Case Study:
ProImmune REVEAL® MHC-peptide binding assay used in study to identify new epitopes in type I diabetes (T1D) patients

Blancou, P. et al. (2007). Immunization of HLA class I transgenic mice identifies autoantigenic epitopes eliciting dominant responses in type 1 diabetes patients. J. Immunol. 178(11): 7458-66. [PubMedID: 17513797]

CD8+ T cells have been shown to have a major role in pancreatic beta cell injury leading to T1D. Defining pancreatic beta cell autoantigenic epitopes is essential for the design of peptide-based immunotherapy in T1D. However, exhaustive screening of peptide libraries with human PBMCs from T1D patients is strongly limited by the quantity of blood that can be obtained from T1D patients (particularly paediatric patients) and the low frequency of autoreactive CD8+ T1D cells in human peripheral blood.

As a consequence Blancou et al. used a combination of epitope identification methods to find novel T cell epitopes in the proteins GAD65 and IA-2, including

  • Pre-screeing of candidate peptides with the algorithm SYFPEITHI
  • DNA and peptide immunization of HLA transgenic HHDII mice
  • ELISpot and T2 killing assays of human and murine PBMC
  • ProImmune REVEAL® MHC-peptide binding assay

 

Strongly immunodominant responses against two GAD peptides GAD114-123 and GAD536-545 and one IA-2 peptide IA-2805-813 were found. The results of the study show that scores from the MHC-peptide binding assay correlate well with the responses observed by ELISpot in immunized HHDII mice. More importantly the three most important new epitopes identified in >25% of T1D patients were all predicted by the MHC-peptide binding assay with scores similar to the positive control peptide used in the assay.

The study shows how the ProImmune REVEAL® MHC-peptide binding assay can play an important role in directing the screening process and validating results in disease areas where relevant cell samples are limited.