Causal relationship between circulating cytokines and follicular lymphoma: a two-sample Mendelian randomization study.

Follicular lymphoma (FL), derived from germinal centre (GC) B cells, is a kind of systemic neoplasm. Even though FL is indolent, it remains an incurable haematology Neoplasm. Accumulating evidence has suggested that the circulating cytokine is associated with the development of FL, yet the causal relationship between FL and circulating cytokines remains undetermined. Therefore, we conducted a two-sample Mendelian randomization (MR) to confirm the causal link between FL and levels of circulating cytokines with the use of summary data on circulating cytokines and FL. All these data from genome-wide association study were derived from the Genome-wide pQTL mapping which contains 14,824 individuals. FL data were acquired exclusively from FinnGen, where 218,792 individuals (522 cases vs. 218,270 controls) were involved. Various statistical methods, including the inverse variance weighted method (IVW), weighted median (WME), simple model, weighted model (WM) and MR-Egger, were used to evaluate the potential causal connection between circulating cytokines and FL. Sensitivity analysis, which involves the examination of the heterogeneity, pleiotropy, and leave-one-out method, was also performed to ensure more trustworthy results. A bidirectional MR test was performed to evaluate the direction of causal association between circulating cytokines and FL. Combining all the steps of MR analysis, we revealed four causal cytokines: C-X-C motif chemokine ligand 5 (CXCL5), interleukin-15 receptor A (IL15RA), interleukin-20 (IL20), and neurotrophin-3 (NT-3). The risk of FL may be inversely linked to CXCL5 (OR=0.73, CI: 0.545-0.979, P=0.036), IL-15RA (OR=0.669, CI: 0.451-0.993, P=0.046), and IL-20 (OR=0.565, CI: 0.325-0.981, P=0.043) but positively linked to NT-3 (OR=1.872, CI: 1.063-3.297, P=0.03). In addition, in our study, no causal effect of FL on cytokines was demonstrated and no significant heterogeneity and pleiotropy were found. Our research revealed the causal relationship between cytokines and FL, along with both the anti-protective effect of CXCL5, IL-15RA, and IL-20 and the protective effect of neurotrophin-3 on FL. These findings aim to provide new clues regarding the pathogenesis of FL and to extend the potential of circulating cytokines to therapeutic interventions.

Inhibition of miR-93 promotes interferon effector signaling to suppress influenza A infection by upregulating JAK1.

Type I interferons play a critical role in host defense against influenza virus infection. Interferon cascade induces the expression of interferon-stimulated genes then subsequently promotes antiviral immune responses. The microRNAs are important regulators of innate immunity, but microRNAs-mediated regulation of interferon cascade during influenza infection remains to be fully identified. Here we found influenza A virus (IAV) infection significantly inhibited miR-93 expression in alveolar epithelial type II cells through RIG-I/JNK pathway. IAV-induced downregulation of miR-93 was found to upregulate JAK1, the target of miR-93, and then feedback promote antiviral innate response by facilitating IFN effector signaling. Importantly, in vivo administration of miR-93 antagomiR markedly suppressed IAV infection, protecting mice form IAVs -associated death. Hence, the inducible downregulation of miR-93 feedback suppress IAV infection by strengthening IFN-JAK-STAT pathway via JAK1 upregulation, and in vivo inhibition of miR-93 bears considerable therapeutic potential for suppressing IAV infection.

Inhibition of allogeneic islet graft rejection by VISTA-conjugated liposome.

The Ig superfamily member V-domain Ig-containing suppressor of T-cell activation (VISTA) is a negative regulator with broad-spectrum activities and has reported that blockade of VISTA or combination with other negative checkpoint receptors sufficiently break tumor tolerance. However, it remains unclear whether VISTA could induce allogeneic T-cell hyporesponsiveness and inhibit allograft rejection. Here we found VISTA treatment significantly inhibited lymphocyte proliferation and activation in allogeneic MLR assay through impairing SYK-VAV pathway. Interestingly, though neither VISTA protein nor VISTA-Fc fusion protein administration exerted satisfactory immunosuppressive effect on allograft survival due to their short half-life in circulation, this problem was solved by conjugating VISTA protein on liposome by biotin-streptavidin system, which markedly prolonged its circulating half-life to 60 h. With islet transplant model, administration of VISTA-conjugated liposome could markedly prolong allograft survival by inhibition of SYK-VAV pathway, thus maintained the normal blood glucose level of recipients during treatment period. The results indicate VISTA is a promising therapeutic target to treat allograft rejection of islet transplantation.

Tanshinone IIA activates autophagy to reduce liver ischemia-reperfusion injury by MEK/ERK/mTOR pathway.

Autophagy is a highly conserved cell program in eukaryotic cells, which plays an important role for cells to deal with adverse external stimuli such as ischemia-reperfusion. Tanshinone IIA (TanIIA) is well known for its protective effect on myocardial disease, and it is know that it also could regulate autophagy in different cells. As this has not yet been shown for hepatocytes, using a mice liver ischemia-reperfusion model, we detected the role of TanIIA in regulating autophagy and the subsequent protective effects on hepatocytes. Our data showed that TanIIA pretreatment could significantly enhance autophagy by the MEK/ERK/mTOR pathway in hepatocytes after liver ischemia-reperfusion, and the enhanced autophagy decreased ROS generation by clearing damaged mitochondria, providing a protective effect on liver ischemia-reperfusion. This protective effect is manifested as reduced serum enzyme levels, reduced liver tissue damage, decreased inflammatory cell infiltration, decreased inflammatory cytokines and reduced hepatocyte apoptosis. In brief, moderate TanIIA utilization might be a potential treatment approach for clinically liver ischemia-reperfusion.

Blocking activity of the HPV18 virus in cervical cancer cells using the CRISPR/Cas9 system.

OBJECTIVE: Specific sgRNA-sequences targeting oncogenes E6 and E7 in HPV18 were designed using the CRISPR/Cas9 system. These sgRNAs knocked out E6 and E7 expressions and were used to study their effects on the proliferation and cell cycle of the cervical cancer HeLa cell line. METHODS: Lentivirus vectors targeting E6 and E7 oncogenes were constructed and transfected into HeLa cells. mRNA and protein expression levels of E6 and E7 were measured by RT-PCR and Western blot, respectively. The cell cycle was detected by flow cytometry. A colony formation assay was applied to evaluate the proliferation capacity of the HeLa cells. RESULTS: Three E6 Cas9-sgRNA vectors targeting E6 and three E7 Cas9-sgRNA vectors targeting E7 genes were constructed and transfected into HeLa cells, respectively. RT-PCR results showed that all three E6 and E7 sgRNAs inhibited the expressions of E6 or E7 mRNA, respectively, when compared with the control groups. The inhibition ratios of the three groups of E6-sgRNAs were 28%, 85%, and 19%; the E7-sgRNAs were 86%, 25%, and 27%, respectively (P<0.05), with E6-sgRNA2 and E7-sgRNA1 having the greatest inhibitory effects. Western blot results showed that, compared with the control group, the protein expressions of E6 and E7 in the sgRNAs transfected group were also decreased, and E6-sgRNA2 and E7-sgRNA1 had the most inhibitory effects on E6 and E7 proteins. Flow cytometry results showed that the number of cells in G1/G0 was increased by 14.2% in the E6-sgRNA2 transfection group, and by 7.1% in the E7-sgRNA1 transfection group. Colony formation assay results showed that after transfection of E6 or E7 sgRNA plasmids, the HeLa cell colony was reduced significantly compared with the control group. CONCLUSIONS: The CRISPR/Cas9 system targeting HPV18 E6 or E7 genes effectively blocked the transcription and expression of oncogenes E6 or E7 in HeLa cells, which resulted in cell cycle arrest and reduced cell proliferation.

Sirtinol regulates the balance of Th17/Treg to prevent allograft rejection.

BACKGROUND: Current immunosuppressive medications used after transplantation induce significant toxicity , and a new medication regimen is needed. Based on recent research, Sirt1 exerts a proinflammatory effect on the immune response. Sirtinol is a Sirt1 inhibitor, but its impact on allograft rejection and its molecular mechanisms of action have not yet been reported. RESLUTS: In this study, we examined the effect of sirtinol on prolonging allograft survival in a mouse cervical heterotopic heart transplantation model. Based on an examination of the allograft, allografts from sirtinol-treated recipients show significantly lower levels of IL-17A expression and higher levels of Foxp3 expression. In vivo, sirtinol reduces the proportion of Th17 cells and increases the proportion of Treg cells in splenocytes from recipients. In vitro, sirtinol reduces the proportion of Th17 cells and decreases the expression of IL-17A and RORγt in an isolated CD4+ T cell population. Moreover, we identified synergistic effects of sirtinol and FK506 on prolonging allograft survival, and sirtinol synergizes with FK506 to promote Foxp3 expression. CONCLUSION: Sirtinol, a Sirt1 inhibitor, may be a promising immunosuppressive drug to prevent the rejection reaction in combination with FK506.

MiR-199a/b-5p inhibits hepatocellular carcinoma progression by post-transcriptionally suppressing ROCK1.

In this study, we explored the actions of miR-199a/b-5p during hepatocellular carcinoma (HCC) progression and its potential target genes. Through heatmap miRNA expression analysis of 15 matched HCC tumor and adjacent non-tumor liver tissues from the TCGA database, we detected 19 mRNAs that were upregulated and 13 that were downregulated specifically in HCC. Among these, miR-199 family members were downregulated in HCC tumors and cell lines, as compared to controls. Low miR-199a/b-5p expression was also associated with poor overall survival of HCC patients. miR-199a/b-5p overexpression in HCC cell lines inhibited cell proliferation, migration and invasion, both in vitro and in vivo. In addition, miR199-a/b-5p post-transcriptionally suppressed Rho-associated coiled-coil kinase 1 (ROCK1). This in turn led to inhibition of ROCK1/MLC and PI3K/Akt signaling, which is necessary for HCC proliferation and metastasis. These results indicate that miR-199a/b acts as tumor suppressors in HCC and represent promising therapeutic targets.

Rb selectively inhibits innate IFN-ß production by enhancing deacetylation of IFN-ß promoter through HDAC1 and HDAC8.

Type I IFN production is tightly controlled by host to generate efficient viral clearance without harmful immunopathology or induction of autoimmune disorders. Epigenetic regulation of type I IFN production in innate immunity and inflammatory disorders remains to be fully understood. Several tumor suppressors have been shown to regulate immune response and inflammation. However, the non-classical functions of tumor suppressors in innate immunity and inflammatory diseases need further identification. Here we report retinoblastoma protein (Rb) deficiency selectively enhanced TLR- and virus-triggered production of IFN-ß which thus induced more IFN-α generation in the later phase of innate stimuli, but had no effect on the production of TNF, IL-6 and early phase IFN-α in macrophages. Rb1(fl/fl)Lyz2cre(+) Rb-deficient mice exhibited more resistant to lethal virus infection and more effective clearance of influenza virus. Rb selectively bound Ifnb1 enhancer region, but not the promoter of Ifna4, Tnf and Il6, by interacting with c-Jun, the component of IFN-ß enhanceosome. Then Rb recruited HDAC1 and HDAC8 to attenuate acetylation of Histone H3/H4 in Ifnb1 promoter, resulting in suppression of Ifnb1 transcription. Therefore, Rb selectively inhibits innate IFN-ß production by enhancing deacetylation of Ifnb1 promoter, exhibiting a previous unknown non-classical role in innate immunity, which also suggests a role of Rb in the regulation of type I IFN production in inflammatory or autoimmune diseases.

Protective role of autophagy in methionine-choline deficient diet-induced advanced nonalcoholic steatohepatitis in mice.

The methionine choline-deficient (MCD) diet leads to severe liver injury similar to human nonalcoholic steatohepatitis (NASH). Autophagy has emerged as a critical lysosomal pathway that maintains cell function and survival through the degradation of cellular components such as organelles and proteins. The goal of this study was to elucidate the role of autophagy in MCD-induced steatosis, fibrosis, inflammation, mitochondrial dysfunction, and endoplasmic reticulum (ER) stress in mice. Mice were fed with MCD diet and treated with rapamycin (an autophagy enhancer) or chloroquine (an autophagy inhibitor) for 10 weeks. Liver injury was evaluated biochemically and histologically together with hepatic gene expression analysis. Autophagic flux was impaired in livers of mice fed with MCD diet, evidenced by reduced ratio of LC3-II/LC3-I and increased protein expression of p62. It was found that autophagy activation by rapamycin attenuated MCD-induced steatosis, fibrosis, inflammation, mitochondrial dysfunction, and ER stress. By contrast, MCD mice treated with chloroquine developed more liver injury. In conclusions, the autophagic pathway plays an important protective role in MCD-induced advanced NASH. Thus, pharmacological promotion of autophagy may provide a novel therapeutic strategy for treatment of NASH.

Adhesion: a confounding bias in murine cervical heterotopic heart transplantation.

Tissue adhesion is a common postsurgical phenomenon among the human population. This complication also occurs in murine transplant models. In this study, we investigated the impact of adhesion on murine cervical heterotopic heart transplantation by using sodium hyaluronate (SH) as an anti-adhesive agent. Our study revealed that SH administration produced no significant effect on histological change, TNF-α, IFN-γ, MCP-1, IL-2, IL-6 and IL-10 expression, CD4(+) T, CD8(+) T, or neutrophil and macrophage counts. Our findings suggest that SH was biocompatible and non-immunogenic. Later, we observed that adhesion not only affected the survival of the graft without mediating rejection, but was closely related to the severity of rejection as manifested by larger and more severe adhesion formation in total-allomismatched and MHC class II-allomismatched murine cardiac allografts. Therefore, we inferred that using the murine cervical heterotopic heart transplant model may lead to an exaggerated p-value in statistical significance testing which could mislead experimenters in considering that the results are more significant than the fact. To the best of our knowledge, this study is the first demonstration that proves that adhesion was a confounding bias in the murine cervical heterotopic heart transplant model and highlights the possibilities for improvement in future use.

Tri-iodothyronine preconditioning protects against liver ischemia reperfusion injury through the regulation of autophagy by the MEK/ERK/mTORC1 axis.

BACKGROUND AND OBJECTIVES: The autophagy pathway has previously been suggested as an important protective factor in liver injury. The purpose of this study is to demonstrate the protective, autophagy-modulating effect of tri-iodothyronine (T3) on liver ischemia reperfusion injury. METHODS: Liver ischemia reperfusion was induced in male C57BL/6 mice after T3 administration. Liver function, histological damage, inflammatory infiltration, cytokine production, oxidative stress, antioxidant capacity, autophagy changing, and autophagy-associated intracellular signaling pathway were assessed to evaluate the impact of antecedent T3 treatment on ischemia reperfusion induced liver injury. RESULTS: After 70% liver ischemia reperfusion injury, mice that were preconditioned with appropriate T3 displayed significantly preserved liver function, less histological damage, less apoptosis, and enhanced antioxidant capacity. Further studies revealed that mice which were preconditioned with T3 before IR induction exhibited an increased level of autophagy mediated by MEK/ERK/mTORC1. CONCLUSIONS: Our results provide the first line of evidence indicating that antecedent T3 injection can provide protection for the liver against ischemia reperfusion induced injury by enhancing autophagy. Therefore, T3 preconditioning could be a potential therapeutic approach to prevent liver IR injury related to various clinical conditions.

TRIF promotes angiotensin II-induced cross-talk between fibroblasts and macrophages in atrial fibrosis.

AIMS: Atrial fibroblasts and macrophages have long been thought to participate in atrial fibrillation (AF). However, which specific mediator may regulate the interaction between them remains unclear. METHODS AND RESULTS: We provided the evidence for the involvement of Toll/IL-1 receptor domain-containing adaptor inducing IFN-ß (TRIF), an important inflammation-related molecule, in the pathophysiology of AF. Patients with AF showed higher levels of angiotensin II (AngII) and TRIF expression and larger number of macrophages infiltration in left atria appendage than individuals with sinus rhythm (SR). In the cell study, AngII induced chemokines expressions in mouse atrial fibroblasts and AngII-stimulated atrial fibroblasts induced the chemotaxis of macrophages, which were reduced by losartan and TRIF siRNA. Meanwhile, AngII-stimulated atrial fibroblasts proliferation was enhanced by macrophages. CONCLUSIONS: Our data demonstrated that TRIF may be a crucial factor promoting the interaction between atrial fibroblasts and macrophages, leading to atrial fibrosis.

Conditional Knockout of Src Homology 2 Domain-containing Protein Tyrosine Phosphatase-2 in Myeloid Cells Attenuates Renal Fibrosis after Unilateral Ureter Obstruction.

BACKGROUND: Src homology 2 domain-containing protein tyrosine phosphatase-2 (SHP-2) is a kind of intracellular protein tyrosine phosphatase. Studies have revealed its roles in various disease, however, whether SHP-2 involves in renal fibrosis remains unclear. The aim of this study was to explore the roles of myeloid cells SHP-2 in renal interstitial fibrosis. METHODS: Myeloid cells SHP-2 gene was conditionally knocked-out (CKO) in mice using loxP-Cre system, and renal interstitial fibrosis was induced by unilateral ureter obstruction (UUO). The total collagen deposition in the renal interstitium was assessed using picrosirius red stain. F4/80 immunostaing was used to evaluate macrophage infiltration in renal tubular interstitium. Quantitative real-time polymerase chain reaction and enzyme linked immunosorbent assay were used to analyze the production of cytokines in the kidney. Transferase-mediated dUTP nick-end labeling stain was used to assess the apoptotic renal tubular epithelial cells. RESULTS: Src homology 2 domain-containing protein tyrosine phosphatase-2 gene CKO in myeloid cells significantly reduced collagen deposition in the renal interstitium after UUO. Macrophage infiltration was evidently decreased in renal tubular interstitium of SHP-2 CKO mice. Meanwhile, the production of pro-inflammatory cytokines was significantly suppressed in SHP-2 CKO mice. However, no significant difference was observed in the number of apoptotic renal tubular epithelial cells between wild-type and SHP-2 CKO mice. CONCLUSIONS: Our observations suggested that SHP-2 in myeloid cells plays a pivotal role in the pathogenesis of renal fibrosis, and that silencing of SHP-2 gene in myeloid cells may protect renal from inflammatory damage and prevent renal fibrosis after renal injury.

The role of 1,25-dyhydroxyvitamin D3 in mouse liver ischemia reperfusion injury: regulation of autophagy through activation of MEK/ERK signaling and PTEN/PI3K/Akt/mTORC1 signaling.

Autophagy is an important mechanism for cellular homeostasis and survival during pathologic stress conditions in the liver, such as ischemia-reperfusion injury. In this study, we hypothesized a protective role of vitamin Din hepatic IR model. The administration of vitamin D displayed significantly preserved liver function as characterized by less histological damage and reduced serum enzymes level. We found that the protective effect was associated with ameliorated oxidative stress as manifested by the increase of antioxidant capacity and decrease of lipid peroxidation. Further, increased autophagic flux after vitamin D administration was demonstrated by the increase of protein light chain 3 (LC3) conversion both in vivo and in vitro. MEK/ERK and PTEN/PI3K/Akt/mTOR were both found critically involved in vitamin D-induced autophagy. By employing intracellular ROS and cell viability assay, we further confirmed this hypothesis with the observation that inhibition either of the MEK/ERK or PTEN/PI3K/Akt/mTOR pathway partly abolished the protective effect of vitamin D-induced autophagy, while inhibiting initiation of autophagy signaling pathway by knockdown of Beclin-1 completely reversed the protection provided by vitamin D. Collectively, the present results indicate that the protective role of vitamin D in murine hepatic IR injury is autophagy dependent, which is regulated by both MEK/ERK and PTEN/PI3K/Akt/mTOR pathway.

Pioglitazone inhibits angiotensin II-induced atrial fibroblasts proliferation via NF-κB/TGF-ß1/TRIF/TRAF6 pathway.

The exact mechanisms underlying inhibitory effects of pioglitazone (Pio) on Angiotensin II (AngII)-induced atrial fibrosis are complex and remain largely unknown. In the present study, we examined the effect of Pio on AngII-induced mice atrial fibrosis in vivo and atrial fibroblasts proliferation in vitro. In vivo study showed that AngII infusion induced atrial fibrosis and increased expressions of Toll/IL-1 receptor domain-containing adaptor inducing IFN-ß (TRIF) and tumor necrosis factor receptor associated factor 6 (TRAF6) in mice models. However, those effects could be attenuated by Pio (P<0.01). As for in vitro experiment, Pio suppressed AngII-induced atrial fibroblasts proliferation via nuclear factor-κB/transforming growth factor-ß1/TRIF/TRAF6 signaling pathway in primary cultured mice atrial fibroblasts (P<0.01). In conclusion, suppression of Pio on AngII-induced atrial fibrosis might be related to its inhibitory effects on above signaling pathway.

Near-term anti-CD25 monoclonal antibody administration protects murine liver from ischemia-reperfusion injury due to reduced numbers of CD4+ T cells.

BACKGROUND: CD4(+) T cell is acknowledged as a key factor in the initiation phase of liver ischemia reperfusion injury. The purpose of current study is to demonstrate the effect of antecedent near-term anti-CD25 monoclonal antibody treatment on IR-induced liver injury by modulation of CD4(+) T cells. METHODS: 70% liver warm IR was induced in male C57BL/6 mice after anti-CD25 mAb or non-specific IgG administration. Liver function, histological damage, in vitro Proliferation, FACS, cytokine production, and immunofluorescence were assessed to evaluate the impact of antecedent near-term PC61 treatment on IR-induced liver injury. RESULTS: After 70% liver ischemia, mice preconditioned with PC61 displayed significantly preserved liver function as characterized by less histological damage and reduced serum enzymes level. Mechanistic studies revealed that the protection effect of anti-CD25 mAb was associated with ameliorated intrahepatic inflammatory milieu and reduced CD4(+) T lymphocytes as manifested by the decrease of proinflammatory cytokine production (less expression of TNF-α, IFN-γ, IL-2, and IL-6) and the lower CD4/CD8 proportion. CONCLUSIONS: Our results provide first line of evidence indicating that near-term treatment with anti-CD25 monoclonal antibody might provide protection for livers against IR-induced injury by reducing CD4(+) T cells, but not influencing functional Treg population. Therefore, our results demonstrate a potential function of anti-CD25 monoclonal antibody which was neglected in the past, and may be helpful in various clinical conditions, particularly in liver and kidney transplantations.

Inhibition of glycogen synthase kinase 3 ameliorates liver ischemia/reperfusion injury via an energy-dependent mitochondrial mechanism.

BACKGROUND & AIMS: The mechanisms of glycogen synthase kinase-3 (GSK-3)-mediated cytoprotection during liver ischemia/reperfusion (I/R) remain controversial, particularly in older organs. This study explores the role and potential mechanisms of GSK-3 in young and aging livers. METHODS: A rodent partial warm I/R model was used to evaluate the therapeutic potential of GSK-3 modulation during hepatic I/R in young and aging Sprague-Dawley rats. RESULTS: GSK-3 inhibition through IPC or SB216763 (SB21) preconditioning protected young rats from I/R-induced liver injury. This protection was absent in old animals but could be restored by glucose infusion prior to the I/R insult. The protection conferred by GSK-3 inhibition depended on mitochondrial metabolism regulation. Indeed, the inhibition of GSK-3 suppressed mitochondrial permeability transition pore (MPTP) opening, triggering mitohormesis in young animals, whereas insufficient fuel suppressed mitochondrial metabolism and inactivated the GSK-3-related protection in old animals. SB21 and glucose reactivated the mitochondrial F0F1-ATPase and subsequent protective cascades in the senescent liver. These effects were antagonized by an ATPase inhibitor and by an MPTP opener. CONCLUSIONS: The protection conferred by GSK-3 inhibition during hepatic I/R insult is energy dependent, particularly in senescent livers. These findings demonstrate a key role for GSK-3-related mitochondrial energy homeostasis, which may shed new light on the clinical use of GSK-3 inhibitors to protect liver function in surgical settings, particularly for older patients.

Tim-1-Fc suppresses chronic cardiac allograft rejection and vasculopathy by reducing IL-17 production.

Previously, we demonstrated that Tim-1-Fc prevents acute cardiac graft rejection by inhibiting Th1 response. In the present report, we tackled the impact of Tim-1-Fc on Th17 cells in a model of cardiac chronic rejection. Administration of Tim-1-Fc did not result in a detectable impact on innate immunity and regulatory T cells, while it provided protection for Bm12-derive cardiac grafts against chronic rejection in B6 recipients, as manifested by the reduction of inflammatory infiltration along with less severity of vasculopathy. Studies in T-bet(-/-) recipients by implanting Bm12-derived cardiac grafts further revealed that Tim-1-Fc significantly protected cardiac grafts from chronic rejection along with attenuated production of IL-17 producing T cells. Depletion of CD4 and CD8 T cells or blockade of IL-17 in T-bet(-/-) recipients demonstrated that Tim-1-Fc selectively suppresses Th17 differentiation along with attenuated IL-17 secretion. Together, our data suggest that Tim-1-Fc protects cardiac grafts from chronic rejection by suppressing CD4 Th17 development and functionality. Therefore, Tim-1-Fc might be a potential immunosuppressive agent in the setting of cardiac transplantation.