1). Interestingly, we found that over 50% of ex vivo purified splenic DCs (CD11c+) constitutively expressed Tim-1 (Fig. 1A). While all DC subsets studied expressed Tim-1, the relative intensity of Tim-1 expression was higher on myeloid (CD11b+) DCs and lower on plasmacytoid (B220+) DCs (Fig. 1B). Although culturing cells overnight with media alone upregulated

Tim-1 expression on DCs, activation by TLR signals (LPS/CpG) further increased Tim-1 expression on DCs (Fig. 1C). We also analyzed Tim-1 expression on various immune cell populations isolated from the central nervous system (CNS) at the peak of EAE. Interestingly, CD4+ and CD11b+ cells showed little Tim-1 expression, whereas the majority of CD11c+ cells clearly showed Tim-1 expression on the surface (Fig. 1D), suggesting that under autoimmune inflammatory conditions, DCs are the major Tim-1-expressing population in CNS-infiltrating CHIR-99021 cell line immune cells. To examine whether Tim-1 crosslinking could induce signaling into DCs, we measured NF-κB activity in DCs after treatment with anti-Tim-1

antibodies. Treatment with agonistic/high-avidity anti-Tim-1 mAb 3B3 increased NF-κB activity in DCs in a dose-dependent manner (Fig. 2A). In contrast, treatment with low-avidity anti-Tim-1 mAb RMT1-10 16 did not change NF-κB activity (Fig. 2A), although treatment with RMT1-10 changed T-cell responses 16. As a positive control, treatment with LPS/CpG increased NF-κB activity in DCs. Because NF-κB is a key transcription factor responsible for click here DC activation 18, 19, we next examined Aprepitant whether Tim-1 signaling could induce DC maturation in terms of the expression of surface molecules and the production of cytokines. Compared with the control rIgG2a treatment, treatment with agonistic/high-avidity anti-Tim-1 3B3 resulted in marked upregulation of MHC class II, CD80, and CD86 on DCs (Fig. 2B). As a positive control, LPS plus anti-CD40 resulted in maximal expression of

all molecules on treated DCs. Furthermore, Tim-1 signaling into DCs enhanced the production of proinflammatory cytokines IFN-γ, TNF-α, and IL-6 as determined by both cytometric bead array and real-time PCR (Fig. 2C and D). Moreover, treatment with 3B3 anti-Tim-1 increased the expression of IL-1β and IL-23 (p19/p40) but did not significantly alter the expression of IL-12 p35, TGF-β, or IL-10 (Fig. 2D). Since low-avidity anti-Tim-1 mAb RMT1-10 did not trigger Tim-1 signaling in DCs, treatment with RMT1-10 neither increased the expression of MHC class II, CD80, or CD86 nor enhanced the production of IFN-γ, TNF-α, or IL-6 (Fig. 2B and C). As a positive control, LPS/CpG increased the production of all tested cytokines in DCs. Since cytokines that promote differentiation of Th1 (e.g. IFN-γ) and Th17 cells (e.g.