- Email: [email protected]
Importance of NKT and NK cells for experimental T cell-dependent liver injury in mice
Poster Sessions
154
Conclusion: By use of two novel, RLAs providing a quantitative measurement of anti-PDC-E2 and BCKADC-E2 about 20% of RA sera without IF A M A recognized one of the twi major mitochondrial target peptides in PBC. Upon a 4-year follow-up, two patients developed PBC. Our data suggest that IF AMA-negative RA patients whose sera specifically recognize human mitochondrial enzyme(s) as established target(s) for A M A seem to be at risk for developing PBC even in the absence of any biochemical and clinical evidence of chronic liver disease.
~']
ME3738 PROTECTS FROM CON-A INDUCED LIVER FAILURE VIA AN IL6-DEPENDENT MECHANISM
Christian Klein, Michael P. Mantas, Christian Trautwein. Department of
Gastroenterology, Hepatology and Endocrinology, Medical school Hannover, lower Saxony, Germany Chronic infection with the hepatitis-B and -C virus induce inflammatory in the liver and are one of the main causes to trigger liver cirrhosis. ME3738 is a new compound that attenuates liver disease in several models of acute and chronic liver inflammation. Here we used the Concanavalin-A model to elucidate the molecular mechanisms of ME3738 to block liver cell damage. Pretreatment of Balb/C mice with ME3738 before Con-A injection results in a significant reduction in liver cell damage. The protective effect of ME3738 before Con-A injection was associated with a reduction in IL6 serum levels and NF-kB DNA binding in liver nuclear extracts. As ME3738 had a direct effect on IL6 serum levels after Con-A injection we used IL6 knock out mice to further elucidate the effect of ME3738 on Con-A induced liver damage. In contrast, while ME3738 was protective in wt animals no protection was found in IL6 knockout animals. Therefore we studied the possibility that ME3738 has an impact on IL6 expression. We found that ME3738 stimulation results in an increase in IL6 serum levels followed by an increased concentration of phosphorylated nuclear STAT3. This IL6 activated pathway leads to a dramatic mRNA expression of acute phase genes. In parallel these experiments were performed in IL6 knockout mice. In these animals none of the described Me3738 induced molecular events were found. In summary we describe that ME3738 protects from Con-A induced liver cell damage via an IL6-dependent mechanism.
~-]
BIOLOGIC EFFECTS OF ANTI-RETROVIRAL THERAPY IN PATIENTS WITH PRIMARY BILIARY CIRRHOSIS
Andrew Mason t , James Neuberger 2. 1Department of Medicine, Ochsner
controlled study of combination antiviral therapy should be considered for patients with PBC.
~'~
IMPORTANCE OF NKT AND NK CELLS FOR EXPERIMENTAL T CELL-DEPENDENT LIVER INJURY IN MICE
Katrin Muehlen I , Jens Schuemann I , Frederick Wittke 2, Steffen Stenger 2, Luc van Kaer 3, Gisa Tiegs I . 1Institute of Pharmacology and Toxicology,
University of Erlangen-Nuremberg, Erlangen; 2Institute of Clinical Microbiology, Immunology, and Hygiene, University of Erlangen-Nuremberg, Erlangen, Germany; 3Department of Microbiology and Immunology, Vanderbilt University School of Medicine, Nashville, USA We have established a novel model of T-cell- and Kupffer cell-dependent liver injury in mice, induced by Pseudomonas exotoxin A (PEA). The most important mediators of liver disease in this model are TNE IL-18, and perforin. IL-18 is known to be a (co-)stimulator of NKT and NK cells, which can cause cytotoxicity by releasing perforin and granzymes. Furthermore, NKT cells have been described to effectively activate NK cells following stimulation. Therefore, we wondered whether NKT and/or NK cells are involved in PEA-induced liver injury. Here we show that NKT cell-deficient CDld-knockout mice are fully susceptible to PEA-induced liver injury. However, depletion of NK cells by pretreatment with antiasialo-GM 1 antibodies conferred resistance to PEA-induced liver disease. Furthermore, the number of hepatic mononuclear cells strongly increased following injection of PEA, the most significantly accumulating cell types being NK cells and neutrophils, as shown by flow cytometry. Cytotoxic activity of hepatic mononuclear cells against typical NK targets (YAC-1 cells) could be observed. Intrahepatic expression of VCAM-1, an adhesion molecule known to mediate infiltration of NK cells into liver parenchyma, was induced following injection of PEA, as shown by real-time RT-PCR (mRNA) and immunohistochemistry (protein). Taken together, our results support a role of NK cells, but not NKT cells, in PEA-induced, T celldependent liver injury.
] DURATION AND SEVERITY OF THE DISEASE BUT NOT MENOPAUSAL STATUS ARE THE MAIN RISK FACTORS FOR OSTEOPOROSIS IN PRIMARY BILIARY CIRRHOSIS Albert Pares 1, Nuria Guafiabens 2, Inmaculada Ros 2, L1. Caballerfa I , Francesca Pons 2, Sergi Vidal 2, Ana Monegal 2, Pilaf Peris 2, Juan Rod6s 1. l Liver Unit, Hospital Clinic, Barcelona,"2Metabolic Bone Diseases Unit,
Clinic Foundation, New Orleans, LA, USA; 2Department of Medicine, Queen Elizabeth Hospital, Birmingham, UK
Hospital Clinic, Barcelona, Spain
Aim: To assess the clinical relevance of retroviral infection in patients with PBC [Hepatology 2000; 32: 297A]. Methods: 11 patients received Lamivudine 150 mg/day and 11 patients received Combivir (Lamivudine 150 mg and Zidovudine 300 mg) B.I.D. for 1 year. Seven patients were enrolled into both studies. In each cohort, 3 patients did not take UDCA, while 8 were on UDCA >6 months. Results: None of the Lamivudine and 5 Combivir patients normalized Alk Phos (p = 0.035, Fishers); 4 Combivir patients completely normalized AST, ALT and Alk Phos (Combivir vs. Lamivudine, p = 0.9): 2 patients relapsed, while 2 have normal hepatic biochemistry 1 and 3 months after discontinuation of Combivir. Serial Alk Phos levels decreased in Combivir patients (p = 0.02, ANOVA) and not Lamivudine (p = 0.56). After treatment, a reduction in serum A M A levels ( h 3 2 0 to 1:240, p < 0.01, Wilcoxin) and serum IgM (364 vs. 321 mg/dl, p = 0.024, t-test) was observed in the entire cohort. Discussion: A biologic response to anti-retroviral treatment is suggested by an improvement in hepatic biochemistry with the commencement of therapy and rebound with the termination of anti-retroviral treatment; an enhanced biochemical response in patients on the more potent combination treatment; decreased A M A and IgM titres as well as a reported reversal of ductopenia [J. Hepatol 2001; 34: 205]. These results suggest that a larger,
Since the clinical spectrum of primary biliary cirrhosis (PBC) has changed in the last years, and the disease is diagnosed usually in postmenopausal women with minor cholestasis, it has been questioned whether PBC itself represents an extra risk for osteoporosis. Therefore this study was carded out to assess the prevalence and risk factors for osteoporosis in an unselected series of 142 women with PBC (age: 54.3 4- 0.8 years) and compared with the prevalence of osteoporosis in the Spanish women. Diagnosis of osteoporosis was established by densitometric criteria (Bone mineral density below - 2 . 5 T-score). Age, duration of PBC, menopausal status, histological stage and severity of liver disease were assessed in all the patients. Prevalence of osteoporosis was significantly higher in PBC (32.4%) than in normal women (11.1%) (RR: 3.83, 95% CI: 2.59 to 5.67, p < 0.001). Osteoporosis in PBC was associated with menopausal status (p < 0.001), older age (60.2 4- 1.2 vs 51.5 4- 0.9 years, p < 0.001), longer PBC duration (4.0 4- 0.6 vs 2.4 4- 0.3 years, p = 0.004), advanced histological stage (p < 0.001) and high bilirubin (1.96 4- 0.36 vs 1.36 4- 0.29 mg/dl, p = 0.003), and alkaline phosphatase levels (946 ± 124 vs 634 4- 48 4 u/l), p -- 0.005), as well as low albumin (40.9 4- 0.6 vs 42.6 4- 0.4 g/l, p = 0.02) and prothrombin index (94 4- 2 vs 99 4- 0.3%, p < 0.001). The stepwise logistic regression analyses identified duration of PBC, age, advanced histological stage and baseline bilimbin > 1.2 mg/dl, but not postmenopausal status as
154
Conclusion: By use of two novel, RLAs providing a quantitative measurement of anti-PDC-E2 and BCKADC-E2 about 20% of RA sera without IF A M A recognized one of the twi major mitochondrial target peptides in PBC. Upon a 4-year follow-up, two patients developed PBC. Our data suggest that IF AMA-negative RA patients whose sera specifically recognize human mitochondrial enzyme(s) as established target(s) for A M A seem to be at risk for developing PBC even in the absence of any biochemical and clinical evidence of chronic liver disease.
~']
ME3738 PROTECTS FROM CON-A INDUCED LIVER FAILURE VIA AN IL6-DEPENDENT MECHANISM
Christian Klein, Michael P. Mantas, Christian Trautwein. Department of
Gastroenterology, Hepatology and Endocrinology, Medical school Hannover, lower Saxony, Germany Chronic infection with the hepatitis-B and -C virus induce inflammatory in the liver and are one of the main causes to trigger liver cirrhosis. ME3738 is a new compound that attenuates liver disease in several models of acute and chronic liver inflammation. Here we used the Concanavalin-A model to elucidate the molecular mechanisms of ME3738 to block liver cell damage. Pretreatment of Balb/C mice with ME3738 before Con-A injection results in a significant reduction in liver cell damage. The protective effect of ME3738 before Con-A injection was associated with a reduction in IL6 serum levels and NF-kB DNA binding in liver nuclear extracts. As ME3738 had a direct effect on IL6 serum levels after Con-A injection we used IL6 knock out mice to further elucidate the effect of ME3738 on Con-A induced liver damage. In contrast, while ME3738 was protective in wt animals no protection was found in IL6 knockout animals. Therefore we studied the possibility that ME3738 has an impact on IL6 expression. We found that ME3738 stimulation results in an increase in IL6 serum levels followed by an increased concentration of phosphorylated nuclear STAT3. This IL6 activated pathway leads to a dramatic mRNA expression of acute phase genes. In parallel these experiments were performed in IL6 knockout mice. In these animals none of the described Me3738 induced molecular events were found. In summary we describe that ME3738 protects from Con-A induced liver cell damage via an IL6-dependent mechanism.
~-]
BIOLOGIC EFFECTS OF ANTI-RETROVIRAL THERAPY IN PATIENTS WITH PRIMARY BILIARY CIRRHOSIS
Andrew Mason t , James Neuberger 2. 1Department of Medicine, Ochsner
controlled study of combination antiviral therapy should be considered for patients with PBC.
~'~
IMPORTANCE OF NKT AND NK CELLS FOR EXPERIMENTAL T CELL-DEPENDENT LIVER INJURY IN MICE
Katrin Muehlen I , Jens Schuemann I , Frederick Wittke 2, Steffen Stenger 2, Luc van Kaer 3, Gisa Tiegs I . 1Institute of Pharmacology and Toxicology,
University of Erlangen-Nuremberg, Erlangen; 2Institute of Clinical Microbiology, Immunology, and Hygiene, University of Erlangen-Nuremberg, Erlangen, Germany; 3Department of Microbiology and Immunology, Vanderbilt University School of Medicine, Nashville, USA We have established a novel model of T-cell- and Kupffer cell-dependent liver injury in mice, induced by Pseudomonas exotoxin A (PEA). The most important mediators of liver disease in this model are TNE IL-18, and perforin. IL-18 is known to be a (co-)stimulator of NKT and NK cells, which can cause cytotoxicity by releasing perforin and granzymes. Furthermore, NKT cells have been described to effectively activate NK cells following stimulation. Therefore, we wondered whether NKT and/or NK cells are involved in PEA-induced liver injury. Here we show that NKT cell-deficient CDld-knockout mice are fully susceptible to PEA-induced liver injury. However, depletion of NK cells by pretreatment with antiasialo-GM 1 antibodies conferred resistance to PEA-induced liver disease. Furthermore, the number of hepatic mononuclear cells strongly increased following injection of PEA, the most significantly accumulating cell types being NK cells and neutrophils, as shown by flow cytometry. Cytotoxic activity of hepatic mononuclear cells against typical NK targets (YAC-1 cells) could be observed. Intrahepatic expression of VCAM-1, an adhesion molecule known to mediate infiltration of NK cells into liver parenchyma, was induced following injection of PEA, as shown by real-time RT-PCR (mRNA) and immunohistochemistry (protein). Taken together, our results support a role of NK cells, but not NKT cells, in PEA-induced, T celldependent liver injury.
] DURATION AND SEVERITY OF THE DISEASE BUT NOT MENOPAUSAL STATUS ARE THE MAIN RISK FACTORS FOR OSTEOPOROSIS IN PRIMARY BILIARY CIRRHOSIS Albert Pares 1, Nuria Guafiabens 2, Inmaculada Ros 2, L1. Caballerfa I , Francesca Pons 2, Sergi Vidal 2, Ana Monegal 2, Pilaf Peris 2, Juan Rod6s 1. l Liver Unit, Hospital Clinic, Barcelona,"2Metabolic Bone Diseases Unit,
Clinic Foundation, New Orleans, LA, USA; 2Department of Medicine, Queen Elizabeth Hospital, Birmingham, UK
Hospital Clinic, Barcelona, Spain
Aim: To assess the clinical relevance of retroviral infection in patients with PBC [Hepatology 2000; 32: 297A]. Methods: 11 patients received Lamivudine 150 mg/day and 11 patients received Combivir (Lamivudine 150 mg and Zidovudine 300 mg) B.I.D. for 1 year. Seven patients were enrolled into both studies. In each cohort, 3 patients did not take UDCA, while 8 were on UDCA >6 months. Results: None of the Lamivudine and 5 Combivir patients normalized Alk Phos (p = 0.035, Fishers); 4 Combivir patients completely normalized AST, ALT and Alk Phos (Combivir vs. Lamivudine, p = 0.9): 2 patients relapsed, while 2 have normal hepatic biochemistry 1 and 3 months after discontinuation of Combivir. Serial Alk Phos levels decreased in Combivir patients (p = 0.02, ANOVA) and not Lamivudine (p = 0.56). After treatment, a reduction in serum A M A levels ( h 3 2 0 to 1:240, p < 0.01, Wilcoxin) and serum IgM (364 vs. 321 mg/dl, p = 0.024, t-test) was observed in the entire cohort. Discussion: A biologic response to anti-retroviral treatment is suggested by an improvement in hepatic biochemistry with the commencement of therapy and rebound with the termination of anti-retroviral treatment; an enhanced biochemical response in patients on the more potent combination treatment; decreased A M A and IgM titres as well as a reported reversal of ductopenia [J. Hepatol 2001; 34: 205]. These results suggest that a larger,
Since the clinical spectrum of primary biliary cirrhosis (PBC) has changed in the last years, and the disease is diagnosed usually in postmenopausal women with minor cholestasis, it has been questioned whether PBC itself represents an extra risk for osteoporosis. Therefore this study was carded out to assess the prevalence and risk factors for osteoporosis in an unselected series of 142 women with PBC (age: 54.3 4- 0.8 years) and compared with the prevalence of osteoporosis in the Spanish women. Diagnosis of osteoporosis was established by densitometric criteria (Bone mineral density below - 2 . 5 T-score). Age, duration of PBC, menopausal status, histological stage and severity of liver disease were assessed in all the patients. Prevalence of osteoporosis was significantly higher in PBC (32.4%) than in normal women (11.1%) (RR: 3.83, 95% CI: 2.59 to 5.67, p < 0.001). Osteoporosis in PBC was associated with menopausal status (p < 0.001), older age (60.2 4- 1.2 vs 51.5 4- 0.9 years, p < 0.001), longer PBC duration (4.0 4- 0.6 vs 2.4 4- 0.3 years, p = 0.004), advanced histological stage (p < 0.001) and high bilirubin (1.96 4- 0.36 vs 1.36 4- 0.29 mg/dl, p = 0.003), and alkaline phosphatase levels (946 ± 124 vs 634 4- 48 4 u/l), p -- 0.005), as well as low albumin (40.9 4- 0.6 vs 42.6 4- 0.4 g/l, p = 0.02) and prothrombin index (94 4- 2 vs 99 4- 0.3%, p < 0.001). The stepwise logistic regression analyses identified duration of PBC, age, advanced histological stage and baseline bilimbin > 1.2 mg/dl, but not postmenopausal status as