Gene-engineered T cells as a superior adjuvant therapy for metastatic cancer

The major limiting factor in the successful application of adjuvant therapy for metastatic disease is the lack of adjuvant specificity that leads to severe side effects. Reasoning that T cells of the immune system are highly specific, we generated tumor-specific T cells by genetic modification of mouse primary T cells with a chimeric receptor reactive with the human breast cancer-associated Ag erbB-2. These T cells killed breast cancer cells and secreted IFN-gamma in an Ag-specific manner in vitro. We investigated their use against metastatic breast cancer in mice in an adjuvant setting, and compared their effectiveness with the commonly applied adjuvants doxorubicin, 5-fluorouracil, and herceptin. Mice were inoculated orthotopically with the human erbB-2-expressing spontaneously metastatic mouse breast cancer 4T1.2 in mammary tissue, and the primary tumor was surgically removed 8 days later., Significant metastatic disease was demonstrated in lung and liver at the time of surgery on day 8 with increased tumor burden at later time points. T cell adjuvant treatment of day 8 metastatic disease resulted in dramatic increases in survival of mice, and this survival was significantly greater than that afforded by either doxorubicin, 5-fluorouracil, or herceptin.

Association of tumor necrosis factor-alpha polymorphisms and ozone-induced change in lung function

Ozone is a major air pollutant with adverse health effects which exhibit marked inter-individual variability. In mice, regions of genetic linkage with ozone-induced lung injury include the tumor necrosis factor-alpha (TNF), lymphotoxin-alpha (LTA), Toll-like receptor 4 (TLR4), superoxide dismutase (SOD2), and glutathione peroxidase (GPX1) genes. We genotyped polymorphisms in these genes in 51 individuals who had undergone ozone challenge. Mean change in FEV1 with ozone challenge, as a percentage of baseline, was -3% in TNF -308G/A or A/A individuals, compared with -9% in G/G individuals (p = 0.024). When considering TNF haplotypes, the smallest change in FEV1 with ozone exposure was associated with the TNF haplotype comprising LTA +252G/TNF -1031T/TNF -308A/TNF -238G. This association remained statistically significant after correction for age, sex, disease, and ozone concentration (p = 0.047). SOD2 or GPX1 genotypes were not associated with lung function, and the TLR4 polymorphism was too infrequent to analyze. The results of this study support TNF as a genetic factor for susceptibility to ozone-induced changes in lung function in humans, and has potential implications for stratifying health risks of air pollution.

Presence of the metabolic syndrome is associated with reduced adiponectin levels and liver dysfunction in patients with type 2 diabetes

No abstract.

Adoptive transfer of gene-engineered CD4+ helper T cells induces potent primary and secondary tumor rejection

Because CD4(+) T cells play a key role in aiding cellular immune responses, we wanted to assess whether increasing numbers of gene-engineered antigen-restricted CD4(+) T cells could enhance an antitumor response mediated by similarly gene-engineered CD8(+) T cells. In this study, we have used retroviral transduction to generate erbB2-reactive mouse T-cell populations composed of various proportions of CD4(+) and CD8(+) cells and then determined the antitumor reactivity of these mixtures. Gene-modified CD4(+) and CD8(+) T cells were shown to specifically secrete Tc1 (T cytotoxic-1) or Tc2 cytokines, proliferate, and lyse erbB2(+) tumor targets following antigen ligation in vitro. In adoptive transfer experiments using severe combined immunodeficient (scid) mice, we demonstrated that injection of equivalent numbers of antigen-specific engineered CD8(+) and CD4(+) T cells led to significant improvement in survival of mice bearing established lung metastases compared with transfer of unfractionated (largely CD8(+)) engineered T cells. Transferred CD4(+) T cells had to be antigen-specific (not just activated) and secrete interferon gamma (IFN-gamma) to potentiate the antitumor effect. Importantly, antitumor responses in these mice correlated with localization and persistence of gene-engineered T cells at the tumor site. Strikingly, mice that survived primary tumor challenge could reject a subsequent re-challenge. Overall, this study has highlighted the therapeutic potential of using combined transfer of antigen-specific gene-modified CD8(+) and CD4(+) T cells to significantly enhance T-cell adoptive transfer strategies for cancer therapy.

Expression of the iron regulatory peptide hepcidin is reduced in patients with chronic liver disease

Disturbances in iron metabolism often accompany liver disease in humans and hepatic iron deposition is a frequent finding. Since the peptide hepcidin, a major regulator of body iron homeostasis, is synthesised in the liver, alterations in hepcidin expression could be responsible for these effects. To investigate this possibility, we studied hepcidin expression in liver biopsies from patients with hepatitis C virus (HCV) infection, non-alcoholic fatty liver disease (NAFLD) and hemochromatosis (HC). Total RNA was extracted from the liver tissue of 24 HCV, 17 NASH and 5 HC patients, and 17 liver transplant donors (controls). The levels of mRNA for hepcidin and several other molecules involved in iron metabolism (DMT1, Dcytb, hephaestin, ferroportin, TfR1, TfR2, HFE and HJV) were examined by ribonuclease protection assay and expressed relative to the housekeeping gene GAPDH. The expression of hepcidin was significantly decreased in HCV and NASH patients relative to control liver (109±16 and 200±44 versus 325±26 respectively; P=0.008 and 0.02). We have previously reported similar findings in patients with HC, and this was confirmed in the current analysis (176±21; P=0.003). In both HCV and NAFLD patients the expression of the iron reductase Dcytb and the transferrin binding regulatory molecule TfR2 was also decreased, while the cellular iron exporter ferroportin showed a significant increase. Levels of the mRNA for the iron oxidase hephaestin were lower in HCV patients alone, while expression of the major transferrin binding molecule TfR1 was decreased only in NAFLD patients. Of particular interest was the finding that the expression of HJV (which is mutated in patients with juvenile HC) was significantly increased in NAFLD patients. No changes were seen in the expression of the iron importer DMT1 or the regulatory molecule HFE. Decreased expression of hepcidin in patients with HCV and NAFLD provides an explanation why iron homeostasis could be perturbed in these disorders. Reduced hepcidin levels would increase intestinal iron absorption and iron release from macrophages, which could contribute to hepatic iron accumulation. This in turn could lead to alterations in the expression of various proteins involved in iron transport and its regulation. Indeed most of the changes in the expression of such molecules observed in this study are consistent with this. However, the mechanisms leading to changes in the expression of hepcidin in these diseases remain to be elucidated.

Review of genetic and epigenetic alterations in hepatocarcinogenesis

Hepatocellular carcinoma (HCC) is associated with multiple risk factors and is believed to arise from pre-neoplastic lesions, usually in the background of cirrhosis. However, the genetic and epigenetic events of hepatocarcinogenesis are relatively poorly understood. HCC display gross genomic alterations, including chromosomal instability (CIN), CpG island methylation, DNA rearrangements associated with hepatitis B virus (HBV) DNA integration, DNA hypomethylation and, to a lesser degree, microsatellite instability. Various studies have reported CIN at chromosomal regions, 1p, 4q, 5q, 6q, 8p, 10q, 11p, 16p, 16q, 17p and 22q. Frequent promoter hypermethylation and subsequent loss of protein expression has also been demonstrated in HCC at tumor suppressor gene (TSG), p16, p14, p15, SOCS1, RIZ1, E-cadherin and 14-3-3 sigma. An interesting observation emerging from these studies is the presence of a methylator phenotype in hepatocarcinogenesis, although it does not seem advantageous to have high levels of microsatellite instability. Methylation also appears to be an early event, suggesting that this may precede cirrhosis. However, these genes have been studied in isolation and global studies of methylator phenotype are required to assess the significance of epigenetic silencing in hepatocarcinogenesis. Based on previous data there are obvious fundamental differences in the mechanisms of hepatic carcinogenesis, with at least two distinct mechanisms of malignant transformation in the liver, related to CIN and CpG island methylation. The reason for these differences and the relative importance of these mechanisms are not clear but likely relate to the etiopathogenesis of HCC. Defining these broad mechanisms is a necessary prelude to determine the timing of events in malignant transformation of the liver and to investigate the role of known risk factors for HCC.

An optimized model for rat liver perfusion studies

Conditions which influence the viability, integrity, and extraction efficiency of the isolated perfused rat liver were examined to establish optimal conditions for subsequent work in reperfusion injury studies including the choice of buffer, use of oncotic agents, hematocrit, perfusion flow rate, and pressure. Rat livers were perfused with MOPS-buffered Ringer solution with or without erythrocytes. Perfusates were collected and analyzed for blood gases, electrolytes, enzymes, radioactivity in MID studies, and lignocaine in extraction studies. Liver tissue was sampled for histological examinations, and wet:dry weight of the liver was also determined. MOPS-buffered Ringer solution was found to be superior to Krebs bicarbonate buffer, in terms of pH control and buffering capacity, especially during any prolonged period of liver perfusion. A pH of 7.2 is chosen for perfusion since this is the physiological pH of the portal blood. The presence of albumin was important as an oncotic agent, particularly when erythrocytes were used in the perfusate. Perfusion pressure, resistance, and vascular volume are how-dependent and the inclusion of erythrocytes in the perfusate substantially altered the flow characteristics for perfusion pressure and resistance but not vascular volume. Lignocaine extraction was relatively flow-independent. Perfusion injury as defined by enzyme release and tissue fine structure was closely related to the supply of O-2. The optimal conditions for liver perfusion depend upon an adequate supply of oxygen. This can be achieved by using either erythrocyte-free perfusate at a how rate greater than 6 ml/min/g liver or a 20% erythrocyte-containing perfusate at 2 ml/min/g. (C) 1996 Academic Press, Inc.

Peripheral blood chimerism following human liver transplantation

The aim of this study was to prospectively investigate the peak levels and kinetics of donor leucocyte chimerism in human recipients following liver transplantation, The peak levels of chimerism mere observed within the first 48 hours following transplantation and ranged from 0.15% to 20% of total peripheral blood mononuclear cells, In all but one patient, who developed graft versus host disease, there was an early peak level of chimerism that declined over time such that donor leukocytes mere only intermittently detectable after 3 to 4 weeks. In 8 patients who had no episodes of graft rejection, the peak level of donor leukocyte chimerism ranged from 1.3% to 20% (mean +/- SEM; 5.5% +/- 2.1%). In 3 patients who were treated for episodes of acute graft rejection during the first four postoperative weeks, the peak level of donor leukocyte chimerism ranged from 0.15% to 0.2% (0.18 +/- 0.02, P = .012), The results demonstrate a marked variation in the total number of donor leukocytes detectable in the peripheral blood early after liver transplantation and also, that lower levels of chimerism may be associated with lower rates of initial graft acceptance and a higher incidence of acute rejection.

Ethanol feeding enhances inflammatory cytokine expression in lipopolysaccharide-induced hepatitis

Elevated concentrations of plasma tumour necrosis factor (TNF)-alpha, interleukin (IL)-1 and IL-6 have been detected in patients with alcoholic hepatitis and have been implicated in the pathogenesis of hepatocyte necrosis. The present study used a rat model to conduct a detailed histological and biochemical examination of the expression of various pro-inflammatory cytokines and associated liver pathology in ethanol-potentiated lipopolysaccharide (LPS)-induced liver injury. Male Wistar rats were pair-fed either the control or ethanol-containing (36% of caloric intake as ethanol) form of the Lieber-DeCarli liquid diet for 6 weeks. Liver injury was induced by the i.v. injection of LPS (1 mu g/g bodyweight), with animals being killed at O, 1, 3, 6, 12 and 24 h after injection. At the later time points, plasma transaminase and transpeptidase activities were significantly elevated in ethanol-fed LPS-treated rats compared with control-fed LPS-treated animals. At these times after LPS treatment, hepatocytes in ethanol-fed animals displayed fatty change and necrosis with an associated neutrophil polymorph infiltrate. Time course analysis revealed that plasma TNF-alpha (1-3 h post-LPS) and IL-6 (3 h post-LPS) bioactivity was significantly elevated in ethanol-fed compared with control-fed animals. No difference was seen in plasma IL-1 alpha concentration (maximal in both groups 6 h post-LPS). The expression of TNF-alpha, IL-1 alpha, IL-1 beta and IL-6 mRNA were elevated between 1 and 6 h post-LPS in the livers of both control and ethanol-fed rats. However, ethanol-fed LPS-treated animals exhibited significantly higher maximal expression of IL-1 and IL-6 mRNA. Comparison of the appearance of cytokine mRNA and plasma bioactivity indicated an effect of ethanol feeding on post-transcriptional processing and/or the kinetics of the circulating cytokines. Elevated levels of both hepatic cytokine mRNA expression and the preceding plasma cytokines are presumably a necessary prerequisite for hepatic injury seen in this model and, therefore, possibly for the damage seen in human alcoholics. Further studies using this model may lead to significant advances in our understanding of the pathogenic mechanisms of alcoholic liver disease in humans.

Mini-microabscess syndrome in liver transplant recipients

Cytomegalovirus (CMV) is a significant cause of morbidity in immunosuppressed patients. It is characterized in the liver by parenchymal microabscesses, usually containing CMV-infected cells. However, not all hepatic microabscesses are due to CMV infection. In 1992, we described ''mini'' microabscess (MMA) syndrome, a distinct clinical syndrome that occurs in transplanted livers. This report analyzes the clinical and laboratory features of 57 cases of MMA syndrome occurring in 52 patients and compares these with 19 biopsy-proven cases of CMV infection. The diagnosis of MMA syndrome can only be made histologically. The microabscesses are smaller and more numerous than in CMV infection, and there are no viral inclusions present. CMV DNA could not be detected in liver biopsy specimens with MMAs by using ''nested'' polymerase chain reaction (PCR), indicating that MMA syndrome is not caused by CMV infection. The pattern of liver enzyme and bilirubin elevation is predominantly hepatocellular, with transaminase levels elevated, on average, six to eight times the upper limit of normal. The clinical features of MMA syndrome are that it predominantly affects female (40 of 52 patients) orthotopic liver transplant (OLT) recipients of all ages (range, 11 months to 66.9 years). MMA syndrome is unrelated to the indication for initial OLT and tends to occur later after transplantation than CMV infection (median, 91 days post-OLT vs. 32 days for CMV hepatitis). Although the etiology of MMA syndrome is not clear, it does not appear to adversely affect graft or patient survival.

Human leukemia inhibitory factor upregulates LDL receptors on liver cells and decreases serum cholesterol in the cholesterol-fed rabbit

In a previous study, we found that the cytokine (human) leukemia inhibitory factor (hLIF) significantly reduced plasma cholesterol levels and the accumulation of lipid in aortic tissues of cholesterol-fed rabbits after 4 weeks of treatment. The mechanisms by which this occurs were investigated in the present study. This involved examining the effect of hLIF on (1) the level of plasma cholesterol at different times throughout the 4-week treatment and diet period; (2) smooth muscle cell (SMC) and macrophage-derived foam cell formation in vitro; and (3) LDL receptor expression and uptake in the human hepatoma cell line HepG2. At time zero, an osmotic minipump (2-mL capacity; infusion rate, 2.5 mu L/h; 28 days) containing either hLIF (30 mu g.kg(-1).d(-1)) or saline was inserted into the peritoneal cavity of New Zealand White rabbits (N=24). Rabbits were divided into four groups of six animals each. Group 1 received a normal diet/saline; group 2, a normal diet/hLIF; group 3, a 1% cholesterol diet/saline; and group 4, a 1% cholesterol diet/hLIF. hLIF had no effect on the plasma lipids or artery wall of group 2 rabbits (normal diet). However, in group 4 rabbits, plasma cholesterol levels and the percent surface area of thoracic aorta covered by fatty streaks was decreased by approximate to 30% and 80%, respectively, throughout all stages of the 4-week treatment period. In vitro, hLIF failed to prevent lipoprotein uptake by either SMCs or macrophages (foam cell formation) when the cells were exposed to P-VLDL for 24 hours. In contrast, hLIF (100 ng/mL) added to cultured human hepatoma HepG2 cells induced a twofold or threefold increase in intracellular lipid accumulation in the medium containing 10% lipoprotein-deficient serum or 10% fetal calf serum, respectively. This was accompanied by a significant non-dose-dependent increase in LDL receptor expression in hLIF-treated HepG2 cells incubated with LDL (20 mu g/mL) when compared with controls (P

Impulse-response studies on tracer doses of [C-14]lignocaine and its multiple metabolites in the perfused rat liver

The outflow-concentration-time profiles for lignocaine (lidocaine) and its metabolites have been measured after bolus impulse administration of [C-14]lignocaine into the perfused rat liver. Livers from female Sprague-Dawley rats were perfused in a once-through fashion with red-blood-cell-free Krebs-Henseleit buffer containing 0 or 2% bovine serum albumin. Perfusate flow rates of 20 and 30 mL min(-1) were used and both normal and retrograde flow directions were employed. Significant amounts of metabolite were detected in the effluent perfusate soon after lignocaine injection. The early appearance of metabolite contributed to bimodal outflow profiles observed for total C-14 radioactivity. The lignocaine outflow profiles were well characterized by the two-compartment dispersion model, with efflux rate << influx rate. The profiles for lignocaine metabolites were also characterized in terms of a simplified two-compartment dispersion model. Lignocaine was found to be extensively metabolized under the experimental conditions with the hepatic availability ranging between 0.09 and 0.18. Generally lignocaine and metabolite availability showed no significant change with alterations in perfusate flow rate from 20 to 30 mt min(-1) or protein content from 0 to 2%. A significant increase in lignocaine availability occurred when 1200 mu M unlabelled lignocaine was added to the perfusate. Solute mean transit times generally decreased with increasing flow rate and with increasing perfusate protein content. The results confirm that lignocaine pharmacokinetics in the liver closely follow the predictions of the well-stirred model. The increase in lignocaine availability when 1200 mu M unlabelled lignocaine was added to the perfusate is consistent with saturation of the hydroxylation metabolic pathways of lignocaine metabolism.