Fig. 3. Generation of chimeric CD8β chains functionally integrated into the immune synapse.

A Schematic of the multi-cistronic vector designs used to integrate CCRs downstream of CD8β. Image created in BioRender. Tang, A. (2026) https://BioRender.com/6wg9k7f. B Histogram of CD8α (left), CD8β (middle), and MAGE-A1 p/HLA multimer (right) binding of CD4 transduced to express T_TCR-MA1 with the indicated CCRs after transduction for equal transduction copy numbers and post-REP (rapid expansion protocol) p/HLA multimer binding. C (left) Fit curves of IFNγ expression in response to decreasing peptide concentrations by CD4 T cells transduced with TTCR-MA1 and the indicated CCRs, as well as CD8αα (negative control), measured 18h post peptide stimulation. (right) Mean half maximal effective concentration (EC₅₀) of IFNγ expression for CD4 T cells transduced with the same constructs. D Fold change of IFNγ levels in T_TCR-MA1 cells transduced to express the different CCR constructs and incubated for 18 h with 1 µM cognate peptide alone (left panel) or incubated with 1 µM cognate peptide following 1 week of priming by co-culture with irradiated ME275 (right panel). E (left) Growth kinetics of the ME275 cell line in the absence (black lines) or presence of CD4 with the indicated CCR constructs from a live tumor visualization assay (Incucyte S3). An E:T ratio of 10:1 was used, and tumors were added to the culture every 72 h. (middle) Final tumor integrated intensity for the same experiment 16 days after start (384 h). (right) Final lymphocyte counts were obtained after 16 days. p-values determined by one-way ANOVA with Tukey’s multiple comparison test. (n = 3 wells/group). All data are presented as mean ± (SD).