TLR4 and colitis: Since LPS preconditioning enhances anti-inflammatory properties of DCs [34], adoptive transfer of TLR-4-primed WTDCs attenuated DSS-induced colitis by increasing serum levels of IL-10 and KYN and by inducing expansion of colon-infiltrating, IL-10-producing Tregs which was accompanied by alleviated Th1 and Th17 cell-driven inflammation (Figure 6).