of autoantigen transcripts provides the structural basis for expression of untolerized epitopes

“…30 In addition, we used 2 widely adapted Web site-based algorithms, the BioInformatics and Molecular Analysis Section algorithm at the National Institutes of Health Web site (http://bimas.dcrt.nih.gov/molbio/hla_bind/) and the SYFPEITHI algorithm (http://syfpeithi.bmi-heidelberg.com/Scripts/MHCServer.dll/EpPredict.htm), to analyze the MHC class I-restricted CD8 + and the MHC class II-restricted CD4 + T-cell antigenic epitopes.…”

“…To test our hypothesis that alternatively spliced isoform-specific regions of autoantigens may encode epitopes recognized by autoantibodies, we used the JamesonWolf antigen index algorithm to evaluate the antigen index of each isoform-specific antigenic region. 31 We used the 43 linear autoantigen epitopes that previously were experimentally defined 30 as the reference epitopes. These 43 reference autoantigen epitopes had Jameson-Wolf antigen index scores that ranged from 1.56 to 4.36 (mean ± 2 SD = 2.96 ± 1.40), which served as the reference range (with a 95% CI) for antibody epitopes.…”