Fig. 2: Single-component cytokine adaptor T.3 converts TGF-β stimulation to IL-2 signaling in human primary T cells.

a Schematic illustrating rationale for designing single-component cytokine adaptors. In the two-component system (top), non-productive pairs of T.1/T.1 and T.2/T.2 are not able to dimerize IL-2Rβ and γ_c. To engineer a single-component adaptor (bottom), the two components are linked by a flexible linker, such that receptor dimerization is compelled only in the presence of TGF-β. b Several single-component cytokine adaptors were designed with varying orientations and linker lengths. Adaptors T.3, T.4, and T.5 contain N-terminal IL-2RβNb6 and linker lengths of 20aa, 30aa, or 10aa respectively, while Adaptor T.6 features a reversed orientation. c, d Single-component adaptors suppress TGF-β-induced pSMAD2/pSMAD3 signaling while stimulating pSTAT5 signaling in human CD4⁺ (c) and CD8⁺ (d) T cell blasts. Data is represented as mean fluorescence intensity of phospho-STAT5 (n = 2) and pSMAD2/pSMAD3 (n = 1) of T cells treated with 10 nM TGF-β +/- Adaptor T.3, T.4, T.5, or T.6. Bar graphs represent mean ± SD. e, f Single-component adaptor T.3 improves dose–response signaling in human primary T cells. Dose–response curves are shown for phospho-STAT5 in human CD4⁺ (e) and CD8⁺ (f) T cell blasts stimulated for 20 min with human IL-2, Adaptor T.3, TGF-β with equimolar Adaptor T.3, or TGF-β with equimolar Adaptor T.1 and Adaptor T.2. Data are plotted as mean, n = 2, N = 3. g Schematic illustrating the suppressive effects of TGF-β and stimulatory effects of IL-2 on T cell proliferation and cytotoxicity in the tumor microenvironment. h–j Adaptor T.3 increases CD8⁺ T cell proliferation (h), IFN-γ (i), and TNF-α (j) production in the presence of TGF-β. Bar graphs represent mean, n = 3, N = 3. * indicates p < 0.05, ** indicates p < 0.01 by one-way non-parametric ANOVA (Kruskal–Wallis test) with multiple comparisons. Bar graphs represent mean ± SD. Source data are provided as a Source data file.