Flow cytometry results showed that DSS-induced colitis reduced the frequencies of these cells among colonic lamina propria cells, and soluble PD-L1-Fc, PD-L1-Fc/PLGA nanoparticles or PD-L1-Fc/Oxi-αCD nanoparticles significantly increased the Treg (Figs. 5D, 6D, Supplementary Figs. 14D and 15D), Th1-cell (Figs. 5E, 6E, Supplementary Figs. 14E and 15E), and Tfh-cell frequencies in the colonic lamina propria of colitis mice (Figs. 5F, 6F, Supplementary Figs. 14F and 15F). Here, CD274 is linked to colitis.