Immunization with an insulin peptide–MHC complex to prevent type 1 diabetes of NOD mice
✍ Scribed by Li Zhang; Brian D. Stadinski; Aaron Michels; John W. Kappler; George S. Eisenbarth
- Publisher
- John Wiley and Sons
- Year
- 2011
- Tongue
- English
- Weight
- 535 KB
- Volume
- 27
- Category
- Article
- ISSN
- 1520-7552
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✦ Synopsis
Abstract
Background
Mutating the insulin B:9–23 peptide prevents diabetes in NOD mice. Thus, the trimolecular complex of I‐A$^{\rm{g7}}$‐insulin B:9–23 peptide‐TCR may be essential for the development of spontaneous diabetes. Pathogenic T cells recognize the B:9–23 peptide presented by I‐A$^{\rm{g7}}$ in what is termed register 3, with the B22 basic amino acid (arginine) of the peptide bound in pocket 9 of I‐A$^{\rm{g7}}$. Our hypothesis is that immunization with an insulin B:12–22 peptide linked to I‐A$^{\rm{g7}}$ in register 3 (I‐A$^{\rm{g7}}$‐B:RE#3 complex) can induce specific antibodies to the complex, block pathogenic TCRs, and thus prevent diabetes.
Methods
We immunized young NOD mice with recombinant I‐A$^{\rm{g7}}$‐B:RE#3 protein, in which two amino acids of the peptide were mutated to fix the peptide in register 3, and investigated the induced antibodies targeted to the peptide in register 3.
Results
Specific antibodies targeting I‐A$^{\rm{g7}}$‐B:RE#3 but not I‐A$^{\rm{g7}}$‐HEL were identified in the sera of I‐A$^{\rm{g7}}$‐B:RE#3 immunized mice. The sera inhibited B:9–23‐induced T‐cell responses in vitro. I‐A$^{\rm{g7}}$‐B:RE#3 immunization delayed progression to diabetes (versus PBS, p = 0.0005), while immunization with I‐A$^{\rm{g7}}$‐HEL control complex did not.
Conclusions
Immunization with I‐A$^{\rm{g7}}$‐B:RE#3 complex significantly delays the development of insulin autoantibodies and the onset of diabetes in NOD mice, which is associated with the induction of I‐A$^{\rm{g7}}$‐B:RE#3 antibodies. Copyright © 2011 John Wiley & Sons, Ltd.