Reduced thymic IL-4 impairs negative T cell selection in nonobese diabetic mice
Alexis N. Cattin-Roy, … , Adam G. Schrum, Habib Zaghouani
Alexis N. Cattin-Roy, … , Adam G. Schrum, Habib Zaghouani
Published December 2, 2024
Citation Information: J Clin Invest. 2024;134(23):e163417. https://doi.org/10.1172/JCI163417.
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Research Article Autoimmunity

Reduced thymic IL-4 impairs negative T cell selection in nonobese diabetic mice

Abstract

Type 1 diabetes (T1D) develops spontaneously despite functional antigen presentation machinery in the thymus and a perceptible central tolerance process. We found that intrathymic enrichment with IL-4 fine tunes signaling through the IL-4/IL-13 heteroreceptor (HR) in early thymic progenitors (ETPs), augments negative selection of self-reactive T cells, sustains a diverse T cell repertoire devoid of clones expressing disease-associated T cell receptor (TCR) genes, and protects the nonobese diabetic (NOD) mouse from T1D. Indeed, optimal IL-4 activates STAT transcription factors to program ETP fate decision toward CD11c+CD8α+ dendritic cells (DCs) agile in negative T cell selection and clonal deletion of diabetogenic T cells. However, due to diminished invariant natural killer T (iNKT) 2 cell frequency in the NOD thymus, IL-4 is as suboptimal level, metering STAT activation to program ETP fate decision toward the T cell lineage leading to diminished negative selection, a clonally restricted TCR repertoire, and manifestation of spontaneous T1D. These insights uncover yet another interplay by which IL-4 affects T1D.

Authors

Alexis N. Cattin-Roy, Kimberly G. Laffey, Luan B. Le, Adam G. Schrum, Habib Zaghouani

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Figure 4

IL-4/IL-13 reverse NOD HR+ETP fate decision toward myeloid cells.

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IL-4/IL-13 reverse NOD HR+ETP fate decision toward myeloid cells. (A and...
(A and B) Sorted NOD HR+ETPs (from 12 mice) were cultured on OP9-DL1 + IL-7/Flt3L in the absence (NIL) or presence (treated) of IL-4 or IL-13 for 10 days. (A) The contour plot shows a representative experiment illustrating reduction in fate decision toward the T cell lineage. (B) The graphs show the frequency of lymphoid lineage cells compiled from 3 experiments. The error bars represent the mean ± SD. *P < 0.01 as determined by 2-tailed, unpaired Student’s t test. (C and D) The HR+ETPs were stimulated with IL-4, IL-13, IL-4 + 13, or NIL (PBS), and phosphorylation of STAT6 and STAT1 transcription factors were analyzed by flow cytometry. (C) The histograms show a representative phosphorylation experiment. (D) The graphs show MFI data compiled from 3 experiments. The error bars represent the mean ± SD. *P < 0.05, ***P < 0.001 as determined by 1-way ANOVA with Tukey’s post test. (E) 4-week-old IL-13Rα1+/+-GFP reporter NOD mice were given i.t. IL-4 weekly for 2 weeks. 7 days later, HR+ETPs were sorted from the thymi of at least 10 mice and cultured on OP9-DL1 stromal cells for 10 days. The contour plots show a representative experiment illustrating the frequency of CD25+ lymphoid lineage cells. The graph shows compiled results from 3 experiments. The error bars represent the mean ± SD. ***P < 0.001 as determined by 2-tailed, unpaired Student’s t test. (F and G) HR+ETPs sorted from CD45.1 IL-13Rα1+/+-GFP reporter NOD mice were stimulated with IL-4 ex vivo and injected i.t. into a congenic NOD host (CD45.2). On day 16 after transfer, thymic cells were analyzed for lineage commitment. (F) The contour plots show a representative experiment illustrating expression of CD3 on ETP-derived cells. The graph represents the average frequency of CD3+ cells as compiled from 3 experiments. (G) The contour plots show a representative experiment illustrating expression of CD11b, CD11c, and CD8α on ETP-derived cells. The graph shows the frequency of CD11b+CD11c+, CD11b+, CD11c+, and CD11c+CD8α+ cells of data compiled from 3 to 4 experiments. For F and G, the error bars represent the the mean ± SD and **P < 0.01, ***P < 0.001 were determined by 2-tailed, unpaired Student’s t test.