High-Throughput Sequencing of Islet-Infiltrating Memory CD4.sup.+ T Cells Reveals a Similar Pattern of TCR V[beta] Usage in Prediabetic and Diabetic NOD Mice

Autoreactive memory CD4.sup.+ T cells play a critical role in the development of type 1 diabetes, but it is not yet known how the clonotypic composition and TCR[beta] repertoire of the memory CD4.sup.+ T cell compartment changes during the transition from prediabetes to diabetes. In this study, we used high-throughput sequencing to analyze the TCR[beta] repertoire of sorted islet-infiltrating memory CD4.sup.+ CD44.sup.high T cells in 10-week-old prediabetic and recently diabetic NOD mice. We show that most clonotypes of islet-infiltrating CD4.sup.+ CD44.sup.high T cells were rare, but high-frequency clonotypes were significantly more common in diabetic than in prediabetic mice. Moreover, although the CD4.sup.+ CD44.sup.high TCR[beta] repertoires were highly diverse at both stages of disease development, dominant use of TRBV1 (V[beta]2), TRBV13-3 (V[beta]8.1), and TRBV19 (V[beta]6) was evident in both prediabetic and diabetic mice. Our findings strongly suggest that therapeutic targeting of cells specifically expressing the dominant TCR[beta] might reduce pancreatic infiltration in prediabetic mice and attenuate the progression to diabetes.