Dectin-1 stimulates IL-33 expression in dendritic cells via upregulation of IRF4.

Interleukin-33 (IL-33) is a potent contributor to antiviral immune responses and antitumor immunity. We recently discovered that IL-33 is overexpressed in dectin-1-activated dendritic cells (DCs). However, mechanisms of dectin-1-induced IL-33 expression in DCs remain elusive. Curdlan, an agonist of dectin-1, was used to mature DCs in this study. We found that dectin-1-induced IL-33 expression in DCs relies on Syk and Raf-1 pathways. By using nuclear factor (NF)-κB inhibitors, we also found that dectin-1-induced IL-33 expression relies on NF-κB signaling. Furthermore, through Syk/Raf-1-NF-κB pathway, dectin-1 signaling stimulates DCs to overexpress interferon regulatory factor 4 (IRF4), which directly upregulates the expression of IL-33 in dectin-1-activated DCs. Thus, our study provides new insights into the mechanisms of dectin-1-induced IL-33 expression in DCs and may provide new targets for improving DC-based cancer immunotherapy.

Identification of a novel autophagy-related prognostic signature and small molecule drugs for glioblastoma by bioinformatics.

OBJECTIVE: To explore the autophagy-related prognostic signature (ARPs) via data mining in gene expression profiles for glioblastoma (GBM). METHODS: Using the Cancer Genome Atlas (TCGA) database, we obtained 156 GBM samples and 5 adjacent normal samples, and denoted them as discovery cohort. Univariate Cox regression analysis was used to screen autophagy genes that related to GBM prognosis. Then, the least absolute shrinkage and selection operator Cox regression model was used to construct an autophagy-based ARPs, which was validated in an external cohort containing 80 GBM samples. The patients in the above-mentioned cohorts were divided into low-risk group and high-risk group according to the median prognostic risk score, and the diagnostic performance of the model was assessed by receiver operating characteristic curve analyses. The gene ontology and Kyoto encyclopedia of genes and genomes pathway enrichment analyses were performed between the high-risk and low-risk patients. Additionally, the genetic features of ARPs, such as genetic variation profiles, correlations with tumor-infiltrating lymphocytes (TILs), and potential drug sensitivity, were further assessed in the TCGA-GBM data set. RESULTS: A signature of ARPs including NDUFB9, BAK1, SUPT3H, GAPDH, CDKN1B, CHMP6, and EGFR were detected and validated. We identified a autophagy-related prognosis 7-gene signature correlated survival prognosis, immune infiltration, level of cytokines, and cytokine receptor in tumor microenvironment. Furthermore, the signature was tested in several pathways related to disorders of tumor microenvironment, as well as cancer-related pathways. Additionally, a range of small molecular drugs, shown to have a potential therapeutic effect on GBM. CONCLUSIONS: We constructed an autophagy-based 7-gene signature, which could serve as an independent prognostic indicator for cases of GBM and sheds light on the role of autophagy as a potential therapeutic target in GBM.

TNF-a Is a Potent Stimulator of Tc9-Cell Differentiation.

Tumor-specific Tc9 cells exhibit an excellent antitumor potential in tumor immunotherapy. Identification of factors that contribute to Tc9-cell differentiation may have important clinical significance. In this study, we found that tumor necrosis factor (TNF)-α promotes Tc9 differentiation in vitro, and the TNF-α-induced Tc9 cells display enhanced cell survival and cell proliferation. More importantly, the TNF-α-induced tumor-specific Tc9 cells have increased antitumor capabilities in vivo. TNF-α activates its downstream signaling through 2 cell surface receptors, TNFR1 and TNFR2. In this study, we found that TNF-α promotes Tc9-cell differentiation through TNFR2, but not TNFR1. Furthermore, we found that TNF-α-TNFR2 activates STAT5 and nuclear factor-κB signaling during Tc9-cell differentiation. Blocking STAT5 or nuclear factor-κB by their specific inhibitors partially abrogates TNF-α-induced promotion of Tc9-cell differentiation. Thus, our study demonstrated TNF-α as a potent stimulator of Tc9-cell differentiation and may have important clinical implications.

Human Cancer Cells Sense Cytosolic Nucleic Acids Through the RIG-I-MAVS Pathway and cGAS-STING Pathway.

Pattern recognition receptors (PRRs) are germline-encoded host sensors of the innate immune system. Some human cancer cells have been reported to express PRRs. However, nucleic acid sensors in human cancers have not been studied in detail. Therefore, we systematically analyzed the expression, molecular cascade, and functions of TLR3, RIG-I, MDA5, LGP2, cGAS, and STING in human cancer cells. TLR3, TRIF, RIG-I, MDA5, LGP2, and MAVS were expressed in 22 cell lines. The majority of cell lines responded to only RIG-I ligands 5'-ppp-dsRNA, Poly(I:C)-HMW, Poly(I:C)-LMW, and/or Poly(dA:dT), as revealed by IRF3 phosphorylation and IFN-ß secretion. IFN-ß secretion was inhibited by RIG-I and MAVS knockdown. cGAS and STING were co-expressed in 10 of 22 cell lines, but IFN-ß secretion was not induced by STING ligands ISD, HSV60, VACV70, Poly(dG:dC), and 3'3'-cGAMP in cGAS and STING intact cell lines. Further experiments revealed that the cGAS-STING pathway was activated, as revealed by TBK1 and IRF3 phosphorylation and IFN-ß and ISG mRNA expression. These results suggest that human epithelial cancer cells respond to cytosolic RNA through the RIG-I-MAVS pathway but only sense cytosolic DNA through the cGAS-STING pathway. These findings are relevant for cancer immunotherapy approaches based on targeting nucleic acid receptors.

TNF-α enhances Th9 cell differentiation and antitumor immunity via TNFR2-dependent pathways.

Tumor specific Th9 cells are potential effector cells for adoptive therapy of human cancers. TNF family members OX40L, TL1A and GITRL have been shown to promote the induction of Th9 cells and antitumor immunity. However, the role of TNF-α, the prototype of the TNF superfamily cytokines, in Th9 cell differentiation and their antitumor efficacy is not defined. Here, we showed that TNF-α potently promoted naïve CD4+ T cells to differentiate into Th9 cells in vitro. Furthermore, the addition of TNF-α during Th9 cell differentiation increased T cell survival and proliferation. More importantly, the adoptive transfer of TNF-α-treated Th9 cells induced more potent antitumor effects than regular Th9 cells in mouse tumor model. TNF-α signals via two cell surface receptors, TNFR1 and TNFR2. Mechanistic studies revealed that TNF-α drove Th9 cell differentiation through TNFR2 but not TNFR1. In addition, under Th9 polarizing condition, TNF-α activated STAT5 and NF-κB pathways in T cells in a TNFR2-dependent manner. Inhibition of STAT5 and NF-κB pathways by their specific inhibitors impaired TNF-α-induced Th9 cell differentiation. Our results identified TNF-α as a new powerful inducer of Th9 cells and clarified the molecular mechanisms underlying TNF-α-induced Th9 cell differentiation.

IL-33 drives the antitumor effects of dendritic cells via the induction of Tc9 cells.

Dendritic cell (DC) tumor vaccines exert their antitumor effects through the induction of effector T cells. We recently identified Tc9 cells as a new potent antitumor effector T cell subset. However, approaches to direct DCs to preferably prime antitumor Tc9 cells should be further exploited. Here, we demonstrate that the addition of interleukin (IL)-33 potently promotes the induction of Tc9 cells by DCs in vitro and in vivo. IL-33 treatment also drives the cytotoxic activities of DC-induced Tc9 cells. Notably, IL-33 treatment enhances cell survival and proliferation of DC-primed CD8+ T cells. More importantly, the addition of IL-33 during in vitro priming of tumor-specific Tc9 cells by DCs increases the antitumor capability of Tc9 cells. Mechanistic studies demonstrated that IL-33 treatment inhibits exhaustive CD8+ T cell differentiation by inhibiting PD-1 and 2B4 expression and increasing IL-2 and CD127 (IL-7 receptor-α, IL-7Rα) expression in CD8+ T cells. Finally, the addition of IL-33 further promotes the therapeutic efficacy of DC-based tumor vaccines in the OT-I mouse model. Our study demonstrates the important role of IL-33 in DC-induced Tc9 cell differentiation and antitumor immunity and may have important clinical implications.

Interleukin-33 Contributes to the Induction of Th9 Cells and Antitumor Efficacy by Dectin-1-Activated Dendritic Cells.

We recently discovered that dectin-1-activated dendritic cells (DCs) drive potent T helper (Th) 9 cell responses and antitumor immunity. However, the underlying mechanisms need to be further defined. The cytokine microenvironment is critical for Th cell differentiation. Here, we show that dectin-1 activation enhances interleukin (IL)-33 expression in DCs. We found that blocking IL-33/ST2 inhibits dectin-1-activated DC-induced Th9 cell differentiation. More importantly, the addition of IL-33 further promotes Th9 cell priming and antitumor efficacy induced by dectin-1-activated DCs. Mechanistically, in addition to the promotion of Th9 and Th1 cells, dectin-1-activated DCs combined with IL-33 abolish the activity of IL-33 in the induction of regulatory T cells. Furthermore, the combined treatment of dectin-1-activated DCs and IL-33 increases the frequencies of CD4+ T cells by fostering their proliferation and inhibiting their exhaustive differentiation. Thus, our results demonstrate the important role of IL-33 in dectin-1-activated DC-induced Th9 cell differentiation and antitumor efficacy, and suggest that the combination of dectin-1-activated DCs and IL-33 may present a new effective modality of DC-based vaccines in tumor immunotherapy.

Dectin-1 signaling inhibits osteoclastogenesis via IL-33-induced inhibition of NFATc1.

Abnormal osteoclast activation contributes to osteolytic bone diseases (OBDs). It was reported that curdlan, an agonist of dectin-1, inhibits osteoclastogenesis. However, the underlying mechanisms are not fully elucidated. In this study, we found that curdlan potently inhibited RANKL-induced osteoclast differentiation and the resultant bone resorption. Curdlan inhibited the expression of nuclear factor of activated T-cells, cytoplasmic 1 (NFATc1), the key transcriptional factor for osteoclastogenesis. Notably, dectin-1 activation increased the expression of MafB, an inhibitor of NFATc1, and IL-33 in osteoclast precursors. Mechanistic studies revealed that IL-33 enhanced the expression of MafB in osteoclast precursors and inhibited osteoclast precursors to differentiate into mature osteoclasts. Furthermore, blocking ST2, the IL-33 receptor, partially abrogated curdlan-induced inhibition of NFATc1 expression and osteoclast differentiation. Thus, our study has provided new insights into the mechanisms of dectin-1-induced inhibition of osteoclastogenesis and may provide new targets for the therapy of OBDs.

Dectin-1-activated dendritic cells trigger potent antitumour immunity through the induction of Th9 cells.

Dectin-1 signalling in dendritic cells (DCs) has an important role in triggering protective antifungal Th17 responses. However, whether dectin-1 directs DCs to prime antitumour Th9 cells remains unclear. Here, we show that DCs activated by dectin-1 agonists potently promote naive CD4(+) T cells to differentiate into Th9 cells. Abrogation of dectin-1 in DCs completely abolishes their Th9-polarizing capability in response to dectin-1 agonist curdlan. Notably, dectin-1 stimulation of DCs upregulates TNFSF15 and OX40L, which are essential for dectin-1-activated DC-induced Th9 cell priming. Mechanistically, dectin-1 activates Syk, Raf1 and NF-κB signalling pathways, resulting in increased p50 and RelB nuclear translocation and TNFSF15 and OX40L expression. Furthermore, immunization of tumour-bearing mice with dectin-1-activated DCs induces potent antitumour response that depends on Th9 cells and IL-9 induced by dectin-1-activated DCs in vivo. Our results identify dectin-1-activated DCs as a powerful inducer of Th9 cells and antitumour immunity and may have important clinical implications.

Effects of sleep deprivation on behaviors and abnormal hippocampal BDNF/miR-10B expression in rats with chronic stress depression.

Being sleep-deprived can relieve the depressed emotions in rats, but the underlying mechanisms remain unknown. In this study, male rats were divided into 3 groups: normal control (NC), chronicunpredictable stress (CUPS) and sleep-deprived (SD). All of the groups were examined using the sucrose consumption test and the open field test. The sucrose consumption test and the open field test were performed for all three groups. The BDNF and miR-10B expressions were examined using real-time PCR and the level of BNDF was discovered by western blotting. In the sucrose consumption test and the open field test, the CUPS rats consumed less sucrose and got fewer score than the NC rats, however the SD rats consumed significantly more sucrose and received higher scores than the CUPS rats. Both the expression of BNDF and the protein levels in the CUPS group was significantly lower than in the NC group. Also, the CUPS group also showed a higher miR-10B expression than the NC group. However, the SD group demonstrated higher BDNF expression and lower miR-10B expression when compared with the CUPS group. Further investigation demonstrated that the BDNF is the direct target gene of miR-10B and BDNF expression, which is negatively correlated with the expression of miR-10B. In the sucrose consumption test, BNDF expression is positively correlated with the sucrose preference rate whereas miR-10B has an opposing correlation. Moreover, the open field test demonstrated that BNDF expression is positively correlated with the scores and the miR-10B expression is negatively correlated. These results indicate that sleep deprivation is closely linked with the downregulation of miR-10B and possibly the upregulation of BDNF in the hippocampus in the CUPS rats.