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In type 1 diabetes a subset of anti-coxsackievirus B4 antibodies recognize autoantigens and induce apoptosis of pancreatic beta cells.

Bason C, Lorini R, Lunardi C, Dolcino M, Giannattasio A, d'Annunzio G, Rigo A, Pedemonte N, Corrocher R, Puccetti A - PLoS ONE (2013)

Bottom Line: Coxsackievirus B infection has been linked to the onset of type 1 diabetes; however its precise role has not been elucidated yet.We identified an immunodominant peptide recognized by the majority of individual patients'sera, that shares homology with Coxsackievirus B4 VP1 protein and with beta-cell specific autoantigens such as phogrin, phosphofructokinase and voltage-gated L-type calcium channels known to regulate beta cell apoptosis.Our results provide evidence that in autoimmune diabetes a subset of anti-Coxsackievirus antibodies are able to induce apoptosis of pancreatic beta cells which is considered the most critical and final step in the development of autoimmune diabetes without which clinical manifestations do not occur.

View Article: PubMed Central - PubMed

Affiliation: Department of Medicine, Section of Internal Medicine, University of Verona, Verona, Italy.

ABSTRACT
Type 1 diabetes is characterized by autoimmune destruction of pancreatic beta cells. The role played by autoantibodies directed against beta cells antigens in the pathogenesis of the disease is still unclear. Coxsackievirus B infection has been linked to the onset of type 1 diabetes; however its precise role has not been elucidated yet. To clarify these issues, we screened a random peptide library with sera obtained from 58 patients with recent onset type 1 diabetes, before insulin therapy. We identified an immunodominant peptide recognized by the majority of individual patients'sera, that shares homology with Coxsackievirus B4 VP1 protein and with beta-cell specific autoantigens such as phogrin, phosphofructokinase and voltage-gated L-type calcium channels known to regulate beta cell apoptosis. Antibodies against the peptide affinity-purified from patients' sera, recognized the viral protein and autoantigens; moreover, such antibodies induced apoptosis of the beta cells upon binding the L-type calcium channels expressed on the beta cell surface, suggesting a calcium dependent mechanism. Our results provide evidence that in autoimmune diabetes a subset of anti-Coxsackievirus antibodies are able to induce apoptosis of pancreatic beta cells which is considered the most critical and final step in the development of autoimmune diabetes without which clinical manifestations do not occur.

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Related in: MedlinePlus

Anti-peptides antibodies bind cell surface phogrin and intracellular PFKP.Preincubation of beta cells with anti T1DM peptide antibodies (A), and with anti COXSA peptide antibodies (B) resulted in an increase of the binding of anti-phogrin antibodies a = anti-IA-2β chicken antibody and secondary PE-tagged anti-chicken antibody; MFI = 111 b = anti-T1DM peptide antibodies followed by anti-IA-2β chicken antibody and by secondary PE-tagged anti-chicken antibody; MFI = 162 d = anti-COXSA peptide antibodies followed by anti-IA-2β chicken antibody and by secondary PE-tagged anti chicken antibody; MFI = 130 c = control; MFI = 6. Preincubation with anti-PFKP rabbit antibody reduced the binding of anti-T1DM peptide antibodies (C) and anti-COXSA peptide antibodies (D) to intracellular PFKP. e = anti-T1DM peptide antibodies and secondary anti-human PE-coniugated antibody, MFI = 16.6 f = anti-PFKP rabbit antibodies followed by anti-T1DM antibodies and secondary anti-human PE-coniugated antibody; MFI = 10.4 g = anti-COXSA peptide antibodies and secondary anti-human PE-coniugated antibody; MFI = 9 h = anti-PFKP rabbit antibodies followed by anti-COXSA peptide antibodies and secondary anti-human PE-coniugated antibody; MFI = 4,6 c = control; MFI = 4.1Representative example of three independently performed experiments that generated similar FACS profiles. x-axis: MFI = Mean Fluorescence Intensity; y-axis: cell counts.
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pone-0057729-g003: Anti-peptides antibodies bind cell surface phogrin and intracellular PFKP.Preincubation of beta cells with anti T1DM peptide antibodies (A), and with anti COXSA peptide antibodies (B) resulted in an increase of the binding of anti-phogrin antibodies a = anti-IA-2β chicken antibody and secondary PE-tagged anti-chicken antibody; MFI = 111 b = anti-T1DM peptide antibodies followed by anti-IA-2β chicken antibody and by secondary PE-tagged anti-chicken antibody; MFI = 162 d = anti-COXSA peptide antibodies followed by anti-IA-2β chicken antibody and by secondary PE-tagged anti chicken antibody; MFI = 130 c = control; MFI = 6. Preincubation with anti-PFKP rabbit antibody reduced the binding of anti-T1DM peptide antibodies (C) and anti-COXSA peptide antibodies (D) to intracellular PFKP. e = anti-T1DM peptide antibodies and secondary anti-human PE-coniugated antibody, MFI = 16.6 f = anti-PFKP rabbit antibodies followed by anti-T1DM antibodies and secondary anti-human PE-coniugated antibody; MFI = 10.4 g = anti-COXSA peptide antibodies and secondary anti-human PE-coniugated antibody; MFI = 9 h = anti-PFKP rabbit antibodies followed by anti-COXSA peptide antibodies and secondary anti-human PE-coniugated antibody; MFI = 4,6 c = control; MFI = 4.1Representative example of three independently performed experiments that generated similar FACS profiles. x-axis: MFI = Mean Fluorescence Intensity; y-axis: cell counts.

Mentions: We also found that the antibodies against the peptides were able to bind IA-2β expressed on the surface of beta cells (Fig. 3A and B) and the intracellular PFKP (Fig. 3C and D) by FACS analysis.


In type 1 diabetes a subset of anti-coxsackievirus B4 antibodies recognize autoantigens and induce apoptosis of pancreatic beta cells.

Bason C, Lorini R, Lunardi C, Dolcino M, Giannattasio A, d'Annunzio G, Rigo A, Pedemonte N, Corrocher R, Puccetti A - PLoS ONE (2013)

Anti-peptides antibodies bind cell surface phogrin and intracellular PFKP.Preincubation of beta cells with anti T1DM peptide antibodies (A), and with anti COXSA peptide antibodies (B) resulted in an increase of the binding of anti-phogrin antibodies a = anti-IA-2β chicken antibody and secondary PE-tagged anti-chicken antibody; MFI = 111 b = anti-T1DM peptide antibodies followed by anti-IA-2β chicken antibody and by secondary PE-tagged anti-chicken antibody; MFI = 162 d = anti-COXSA peptide antibodies followed by anti-IA-2β chicken antibody and by secondary PE-tagged anti chicken antibody; MFI = 130 c = control; MFI = 6. Preincubation with anti-PFKP rabbit antibody reduced the binding of anti-T1DM peptide antibodies (C) and anti-COXSA peptide antibodies (D) to intracellular PFKP. e = anti-T1DM peptide antibodies and secondary anti-human PE-coniugated antibody, MFI = 16.6 f = anti-PFKP rabbit antibodies followed by anti-T1DM antibodies and secondary anti-human PE-coniugated antibody; MFI = 10.4 g = anti-COXSA peptide antibodies and secondary anti-human PE-coniugated antibody; MFI = 9 h = anti-PFKP rabbit antibodies followed by anti-COXSA peptide antibodies and secondary anti-human PE-coniugated antibody; MFI = 4,6 c = control; MFI = 4.1Representative example of three independently performed experiments that generated similar FACS profiles. x-axis: MFI = Mean Fluorescence Intensity; y-axis: cell counts.
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Related In: Results  -  Collection

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pone-0057729-g003: Anti-peptides antibodies bind cell surface phogrin and intracellular PFKP.Preincubation of beta cells with anti T1DM peptide antibodies (A), and with anti COXSA peptide antibodies (B) resulted in an increase of the binding of anti-phogrin antibodies a = anti-IA-2β chicken antibody and secondary PE-tagged anti-chicken antibody; MFI = 111 b = anti-T1DM peptide antibodies followed by anti-IA-2β chicken antibody and by secondary PE-tagged anti-chicken antibody; MFI = 162 d = anti-COXSA peptide antibodies followed by anti-IA-2β chicken antibody and by secondary PE-tagged anti chicken antibody; MFI = 130 c = control; MFI = 6. Preincubation with anti-PFKP rabbit antibody reduced the binding of anti-T1DM peptide antibodies (C) and anti-COXSA peptide antibodies (D) to intracellular PFKP. e = anti-T1DM peptide antibodies and secondary anti-human PE-coniugated antibody, MFI = 16.6 f = anti-PFKP rabbit antibodies followed by anti-T1DM antibodies and secondary anti-human PE-coniugated antibody; MFI = 10.4 g = anti-COXSA peptide antibodies and secondary anti-human PE-coniugated antibody; MFI = 9 h = anti-PFKP rabbit antibodies followed by anti-COXSA peptide antibodies and secondary anti-human PE-coniugated antibody; MFI = 4,6 c = control; MFI = 4.1Representative example of three independently performed experiments that generated similar FACS profiles. x-axis: MFI = Mean Fluorescence Intensity; y-axis: cell counts.
Mentions: We also found that the antibodies against the peptides were able to bind IA-2β expressed on the surface of beta cells (Fig. 3A and B) and the intracellular PFKP (Fig. 3C and D) by FACS analysis.

Bottom Line: Coxsackievirus B infection has been linked to the onset of type 1 diabetes; however its precise role has not been elucidated yet.We identified an immunodominant peptide recognized by the majority of individual patients'sera, that shares homology with Coxsackievirus B4 VP1 protein and with beta-cell specific autoantigens such as phogrin, phosphofructokinase and voltage-gated L-type calcium channels known to regulate beta cell apoptosis.Our results provide evidence that in autoimmune diabetes a subset of anti-Coxsackievirus antibodies are able to induce apoptosis of pancreatic beta cells which is considered the most critical and final step in the development of autoimmune diabetes without which clinical manifestations do not occur.

View Article: PubMed Central - PubMed

Affiliation: Department of Medicine, Section of Internal Medicine, University of Verona, Verona, Italy.

ABSTRACT
Type 1 diabetes is characterized by autoimmune destruction of pancreatic beta cells. The role played by autoantibodies directed against beta cells antigens in the pathogenesis of the disease is still unclear. Coxsackievirus B infection has been linked to the onset of type 1 diabetes; however its precise role has not been elucidated yet. To clarify these issues, we screened a random peptide library with sera obtained from 58 patients with recent onset type 1 diabetes, before insulin therapy. We identified an immunodominant peptide recognized by the majority of individual patients'sera, that shares homology with Coxsackievirus B4 VP1 protein and with beta-cell specific autoantigens such as phogrin, phosphofructokinase and voltage-gated L-type calcium channels known to regulate beta cell apoptosis. Antibodies against the peptide affinity-purified from patients' sera, recognized the viral protein and autoantigens; moreover, such antibodies induced apoptosis of the beta cells upon binding the L-type calcium channels expressed on the beta cell surface, suggesting a calcium dependent mechanism. Our results provide evidence that in autoimmune diabetes a subset of anti-Coxsackievirus antibodies are able to induce apoptosis of pancreatic beta cells which is considered the most critical and final step in the development of autoimmune diabetes without which clinical manifestations do not occur.

Show MeSH
Related in: MedlinePlus