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Oren Shibolet

Publications and source records attributed to Oren Shibolet.

28 records · Page 2Linked to original sources
PubMed2003

NKT and CD8 lymphocytes mediate suppression of hepatocellular carcinoma growth via tumor antigen-pulsed dendritic cells.

Dendritic cells (DCs) are antigen presenting cells that play a role in T-cell activation. Liver-associated natural killer T lymphocytes (NKTs) are a unique subset of lymphocytes that may be important in antitumor immunity. Hepatitis B virus (HBV)-associated hepatocellular carcinoma (HCC) expresses hepatitis B virus surface antigen (HBsAg) on its cell surface and may serve as a tumor-associated antigen. The aim of the study was to evaluate the antitumor effect of DC pulsed with tumor or viral-associated antigens in HBV-expressing HCC in mice and to determine the role of NKT lymphocytes in this process. Balb/c mice were sublethally irradiated and transplanted with Hep3b HCC cell line, followed by transplantation of naive splenocytes. DCs were separated using CD11c beads and pulsed with HBV-enveloped proteins (group A), HCC cell lysate (group B), or BSA (control group C). Mice were followed for survival and tumor size. To determine the mechanism of the antitumor effect, intrasplenic and intrahepatic lymphocyte subpopulations were analyzed by FACS for NKT, CD4 and CD8 markers. Tumor-associated antigens-specific IFNgamma ELISPOT, T-cell proliferation assays and serum cytokine analysis were performed. Treatment with tumor-associated antigen-pulsed DC significantly improved survival (40% and 50% as compared with 0% in groups A, B, and control group C, respectively; p < 0.005). Tumor size decreased to 12.8 +/- 0.4 and 0 from 60.4 +/- 0.9 mm(3) in groups A, B, and control group C, respectively (p < 0.005). Adoptive transfer of HBV or Hep3b-associated antigens-pulsed DC induced a 6-fold increase in peripheral CD8(+) lymphocytes (from 1% in control mice to 6% and 5.5% in groups A and B, respectively), along with a decrease in CD4(+) lymphocytes (from 3.5% in controls to 1.4% and 2.3% in A and B, respectively; p < 0.005). The CD8(+)/CD4(+) ratio increased from 0.28 in controls to 4.28 and 2.39 in groups A and B, respectively (p < 0.005). Intrasplenic NKT cells increased from 7% in control mice to 7.98% and 14.6% in groups A and B, respectively. In contrast, an opposite shift was observed inside the liver. Intrahepatic lymphocyte analysis showed a marked increase in CD4(+) and a decrease in CD8(+) lymphocytes in treated groups. The intrahepatic CD4(+) number increased from 0.5% in controls to 2.15% and 25.8% in groups A and B, respectively (p < 0.005). In contrast, a significant decrease in the intrahepatic CD8(+) numbers was observed (from 7% in controls to 1.0% and 2.4% in groups A and B, respectively; p < 0.005). A significant increase was noted in HBV-specific IFNgamma spot-forming T-cell colonies from 0.0 to 8.8 +/- 1.7 and 1.8 +/- 2.9 in groups C, A, and B, respectively (p < 0.005). Similarly, a significant increase in the HBV-specific T-cell stimulation index, from 0.8 +/- 0.2 to 7.2 +/- 0.4, in groups C and B, respectively, was noted (p < 0.002). IFNgamma and IL12 serum levels increased significantly in treated groups. IFNgamma and IL12 serum levels increased to 380 +/- 30 and 400 +/- 20, and 960 +/- 40 and 760 +/- 60 in groups A and B, compared with 150 +/- 16 and 490 +/- 40 pg/ml in control mice (p < 0.005). Tumor antigen-pulsed DCs effectively suppressed the growth of hepatocellular carcinoma in mice. This effect was associated with enhanced NKT and CD8(+) lymphocyte function and augmentation of the antitumor/antiviral-specific IFNgamma production.

Administration, Oral↗
PubMed2003

Late cytomegalovirus disease following liver transplantation.

The widespread use of antiviral prophylaxis or preemptive therapy among orthotopic liver transplantation (OLT) recipients has reduced the occurrence of early cytomegalovirus (CMV) disease. Late disease is increasingly reported. Little is known about CMV disease occurring beyond the first year after transplantation. The aim of this study was to evaluate the occurrence of CMV disease two or more years after OLT and to determine its risk factors and clinical features. Eighty-one consecutive OLT recipients followed for 2 years or longer after transplantation were included in the study. Data were collected on demographic and clinical variables, clinical presentation, treatment, and outcome of late CMV disease. Late CMV disease occurred in 7/81 liver recipients (8.5%) at a mean time of 5.9 years after OLT (range: 3.5--9.3, median: 6.3 years). All seven patients were women, with a mean age of 47.7 years (range: 26--60, median: 59 years). There was no association between the development of late CMV disease and the occurrence of rejection episodes, treatment with corticosteroids, or the early use of antiviral prophylaxis. Clinical presentation included fever and disturbed liver functions in all patients, one patient had concurrent CMV pneumonitis and one CMV retinitis. Though all patients responded to ganciclovir, two had recurrent disease episodes and one patient died of secondary bacterial sepsis. Late-onset CMV disease can occur several years after OLT. Although it manifests classic clinical features of early disease, it is not associated with traditional risk factors and its pathogenesis may differ from that of early disease.

Adult↗
PubMed2003

Early expression of interferon gamma following oral antigen administration is associated with peripheral tolerance induction.

Oral tolerance is the induction of immune hyporesponsiveness to orally administered antigens. It was described in association with a decrease in interferon gamma (IFNgamma) production by activated T cells. To determine the role of IFNgamma and IL10 in immunemodulation via oral tolerization. Colitis was induced by intracolonic instillation of trinitrobenzene sulfonic acid. Treated mice received five oral doses of colitis-extracted proteins (CEPs) every other day, starting immediately after colitis induction. Control mice received similar doses of bovine serum albumin. Colitis was assessed in both groups by standard clinical, micro- and macroscopic scores. IFNgamma and IL10 expression in splenic lymphocytes from both groups was tested by RT-PCR immediately after oral feeding, 1, 4, 8, 12, and 24 h thereafter and then every 24 h for 2 weeks. Feeding of CEPs markedly ameliorated experimental colitis. These mice gained weight and showed markedly improved macro- and microscopic parameters of colitis. Tolerized mice exhibited IFNgamma expression in splenic lymphocytes starting immediately following oral CEP immunization and up to 14 d thereafter. IL10 was expressed starting 1 h after CEP feeding and during the first 48 h thereafter. In contrast, non-tolerized control mice manifested IFNgamma expression starting on day 6 and had no IL10 expression. Early induction of IFNgamma expression by oral antigen may be associated with systemic tolerance in the experimental colitis setting. In contrast, late expression of IFNgamma is associated with a pro-inflammatory response in non-tolerized controls.

Administration, Oral↗
PubMed2003

Treatment of chronic hepatitis B virus infection via oral immune regulation toward hepatitis B virus proteins.

OBJECTIVES: Hepatitis B virus (HBV) is a noncytopathic virus, and hepatocellular injury is mediated by a defective host antiviral immune response. We have previously shown that antiviral immunity can be modulated through oral feeding of viral proteins. The aims of this study were to determine the safety and efficacy of treatment of patients with chronic HBV by means of p.o. administration of HBV envelope proteins. METHODS: A total of 42 chronic HBV patients were treated p.o. with HBV envelope proteins (HBsAg+preS1+preS2), three times/wk for 20-30 wk, and followed for an additional 20 wk. Patients were monitored for HBV-DNA levels, liver enzymes, and liver histology. HBV-directed T cell immune modulation was assessed in vitro by HBV specific T cell-proliferation, cytotoxicity, IFN gamma, and IL10 ELISPOT assays, and reverse transcription-polymerase chain reaction cytokines assay. RESULTS: Favorable response in one of the primary endpoints was achieved in 28/42 patients (66.6%) by means of p.o. immune regulation. A significant decrease in viral load was observed in 15 patients (35.7%). HBsAg/HBcAg biopsy scores improved in 41% and 57.1% of patients, respectively. Histological improvement in liver necroinflammatory score was noted in 12/40 patients (30%). In all, 80% showed biochemical response. Five of 19 HBeAg positive patients (26.3%) became negative for HBeAg. A favorable augmentation in anti-HBV specific T cell response, with increased HbsAg specific T cell proliferation (78%), cytotoxicity (75%), and IFN gamma positive T cell clones (62.9%) was noted. In addition, a decrease in the IL10 gamma positive T cell clones was achieved (48.1%). Natural killer T (NKT) lymphocytes increased significantly in all treated patients. CONCLUSIONS: Immune regulation of the anti-HBV immune response via p.o. administration of HBV envelope proteins alleviated the immune-mediated liver injury while augmenting the effective antiviral immunity.

Administration, Oral↗
PubMed2002

Lamivudine therapy for prevention of immunosuppressive-induced hepatitis B virus reactivation in hepatitis B surface antigen carriers.

Viral reactivation in hepatitis B surface antigen (HBsAg) carriers undergoing immunosuppressive therapy is well documented. To evaluate the role of lamivudine prophylaxis in Hepatitis B virus (HBV) carriers treated with immunosuppression for nonhepatic disorders, we reviewed our experience between 1997 and 2000 at Hadassah University Hospital (Jerusalem, Israel). Controls were patients who were HBV carriers and who, between 1990 and 1995, were treated for hematological malignancies but were not treated with lamivudine. Eighteen HBsAg-positive patients were treated with immunosuppression. Fourteen were males, with a mean age of 48 years. Eleven patients had lymphoma; 2 had colonic adenocarcinoma; and 5 had cryoglobulinemia, enophthalmitis, vasculitis, malignant histocytosis, or ulcerative colitis. Fourteen patients were treated with chemotherapy, and 4 with prolonged high-dose corticosteroids. All patients were HBsAg-positive; 4 had hepatitis B e antigen, and 10 had HBV DNA by polymerase chain reaction. Lamivudine was administered to 13 patients in the treatment group 1 to 60 days (mean, 15 days) before immunosuppressive treatment and continued 0.5 to 24 months (mean, 7 months) following initiation of immunosuppression. Mean follow-up after lamivudine administration was 21 months. Three patients died of lymphoma complications and 10 (77%) survived. None of the patients had clinical or serological evidence of HBV reactivation during or after lamivudine prophylaxis. Of 6 patients who presented with liver function test disturbances, 5 improved during combined lamivudine and immunosuppression treatment. At the end of follow-up, HBV DNA became undetectable in 2 of 10 patients. In 2 patients, seroconversion from HBsAg to anti-HBs was observed. In contrast, 2 of 5 control patients had HBV reactivation. Lamivudine prophylaxis in HBsAg carriers receiving immunosuppressive therapy may prevent HBV reactivation and hepatic failure.

Adolescent↗
PubMed2002

Immunomodulation of experimental colitis via caloric restriction: role of Nk1.1+ T cells.

Inflammatory bowel diseases are immune-mediated disorders. Dietary restriction and NK1.1+ liver-associated lymphocytes (LAL) are considered to be involved in immunomodulation of autoimmune diseases. Our aim was to evaluate the effect of caloric restriction on experimental colitis and to determine NK1.1+ LAL function in immunoregulation. Experimental colitis was induced in C57 black mice by intracolonic instillation of trinitrobenzene sulfonic acid. Caloric restriction to 60% of the daily requirement was started 2 weeks prior to, or simultaneously with, colitis induction and continued throughout the study. Control mice were fed ad libitum. Colitis was assessed by standard clinical and macroscopic scores. To determine the mechanism involved in immunomodulation, liver lymphocytes were isolated and analyzed for NK1.1+ T-cell markers by FACS. T-cell function was evaluated by T-cell proliferation. Serum cytokines were measured by ELISA. Dietary restriction to 60% markedly ameliorated experimental colitis in both groups. These mice gained weight and showed improved macroscopic parameters of colitis. NK1.1+ LAL numbers increased fourfold and NKT cytotoxicity twofold in caloric-restricted mice. The antigen-specific T-cell proliferation index decreased (from 4.45 in controls to 1.15), and IFN-gamma and IL-12 serum levels decreased (from 290 to 200 pg and from 122 to 53 pg, respectively) in caloric-restricted mice. Our conclusion was that dietary restriction induced immunomodulation of experimental colitis and ameliorated the disease. This effect was mediated via an increase in NK1.1+ T lymphocytes, which may play a critical role in keeping the T-cell balance in immunoregulation.

Animals↗
PubMed2002

Exacerbation of pulmonary sarcoidosis after liver transplantation.

Patients with hepatic sarcoidosis rarely require orthotopic liver transplantation (OLT). Progression of granulomatous activity involving other organs after OLT has rarely been described. We describe a 32-year-old woman who underwent liver transplantation for sarcoidosis-associated end-stage liver disease. She presented 4 years later with shortness of breath, hilar lymphadenopathy, and interstitial lung abnormalities. Liver functions were normal. Open lung biopsy results revealed granulomata compatible with sarcoidosis. The patient made a complete recovery after corticosteroid treatment. To the best of our knowledge, this is a first description of severe exacerbation of pulmonary sarcoidosis in an immunosuppressed patient who underwent liver transplantation for sarcoidosis-associated liver disease.

Adult↗
PubMed2002

Variable response to probiotics in two models of experimental colitis in rats.

BACKGROUND AND AIM: Clinical and experimental data suggest an important role for intestinal microflora in the pathogenesis of inflammatory bowel disease, and probiotics have been shown to ameliorate pouchitis. We evaluated the effect of different preparations of probiotic bacteria on experimental colitis in rats. METHODS: Rats were treated daily intragastrically with two probiotic preparations, VSL#3 or strain GG (LGG), 7 days before induction of colitis and for another week thereafter. Colitis was induced by intracolonic administration of either dinitrobenzene sulfonic acid (DNBS) or iodoacetamide. Rats were killed 7 days after induction of colitis, the colon isolated, washed, weighed, lesion area measured, and mucosa processed for determination of myeloperoxidase (MPO) and nitric oxide synthase (NOS) activities and prostaglandin E2 (PGE2) generation. RESULTS: In rats cotreated with VSL#3 or LGG and iodoacetamide, there was a significant decrease in the lesion area, 98 +/- 37 mm and 142 +/- 43 mm, respectively, as compared with 342 +/- 66 mm in the control group. Colonic wet weight significantly decreased to 1.3 +/- 0.1 g/10 cm and 1.4 +/- 0.1 g/10 cm, respectively, as compared with 1.7 +/- 0.1 g/10 cm. There was also a significant decrease in PGE2 generation, MPO, and NOS activities in the VSL#3 and LGG treatment groups. Presence of VSL#3 bacteria in the rat's colon was confirmed by culture and polymerase chain reaction (PCR) amplification. Neither probiotic preparation had an effect on the extent of colonic damage in DNBS-induced colitis. CONCLUSION: Both VSL#3 and LGG significantly ameliorated colitis induced by the sulfhydryl-blocker iodoacetamide, but had no effect on the immune-mediated DNBS-induced colitis. The results suggest a possible role for sulfhydryl compounds in the protective effect of probiotic bacteria, and support their use in patients with inflammatory bowel disease.

Alkylating Agents↗
PubMed2002

[Neurologic complications following liver transplantation].

Neurologic complications are very common following liver transplantation and appear in 30%-90% of the patients. These complications represent a wide array of etiologies, often presenting complicated diagnostic options. The primary liver disease for which the patient underwent the transplantation can cause neurologic complications, or they can be a presentation of a metabolic or vascular derangement. The medications given to liver transplanted patients can cause neurologic complication either directly via drug side effects or indirectly via immune-suppression and secondary opportunistic infections of the nervous system. We present two cases of liver transplanted patients, one suffering from a complex neurologic syndrome attributed to her primary Wilsons disease and the second with recurrent encephalopathy following transplantation attributed to a porto-systemic shunt. We review the current literature on the subject.

Adult↗