Ulcerative colitis(UC)and Crohn’s disease(CD)are part of Inflammatory Bowel Diseases(IBD)and have pathophysiological processes such as bowel necrosis and enteric neurons and enteric glial cells.In addition,the main i...Ulcerative colitis(UC)and Crohn’s disease(CD)are part of Inflammatory Bowel Diseases(IBD)and have pathophysiological processes such as bowel necrosis and enteric neurons and enteric glial cells.In addition,the main inflammatory mediator is related to the tumor necrosis factor-alpha(TNF-α).TNF-αis a mediator of the intestinal inflammatory processes,thus being one of the main cytokines involved in the pathogenesis of IBD,however,its levels,when measured,are present in the serum of patients with IBD.In addition,TNF-αplays an important role in promoting inflammation,such as the production of interleukins(IL),for instance IL-1βand IL-6.There are two receptors for TNF as following:The tumor necrosis factor 1 receptor(TNFR1);and the tumor necrosis factor 2 receptor(TNFR2).They are involved in the pathogenesis of IBD and their receptors have been detected in IBD and their expression is correlated with disease activity.The soluble TNF form binds to the TNFR1 receptor with,and its activation results in a signaling cascade effects such as apoptosis,cell proliferation and cytokine secretion.In contrast,the transmembrane TNF form can bind both to TNFR1 and TNFR2.Recent studies have suggested that TNF-αis one of the main pro-inflammatory cytokines involved in the pathogenesis of IBD,since TNF levels are present in the serum of both patients with UC and CD.Intravenous and subcutaneous biologics targeting TNF-αhave revolutionized the treatment of IBD,thus becoming the best available agents to induce and maintain IBD remission.The application of antibodies aimed at neutralizing TNF-αin patients with IBD that induce a satisfactory clinical response in up to 60%of patients,and also induced long-term maintenance of disease remission in most patients.It has been suggested that anti-TNF-αagents inactivate the pro-inflammatory cytokine TNF-αby direct neutralization,i.e.,resulting in suppression of inflammation.However,anti-TNF-αantibodies perform more complex functions than a simple blockade.展开更多
The course and severity of periodontitis can be significantly affected by bacterial virulence as well as host immunity dysfunction. Periodontal tissue destruction has been proved to result from cascade of cytokines sy...The course and severity of periodontitis can be significantly affected by bacterial virulence as well as host immunity dysfunction. Periodontal tissue destruction has been proved to result from cascade of cytokines synthesized by reactive cells upon stimulation by pathogenic bacteria and lipopolysaccharides within their cell membranes. The clinical use of genetically programmed cells, producing substances blocking IL-1, based on recombinant IL-1 antagonist, as well as cytokines activating fibroblasts and osteoblasts to regenerate the destroyed periodontal tissue could prove alternative to the conventional treatment. Another cytokine of interest in respect to periodontitis ethiopathogenesis is soluble tumor necrosis factor receptor I (sTNF RI). Observation of soluble TNF receptors as physiologic inhibitors of TNF led to its administration in therapeutic process as well as in therapy selected cases of aggressive periodontitis.展开更多
AIM: To determine the expression statuses of tumor necrosis factor (TNF)-α, its receptors (TNF-R) and downstream effector molecules in human colorectal adenomas. METHODS: We measured the serum concentrations of TNF-...AIM: To determine the expression statuses of tumor necrosis factor (TNF)-α, its receptors (TNF-R) and downstream effector molecules in human colorectal adenomas. METHODS: We measured the serum concentrations of TNF-α and its receptors in 62 colorectal adenoma patients and 34 healthy controls. The protein expression of TNF-α, TNF-R1, TNF-R2 and downstream signals of the TNF receptors, such as c-Jun N-terminal kinase (JNK), nuclear factor-κ B and caspase-3, were also investigated in human colorectal adenomas and in normal colorectal mucosal tissues by immunohistochemistry. Immunofluorescence confocal microscopy was used to investigate the consistency of expression of TNF-R1 and phospho-JNK (p-JNK). RESULTS: The serum levels of soluble TNF-R1 (sTNF-R1) in adenoma patients were significantly higher than in the control group (3.67 ± 0.86 ng/mL vs 1.57 ± 0.72 ng/mL, P < 0.001). Receiver operating characteristic analysis revealed the high diagnostic sensitivity of TNF-R1 measurements (AUC was 0.928) for the diagnosis of adenoma, and the best cut-off level of TNF-R1 was 2.08 ng/mL, with a sensitivity of 93.4% and a specificity of 82.4%. There were no significant differences in the serum levels of TNF-α or sTNF-R2 between the two groups. Immunohistochemistry showed high levels of TNF-R1 and p-JNK expression in the epithelial cells of adenomas. Furthermore, a high incidence of co-localization of TNF-R1 and p-JNK was identified in adenoma tissue. CONCLUSION: TNF-R1 may be a promising biomarker of colorectal adenoma, and it may also play an important role in the very early stages of colorectal carcinogenesis.展开更多
Objective: To investigate membrane tumor necrosis factor receptor 1 protein expression level in decidua and concentration of soluble tumor necrosis factor receptor 1 in serum in women with unexplained early spontaneou...Objective: To investigate membrane tumor necrosis factor receptor 1 protein expression level in decidua and concentration of soluble tumor necrosis factor receptor 1 in serum in women with unexplained early spontaneous abortion, threatened abortion, and compare the levels with healthy pregnant women. Methods: Thirty-seven women with unexplained early spontaneous abortion, 27 women with threatened abortion, and 34 healthy pregnant women undergoing artificial abortion of pregnancy at 6 - 10 weeks of gestation were selected. Decidual samples were collected when women were undergoing artificial abortion, and blood samples were collected at the same time. The level of membrane tumor necrosis factor receptor 1 in decidua was detected by flow cytometer, and the concentration of soluble tumor necrosis factor receptor 1 in sera was measured with an enzyme-linked immunosorbent assay. Results: The percentages of membrane tumor necrosis factor receptor 1 positive decidual cells were 16.42 ± 7.10 Mean ± SD for women with unexplained early spontaneous abortion and 13. 14 ± 6.30 for healthy pregnant women ( P < 0.05). Serum concentration of soluble tumor necrosis factor receptor 1 was significantly higher in women with unexplained early spontaneous abortion than in healthy pregnant women and in women with threatened abortion, and no difference was found between healthy pregnant women and women with threatened abortion. Conclusion: Women with unexplained early spontaneous abortion present significantly higher expression of tumor necrosis factor receptor 1 than healthy pregnant women, suggesting that over-expression of tumor necrosis factor receptor 1 may contribute to the development of early spontaneous abortion.展开更多
BACKGROUND End-stage liver disease caused by non-alcoholic steatohepatitis(NASH)is the second leading indication for liver transplantation.To date,only moderately effective pharmacotherapies exist to treat NASH.Unders...BACKGROUND End-stage liver disease caused by non-alcoholic steatohepatitis(NASH)is the second leading indication for liver transplantation.To date,only moderately effective pharmacotherapies exist to treat NASH.Understanding the pathogenesis of NASH is therefore crucial for the development of new therapies.The inflammatory cytokine tumor necrosis factor alpha(TNF-α)is important for the progression of liver disease.TNF signaling via TNF receptor 1(TNFR1)has been hypothesized to be important for the development of NASH and hepatocellular carcinoma in whole-body knockout animal models.AIM To investigate the role of TNFR1 signaling in hepatocytes for steatohepatitis development in a mouse model of diet-induced NASH.METHODS NASH was induced by a western-style fast-food diet in mice deficient for TNFR1 in hepatocytes(TNFR1ΔHEP)and their wild-type littermates(TNFR1fl/fl).Glucose tolerance was assessed after 18 wk and insulin resistance after 19 wk of feeding.After 20 wk mice were assessed for features of NASH and the metabolic syndrome such as liver weight,liver steatosis,liver fibrosis and markers of liver inflammation.RESULTS Obesity,liver injury,inflammation,steatosis and fibrosis was not different between TNFR1ΔHEP and TNFR1fl/fl mice.However,Tnfr1 deficiency in hepatocytes protected against glucose intolerance and insulin resistance.CONCLUSION Our results indicate that deficiency of TNFR1 signaling in hepatocytes does not protect from diet-induced NASH.However,improved insulin resistance in this model strengthens the role of the liver in glucose homeostasis.展开更多
Objective: To explore the effect of Irbesartan and Metformin on tumor necrosis factor receptor 1 and monocyte chemoattractant protein-1 in patients with early diabetic nephropathy. Methods: A total of 162 patients wit...Objective: To explore the effect of Irbesartan and Metformin on tumor necrosis factor receptor 1 and monocyte chemoattractant protein-1 in patients with early diabetic nephropathy. Methods: A total of 162 patients with early diabetic nephropathy who had been admitted to the Hospital between February 2017 and February 2018 were randomly assigned into a Metformin group, an Irbesartan group, and a combination therapy group. The Metformin group were treated with oral Metformin, those in the Irbesartan group were given oral Irbesartan for treatment, and the combination therapy group was treated with Metformin combined with Irbesartan. After 3 months of continuous treatment, the levels of sTNFR1, high-sensitivity C-reactive protein, monocyte chemoattractant protein-1, glucose metabolism index, proteinuria, and serum creatinine levels in the two groups were compared. Results:After treatment, the levels of sTNFR1, sICAM-1, hs-CRP, and MCP-1 in the three groups decreased compared with those before treatment, and the levels in the combination therapy group were all shown to be lower than those of the Metformin group and the Irbesartan group, with statistically significant differences (P<0.05). The levels of glycosylated hemoglobin and fasting blood glucose in the three groups were significantly lower than before treatment, and those in the combination therapy group were lower than the Metformin group and Irbesartan group, where the difference was statistically significant (P<0.05). The 24-hour urinary protein quantification, urinary albumin excretion rate, and serum creatinine in the combination therapy group were lower than those in the Metformin group and in the Irbesartan group, where the differences were statistically significant (P<0.05). Conclusion: The effects of metformin combined with irbesartan on early diabetic nephropathy patients were significant, which can effectively reduce the levels of serum sTNFR1 and MCP-1, relieve inflammation and improve glucose metabolism and proteinuria level.展开更多
Objective:To explore the effect of Linagliptin on tumor necrosis factor receptor and monocyte chemoattractant protein-1 in patients with diabetic nephropathy.Methods: A total of 98 patients with diabetic nephropathy a...Objective:To explore the effect of Linagliptin on tumor necrosis factor receptor and monocyte chemoattractant protein-1 in patients with diabetic nephropathy.Methods: A total of 98 patients with diabetic nephropathy admitted to the Hospital from January 2017 to September 2018 were enrolled. The patients were divided into two groups according to the random double-blind method, with 49 cases in each group. The control group was treated with Metformin, whereas the experimental group was treated with Linagliptin plus Metformin. After 3 months of continuous treatment, the renal function [urinary albumin excretion rate, 24 h urine protein quantitation and serum creatinine], glycolipids metabolic levels [glycated hemoglobin, fasting blood glucose, total cholesterol and triglycerides], monocyte chemoattractant protein-1, tumor necrosis factor receptor, high-sensitivity C-reactive protein, and adverse reactions were compared between the two groups.Results:After 3 months of treatment, the levels of UAER, 24 h Upor and Scr in the experimental group were shown to be lower than those in the control group, and the difference was statistically significant. After 3 months of treatment, the levels of HbA1c, FPG, TC and TG in the experimental group were shown to be lower than the control group, and the difference was statistically significant. After 3 months of treatment, the levels of MCP-1, sTNFR1 and hs-CRP in the experimental group were lower than those in the control group, and the difference was statistically significant. There was no significant difference in incidence of adverse reactions between the two groups.Conclusion: For patients with diabetic nephropathy, Linagliptin is with higher safety, which can help improve their glycolipids metabolic levels and renal function, reduce the inflammatory response and the levels of MCP-1 and sTNFR1, and yet incur fewer adverse reactions.展开更多
Hepatitis C virus(HCV)infection is an excellent immunological model for understanding the mechanisms developed by non-cytopathic viruses and tumors to evade the adaptative immune response.The antigen-specific cytotoxi...Hepatitis C virus(HCV)infection is an excellent immunological model for understanding the mechanisms developed by non-cytopathic viruses and tumors to evade the adaptative immune response.The antigen-specific cytotoxic T cell response is essential for keeping HCV under control,but during persistent infection,these cells become exhausted or even deleted.The exhaustion process is progressive and depends on the infection duration and level of antigenemia.During high antigenic load and long duration of infection,T cells become extremely exhausted and ultimately disappear due to apoptosis.The development of exhaustion involves the impairment of positive co-stimulation induced by regulatory cytokines,such as transforming growth factor beta 1.This cytokine downregulates tumor necrosis factor receptor(TNFR)-associated factor 1(TRAF1),the signal transducer of the T cell co-stimulatory molecule TNFR superfamily member 9(known as 4-1BB).This impairment correlates with the low reactivity of T cells and an exhaustion phenotype.Treatment with interleukin-7 in vitro restores TRAF1 expression and rescues T cell effector function.The process of TRAF1 loss and its in vitro recovery is hierarchical,and more affected by severe disease progression.In conclusion,TRAF1 dynamics on T cells define a new pathogenic model that describes some aspects of the natural history of HCV,and sheds light on novel immunotherapy strategies for chronic viral infections and cancer.展开更多
基金Research Support Foundation of the State of São Paulo(FAPESP,Brazil),No.2014/25927-2,No.2018/07862-1National Council for Scientific and Technological Development(CNPq,Brazil)Higher Education Personnel Improvement Coordination(CAPES,Brazil).
文摘Ulcerative colitis(UC)and Crohn’s disease(CD)are part of Inflammatory Bowel Diseases(IBD)and have pathophysiological processes such as bowel necrosis and enteric neurons and enteric glial cells.In addition,the main inflammatory mediator is related to the tumor necrosis factor-alpha(TNF-α).TNF-αis a mediator of the intestinal inflammatory processes,thus being one of the main cytokines involved in the pathogenesis of IBD,however,its levels,when measured,are present in the serum of patients with IBD.In addition,TNF-αplays an important role in promoting inflammation,such as the production of interleukins(IL),for instance IL-1βand IL-6.There are two receptors for TNF as following:The tumor necrosis factor 1 receptor(TNFR1);and the tumor necrosis factor 2 receptor(TNFR2).They are involved in the pathogenesis of IBD and their receptors have been detected in IBD and their expression is correlated with disease activity.The soluble TNF form binds to the TNFR1 receptor with,and its activation results in a signaling cascade effects such as apoptosis,cell proliferation and cytokine secretion.In contrast,the transmembrane TNF form can bind both to TNFR1 and TNFR2.Recent studies have suggested that TNF-αis one of the main pro-inflammatory cytokines involved in the pathogenesis of IBD,since TNF levels are present in the serum of both patients with UC and CD.Intravenous and subcutaneous biologics targeting TNF-αhave revolutionized the treatment of IBD,thus becoming the best available agents to induce and maintain IBD remission.The application of antibodies aimed at neutralizing TNF-αin patients with IBD that induce a satisfactory clinical response in up to 60%of patients,and also induced long-term maintenance of disease remission in most patients.It has been suggested that anti-TNF-αagents inactivate the pro-inflammatory cytokine TNF-αby direct neutralization,i.e.,resulting in suppression of inflammation.However,anti-TNF-αantibodies perform more complex functions than a simple blockade.
文摘The course and severity of periodontitis can be significantly affected by bacterial virulence as well as host immunity dysfunction. Periodontal tissue destruction has been proved to result from cascade of cytokines synthesized by reactive cells upon stimulation by pathogenic bacteria and lipopolysaccharides within their cell membranes. The clinical use of genetically programmed cells, producing substances blocking IL-1, based on recombinant IL-1 antagonist, as well as cytokines activating fibroblasts and osteoblasts to regenerate the destroyed periodontal tissue could prove alternative to the conventional treatment. Another cytokine of interest in respect to periodontitis ethiopathogenesis is soluble tumor necrosis factor receptor I (sTNF RI). Observation of soluble TNF receptors as physiologic inhibitors of TNF led to its administration in therapeutic process as well as in therapy selected cases of aggressive periodontitis.
基金Supported by Grant-in-Aid for Research from the Third-Term Comprehensive Control Research for Cancer Center of the Ministry of Health, Labor and Welfare, JapanGrant from the Ministry of Education, Culture, Sports, Science and Technology, Japan(KIBAN-B)the "Collaborative Development of Innovative Seeds" Grant Program from the Japan Science and Technology Agency
文摘AIM: To determine the expression statuses of tumor necrosis factor (TNF)-α, its receptors (TNF-R) and downstream effector molecules in human colorectal adenomas. METHODS: We measured the serum concentrations of TNF-α and its receptors in 62 colorectal adenoma patients and 34 healthy controls. The protein expression of TNF-α, TNF-R1, TNF-R2 and downstream signals of the TNF receptors, such as c-Jun N-terminal kinase (JNK), nuclear factor-κ B and caspase-3, were also investigated in human colorectal adenomas and in normal colorectal mucosal tissues by immunohistochemistry. Immunofluorescence confocal microscopy was used to investigate the consistency of expression of TNF-R1 and phospho-JNK (p-JNK). RESULTS: The serum levels of soluble TNF-R1 (sTNF-R1) in adenoma patients were significantly higher than in the control group (3.67 ± 0.86 ng/mL vs 1.57 ± 0.72 ng/mL, P < 0.001). Receiver operating characteristic analysis revealed the high diagnostic sensitivity of TNF-R1 measurements (AUC was 0.928) for the diagnosis of adenoma, and the best cut-off level of TNF-R1 was 2.08 ng/mL, with a sensitivity of 93.4% and a specificity of 82.4%. There were no significant differences in the serum levels of TNF-α or sTNF-R2 between the two groups. Immunohistochemistry showed high levels of TNF-R1 and p-JNK expression in the epithelial cells of adenomas. Furthermore, a high incidence of co-localization of TNF-R1 and p-JNK was identified in adenoma tissue. CONCLUSION: TNF-R1 may be a promising biomarker of colorectal adenoma, and it may also play an important role in the very early stages of colorectal carcinogenesis.
文摘Objective: To investigate membrane tumor necrosis factor receptor 1 protein expression level in decidua and concentration of soluble tumor necrosis factor receptor 1 in serum in women with unexplained early spontaneous abortion, threatened abortion, and compare the levels with healthy pregnant women. Methods: Thirty-seven women with unexplained early spontaneous abortion, 27 women with threatened abortion, and 34 healthy pregnant women undergoing artificial abortion of pregnancy at 6 - 10 weeks of gestation were selected. Decidual samples were collected when women were undergoing artificial abortion, and blood samples were collected at the same time. The level of membrane tumor necrosis factor receptor 1 in decidua was detected by flow cytometer, and the concentration of soluble tumor necrosis factor receptor 1 in sera was measured with an enzyme-linked immunosorbent assay. Results: The percentages of membrane tumor necrosis factor receptor 1 positive decidual cells were 16.42 ± 7.10 Mean ± SD for women with unexplained early spontaneous abortion and 13. 14 ± 6.30 for healthy pregnant women ( P < 0.05). Serum concentration of soluble tumor necrosis factor receptor 1 was significantly higher in women with unexplained early spontaneous abortion than in healthy pregnant women and in women with threatened abortion, and no difference was found between healthy pregnant women and women with threatened abortion. Conclusion: Women with unexplained early spontaneous abortion present significantly higher expression of tumor necrosis factor receptor 1 than healthy pregnant women, suggesting that over-expression of tumor necrosis factor receptor 1 may contribute to the development of early spontaneous abortion.
基金Supported by the Swiss National Science Foundation,No.P2SKP3_158649,No.P3400PB_171581,and No.P3P3PB_171582(to Bluemel S)NIH grants(in part),No.R01 AA24726,No.U01 AA026939,and services provided by P30 DK120515(to Schnabl B).
文摘BACKGROUND End-stage liver disease caused by non-alcoholic steatohepatitis(NASH)is the second leading indication for liver transplantation.To date,only moderately effective pharmacotherapies exist to treat NASH.Understanding the pathogenesis of NASH is therefore crucial for the development of new therapies.The inflammatory cytokine tumor necrosis factor alpha(TNF-α)is important for the progression of liver disease.TNF signaling via TNF receptor 1(TNFR1)has been hypothesized to be important for the development of NASH and hepatocellular carcinoma in whole-body knockout animal models.AIM To investigate the role of TNFR1 signaling in hepatocytes for steatohepatitis development in a mouse model of diet-induced NASH.METHODS NASH was induced by a western-style fast-food diet in mice deficient for TNFR1 in hepatocytes(TNFR1ΔHEP)and their wild-type littermates(TNFR1fl/fl).Glucose tolerance was assessed after 18 wk and insulin resistance after 19 wk of feeding.After 20 wk mice were assessed for features of NASH and the metabolic syndrome such as liver weight,liver steatosis,liver fibrosis and markers of liver inflammation.RESULTS Obesity,liver injury,inflammation,steatosis and fibrosis was not different between TNFR1ΔHEP and TNFR1fl/fl mice.However,Tnfr1 deficiency in hepatocytes protected against glucose intolerance and insulin resistance.CONCLUSION Our results indicate that deficiency of TNFR1 signaling in hepatocytes does not protect from diet-induced NASH.However,improved insulin resistance in this model strengthens the role of the liver in glucose homeostasis.
文摘Objective: To explore the effect of Irbesartan and Metformin on tumor necrosis factor receptor 1 and monocyte chemoattractant protein-1 in patients with early diabetic nephropathy. Methods: A total of 162 patients with early diabetic nephropathy who had been admitted to the Hospital between February 2017 and February 2018 were randomly assigned into a Metformin group, an Irbesartan group, and a combination therapy group. The Metformin group were treated with oral Metformin, those in the Irbesartan group were given oral Irbesartan for treatment, and the combination therapy group was treated with Metformin combined with Irbesartan. After 3 months of continuous treatment, the levels of sTNFR1, high-sensitivity C-reactive protein, monocyte chemoattractant protein-1, glucose metabolism index, proteinuria, and serum creatinine levels in the two groups were compared. Results:After treatment, the levels of sTNFR1, sICAM-1, hs-CRP, and MCP-1 in the three groups decreased compared with those before treatment, and the levels in the combination therapy group were all shown to be lower than those of the Metformin group and the Irbesartan group, with statistically significant differences (P<0.05). The levels of glycosylated hemoglobin and fasting blood glucose in the three groups were significantly lower than before treatment, and those in the combination therapy group were lower than the Metformin group and Irbesartan group, where the difference was statistically significant (P<0.05). The 24-hour urinary protein quantification, urinary albumin excretion rate, and serum creatinine in the combination therapy group were lower than those in the Metformin group and in the Irbesartan group, where the differences were statistically significant (P<0.05). Conclusion: The effects of metformin combined with irbesartan on early diabetic nephropathy patients were significant, which can effectively reduce the levels of serum sTNFR1 and MCP-1, relieve inflammation and improve glucose metabolism and proteinuria level.
文摘Objective:To explore the effect of Linagliptin on tumor necrosis factor receptor and monocyte chemoattractant protein-1 in patients with diabetic nephropathy.Methods: A total of 98 patients with diabetic nephropathy admitted to the Hospital from January 2017 to September 2018 were enrolled. The patients were divided into two groups according to the random double-blind method, with 49 cases in each group. The control group was treated with Metformin, whereas the experimental group was treated with Linagliptin plus Metformin. After 3 months of continuous treatment, the renal function [urinary albumin excretion rate, 24 h urine protein quantitation and serum creatinine], glycolipids metabolic levels [glycated hemoglobin, fasting blood glucose, total cholesterol and triglycerides], monocyte chemoattractant protein-1, tumor necrosis factor receptor, high-sensitivity C-reactive protein, and adverse reactions were compared between the two groups.Results:After 3 months of treatment, the levels of UAER, 24 h Upor and Scr in the experimental group were shown to be lower than those in the control group, and the difference was statistically significant. After 3 months of treatment, the levels of HbA1c, FPG, TC and TG in the experimental group were shown to be lower than the control group, and the difference was statistically significant. After 3 months of treatment, the levels of MCP-1, sTNFR1 and hs-CRP in the experimental group were lower than those in the control group, and the difference was statistically significant. There was no significant difference in incidence of adverse reactions between the two groups.Conclusion: For patients with diabetic nephropathy, Linagliptin is with higher safety, which can help improve their glycolipids metabolic levels and renal function, reduce the inflammatory response and the levels of MCP-1 and sTNFR1, and yet incur fewer adverse reactions.
基金Supported by Instituto de Salud Carlos III and European Structural Funds in SpainEuropean Regional Development Fund,No.PI19/00206.
文摘Hepatitis C virus(HCV)infection is an excellent immunological model for understanding the mechanisms developed by non-cytopathic viruses and tumors to evade the adaptative immune response.The antigen-specific cytotoxic T cell response is essential for keeping HCV under control,but during persistent infection,these cells become exhausted or even deleted.The exhaustion process is progressive and depends on the infection duration and level of antigenemia.During high antigenic load and long duration of infection,T cells become extremely exhausted and ultimately disappear due to apoptosis.The development of exhaustion involves the impairment of positive co-stimulation induced by regulatory cytokines,such as transforming growth factor beta 1.This cytokine downregulates tumor necrosis factor receptor(TNFR)-associated factor 1(TRAF1),the signal transducer of the T cell co-stimulatory molecule TNFR superfamily member 9(known as 4-1BB).This impairment correlates with the low reactivity of T cells and an exhaustion phenotype.Treatment with interleukin-7 in vitro restores TRAF1 expression and rescues T cell effector function.The process of TRAF1 loss and its in vitro recovery is hierarchical,and more affected by severe disease progression.In conclusion,TRAF1 dynamics on T cells define a new pathogenic model that describes some aspects of the natural history of HCV,and sheds light on novel immunotherapy strategies for chronic viral infections and cancer.