László Romics

Hepatitis C Virus Core and Nonstructural Protein 3 Proteins Induce Pro- and Anti-inflammatory Cytokines and Inhibit Dendritic Cell Differentiation

Antiviral immunity requires recognition of viral pathogens and activation of cytotoxic and Th cells by innate immune cells. In this study, we demonstrate that hepatitis C virus (HCV) core and nonstructural protein 3 (NS3), but not envelope 2 proteins (E2), activate monocytes and myeloid dendritic cells (DCs) and partially reproduce abnormalities found in chronic HCV infection. HCV core or NS3 (not E2) triggered inflammatory cytokine mRNA and TNF-α production in monocytes. Degradation of I-κBα suggested involvement of NF-κB activation. HCV core and NS3 induced production of the anti-inflammatory cytokine, IL-10. Both monocyte TNF-α and IL-10 levels were higher upon HCV core and NS3 protein stimulation in HCV-infected patients than in normals. HCV core and NS3 (not E2) inhibited differentiation and allostimulatory capacity of immature DCs similar to defects in HCV infection. This was associated with elevated IL-10 and decreased IL-2 levels during T cell proliferation. Increased IL-10 was produced by HCV patients’ DCs and by core- or NS3-treated normal DCs, while IL-12 was decreased only in HCV DCs. Addition of anti-IL-10 Ab, not IL-12, ameliorated T cell proliferation with HCV core- or NS3-treated DCs. Reduced allostimulatory capacity in HCV core- and NS3-treated immature DCs, but not in DCs of HCV patients, was reversed by LPS maturation, suggesting more complex DC defects in vivo than those mediated by core or NS3 proteins. Our results reveal that HCV core and NS3 proteins activate monocytes and inhibit DC differentiation in the absence of the intact virus and mediate some of the immunoinhibitory effects of HCV via IL-10 induction.

Liver in sepsis and systemic inflammatory response syndrome

In patients with sepsis and SIRS, the liver has two opposing roles: a source of inflammatory mediators and a target organ for the effects of the inflammatory mediators. The liver is pivotal in modulating the systemic response to severe infection, because it contains the largest mass of macrophages (Kupffer cells) in the body; these macrophages can clear the endotoxin and bacteria that initiate the systemic inflammatory response. This article summarizes the functional changes that take place in the liver during sepsis and systemic inflammatory response syndrome and discusses the cellular and molecular mechanisms that underlie clinical outcomes.

Lipoprotein (a) and plasminogen are immunochemically related

Earlier studies demonstrated that lipoprotein (a), a lipoprotein of high atherogenicity, possesses proteolytic activity. In this report, we provide evidence that the lipoprotein (a)-specific antigen, apoprotein (a) is immunochemically related to plasminogen. This was demonstrated by polyclonal antisera from rabbit, sheep and horse, and with three monoclonal antibodies from mouse. Using immunospecific adsorbers against lipoprotein (a), all plasminogen could be adsorbed from lipoprotein (a)-positive and apparently lipoprotein (a)-negative plasma. As an additional similarity to plasminogen, lipoprotein (a) binds selectively to lysine-Sepharose, but with a somewhat lower affinity. In an assay system for measuring the fibrinolytic activity challenged with streptokinase, lipoprotein (a) prolonged strikingly the fibrinolysis time under certain experimental conditions.

Heme Oxygenase-1 Mediates the Anti-Inflammatory Effects of Acute Alcohol on IL-10 Induction Involving p38 MAPK Activation in Monocytes

Inflammation and immunoregulatory cytokines play a central role in alcohol-induced liver damage. We previously reported that acute alcohol treatment augments IL-10 and inhibits TNF-α production in monocytes. Heme oxygenase-1 (HO-1), a stress-inducible protein, also regulates IL-10 and TNF-α production. Here, we report that augmentation of LPS-induced IL-10 production by alcohol was prevented by inhibition of HO-1 activity. Acute ethanol increased LPS-induced enzyme activity and RNA levels of HO-1, and DNA binding of AP-1, a transcription factor essential in HO-1 regulation. LPS-induced phospho-p38 MAPK levels were augmented by ethanol treatment and the p38 inhibitor, SB203580, prevented both the ethanol-induced increase in IL-10 production and the inhibitory effect of ethanol on TNF-α production. Ethanol-induced down-regulation of TNF-α production was abrogated by inhibition of HO-1. We found that LPS-induced activation of NF-κB, a regulator of TNF-α, was inhibited by both ethanol treatment and HO-1 activation, but the ethanol-induced inhibition of NF-κB was HO-1 independent. In LPS-challenged mice in vivo, both acute alcohol administration and HO-1 activation augmented IL-10 and inhibited TNF-α serum levels. These results show that 1) acute alcohol augments HO-1 activation in monocytes, 2) HO-1 activation plays a role in alcohol-induced augmentation of IL-10 production likely via increased p38 MAPK activation, and 3) HO-1 activation is involved in attenuation of TNF-α production by alcohol independent of inhibition of NF-κB activation by alcohol. Thus, HO-1 activation is a key mediator of the anti-inflammatory effects of acute alcohol on monocytes.

Diverse regulation of NF-κB and peroxisome proliferator-activated receptors in murine nonalcoholic fatty liver

Fatty liver is highly sensitive to inflammatory activation. Peroxisome proliferator‐activated receptors (PPAR) have anti‐inflammatory effects and regulate lipid metabolism in the fatty liver. We hypothesized that fatty liver leads to endotoxin sensitivity through an imbalance between pro‐ and anti‐inflammatory signals. Leptin‐deficient, ob/ob mice and their lean littermates were challenged with single or double insults and pro‐ and anti‐inflammatory pathways were tested on cytokine production and activation of nuclear regulatory factors NF‐κB and peroxisome proliferator receptor element (PPRE). Ob/ob mice produced significantly higher serum tumor necrosis factor α (TNF‐α) and interleukin (IL) 6 and showed increased hepatic NF‐κB activation compared to lean littermates after stimulation with a single dose of lipopolysaccharide (LPS) or alcohol. In ob/ob mice, double insults with alcohol and LPS augmented proinflammatory responses mediated by increased degradation of inhibitory κB (IκB)‐α and IκB‐β and preferential induction of the p65/p50 NF‐κB heterodimer. In lean mice, in contrast, acute alcohol attenuated LPS‐induced TNF‐α, IL‐6 production, and NF‐κB activation through reduced IκB‐α degradation and induction of p50/p50 homodimers. PPRE binding was increased in fatty but not in lean livers after alcohol or LPS stimulation. However, cotreatment with alcohol and LPS reduced both PPRE binding and nuclear levels of PPAR‐α in fatty livers but increased those in lean livers. In conclusion, our results show opposite PPRE and NF‐κB activation in fatty and lean livers. PPAR activation may represent an anti‐inflammatory mechanism that fails in the fatty liver on increased proinflammatory pressure. Thus, an imbalance between PPAR‐mediated anti‐inflammatory and NF‐κB‐mediated proinflammatory signals may contribute to increased inflammation in the fatty liver. (HEPATOLOGY 2004;40:376–385.)

Comparative study on antibodies to human and bacterial 60 kDa heat shock proteins in a large cohort of patients with coronary heart disease and healthy subjects

Background Recent observations indicate an association between antibodies against mycobacterial heat shock protein (hsp65) and coronary heart disease (CHD). Previously, we reported on marked differences in antigen specificity and complement activating ability of anti‐hsp65 antibodies and auto‐antibodies against human heat shock protein, hsp60. Here, we investigated whether there are differences between antih‐sp65 and anti‐hsp60 antibodies in their association with CHD.

Detection of factor V Leiden mutation in severe pre-eclamptic Hungarian women

Pre‐eclampsia is a pregnancy‐related disorder that complicates approximately 5% of all pregnancies and is cited as the primary cause of worldwide maternal and fetal mortality. The factor V Leiden mutation has been implicated in the development of severe pre‐eclampsia. In order to investigate this association, a sample of 198 Hungarian women was recruited and enrolled in one of the three groups based on reproductive and health status: those as classified as pregnant and healthy (n = 71), those diagnosed as pregnant and severe pre‐eclamptic (n = 69), and those found to be healthy and non‐pregnant (n = 58). The presence of factor V Leiden mutation was determined by using polymerase chain reaction (PCR) followed by restriction fragment length polymorphism analysis (RFLP). We identified three (5.2%) heterozygous among healthy non‐pregnant participants, five (7.0%) heterozygous among healthy pregnant participants and 13 (18.8%) heterozygous among preeclamptic women (p < 0.05, 95% CI). Our result supports the previous observation that carriers of factor V Leiden mutation are at increased risk for developing severe pre‐eclampsia.

Relationship of Anti-60 kDa Heat Shock Protein and Anti-Cholesterol Antibodies to Cardiovascular Events

Background—Several recent studies have indicated an association between key inflammatory mediators and atherosclerotic diseases. We evaluated whether high levels of antibodies against heat shock proteins and cholesterol (ACHA) predicted cardiovascular (CV) events. Methods and Results—We used blood samples from the Heart Outcomes Prevention Evaluation (HOPE) study to conduct a nested case-control study of 386 cases with CV events and 386 age- and sex-matched HOPE study controls without events. We explored the relationship between anti-hsp antibodies, ACHA, and subsequent outcomes (incident myocardial infarction, stroke, or CV death) during a mean follow-up of 4.5 years using conditional logistic regression. High levels of anti-hsp65 antibodies (≥90th percentile) predicted CV events (OR, 2.1; 95% CI, 1.2 to 3.9, P =0.01). Anti-hsp60 antibodies did not predict any event type, whereas incident stroke developed significantly less frequently in patients with high ACHA levels. Anti-hsp antibodies and ACHA did not correlate with inflammatory (fibrinogen, C-reactive protein, interleukin-6, intracellular adhesion molecule-1) or infectious markers (C pneumoniae or cytomegalovirus antibodies). Anti-hsp65 antibodies (≥90th percentile) and fibrinogen (highest tertile) had a strong joint effect: patients with high concentrations of both had more CV events (OR, 5.5; 95% CI, 1.8 to 17.5, P =0.004) than patients with low levels of both. A similar joint effect (OR, 2.7; 95% CI, 1.3 to 5.7, P =0.01) was found for high levels of anti-hsp65 and presence of cytomegalovirus antibodies. Conclusions—Serum antibodies to hsp65 were associated with subsequent CV events in this study of high-risk patients, independent of conventional cardiovascular risk factors and other inflammatory markers.

Selective priming to Toll‐like receptor 4 (TLR4), not TLR2, ligands by P. acnes involves up‐regulation of MD‐2 in mice

Lipopolysaccharide (LPS) triggers cytokine production through Toll‐like receptor 4 (TLR4), which shares downstream signaling pathways with TLR2. We investigated the roles of TLR2 and TLR4 in Propionibacterium acnes (P. acnes)–primed, LPS‐induced liver damage using selective TLR ligands. Stock LPS induced interleukin 8 in both TLR4‐ and TLR2‐expressing human embryonic kidney (HEK) 293 cells. Purified LPS (TLR4 ligand) activated HEK/TLR4 cells, while peptidoglycan and lipoteichoic acid (TLR2 ligands) activated HEK/TLR2 cells, respectively. In mice, P. acnes priming resulted in increased liver messenger RNA (mRNA) and serum levels of tumor necrosis factor α, interleukin 12, and interferon γ (IFN‐γ) by both stock LPS and purified LPS challenges compared with nonprimed controls. In contrast, P. acnes failed to sensitize to TLR2 ligands (peptidoglycan + lipoteichoic acid). In the liver, P. acnes–priming was associated with up‐regulation of TLR4 and MD‐2 proteins, and subsequent LPS challenge further increased MD‐2 and CD14 mRNA levels. The lack of sensitization to TLR2 ligands by P. acnes correlated with no increase in hepatic TLR1 or TLR6 mRNA. In vitro, P. acnes pretreatment desensitized RAW macrophages to a secondary stimulation via both TLR2 and TLR4. However, IFN‐γ could selectively prevent desensitization to TLR4 but not to TLR2 ligands. Furthermore, P. acnes induced production of IFN‐γ in vivo as well as in isolated splenocytes. In vitro, P. acnes–primed Hepa 1‐6 hepatocytes but not RAW macrophages produced increased MD‐2 and CD14 mRNA levels after an LPS challenge. In conclusion, P. acnes priming to selective TLR4‐mediated liver injury is associated with up‐regulation of TLR4 and MD‐2 and is likely to involve IFN‐γ and prevent TLR4 desensitization by P. acnes. (HEPATOLOGY 2004;40:555–564.)

Interpopulation effect of ACE I/D polymorphism on serum concentration of ACE in diagnosis of sarcoidosis

518 Vol 350 • August 16, 1997 of sACE activity was linked to the presence of allele D. Increased sACE concentrations in patients with sarcoidosis and the contribution of ACE gene polymorphism to sACE activity in both controls and patients was verified in Japan. All these workers proposed that ACE genotypes should be determined to avoid falsenegative results in the diagnosis of sarcoidosis, selection bias, and the underestimation of sACE concentration in patients with genotype II compared with controls with genotype DD (mean 29·5 vs 27·5 U/mL). The ACE-gene polymorphism does not have an important role as a genetic risk factor for susceptibility for sarcoidosis, however, the detection of abnormal ACE concentrations would be more accurate if new normal reference intervals based on individual genotypes were established.