Suppression of hepatitis C virus by the flavonoid quercetin is mediated by inhibition of NS3 protease activity.

Phytochemicals exert antiviral activity and may play a potential therapeutic role in hepatitis C virus (HCV) infection. In this work, we aimed to isolate NS3 inhibitors from traditional Indian medicinal plants that were found, in our earlier study, to inhibit HCV NS3 protease activity and to evaluate their potential to inhibit HCV replication. A potent inhibitory effect of NS3 catalytic activity was obtained with Embelia ribes plant extracts. Quercetin, a ubiquitous plant flavonoid, was identified as the active substance in the fractioned extract. It was found to inhibit NS3 activity in a specific dose-dependent manner in an in vitro catalysis assay. Quercetin inhibited HCV RNA replication as analysed in the subgenomic HCV RNA replicon system. It also inhibited HCV infectious virus production in the HCV infectious cell culture system (HCVcc), as analysed by the focus-forming unit reduction assay and HCV RNA real-time PCR. The inhibitory effect of quercetin was also obtained when using a model system in which NS3 engineered substrates were introduced in NS3-expressing cells, providing evidence that inhibition in vivo could be directed to the NS3 and do not involve other HCV proteins. Our work demonstrates that quercetin has a direct inhibitory effect on the HCV NS3 protease. These results point to the potential of quercetin as a natural nontoxic anti-HCV agent reducing viral production by inhibiting both NS3 and heat shock proteins essential for HCV replication.

Rapid seroconversion and persistent functional IgG antibodies in severe COVID-19 patients correlates with an IL-12p70 and IL-33 signature.

Despite ongoing efforts to characterize the host response toward SARS-CoV-2, a major gap in our knowledge still exists regarding the magnitude and duration of the humoral response. Analysis of the antibody response in mild versus moderate/severe patients, using our new developed quantitative electrochemiluminescent assay for detecting IgM/IgA/IgG antibodies toward SARS-CoV-2 antigens, revealed a rapid onset of IgG/IgA antibodies, specifically in moderate/severe patients. IgM antibodies against the viral receptor binding domain, but not against nucleocapsid protein, were detected at early stages of the disease. Furthermore, we observed a marked reduction in IgM/IgA antibodies over-time. Adapting our assay for ACE2 binding-competition, demonstrated that the presence of potentially neutralizing antibodies is corelated with IgG/IgA. Finally, analysis of the cytokine profile in COVID-19 patients revealed unique correlation of an IL-12p70/IL33 and IgG seroconversion, which correlated with disease severity. In summary, our comprehensive analysis has major implications on the understanding and monitoring of SARS-CoV-2 infections.

Magnetic resonance cholangiopancreatography for the accurate diagnosis of biliary complications after liver transplantation: comparison with endoscopic retrograde cholangiography and percutaneous transhepatic cholangiography - long-term follow-up.

Biliary complications after liver transplantation remain a serious cause of morbidity and mortality. Direct invasive cholangiographic techniques, endoscopic retrograde cholangiography (ERCP) or percutaneous transhepatic cholangiography (PTC), have procedure-related complications. Magnetic resonance cholangiopancreatography (MRCP) is non-invasive, safe, and accurate. The aim of this study was to evaluate MRCP in detecting biliary complications following liver transplantation and comparing findings with ERCP and PTC. Twenty-seven consecutive liver transplant recipients who presented with clinical and biochemical, ultrasonographic, or histological evidence of biliary complications were evaluated with MRCP. Patients were followed up for a median period of 36 months. The presence of a biliary complication was confirmed in 18 patients (66.6%): anastomotic biliary stricture in 12 (66.6%); diffuse intrahepatic biliary stricture in 5 (27.7%): ischemic (n = 3), recurrence of primary sclerosing cholangitis (n = 2), and choledocholithiasis in one. In nine patients (33.3%), MRCP was normal. Six patients underwent ERCP, and eight PTC. There was a statistically significant correlation between the MRCP and both ERCP and PTC (p = 0.01) findings. The sensitivity and specificity of the MRCP were 94.4% and 88.9%, respectively, and the positive and negative predictive values, 94.4% and 89.9%, respectively. MRCP is an accurate imaging tool for the assessment of biliary complications after liver transplantation. We recommend that MRCP be the diagnostic imaging modality of choice in this setting, reserving direct cholangiography for therapeutic procedures.

Prevention of recurrent hepatitis B virus infection after liver transplantation: hepatitis B immunoglobulin, antiviral drugs, or both? Systematic review and meta-analysis.

OBJECTIVES: To evaluate antiviral prophylaxis against hepatitis B virus (HBV) following liver transplantation. METHODS: Systematic review and meta-analysis. Clinical trials and comparative cohort studies comparing the use of hepatitis B immunoglobulin (HBIg), antivirals, or both following liver transplantation for HBV infection were included. The primary outcome was reappearance of hepatitis B surface antigen (HBsAg). Other outcomes included all-cause and HBV-related mortality, HB-related active liver disease, and reappearance of HBV DNA after transplantation. Relative risks (RR) with 95% confidence intervals (CIs) are reported. RESULTS: Twenty studies (22 comparisons) were included. Ten studies compared HBIg to combination treatment, 9 compared antivirals to combination treatment, and 3 compared lamivudine (LAM) to HBIg. Combination treatment reduced HBsAg reappearance (RR 0.28; 95% CI 0.12-0.66), and was superior to HBIg alone in all other outcome measures. Combination treatment was significantly better than antivirals in preventing reappearance of HBsAg (RR 0.31; 95% CI 0.22-0.44), even when low-dose HBIg was given. No significant difference was found between HBIg and LAM monotherapy for all measured outcomes. Major limitations with regard to comparability of the study groups in non-randomized trials were revealed. CONCLUSIONS: Combination treatment with HBIg and LAM reduced HBV recurrence following liver transplantation, compared with HBIg or LAM alone, and reduced mortality compared with HBIg alone.

Low weight predicts neutropenia and peginterferon alfa-2a dose reductions during treatment for chronic hepatitis C.

Treatment-induced neutropenia frequently complicates the treatment course of patients treated with pegylated interferon alfa and ribavirin for chronic hepatitis C. We investigated the effect of weight on the risk for dose reductions caused by neutropenia in patients treated with a weight-independent dose of peginterferon alfa-2a. We retrospectively analysed single centre data for 172 patients enrolled in a multi-centre, open-label trial of peginterferon alfa-2a and ribavirin for chronic hepatitis C. Low body weight was significantly associated with dose reductions due to neutropenia. Patients weighing less than 62 kg had a 35% risk for significant neutropenia as opposed to a 12% risk for heavier patients (P = 0.001), and this side-effect occurred earlier during treatment. Low weight was an independent risk factor by multivariate analysis (hazard ratio 0.956/kg). The risk for treatment-induced neutropenia was associated with body surface area more than with the body mass index. In conclusion, a low pre-treatment weight strongly predicts the need for peginterferon alfa-2a dose reductions. This apparently reflects overall body size more than body fat content. It is prudent to frequently monitor blood counts for smaller-sized patients, especially during the first weeks of treatment.

Immunohistochemical evaluation of hepatic oval cell activation and differentiation toward pancreatic beta-cell phenotype in streptozotocin-induced diabetic mice.

Oval cell (OvCs) involvement in regeneration is a well known phenomenon in models of liver injury, however, the activation of these cells following streptozotocin (STZ)-induced diabetes has not been studied yet. Differentiation of liver cells toward insulin-producing cells in diabetes has been reported, but the cell phenotype is still unclear. The aim of the present study was to confirm by immunohistochemical analysis, the activation of OvCs and their ability to express pancreatic beta-cell phenotype in STZ-induced diabetic mice. Using specific anti-A6 antibodies for mouse OvCs, we found a three-fold increase in periportal number and two-fold higher density of OvCs in diabetic livers, when compared to controls. Unlike non-diabetic controls, double staining technique showed co-localization of A6 and proinsulin in the cytoplasm of OvCs of diabetic animals, but no insulin staining was detected, probably reflecting the premature character of OvCs differentiation toward beta-cell-like phenotype. These data add valuable information concerning the nature and the stage of functional maturity of liver cells undergoing differentiation toward beta-cell phenotype in STZ-induced diabetic animals.

Use of electroporation to introduce biologically active foreign genes into primary rat hepatocytes.

A method is described for introducing and expressing cloned genes in isolated hepatocytes. Primary rat hepatocytes isolated by collagenase perfusion were transfected in suspension with plasmid pSV2CAT by electroporation. Forty-eight hours later, soluble extracts from transfected hepatocytes showed chloramphenicol acetyltransferase activity comparable to that obtained in rat hepatoma cell line H4AzC2 by calcium phosphate or DEAE-dextran transfection. The latter two methods could not be used successfully for primary hepatocytes because of cytotoxicity of these reagents. This indicates that electroporation is a useful method to obtain transient expression of foreign genes in primary epithelial cells, such as rat hepatocytes, which are difficult to maintain in cell culture.

Fulminant non--A-G viral hepatitis leading to liver transplantation.

BACKGROUND: All hepatotropic viruses are known to cause fulminant hepatic failure (FHF). However, in 30% to 40% of patients with FHF, the precise cause remains unknown. We aimed to better define this subgroup. METHODS: We evaluated the clinical course and outcome of 7 patients admitted during a 22-month period with fulminant viral hepatitis leading to liver transplantation; none had serologic or molecular evidence of hepatitis A, B, C, D, E, or G viral infection, thus the term non-A-G viral hepatitis. All known etiologies of FHF were excluded. RESULTS: All patients had prodromal symptoms suggestive of viral causes. Mean age was 30 years. The interval between onset of jaundice and appearance of encephalopathy was 23 days (range, 4-50 days). Five patients had grade III/IV encephalopathy. Serum alanine aminotransferase levels showed a single peak of activity. The duration between first symptoms and liver transplantation was 28 days (range, 12-71 days). Results of histological study of the explanted liver showed submassive (4 patients) or massive (3 patients) hepatocyte necrosis. In all patients, results of polymerase chain reaction analysis did not detect hepatitis B virus DNA, hepatitis C virus RNA, or hepatitis G virus RNA in the explanted liver. After transplantation, 2 patients showed (6 months later) increased liver enzyme levels of undetermined cause, and results of a liver biopsy showed mild lobular hepatitis; 1 patient had lymphoproliferative disorder (Epstein-Barr virus-originated); and 1 patient, aplastic anemia, which is known to be associated with seronegative viral hepatitis. The latter patient died, whereas the other 6 patients are alive (survival rate, 86%). CONCLUSIONS: Our patients with non-A-G viral hepatitis had a severe acute onset with progressive FHF requiring liver transplantation. There is some suggestion of recurrent viral disease after transplantation implicating other unknown viruses in the etiology.

Relapsing hepatitis A. Review of 14 cases and literature survey.

We have reviewed our experience with 14 cases of relapsing hepatitis A (RH-A), as well as 68 cases reported in the literature. Relapse occurs in 3 to 20% of patients with acute hepatitis A, and rarely takes the form of a polyphasic disease (multiple relapses). After a stage of typical hepatitis A, remission phase ensues, with partial or complete resolution of clinical and biochemical manifestations. Relapse usually occurs after a short period (usually less than 3 weeks). Relapse is usually clinically milder than the first phase, with variable liver function abnormalities and a tendency toward more marked cholestatic features. Not uncommonly, immune manifestations occur during this phase, including purpura, nephritis, and arthralgia, with common laboratory findings of rheumatoid factor as well as false-positive reaction to HCV-EIA tests. The clinical course in relapsing hepatitis A is almost always benign, and uneventful recovery is the rule with few exceptions. Steroid treatment, first reported in the present series, resulted in marked clinical improvement. Preliminary results suggest that R-HA is associated with a continuing viremia as well as shedding of virus in stools during the relapse phase. The pathogenesis of R-HA probably involves an interaction between persistent viral infection and immune mechanisms responding to the continuing antigenic stimulation.

The addition of mycophenolate mofetil for suppressing hepatitis B virus replication in liver recipients who developed lamivudine resistance--no beneficial effect.

BACKGROUND: Mycophenolate mofetil is used as an immunosuppressive agent in liver transplant recipients. Its active compound, mycophenolic acid, also inhibits the replication of Epstein-Barr virus and human immunodeficiency virus. Based on a study indicating the effectiveness of mycophenolate mofetil on hepatitis B virus (HBV) replication in infected human hepatocyte cells in culture, we examined the efficacy of mycophenolate mofetil in suppressing HBV replication in lamivudine-resistant liver allograft recipients with recurrent HBV infection. METHOD: The study population included four liver allograft recipients (three males, one female), median age 51 years (range 41-57 years), with recurrent HBV infection who proved to be resistant to lamivudine. All received standard maintenance immunosuppression therapy. Median pretreatment serum alanine aminotransferase level was 75 mu/L (range 39-182 mu/L) and HBV DNA level (quantitative dot blot), 70 pg/ml (range: 10-5,000 pg/ml). Mycophenolate mofetil, 1.0 g p.o. twice daily, was administered for 8 weeks, concomitant with a reduction in the maintenance corticosteroid and cyclosporine doses. RESULTS: After mycophenolate mofetil was administered, the serum alanine aminotransferase level increased in two patients, did not change in one, and decreased in one. Serum HBV DNA levels increased in three patients and decreased (nonsignficantly) in only one patient. Two patients complained of abdominal pain and nausea. CONCLUSIONS: Mycophenolate mofetil at the dosage used is not effective in suppressing HBV replication after liver transplantation.

Systemic chimerism in sex-mismatched liver transplant recipients detected by fluorescence in situ hybridization.

Fluorescent in situ hybridization (FISH) is a reliable, rapid, sensitive, and quantitative method for detection of residual host cells following sex-mismatched bone marrow transplantation. Recently, donor-derived long-term multilineage hematopoiesis was detected in a sex-mismatched liver transplant recipient. We therefore assessed chimeric status in 12 patients (F 9, M3), mean age 42.5 years (range 16-57), for a median period of 18 months (range 7-32) following sex-mismatched liver transplantation. Peripheral blood hematolymphoid cells were hybridized with Y- or X-chromosome fluorescently labeled specific probes, and the donor-typed hematopoietic cells were enumerated. In two F recipients 4-5% male hematolymphoid cells were detected in the peripheral blood at 15 and 22 months after sex-mismatched liver transplantation, respectively. These two patients with systemic chimerism suffered from primary biliary cirrhosis and fulminant Wilson's disease before transplantation. One of them had evidence of graft rejection only once during the posttransplant course and the other had no episode of graft rejection. Two other female patients who were found to have approximately 2% male hematolymphoid cells, which is considered to be in the false-positive range, also had no signs of graft rejection during the posttransplant follow-up period. Among the remaining eight patients, in whom systemic chimerism was undetectable, there was at least one episode of acute cellular rejection during the posttransplant period. In summary, the FISH technique enables us to detect systemic chimerism following sex-mismatched liver allografts. Inasmuch as balanced systemic chimerism after organ transplantation is of major importance for self tolerance, our findings may enable us to treat patients after liver transplantation without the need for immunosuppression.

Hepatitis C-associated cryoglobulinemia after liver transplantation.

Mixed cryoglobulinemia is well known to be associated with hepatitis C virus (HCV) infection. We report two cases in which cryoglobulinemia appeared or became grossly exacerbated after orthotopic liver transplantation. In both cases, there was co-appearance of cryoglobulinemia with the reinfection of the grafted liver with HCV. It is postulated that the cryoglobulinemia might be related to secondary HCV infection in these patients.

Association of lamivudine resistance in recurrent hepatitis B after liver transplantation with advanced hepatic fibrosis.

BACKGROUND: Orthotopic liver transplantation (OLT) in patients with hepatitis B virus (HBV) infection is known to be associated with a high recurrence rate and poor prognosis. Lamivudine, a nucleoside analogue, is a potent inhibitor of HBV replication, but it is associated with a 14-39% rate of resistance. METHODS: We report on four patients who underwent OLT for HBV infection. In all cases, the HBV infection recurred in the grafted liver and was treated with lamivudine (100 mg daily) on a compassionate-use basis. The patients were monitored closely for serum liver enzymes, hepatitis B surface antigen and HBV DNA (by hybridization). Liver biopsy was performed before and after lamivudine therapy. HBV DNA was amplified from serum for each patient and sequenced through a conserved polymerase domain, the tyrosine-methionine-aspartate-aspartate (YMDD) locus. RESULTS: All four patients exhibited lamivudine resistance 9-20 months after initiation of the drug. In all patients with a clinically mild disease, liver histology findings (12-24 months after lamivudine therapy) showed progressive fibrosis as compared to biopsies performed before lamivudine therapy, with a significant increase (> or =2 points) in the Knodell score in three patients. Moreover, two patients exhibited worsening of the necroinflammatory process. A mutation at the YMDD motif of the HBV polymerase gene was detected in all cases. CONCLUSIONS: Lamivudine resistance frequently occurs in patients with recurrent HBV infection after OLT and is associated with advanced hepatic fibrosis and necroinflammatory process. A combination of antiviral therapies may be necessary.

Beneficial effect of lamivudine in recurrent hepatitis B after liver transplantation.

Orthotopic liver transplantation (OLT) in patients infected with hepatitis B virus (HBV) is known to be associated with a high recurrence rate and poor prognosis. Interferon treatment in these patients offers little benefit and may lead to further complications. Lamivudine, the (-)enantiomer of 3'-thiacytidine, a 2'3'-dideoxynucleoside, is known to be a potent inhibitor of HBV replication in patients with chronic HBV infection. Three HBV-positive OLT patients were administrated lamivudine, 100 mg x 1 orally, for a period of at least 20 weeks, in an open, compassionate-use basis. All three patients were HBV DNA-negative before OLT. HBV reinfection occurred at a median time of 7 months (range, 6-9 months) after OLT, in spite of adequate immunoprophylaxis. All three patients had high serum transaminase levels (alanine aminotransferase [ALT], 103-324 U/L) and histologic evidence of recurrent HBV infection of the grafted liver, and HBV DNA was evident in the sera of all of them. Six weeks after lamivudine treatment, HBV DNA disappeared from the serum of all patients (detected by hybridization); by the 10th week, HBV DNA was also negative by polymerase chain reaction in two out of three patients. Interestingly, the one patient who was HBV DNA positive by polymerase chain reaction still has mildly elevated ALT levels, whereas the other two patients have normal ALT levels. We also noted that on the 5th week there was a transient elevation of serum ALT levels in two patients. No adverse effects or rejection episodes were noted. In conclusion, lamivudine is a beneficial and well-tolerated therapy in OLT patients with recurrent HBV infection. We are studying the effect of lamivudine in other patients and for a longer period of time.

Extension of transplantation free time by lamivudine in patients with hepatitis B-induced decompensated cirrhosis.

BACKGROUND: Liver transplantation for hepatitis B virus (HBV)-induced cirrhosis carries a high risk of graft reinfection and poor prognosis. Active viral replication is considered a contraindication for transplantation in most centers. Lamivudine, a new nucleoside analog, is a potent inhibitor of HBV replication that has been used safely for pretransplantation suppression of HBV replication. METHODS: We report the pattern of response to lamivudine treatment in three consecutive patients with decompensated cirrhosis due to the replicative phase of chronic HBV infection. RESULTS: In addition to virological and biochemical response, impressive clinical improvement was noted in all three patients, with disappearance of the ascites and marked improvement of synthetic liver function tests. One patient converted to anti-hepatitis B surface and is free of symptoms 20 months after initiation of treatment. The other two patients experienced significant clinical improvement for 8 to 9 months and were removed from the waiting list for transplantation. However, progressive liver disease recurred in both patients--one underwent liver transplantation and the other is a candidate for the procedure. CONCLUSION: The administration of lamivudine for pretransplantation HBV suppression was associated with impressive clinical and biochemical improvement. Lamivudine may extend the transplantation free time in such patients. The mechanism of this desirable effect should be explored.

Defibrotide for the treatment of veno-occlusive disease after liver transplantation.

BACKGROUND: Veno-occlusive disease (VOD) after liver transplantation is associated with acute rejection and poor outcome. The use of antithrombotic and thrombolytic agents is limited by their toxicity. Defibrotide is a polydeoxyribonucleotide with thrombolytic and antithrombotic properties and no systemic anticoagulant effect. METHODS: Defibrotide, 35-40 mg/kg/day, was administered intravenously for 21 days on a compassionate-use basis to two patients aged 66 and 49 years. VOD had developed 6 weeks and 4 months after orthotopic liver transplantation for hepatitis C and hepatitis B infection, respectively. VOD was diagnosed clinically by findings of weight gain (8.5% and 16%), ascites, jaundice (serum bilirubin 5.4 mg/dl and 21.7 mg/dl), and severe coagulopathy (in one patient), and histologically by the presence of hemorrhagic centrilobular necrosis and fibrous stenosis of the hepatic venules. One of the patients had received azathioprine as part of the immunosuppressive regimen. There was no evidence of acute cellular rejection histologically. RESULTS: After 3 weeks of defibrotide administration, the first patient showed complete clinical resolution of the VOD, and serum bilirubin level normalized. He is alive 6 months after transplantation. The second patient, treated at a later stage of disease, showed marked improvement in the coagulopathic state, but there was no resolution of the VOD. He died 2 months later of multiorgan failure due to Escherichia coli sepsis. Neither patient had side effects from the drug. CONCLUSIONS: Defibrotide is a promising drug for the treatment of VOD after liver transplantation and needs to be evaluated in large, prospective studies.

Efficacy of lamivudine for the treatment of hepatitis B virus infection after liver transplantation in children.

BACKGROUND: There is at present very little information about hepatitis B virus (HBV) infection in children after liver transplantation. This is the first study to assess the safety and efficacy of lamivudine in this patient population. METHODS: We describe three children aged 5-14 years who underwent liver transplantation for fulminant hepatitis A, hyperoxaluria, and cystic fibrosis. Despite adequate immunoprophylaxis, two of the children who were serum hepatitis B surface antigen-positive before transplantation (HBV DNA-negative by hybridization) had a reactivation of the disease, and one had a de novo HBV infection, at 12-18 months after transplantation. Lamivudine 3 mg/kg was administered on a compassionate-use basis for 14-36 months. RESULTS: After 1 month of therapy, HBV DNA disappeared from the serum in all patients by hybridization and in two patients by polymerase chain reaction. In all three children, alanine transaminase levels normalized. One child developed lamivudine resistance after 22 months with no evidence of hepatic decompensation. Repeated liver histological studies revealed progression of hepatic fibrosis in one child. All children remained serum hepatitis B surface antigen- and hepatitis B e antigen-positive. No adverse effects of the drug were noted. CONCLUSION: Lamivudine is beneficial and well tolerated in children with HBV infection after liver transplantation.

Role of cytokine gene polymorphism in hepatitis C recurrence and allograft rejection among liver transplant recipients.

BACKGROUND: Cytokines play a key role in the regulation of immune responses. The maximal capacity of cytokine production varies between individuals and was shown to correlate with polymorphism in cytokine gene promoters. The objective of this study was to analyze the role of cytokine allelic variations in susceptibility to early graft rejection episodes and recurrence of hepatitis C infection in liver transplant (LTx) recipients. METHODS: The genetic profile of five cytokines was studied in 68 LTx recipients and 49 controls using polymerase chain reaction sequence specific primers. All individuals were genotyped as high or low producers of TNF-alpha and IL-6 and high, intermediate, or low producers of transforming growth factor beta (TGF-beta), interferon gamma (IFN-gamma), and interleukin 10 (IL-10) based on single nucleotide substitutions. RESULTS: No statistically significant differences were observed between patients with or without early rejection episodes. A significant proportion of patients more prone to rejection were genotyped as having a low production profile of IL-10 compared with the control population (P=0.04). These data are in accordance with reports regarding other solid-organ transplant recipients. Patients with no recurrence of hepatitis C had the inherent ability to produce higher TGF-beta levels than did patients with recurrent disease (P=0.042). Among nonrecurrent patients, the percentage of genetically low IL-10 producers was higher than among recurrent patients (P=0.07). Furthermore, a genetic tendency to produce higher levels of IFN-gamma was noted among LTx recipients with nonrecurrent hepatitis C than among those with recurrent hepatitis C. CONCLUSIONS: While no significant correlation was detected between particular cytokine profile and early rejection episodes, our data strongly suggest an association between cytokine gene polymorphism of TGF-beta, IL-10, and INF-gamma and recurrence of hepatitis C in LTx recipients.

The TATA-less promoter of hepatitis B virus S gene contains a TBP binding site and an active initiator.

The surface antigen (S) gene promoter, one of the major hepatitis B virus (HBV) promoters, directs the synthesis of a 2.1 kb mRNA which encodes the preS2 and S polypeptides. The preS2/S promoter does not contain a classical TATA box, and transcription regulation of the preS2/S gene has not been fully elucidated. We analysed two regions involved in preS2/S gene transcription of the HBV adw subtype: the diverged TATA box and a putative initiator element. We demonstrated sequence specific promoter activity of the putative TATA-like sequences in the preS2/S gene promoter (-25 to -32 bp). Using end labeled synthetic oligonucleotides we observed specific binding of nuclear extracts to the diverged TATA sequence, that was significantly reduced using a mutated oligonucleotide. Specific binding of yeast TBP to the diverged TATA sequence was shown which was increased in the mutant containing a classical TATA box. We analysed the proposed initiator (Inr) sequence of the preS2/S promoter region (-13 to -16 bp). Deletion of the inr element markedly reduced promoter activity as assessed by CAT expression. Gel shift assays showed specific binding of nuclear extracts to wild type but not to mutant Inr. Expression studies with double mutants of the diverged TATA and the Inr element established that both elements are active in transcription regulation.