A pilot study of preproinsulin peptides reactivity in Chinese patients with type 1 diabetes.

ABSTRACT:

Background

The aim of our study is to investigate whether preproinsulin (PPI) could trigger a proinflammatory CD4⁺ T cell response in Chinese patients with type 1 diabetes (T1D).

Methods

Peripheral blood mononuclear cells were stimulated by a pool of 13 PPI peptides. Additional five PPI peptides previously proved to be antigenic in other cohorts of patients with T1D were also used. PPI reactive T cell responses were measured by interferon (IFN)-? ELISPOT assay.

Results

Fifty-one Chinese patients with T1D were enrolled in this study and 72.34% of them were positive for at least one islet autoantibody. The stimulation index (SI) value of IFN-? response to PPI peptide pool or peptides with dominant epitopes was below 3 in patients when SI?3 was used as the positive cut-off value. Two peptides (B9-23 and C19-A3) restricted to DQ8 or DR4 molecule failed to induce positive IFN-? response in patients with high-risk HLA-DQ8 or HLA-DR4/DR9 alleles. RNA-seq analysis of PPI specific CD4⁺ T cell lines further showed that most of the IFN-? associated genes remained unchanged.

Conclusions

This is the first report of CD4⁺ T cell epitope mapping of PPI in Chinese T1D. The lack of positive IFN-? response to PPI peptides indicates that PPI might not be the principal antigenic candidate for autoreactive CD4⁺ T cells in Chinese T1D. Therefore, the efficacy of PPI-based immunotherapies in attenuating proinflammatory CD4⁺ T cell response requires further investigation.

SUBMITTER: Xian Y 

PROVIDER: S-EPMC7027544 | biostudies-literature | 2020 Feb

REPOSITORIES: biostudies-literature