PT  - JOURNAL ARTICLE
AU  - Delong, Thomas
AU  - Baker, Rocky L.
AU  - Reisdorph, Nichole
AU  - Reisdorph, Richard
AU  - Powell, Roger L.
AU  - Armstrong, Michael
AU  - Barbour, Gene
AU  - Bradley, Brenda
AU  - Haskins, Kathryn
TI  - Islet Amyloid Polypeptide Is a Target Antigen for Diabetogenic CD4<sup>+</sup> T Cells
AID  - 10.2337/db11-0288
DP  - 2011 Sep 01
TA  - Diabetes
PG  - 2325--2330
VI  - 60
IP  - 9
4099  - http://diabetes.diabetesjournals.org/content/60/9/2325.short
4100  - http://diabetes.diabetesjournals.org/content/60/9/2325.full
SO  - Diabetes2011 Sep 01; 60
AB  - OBJECTIVE To investigate autoantigens in β-cells, we have used a panel of pathogenic T-cell clones that were derived from the NOD mouse. Our particular focus in this study was on the identification of the target antigen for the highly diabetogenic T-cell clone BDC-5.2.9.RESEARCH DESIGN AND METHODS To purify β-cell antigens, we applied sequential size exclusion chromatography and reverse-phase high-performance liquid chromatography to membrane preparations of β-cell tumors. The presence of antigen was monitored by measuring the interferon-γ production of BDC-5.2.9 in response to chromatographic fractions in the presence of NOD antigen-presenting cells. Peak antigenic fractions were analyzed by ion-trap mass spectrometry, and candidate proteins were further investigated through peptide analysis and, where possible, testing of islet tissue from gene knockout mice.RESULTS Mass-spectrometric analysis revealed the presence of islet amyloid polypeptide (IAPP) in antigen-containing fractions. Confirmation of IAPP as the antigen target was demonstrated by the inability of islets from IAPP-deficient mice to stimulate BDC-5.2.9 in vitro and in vivo and by the existence of an IAPP-derived peptide that strongly stimulates BCD-5.2.9.CONCLUSIONS IAPP is the target antigen for the diabetogenic CD4 T-cell clone BDC-5.2.9.