<em>Interferon</em> lambda 1 (IFN-lambda1) is a type III IFN that produces intracellular responses similar to those of IFN-<em>alpha</em> but in fewer cell types because of differences in the receptor distribution pattern, and this could potentially result in an improved safety profile. This was an open-label three-part study of patients with chronic hepatitis C virus (HCV) genotype 1 infection. Part 1 evaluated single-agent pegylated <em>interferon</em> lambda (PEG-IFN-lambda) at 1.5 or <em>3</em>.0 microg/kg administered every 2 weeks or weekly for 4 weeks in patients who had relapsed after previous IFN-<em>alpha</em>-based treatment. Part 2 evaluated weekly doses of PEG-IFN-lambda ranging from 0.5 to 2.25 microg/kg in combination with ribavirin (RBV) for 4 weeks in treatment-relapse patients. Part <em>3</em> evaluated weekly PEG-IFN-lambda at 1.5 microg/kg in combination with RBV for 4 weeks in treatment-naive patients. Fifty-six patients were enrolled: 24 patients in part 1, 25 patients in part 2, and 7 patients in part <em>3</em>. Antiviral activity was observed at all PEG-IFN-lambda dose levels (from 0.5 to <em>3</em>.0 microg/kg). Two of seven treatment-naive patients (29%) achieved rapid virological response. Treatment was well tolerated with minimal flu-like symptoms and no significant hematologic changes other than RBV-associated decreases in hemoglobin. The most common adverse events were fatigue (29%), nausea (12%), and myalgia (11%). Six patients experienced increases in aminotransferases that met protocol-defined criteria for dose-limiting toxicity (DLT) or temporarily holding therapy with PEG-IFN-lambda. Most DLT occurred in patients with high PEG-IFN-lambda exposure.

CONCLUSIONS

Weekly PEG-IFN-lambda with or without daily RBV for 4 weeks is well tolerated with minimal adverse events and hematologic effects and is associated with clear antiviral activity across a broad range of doses in patients with chronic HCV.

The pathogenesis of rheumatoid arthritis (RA) may be mediated by Th1-type T cells. Since chemokine receptors CXCR<em>3</em> and CCR5 are preferentially expressed on Th1 cells, we tested the expression and regulation of several chemokines, including those that signal through CXCR<em>3</em> (<em>interferon</em>-gamma-inducible protein of 10 kDa, IP-10, CXCL10; and monokine induced by <em>interferon</em>-gamma, Mig, CXCL9) and CCR5 (macrophage inflammatory protein (Mip)-1 <em>alpha</em>, CCL<em>3</em>; and Mip-1 beta, CCL4) in RA synovial fluids, synovial tissues, and blood. Synovial fluid (SF) protein levels of IP-10 (<em>3</em>2.1 +/- 10.5 ng/ml), Mig (15.0 +/- 6.4 ng/ml), Mip-1 beta (0.7 +/- 0.<em>3</em> ng/ml), and Mip-1 <em>alpha</em> (0.8 +/- 0.1 ng/ml) were 100-, 50-, 25-, and 2-fold elevated in RASF compared to control SF (P < 0.001, P < 0.001, P < 0. 001, and P < 0.02, respectively). Tissue levels of IP-10, Mig, and Mip-1 beta were significantly higher in RA than in OA (P < 0.01). Serum levels of IP-10 (<em>3</em>.1 +/- 1.2 ng/ml) were higher in patients with seropositive RA compared to controls (1.2 +/- 0.2 ng/ml) (P < 0.02). There was a gradient of IP-10, Mig, Mip-1 <em>alpha</em>, and Mip-1 beta from the blood into the synovial fluid in RA. Infiltrating T cells around high endothelial venules in RA synovium and 90 +/- <em>3</em>% of SF CD<em>3</em>(+)CD4(+) T cells expressed CXCR<em>3</em>, and 85 +/- 2% of SF CD<em>3</em>(+)CD4(+) T cells expressed CCR5. Chemokines, including IP-10, Mig, Mip-1 <em>alpha</em>, and Mip-1 beta, may participate in the selective recruitment of CCR5(+)CXCR<em>3</em>(+) T cells to the inflamed synovium.

Hepatitis C virus (HCV), a major cause of liver disease worldwide, is frequently resistant to the antiviral <em>alpha</em> <em>interferon</em> (IFN). The HCV nonstructural 5A (NS5A) protein has been implicated in HCV antiviral resistance in many studies. NS5A antagonizes the IFN antiviral response in vitro, and one mechanism is via inhibition of a key IFN-induced enzyme, the double-stranded-RNA-activated protein kinase (PKR). In the present study we determined if NS5A uses other strategies to subvert the IFN system. Expression of full-length NS5A proteins from patients who exhibited a complete response (FL-NS5A-CR) or were nonresponsive (FL-NS5A-NR) to IFN therapy in HeLa cells had no effect on IFN induction of IFN-stimulated gene factor <em>3</em> (ISGF-<em>3</em>). Expression of mutant NS5A proteins lacking 110 (NS5A-DeltaN110), 222 (NS5A-DeltaN222), and <em>3</em><em>3</em>4 amino-terminal amino acids and mutants lacking 117 and 2<em>3</em>0 carboxy-terminal amino acids also had no effect on ISGF-<em>3</em> induction by IFN. Expression of FL-NS5A-CR and FL-NS5A-NR did not affect IFN-induced STAT-1 tyrosine phosphorylation or upregulation of PKR and major histocompatibility complex class I antigens. However, NS5A expression in human cells induced interleukin 8 (IL-8) mRNA and protein, and this effect correlated with inhibition of the antiviral effects of IFN in an in vitro bioassay. NS5A induced transcription of a reporter gene driven by the IL-8 promoter, and the first 1<em>3</em><em>3</em> bp of the IL-8 promoter made up the minimal domain required for NS5A transactivation. NS5A-DeltaN110 and NS5A-DeltaN222 stimulated the IL-8 promoter to higher levels than did the full-length NS5A protein, and this correlated with increased nuclear localization of the proteins. Additional mutagenesis of the IL-8 promoter suggested that NF-kappaB and AP-1 were important in NS5A-DeltaN222 transactivation in the presence of tumor necrosis factor <em>alpha</em> and that NF-IL-6 was inhibitory to this process. This study suggests that NS5A inhibits the antiviral actions of IFN by at least two mechanisms and provides the first evidence for a biological effect of the transcriptional activity of the NS5A protein. During HCV infection, viral proteins may induce chemokines that contribute to HCV antiviral resistance and pathogenesis.

Mounting an immune response to a viral pathogen involves the initial recognition of viral antigens through Toll-like receptor-dependent and -independent pathways and the subsequent triggering of signal transduction cascades. Among the many cellular kinases stimulated in response to virus infection, the noncanonical IKK-related kinases TBK1 and IKKepsilon have been shown to phosphorylate and activate <em>interferon</em> regulatory factor <em>3</em> (IRF-<em>3</em>) and IRF-7, leading to the production of <em>alpha</em>/beta <em>interferons</em> and the development of a cellular antiviral state. In the present study, we examine the activation of TBK1 and IKKepsilon kinases by vesicular stomatitis virus (VSV) infection in human lung epithelial A549 cells. We demonstrate that replication-competent VSV is required to induce activation of the IKK-related kinases and provide evidence that ribonucleoprotein (RNP) complex of VSV generated intracellularly during virus replication can activate TBK1 and IKKepsilon activity. In TBK1-deficient cells, IRF-<em>3</em> and IRF-7 activation is significantly reduced, although transcriptional upregulation of IKKepsilon following treatment with VSV, double-stranded RNA, or RNP partially compensates for the loss of TBK1. Biochemical analyses with purified TBK1 and IKKepsilon kinases in vitro demonstrate that the two kinases exhibit similar specificities with respect to IRF-<em>3</em> and IRF-7 substrates and both kinases target serine residues that are important for full transcriptional activation of IRF-<em>3</em> and IRF-7. These data suggest that intracellular RNP formation contributes to the early recognition of VSV infection, activates the catalytic activity of TBK1, and induces transcriptional upregulation of IKKepsilon in epithelial cells. Induction of IKKepsilon potentially functions as a component of the amplification mechanism involved in the establishment of the antiviral state.

Adult immunocompetent mice inoculated with Ebola (EBO) or Marburg (MBG) virus do not become ill. A suckling-mouse-passaged variant of EBO Zaire '76 ('mouse-adapted EBO-Z') causes rapidly lethal infection in adult mice after intraperitoneal (i.p.) inoculation, but does not cause apparent disease when inoculated subcutaneously (s.c.). A series of experiments showed that both forms of resistance to infection are mediated by the Type I <em>interferon</em> response. Mice lacking the cell-surface IFN-<em>alpha</em>/beta receptor died within a week after inoculation of EBO-Z '76, EBO Sudan, MBG Musoke or MBG Ravn, or after s.c. challenge with mouse-adapted EBO-Z. EBO Reston and EBO Ivory Coast did not cause illness, but immunized the mice against subsequent challenge with mouse-adapted EBO-Z. Normal adult mice treated with antibodies against murine IFN-<em>alpha</em>/beta could also be lethally infected with i.p.-inoculated EBO-Z '76 or EBO Sudan and with s.c.-inoculated mouse-adapted EBO-Z. Severe combined immunodeficient (SCID) mice became ill <em>3</em>-4 weeks after inoculation with EBO-Z '76, EBO Sudan or MBG Ravn, but not the other viruses. Treatment with anti-IFN-<em>alpha</em>/beta antibodies markedly accelerated the course of EBO-Z '76 infection. Antibody treatment blocked the effect of a potent antiviral drug, <em>3</em>-deazaneplanocin A, indicating that successful filovirus therapy may require the active participation of the Type I IFN response. Mice lacking an IFN-<em>alpha</em>/beta response resemble primates in their susceptibility to rapidly progressive, overwhelming filovirus infection. The outcome of filovirus transfer between animal species appears to be determined by interactions between the virus and the innate immune response.

The Toll-like receptor <em>3</em> (TLR<em>3</em>) and TLR4-signaling pathway that involves the adaptor protein TRIF activates type I <em>interferon</em> (IFN) and proinflammatory cytokine expression. Little is known about how TRIF pathway-dependent gene expression is regulated. SH2-containing protein tyrosine phosphatase 2 (SHP-2) is a widely expressed cytoplasmic tyrosine phosphatase. Here we demonstrate that SHP-2 negatively regulated TLR4- and TLR<em>3</em>-activated IFN-beta production. SHP-2 inhibited TLR<em>3</em>-activated but not TLR2-, TLR7-, and TLR9-activated proinflammatory cytokine IL-6 and TNF-<em>alpha</em> production. SHP-2 inhibited poly(I:C)-induced cytokine production by a phosphatase activity-independent mechanism. C-terminal domain of SHP-2 directly bound TANK binding kinase (TBK1) by interacting with the kinase domain of TBK1. SHP-2 deficiency increased TBK1-activated IFN-beta and TNF-<em>alpha</em> expression. TBK1 knockdown inhibited poly(I:C)-induced IL-6 production in SHP-2-deficient cells. SHP-2 also inhibited poly(I:C)-induced activation of MAP kinase pathways. These results demonstrate that SHP-2 specifically negatively regulate TRIF-mediated gene expression in TLR signaling, partially through inhibiting TBK1-activated signal transduction.

Secretion of <em>interferon</em> (IFN) by virus-infected cells is essential for activating autocrine and paracrine pathways that promote cellular transition to an antiviral state. In most mammalian cells, IFN production is initiated by the activation of constitutively expressed IFN regulatory factor <em>3</em>, IRF<em>3</em>, which in turn leads to the induction of IRF7, the "master regulator" of IFN type I synthesis (<em>alpha</em>/beta IFN). Previous studies established that rotavirus NSP1 antagonizes IFN signaling by inducing IRF<em>3</em> degradation. In the present study, we have determined that, in comparison to wild-type rotaviruses, rotaviruses encoding defective NSP1 grow to lower titers in some cell lines and that this poor growth phenotype is due to their failure to suppress IFN expression. Furthermore, we provide evidence that rotaviruses encoding wild-type NSP1 subvert IFN signaling by inducing the degradation of not only IRF<em>3</em>, but also IRF7, with both events occurring through proteasome-dependent processes that proceed with similar efficiencies. The capacity of NSP1 to induce IRF7 degradation may allow rotavirus to move across the gut barrier by enabling the virus to replicate in specialized trafficking cells (dendritic cells and macrophages) that constitutively express IRF7. Along with IRF<em>3</em> and IRF7, NSP1 was found to induce the degradation of IRF5, a factor that upregulates IFN expression and that is involved in triggering apoptosis during viral infection. Our analysis suggests that NSP1 mediates the degradation of IRF<em>3</em>, IRF5, and IRF7 by recognizing a common element of IRF proteins, thereby allowing NSP1 to act as a broad-spectrum antagonist of IRF function.

Among the molecules that determine the developmental fate of sympathetic neurons from noradrenergic to cholinergic function are two apparently unrelated proteins, cholinergic differentiation factor and ciliary neurotrophic factor (CDF and CNTF, respectively). The present work suggests a structural basis for their functional overlap: sequence pattern-matching and predictive structure analysis contends that CDF and CNTF are homologous and share a common helical framework. An integrated CDF/CNTF profile also reveals similar sequence/structure motifs in a group of hematopoietic cytokines composed of granulocyte colony-stimulating factor, interleukin-6, and a novel factor called oncostatin M; a more distant relationship is indicated with interleukin-<em>3</em> and <em>interferons</em>-<em>alpha</em>/beta. Evolutionary ties between neuropoietic and hematopoietic cytokines predict a distinctive tertiary architecture for the uncharacterized CDF and CNTF receptors. The intertwined cytokine/receptor networks signal a closer relationship between the molecular mechanisms underlying neuro- and hematopoiesis.

We studied the effect of filovirus infection on host cell gene expression by characterizing the regulation of gene expression responses in human liver cells infected with Zaire Ebolavirus (ZEBOV), Reston Ebolavirus (REBOV), and Marburgvirus (MARV), using transcriptional profiling and bioinformatics. Expression microarray analysis demonstrated that filovirus infection resulted in the up-regulation of immune-related genes and the down-regulation of many coagulation and acute-phase proteins. These studies further revealed that a common feature of filovirus virulence is suppression of key cellular antiviral responses, including TLR-, <em>interferon</em> (IFN) regulatory factor <em>3</em>-, and PKR-related pathways. We further showed that ZEBOV and MARV were more potent antagonists of the IFN response and inhibited the expression of most of the IFN-stimulated genes (ISGs) observed in mock-infected IFN-<em>alpha</em>-2b treated cells, compared to REBOV infection, which activated more than 20% of these ISGs. Finally, we examined IFN-related gene expression in filovirus-infected cells treated with IFN-<em>alpha</em>-2b. These experiments revealed that a majority of genes induced in mock-infected cells treated with type I IFN were antagonized in treated ZEBOV- and MARV-infected cells, while in contrast, REBOV infection resulted in a significant increase in ISG expression. Analysis of STAT1 and -2 phosphorylation following IFN treatment showed a significant reduction of STAT phosphorylation for MARV but not for ZEBOV and REBOV, indicating that different mechanisms might be involved in antagonizing IFN signaling pathways by the different filovirus species. Taken together, these studies showed a correlation between antagonism of type I IFN responses and filovirus virulence.

OBJECTIVE

To analyze the distribution of hepatitis C virus (HCV) genotypes among patients positive for antibody to HCV (anti-HCV) according to age, severity of liver disease, and duration of infection; to investigate the influence of HCV genotypes on response to interferon-alpha therapy; and to study HCV viremia levels in relation to genotypes and severity of liver disease.

METHODS

Cross-sectional study.

METHODS

<em>3</em> university hospitals and 2 research units.

METHODS

<em>3</em> groups of French and Italian patients with chronic HCV infection and detectable serum HCV RNA: Group 1 included <em>3</em>5 patients with hepatocellular carcinoma; group 2, 71 patients with cirrhosis who did not have hepatocellular carcinoma; and group <em>3</em>, 114 patients with chronic active hepatitis. 106 of the patients with chronic hepatitis or cirrhosis were treated with <em>interferon</em>-<em>alpha</em> (<em>3</em> MU subcutaneously <em>3</em> times/wk for>> or = 6 months).

METHODS

Genotyping by polymerase chain reaction with capsid-specific primers; serum HCV RNA by branched DNA (bDNA) signal amplification.

RESULTS

Hepatitis C virus genotype 1b (II) was the most prevalent genotype (61.8%). In a univariate analysis, it was associated with older age (< 40 years, 47.4%;>> or = 60 years, 80.4%; P = 0.001), longer duration of disease (< or = 10 years, 40.4%;>> or = 20 years, 86.7%; P = 0.005), and cirrhosis with or without hepatocellular carcinoma (78.4% compared with 5<em>3</em>.8% for chronic hepatitis; P < 0.001). Viremia levels did not differ between patients infected with HCV type 1b (II) and those infected with other HCV genotypes. Patients with HCV type 1b (II) responded to <em>interferon</em>-<em>alpha</em> therapy significantly less than did patients with other HCV genotypes (P = 0.01). In a multivariate analysis, age and cirrhosis were independently associated with HCV genotype 1b (II). Genotype and HCV viremia level were independent predictors of response to <em>interferon</em>-<em>alpha</em> therapy.

CONCLUSIONS

The prevalence of HCV genotypes in French and Italian patients has been changing; the prevalence of HCV type 1b (II) infection has progressively decreased, although it still accounts for most HCV-related cirrhosis and hepatocellular carcinoma. High HCV viremia levels and HCV genotype type 1b (II) are independent predictors for poor response to interferon-alpha therapy and should be considered in the management of patients with HCV infection.

Cell-mediated immunity to malaria may involve macrophages, the monokines that mediate endotoxicity, and reactive oxygen species. Since <em>interferon</em>-gamma activates macrophages to release reactive oxygen species, and tumor necrosis factor-<em>alpha</em> (TNF-<em>alpha</em>) helps both to mediate endotoxicity and to induce leukocytes to secrete reactive oxygen, we monitored the effects of administering recombinant forms of these cytokines on Plasmodium chabaudi adami infections in mice. We also fed infected mice a diet containing 0.75% butylated hydroxyanisole, a scavenger of free radicals. Infections were suppressed by daily i.p. injections of 5 x 10(4) U of recombinant mouse <em>interferon</em>-gamma from day -1 or by recombinant human TNF released from i.p. osmotic pumps at the rate of 6 x 10(<em>3</em>) U/hr. Degenerate intraerythrocytic parasites (crisis forms) were evident much sooner in the course of the suppressed infections, and parasitemias fell correspondingly earlier. The butylated hydroxyanisole diet, in contrast, enhanced the infections. In these mice crisis forms were seen later, and at higher parasitemias, than they normally occur. These observations are consistent with the concept that T cell-dependent, macrophage-derived mediators are central to the type of malarial immunity that kills parasites inside circulating red cells. They also suggest, but do not prove, that both TNF and reactive oxygen species are involved, and that the role of TNF may be more indirect, although no less important, than that of reactive forms of oxygen.

Natural killer (NK) cells play an important role in early defense against viral infection. The cytotoxic activity of NK cells is increased by <em>interferon</em>-<em>alpha</em>/beta (IFN-<em>alpha</em>/beta), produced en masse in virally infected cells. However, the mechanism(s) by which IFN-<em>alpha</em>/beta contribute to the NK-cell-mediated antiviral response is not well understood. Here we provide evidence that the cytotoxicity of NK cells is enhanced by IFN-<em>alpha</em>/beta through induction of TNF-related apoptosis-inducing ligand (TRAIL). Isolation and analysis of the murine TRAIL promoter revealed the presence of an IFN-stimulated response element (ISRE), which binds to the transcription factor ISGF<em>3</em> (<em>interferon</em> stimulated gene factor-<em>3</em>). This promoter is indeed activated by IFN-beta in ISGF<em>3</em>-dependent manner. We also show that virally infected cells, but not uninfected cells, are susceptible to TRAIL-mediated cytotoxicity in vitro, and that the TRAIL expressed in NK cells is indeed crucial in limiting virus replication in vivo. Thus, our study reveals a new molecular link between IFN-<em>alpha</em>/beta signaling and activation of NK cells in antiviral response of the host.

BACKGROUND

T-cell-mediated immunity contributes to the pathogenesis of atherosclerosis, but little is known about how these responses are regulated. We explored the influence of the inducible costimulatory molecule (ICOS) on atherosclerosis and associated immune responses.

RESULTS

Bone marrow chimeras were generated by transplanting ICOS-deficient or wild-type bone marrow into irradiated atherosclerosis-prone, LDR receptor-deficient mice, and the chimeric mice were fed a high-cholesterol diet for 8 weeks. Compared with controls, mice transplanted with ICOS-deficient marrow had a 4<em>3</em>% increase in the atherosclerotic burden, and importantly, their lesions had a <em>3</em>-fold increase in CD4+ T cells, as well as increased macrophage, smooth muscle cell, and collagen content. CD4+ T cells from ICOS-deficient chimeras proliferated more and secreted more <em>interferon</em>-gamma and tumor necrosis factor-<em>alpha</em> than T cells from control mice, which suggests a lack of regulation. FoxP<em>3</em>+ regulatory T cells (Treg) were found to constitutively express high ICOS levels, which suggests a role for ICOS in Treg function. ICOS-deficient mice had decreased numbers of FoxP<em>3</em>+ Treg and impaired in vitro Treg suppressive function compared with control mice.

CONCLUSIONS

ICOS has a key role in regulation of atherosclerosis, through its effect on regulatory T-cell responses.

Purpose Exploratory subgroup analyses from the phase <em>3</em> global advanced renal cell carcinoma (ARCC) trial were conducted to assess the influence of tumor histology on outcome of patients treated with temsirolimus (Torisel) or <em>interferon</em>-<em>alpha</em> (IFN). Patients and methods Patients with ARCC including clear cell and other types such as papillary and chromophobe histologies received either IFN (<em>3</em> million units [MU] subcutaneously three times weekly, escalating to 18 MU) or temsirolimus (25 mg intravenously weekly). Results Approximately 80% of patients had clear cell and 20% of patients had other histologies, the majority of which were papillary. Patients with clear cell and other RCC histologies, treated with temsirolimus, demonstrated comparable median overall and progression-free survival. In contrast, patients with other RCC histologies, treated with IFN, demonstrated shorter median overall and progression-free survival than patients with clear cell RCC. Hazard ratios for death for treatment with temsirolimus versus IFN were less than 1 for patients regardless of tumor histology. For patients treated with temsirolimus, 59% with clear cell and 68% with other RCC histologies experienced tumor reductions. For patients treated with IFN, <em>3</em>5% with clear cell and 14% with other RCC histologies had tumor reductions. However, temsirolimus did not appear to improve the objective response rate compared to IFN. Temsirolimus resulted in a superior clinical benefit rate compared with IFN, regardless of tumor histology. Conclusion Temsirolimus appears to be efficacious in patients with clear cell and non-clear cell histologies and can, therefore, be used for the treatment of all types of RCC.

Serum levels of interleukin-10 (IL-10) are elevated in a proportion of patients with untreated chronic hepatitis C, and this may compromise the host immune response to the virus. The capacity for IL-10 production varies according to the genetic composition of the IL-10 locus. We examined the inheritance of <em>3</em> biallelic polymorphisms in the IL-10 gene promoter in patients with chronic hepatitis C and their association with response to treatment with <em>interferon</em> alfa (IFN-<em>alpha</em>). After adjusting for potential confounding variables, a highly significant relationship was found between inheritance of the IL-10 promoter -592*A and -819*T alleles or the ATA haplotype and response to IFN-<em>alpha</em> therapy (P =.016). Response to treatment was also associated with viral genotype <em>3</em>a, a low viral load, and less fibrosis on liver biopsy. Following in vitro stimulation of peripheral blood mononuclear cells, the IL-10 promoter haplotypes, GCC, ACC, and ATA, were associated with high, intermediate, and low IL-10 production, respectively. These findings indicate that heterogeneity in the promoter region of the IL-10 gene has a role in determining the initial response of chronic hepatitis C to IFN-<em>alpha</em> therapy. Patients who are genetically predisposed to high IL-10 production have a poor response to IFN-<em>alpha</em> and may benefit from additional treatment strategies designed to enhance a T-helper type 1 (Th1) response.

We treated 17 patients who had Philadelphia-chromosome-positive chronic myelogenous leukemia (4 of whom had not received therapy and 1<em>3</em> of whom had been treated with hydroxyurea or busulfan for less than six months) with recombinant human <em>interferon</em> <em>alpha</em> A (Roferon-A). The <em>interferon</em> was given as 5 X 10(6) units per square meter of body-surface area per day intramuscularly during induction therapy. Fourteen patients responded to the treatment, of whom 1<em>3</em> had a hematologic remission and 1 had a partial hematologic remission. The median number of white cells in those patients declined from 60.9 X 10(<em>3</em>) to <em>3</em>.4 X 10(<em>3</em>) per microliter, and the median number of platelets decreased from 476 X 10(<em>3</em>) to 2<em>3</em>1 X 10(<em>3</em>) per microliter. Among the five responding patients who had splenomegaly before treatment, the spleen size returned to normal in four and decreased by 75 percent in one, although it remained enlarged. Bone marrow cellularity declined from a median of 92.5 percent to a median of 57.5 percent. In six of the patients with hematologic remission, complete suppression of Philadelphia cells was observed on at least one examination. Of the 14 patients who responded, 11 have received the <em>interferon</em> therapy for 9 to 15 months. One patient relapsed during the treatment, and the treatment has been temporarily interrupted in two patients because of toxicity. These data are preliminary and will need further confirmation, but they suggest that recombinant human <em>interferon</em> <em>alpha</em> A is effective in inducing hematologic remission in most patients with benign-phase chronic myelogenous leukemia and in suppressing the Philadelphia chromosome in some of these patients.

Docosahexaenoic acid, a major omega-<em>3</em> fatty acid in human brain, synapses, retina, and other neural tissues, displays beneficial actions in neuronal development, cancer, and inflammatory diseases by mechanisms that remain to be elucidated. In this study we found, using lipid mediator informatics employing liquid chromatography-tandem mass spectrometry, that (10,17S)-docosatriene/neuroprotectin D1, now termed protectin D1 (PD1), is generated from docosahexaenoic acid by T helper type 2-skewed peripheral blood mononuclear cells in a lipoxygenase-dependent manner. PD1 blocked T cell migration in vivo, inhibited tumor necrosis factor <em>alpha</em> and <em>interferon</em>-gamma secretion, and promoted apoptosis mediated by raft clustering. These results demonstrated novel anti-inflammatory roles for PD1 in regulating events associated with inflammation and resolution.

A short model genome RNA and also the genome RNA of influenza A virus bearing both 5'- and <em>3</em>'-terminal common sequences activated the <em>interferon</em>-induced double-stranded-RNA-dependent protein kinase, PKR, by stimulating autophosphorylation in vitro. The activated PKR catalyzed phosphorylation of the <em>alpha</em> subunit of eucaryotic translation initiation factor 2 (eIF2<em>alpha</em>). The NS1 protein efficiently eliminated the PKR-activating activity of these RNAs by binding to them. Two mutant NS1 proteins, each harboring a single amino acid substitution at different regions, exhibited temperature sensitivity in their RNA binding activity in the mutant virus-infected cell lysates as well as when they were prepared as fusion proteins expressed in bacteria. The virus strains carrying these mutant NS1 proteins exhibited temperature sensitivity in virus protein synthesis at the translational level, as reported previously, and could not repress the autophosphorylation of PKR developing during the virus growth, which is normally suppressed by a viral function(s). As a result, the level of eIF2<em>alpha</em> phosphorylation was elevated 2.5- to <em>3</em>-fold. The defect in virus protein synthesis was well correlated with the level of phosphorylation of PKR and eIF2<em>alpha</em>.

Toll-like receptors (TLRs) are crucial components of innate immunity that participate in host defense against microbial pathogens. We evaluated the expression and function of TLRs in human retinal pigment epithelial (RPE) cells. Real time PCR analysis revealed gene expression for TLRs 1-7, 9, and 10 in RPE cells. TLRs 1 and <em>3</em> were the most highly expressed TLRs. Protein expression for TLRs 2, <em>3</em>, and 4 was observed on RPE cells and this expression was augmented by treatment with poly I:C or <em>interferon</em>-gamma (IFN-gamma). TLR <em>3</em> is the receptor for dsRNA, an intermediate of virus replication. Because RPE cells express TLR <em>3</em> and are frequently the site of virus replication within the retina, we evaluated TLR <em>3</em> signaling. RPE cells treated with poly I:C produced IFN-beta but not IFN-<em>alpha</em>, and this was inhibited by the treatment of RPE cells with anti-TLR <em>3</em> antibody. Human recombinant IFN-beta was shown to be biologically active on RPE cells by inhibiting viral replication. Poly I:C treatment of RPE resulted in an increase in the production of IL-6, IL-8, MCP-1, and sICAM-1. The presence of TLRs on RPE cells and the resultant TLR signaling in RPE cells suggest that these molecules may play an important role in innate and adaptive immune responses within the retina.

BACKGROUND

Less than 20% of patients with chronic hepatitis C have a sustained response to interferon-alpha therapy. The long-term benefit of interferon-alpha with regard to hepatic viral clearance and histologic improvement remains unknown.

OBJECTIVE

To determine the long-term biochemical, virologic, and histologic outcomes in patients with chronic hepatitis C who have a sustained response to interferon-alpha therapy.

METHODS

Prospective cohort study.

METHODS

University hospital.

METHODS

80 patients who had chronic hepatitis C, had a sustained biochemical and virologic response to interferon-alpha therapy, and were followed for at least 12-months.

METHODS

Serum hepatitis C virus (HCV) RNA detected by polymerase chain reaction (PCR); HCV genotyping determined by line probe assay; liver histologic studies; liver HCV RNA detected by PCR on frozen liver tissue samples (in 27 patients); and repeated measurements of serum alanine aminotransferase (ALT) levels. Liver biopsy was done before treatment in all 80 patients, and at least one biopsy was done in 69 patients 1 to 6 years after treatment.

RESULTS

The 80 patients had follow-up 1 to 7.6 years (mean +/- SD, 4.0 +/- 2.0 years) after interferon-alpha treatment. The follow-up period was 1, 2, 3, 4, 5, 6, and more than 6 years in 11, 13, 14, 18, 10, 12, and 2 patients, respectively, after the end of therapy. During the entire follow-up period, 93% (95% CI, 84% to 97%) of patients had persistently normal serum ALT levels. Serum HCV RNA remained undetectable in 96% (CI, 89% to 99%) of patients. A comparison of liver histologic findings before and 1 to 6.2 years after interferon-alpha treatment showed a clear improvement in 94% (CI, 83% to 99%) of patients. In 62% of patients, the last biopsy done showed normal or nearly normal histologic findings. Liver HCV RNA was detectable before treatment in all 13 patients tested and was undetectable 1 to 5 years after treatment in all 27 patients tested.

CONCLUSIONS

In patients with chronic hepatitis C who have persistently normal serum ALT levels and no detectable serum HCV RNA 6 months after interferon-alpha therapy, a long-term sustained biochemical and virologic response is generally seen. This response is associated with an absence of detectable intrahepatic HCV RNA and marked histologic improvement.

Obese individuals often have low plasma adiponectin and concomitant chronic inflammation with a predisposition to metabolic and cardiovascular diseases. The present study reports a novel antiinflammatory action of adiponectin in human monocyte-derived macrophages (MPhi) suppressing T-lymphocyte accumulation in atherogenesis. RNA profiling of lipopolysaccharide-stimulated human MPhi identified CXC chemokine ligands (CXCLs), such as IP-10 (<em>interferon</em> [IFN]-inducible protein 10) (CXCL10), I-TAC (IFN-inducible T-cell <em>alpha</em> chemoattractant) (CXCL11), and Mig (monokine induced by IFN-gamma) (CXCL9), T-lymphocyte chemoattractants associated with atherogenesis, among the top 14 transcripts suppressed by adiponectin. Real-time quantitative RT-PCR and ELISA verified that adiponectin inhibited expression of these chemokines at both the mRNA and protein levels in a concentration-dependent manner. Adiponectin reduced the release by lipopolysaccharide-stimulated MPhi of chemoattractant activity for CXC chemokine receptor <em>3</em>-transfected (receptor for IP-10, Mig, and I-TAC) lymphocytes. Adiponectin decreased lipopolysaccharide-inducible IP-10 promoter activity in promoter-transfected THP-1 MPhi but did not change IP-10 mRNA stability. In lipopolysaccharide-stimulated MPhi, reduction of IFN-beta by adiponectin preceded inhibition of IP-10 mRNA expression. Immunoblot and chromatin immunoprecipitation analyses demonstrated that adiponectin attenuated activation of the transcription factor IFN regulatory factor <em>3</em>, involved in the MyD88-independent pathway of Toll-like receptor 4 signaling, and subsequent IFN regulatory factor <em>3</em> binding to IFN-beta promoter. In vivo studies further demonstrated that apolipoprotein E/adiponectin double-deficient (apoE-/-APN-/-) mice had increased plasma IP-10 levels, accelerated T-lymphocyte accumulation in atheromata, and augmented atherogenesis compared with apoE single-deficient (apoE-/-APN+/+) mice. This study establishes that low levels of adiponectin associated with obesity, the metabolic syndrome, and diabetes favor T-lymphocyte recruitment and contribute to adaptive immune response during atherogenesis.

OBJECTIVE

Crohn's disease (CD) is a chronic debilitating disease of unknown etiology that is characterized by severe inflammation of the colon. Vasoactive intestinal peptide (VIP) has recently emerged as a promising candidate for treatment of inflammatory Th1-driven diseases. We studied the effect of VIP in trinitrobenzene sulfonic acid (TNBS)-induced colitis, which has clinical and molecular features in common with CD.

METHODS

A <em>3</em>-mg enema of TNBS was given to BALB/c mice, and VIP (1 nmol) was given either as a single dose at 12 hours or every other day. Weight loss, histopathology, and chemokine and cytokine levels in serum and colon extracts were assessed. VIP was also tested given 5 days after the onset of TNBS-induced colitis, and its effect was analyzed given a second dose of TNBS.

RESULTS

Treatment with VIP reduced the clinical and histopathologic severity of TNBS-induced colitis, abrogating body weight loss, diarrhea, and macroscopic and microscopic intestinal inflammation. The therapeutic effects of VIP were associated with down-regulation of both inflammatory and Th1-driven autoimmune responses, including tumor necrosis factor alpha, interleukin 1, and interleukin 6 in colon extracts and serum as well as interferon gamma by splenic and lamina propria CD4(+) T cells. VIP reduced disease severity when given after disease onset and dramatically reduced disease recurrence given a second dose of TNBS.

CONCLUSIONS

Our data suggest that VIP has beneficial prophylactic and therapeutic effects in TNBS-induced colitis and is a promising candidate to test for potential benefits in CD.

BACKGROUND

We investigated associations between interferon (IFN)-gamma-inducible protein (IP)-10 and liver histological results, viral kinetic response, and treatment outcome in patients infected with hepatitis C virus (HCV) genotypes 1-4.

METHODS

Plasma IP-10 was monitored before, during, and after treatment with pegylated IFN- alpha 2a and ribavirin in 265 HCV-infected patients.

RESULTS

In univariate analyses, a low baseline IP-10 level was significantly associated with low baseline viral load, rapid viral response (RVR), a sustained viral response (SVR), body mass index <25 kg/m2, and less-pronounced fibrosis, inflammation, and steatosis (for HCV genotypes other than 3). When the results of the univariate analyses were included in multivariate analyses, a low plasma IP-10 level, low baseline viral load, and genotype 2 or 3 infection were independent predictors of an RVR and SVR. IP-10 levels decreased 6 weeks into treatment and remained low in patients with an SVR. By contrast, plasma levels of IP-10 rebounded in patients who had detectable HCV RNA after the completion of treatment. Using cutoff IP-10 levels of 150 and 600 pg/mL for predicting an SVR in patients infected with HCV genotype 1 yielded a specificity and sensitivity of 81% and 95%, respectively.

CONCLUSIONS

Baseline IP-10 levels are predictive of the response to HCV treatment.

We have previously described a murine model of hematogenously induced Staphylococcus aureus sepsis and arthritis. In this model, large numbers of granulocytes can be observed both in the circulation and locally in the inflamed synovium within 24 h after bacterial inoculation. To assess the role of neutrophils in this severe infection, mice were given granulocyte-depleting monoclonal antibody RB6-8C5 before being inoculated with S. aureus. All the control mice survived their intravenous injection with <em>3</em> x 10(7) CFU of S. aureus, whereas all the mice given RB6-8C5 antibody died of sepsis within 2 to <em>3</em> days. Even when the inoculum size was reduced sixfold (i.e., 6 x 10(6) CFU/mouse), 50% of the RB6-8C5-treated animals died within 6 days. The RB6-8C5-treated mice had a significantly higher burden of bacteria in their blood and kidneys 24 and 48 h after bacterial inoculation. In addition, when a suboptimal dose of bacteria was administered, the neutrophil-depleted animals displayed a higher frequency of arthritis than did the controls. The granulocyte-depleted animals exhibited increased levels of the proinflammatory cytokines tumor necrosis factor <em>alpha</em>, interleukin-6, and gamma <em>interferon</em>, reflecting the severity of their disease. This is the first direct demonstration of neutrophils playing a crucial protective role in the early phase of S. aureus infection.