Follicular helper T cells (Tfh) regulate the differentiation of germinal center B cells and maintain humoral immunity. Notably, imbalances in Tfh differentiation often lead to the development of
autoimmune diseases, including
inflammatory bowel disease (IBD).
Curcumin, a natural product derived from Curcuma longa, is effective in relieving IBD in humans and animals, and its mechanisms of immune regulation need further elaboration. In this study,
dextran sodium sulfate induced
ulcerative colitis in BALB/c mice, and
curcumin was administered simultaneously for 7 days.
Curcumin effectively upregulated the change rate of mouse weight, colonic length, down-regulated colonic weight, index of colonic weight, colonic damage score and the levels of pro-inflammatory
cytokines IL-6,
IL-12,
IL-23 and TGF-[Formula: see text]1 in colonic tissues of
colitis mice. Importantly,
curcumin regulated the differentiation balance of Tfh and their subpopulation in
colitis mice; the percentages of Tfh (CD4[Formula: see text]CXCR5[Formula: see text]BCL-6[Formula: see text], CD4[Formula: see text]CXCR5[Formula: see text]PD-1[Formula: see text], CD4[Formula: see text]CXCR5[Formula: see text]PD-L1[Formula: see text], CD4[Formula: see text]CXCR5[Formula: see text]ICOS[Formula: see text], Tfh17 and Tem-Tfh were downregulated significantly, while CD4[Formula: see text]CXCR5[Formula: see text]Blimp-1[Formula: see text], Tfh1, Tfh10, Tfh21, Tfr, Tcm-Tfh and Tem-GC Tfh were upregulated. In addition,
curcumin inhibited the expression of Tfh-related
transcription factors BCL-6, p-STAT3, Foxp1, Roquin-1, Roquin-2 and SAP, and significantly upregulated the
protein levels of Blimp-1 and STAT3 in colon tissue. In conclusion,
curcumin may be effective in alleviating
dextran sulfate sodium-induced
colitis by regulating Tfh differentiation.