High-throughput sequencing reveals restricted TCR Vβ usage and public TCRβ clonotypes among pancreatic lymph node memory CD4 + T cells and their involvement in autoimmune diabetes

Abstract

Islet-reactive memory CD4(+) T cells are an essential feature of type 1 diabetes (T1D) as they are involved in both spontaneous disease and in its recurrence after islet transplantation. Expansion and enrichment of memory T cells have also been shown in the peripheral blood of diabetic patients. Here, using high-throughput sequencing, we investigated the clonal diversity of the TCRβ repertoire of memory CD4(+) T cells in the pancreatic lymph nodes (PaLN) of non-obese diabetic (NOD) mice and examined their clonal overlap with islet-infiltrating memory CD4T cells. Both prediabetic and diabetic NOD mice exhibited a restricted TCRβ repertoire dominated by clones expressing TRBV13-2, TRBV13-1 or TRBV5 gene segments. There is a limited degree of TCRβ overlap between the memory CD4 repertoire of PaLN and pancreas as well as between the prediabetic and diabetic group. However, public TCRβ clonotypes were identified across several individual animals, some of them with sequences similar to the TCRs from the islet-reactive T cells suggesting their antigen-driven expansion. Moreover, the majority of the public clonotypes expressed TRBV13-2 (Vβ8.2) gene segment. Nasal vaccination with an immunodominat peptide derived from the TCR Vβ8.2 chain led to protection from diabetes, suggesting a critical role for Vβ8.2(+) CD4(+) memory T cells in T1D. These results suggest that memory CD4(+) T cells bearing limited dominant TRBV genes contribute to the autoimmune diabetes and can be potentially targeted for intervention in diabetes. Furthermore, our results have important implications for the identification of public T cell clonotypes as potential novel targets for immune manipulation in human T1D.

Distinct PLZF+CD8αα+ Unconventional T Cells Enriched in Liver Use a Cytotoxic Mechanism to Limit Autoimmunity

“…The TCRb CDR3 regions were amplified and sequenced from sorted CD8aa T unc and CD8 T con from liver MNCs of naive B6 mice or from human PBMC. Amplification and sequencing of TCRb CDR3 regions were performed on the ImmunoSEQ platform at Adaptive Biotechnologies (Seattle, WA) as previously described (24). Sequences that did not match CDR3 sequences were removed from the analysis.…”

Prenatal Administration of Betamethasone Causes Changes in the T Cell Receptor Repertoire Influencing Development of Autoimmunity

“…Autoreactive T cell clones bearing distinct TCR Vβ chains expand in the target organs of autoimmune disease. For instance, T cells of the Vβ8.2 family recognizing MOG 35–55 are predominant in the brain of C57BL/6 mice ( 47 ), and the repertoire of T cells infiltrating the pancreas of the NOD mouse is skewed to a limited set of families, including Vβ2, Vβ4, Vβ6, Vβ8.1, and Vβ12 ( 37 – 41 , 56 ). Interestingly, injection of dexamethasone in the first 3 days of life has been shown to exert long-lasting effects on the expression of several Vβ genes in rats ( 57 ).…”

T Cell Receptor Profiling in Type 1 Diabetes

“…Marrero et al identified islet antigen-reactive TRBV13-2 (Vβ8.2) public clones from the pLN of NOD mice. Importantly, a tolerogenic vaccine composed of an immunodominant peptide that binds the TCR Vβ8.2 chain prevented T1D in NOD mice [ 47 ] supporting the notion that public TCRs may serve as biomarkers and potential therapeutic targets. Currently, autoantibodies represent the best available biomarker to predict human T1D onset.…”