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bioRxiv · 10.64898/2026.03.20.712252

Donor-derived CD8+CD122+ Tregs generated in mixed donor chimeric NOD mice delete autoreactive T cells

Pathak, S.·Bader, C. S.·Iliopoulou, B. P.·Regmi, S.·Chen, P.-I.·Gupta, B.·Wu, X.·Mosher, B.·Wells, A.·Witherspoon, L.·jenkins, K.·Harper, W.·SooHoo, E.·Twoy, A.·Ahmed, R.·Dutt, S.·Nagy, N.·Jensen, K. P.·Fathman, G.·Thakor, A. S.·Davis, M. M.·Meyer, E. H.
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Abstract

The establishment of mixed hematopoietic chimerism is a promising way to induce immune tolerance for islet replacement therapy and to treat the underlying autoimmunity in type 1 diabetes (T1D). Mixed chimerism not only promotes effective thymic negative selection of autoreactive cells but also restores regulatory T cell (Treg) function and peripheral tolerance. In the current study, we determined that a novel class of donor-derived CD8+CD44+CD122+ Tregs (d-CD8+CD122+ Tregs) plays a crucial role in controlling autoimmunity in non-obese diabetic (NOD) mice with induced mixed chimerism. Using adoptive T cell transfer experiments, we showed that d-CD8+CD122+ Tregs abrogate autoimmunity by selectively depleting the exogenously injected diabetogenic T cells in Recombination-Activating Gene deficient NOD mice. These d-CD8+CD122+ Tregs from NOD chimeras show upregulation of Helios, Programmed cell death protein 1, perforin, granzyme-B, CD39, Folate receptor 4, and downregulation of proinflammatory markers like Scart1 and Scart2. Using in vitro assays, we show that d-CD8+CD122+ Tregs respond specifically to a Complementarity-Determining Region-3 peptide sequence derived from T cell receptors of islet antigen-specific autoreactive T cells. Similarly, we found that individuals with T1D have a deficiency in CD8+CD122+ Tregs, suggesting a potential loss of regulatory function accompanies disease onset. Revitalizing CD8+CD122+ Tregs may offer a new therapeutic strategy of restoring immune tolerance in autoimmune diabetes.

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Pathak, S., Bader, C. S., Iliopoulou, B. P., Regmi, S., Chen, P.-I., Gupta, B., Wu, X., Mosher, B., Wells, A., Witherspoon, L., jenkins, K., Harper, W., SooHoo, E., Twoy, A., Ahmed, R., Dutt, S., Nagy, N., Jensen, K. P., Fathman, G., Thakor, A. S., Davis, M. M., Meyer, E. H.. 2026-03-22. Donor-derived CD8+CD122+ Tregs generated in mixed donor chimeric NOD mice delete autoreactive T cells. https://doi.org/10.64898/2026.03.20.712252

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