Fig. 4: Integration of CD4⁺ naive T cells in GuMI-APC demonstrates the contribution of CD4⁺ naive T cells in the systemic immune response to bacterium F. prausnitzii.

a Workflow to establish GuMI-APCT with and without F. prausnitzii. b Illustration of designed co-culture of colonic epithelium, APCs, CD4⁺ T cells, and F. prausnitzii in the GuMI platform. Magenta highlights the inclusion of CD4⁺ T cells. c Live bacterial density of F. prausnitzii at 0 and 48 hours. CFU colony-forming unit. *p < 0.05, two-tailed unpaired t test. Magenta in c–g indicates the effects of F. prausnitzii in the presence of CD4⁺ T cells. d The introduction of CD4⁺ T cells does not influence the TEER values of the monolayer in GuMI. TEER transepithelial electrical resistance. FP F. prausnitzii, NB no bacteria. ns not significant, two-tailed unpaired t test. e The volcano plot compares cytokines/chemokines in apical media in the presence or absence of F. prausnitzii (GuMI-APCT-FP vs. GuMI-APCT-NB). f Significantly increased cytokines in apical media induced by F. prausnitzii in GuMI-APCT. e, f Multiple t test corrected by the Holm–Sidak method. g Transcriptional change of selected inflammation-related genes induced by F. prausnitzii in GuMI-APCT. Magenta boxes indicate a <0.75-fold decrease or >1.5-fold increase, and black boxes indicate no significant difference. Two-tailed unpaired t test. Error bars in c, d, f represent standard deviation.