Fig. 2: Myeloid knockout of Wdfy3 augments CD4⁺ T cell activation by promoting MHC-II-mediated antigen presentation.

a Schematics of study design. Cre⁻ and Cre⁺ littermates were used to assess T cell activation. b The percentage of CD44^highCD62L^low activated T cells in CD4⁺ and CD8⁺ T cells in the blood. n = 12 Cre⁻ vs 14 Cre⁺ mice and n = 11 Cre⁻ vs 13 Cre⁺ mice, respectively. c The percentage of CXCR3⁺ activated T cells in CD4⁺ and CD8⁺ T cells in the blood. n = 10 Cre⁻ vs 13 Cre⁺ mice. d The percentage of CD44^highCD62L^low activated T cells in splenic CD4⁺ and CD8⁺ T cells. n = 6 Cre⁻ vs 8 Cre⁺ mice. e, f In vitro antigen presentation assay. BMDMs were pre-treated with synthetic ovalbumin (OVA) for 24 h, followed by incubating with splenic T cells isolated from OT-II or OT-I transgenic mice for 72 h to assess OVA_323-339 or OVA_257-264-specific activation of CD4⁺ T cells (OT-II mice) or CD8⁺ T cells (OT-I mice) that recognize OVA peptide residues when presented by the MHC-II or MHC-I molecules, respectively. The OT-II or OT-I mouse T cells were pre-labeled by carboxy-fluorescein succinimidyl ester (CFSE) to monitor the dilution of CFSE signal in daughter cells as T cells divide. n = 6 Cre⁻ vs 5 Cre⁺ mice. Effector T cell differentiation was assessed using a set of markers as indicated in the figures. n = 3 Cre⁻ vs 3 Cre⁺ mice. g–l In vivo antigen presentation assay. g–i Mice were immunized with OVA_323-339 for 24 h before the injection of CFSE-labeled splenic CD4⁺ T cells from CD90.1⁺ OT-II mice. 72 h after injection, CFSE dilution in CD4⁺CD90.1⁺ blood and splenic T cells, and splenic T cell activation were assessed. n = 5 Cre⁻ vs 5 Cre⁺ mice for blood, and n = 5 Cre⁻ vs 7 Cre⁺ mice for spleen. j–l Mice were immunized with OVA_257-264 for 24 h before the injection of CFSE-labeled splenic CD8⁺ T cells from CD90.1⁺ OT-I mice. Seventy-two hours after injection, CFSE dilution in CD8⁺CD90.1⁺ blood and splenic T cells, and splenic T cell activation were assessed. For blood, n = 6 Cre⁻ vs 6 Cre⁺ mice; for spleen, n = 5 Cre⁻ vs 5 Cre⁺ mice (proliferation) and 6 Cre⁻ vs 6 Cre⁺ mice (T cell subsets). Data are shown as mean ± SEM. A two-tailed Student’s t-test was applied to all data.