We identified antibacterial components in human T and natural killer (NK) cells by using freshly isolated lymphocytes enriched for T and NK cells as starting material. After growing these lymphocytes for 5 days in the presence of interleukin (IL)-2, we isolated and characterized several antibacterial peptides/proteins from the supernatant-<em>alpha</em>-defensins (HNP 1-<em>3</em>), LL-<em>3</em>7, lysozyme, and a fragment of histone H2B-although other active components were also present. We then used reverse transcriptase-polymerase chain reaction to search for expression of the gene coding for LL-<em>3</em>7 in several B-cell lines, gammadelta T-cell lines, NK clones, and one monocytic cell line, with positive results, but found no expression in several <em>alpha</em>beta T-cell lines. The <em>alpha</em>-defensins (HNP 1-<em>3</em>) were also found to be expressed in several of these cell lines. To confirm the presence of these antibacterial peptides in lymphocytes, we localized them to NK, gammadelta T cells, B cells, and monocytes/macrophages by using double-staining immunohistochemical analysis of freshly isolated lymphocytes. We also found that primary cultures of lymphocytes transcribe and secrete LL-<em>3</em>7 and that these processes are affected by IL-6 and <em>interferon</em>-gamma. In addition, we demonstrated that LL-<em>3</em>7 has chemotactic activity for polymorphonuclear leukocytes and CD4 T lymphocytes, whereas others have shown chemotactic activity for human <em>alpha</em>-defensins (HNP 1-2). These findings suggest that microbicidal peptides are effector molecules of lymphocytes and that antibacterial activity previously shown to be derived from T and NK cells may be partly mediated by the antibacterial peptides LL-<em>3</em>7 and HNP 1-<em>3</em>.

TIA-1 and TIAR are related proteins that bind to an AU-rich element (ARE) in the <em>3</em>' untranslated region of tumor necrosis factor <em>alpha</em> (TNF-<em>alpha</em>) transcripts. To determine the functional significance of this interaction, we used homologous recombination to produce mutant mice lacking TIA-1. Although lipopolysaccharide (LPS)-stimulated macrophages derived from wild-type and TIA-1(-/-) mice express similar amounts of TNF-<em>alpha</em> transcripts, macrophages lacking TIA-1 produce significantly more TNF-<em>alpha</em> protein than wild-type controls. The half-life of TNF-<em>alpha</em> transcripts is similar in wild-type and TIA-1(-/-) macrophages, indicating that TIA-1 does not regulate transcript stability. Rather, the absence of TIA-1 significantly increases the proportion of TNF-<em>alpha</em> transcripts that associate with polysomes, suggesting that TIA-1 normally functions as a translational silencer. TIA-1 does not appear to regulate the production of interleukin 1 beta, granulocyte-macrophage colony-stimulating factor or <em>interferon</em> gamma, indicating that its effects are, at least partially, transcript specific. Mice lacking TIA-1 are hypersensitive to the toxic effects of LPS, indicating that this translational control pathway may regulate the organismal response to microbial stress.

Innate immune responses to pathogens critically impact the development of adaptive immune responses. However, it is not completely understood how innate immunity controls the initiation of adaptive immunities or how it determines which type of adaptive immunity will be induced to eliminate a given pathogen. Here we show that viral stimulation not only triggers natural <em>interferon</em> (IFN)-<em>alpha</em>/beta-producing cells (IPCs) to produce vast amounts of antiviral IFN-<em>alpha</em>/beta but also induces these cells to differentiate into dendritic cells (DCs). IFN-<em>alpha</em>/beta and tumor necrosis factor <em>alpha</em> produced by virus-activated IPCs act as autocrine survival and DC differentiation factors, respectively. The virus-induced DCs stimulate naive CD4(+) T cells to produce IFN-gamma and interleukin (IL)-10, in contrast to IL-<em>3</em>-induced DCs, which stimulate naive CD4(+) T cells to produce T helper type 2 cytokines IL-4, IL-5, and IL-10. Thus, IPCs may play two master roles in antiviral immune responses: directly inhibiting viral replication by producing large amounts of IFN-<em>alpha</em>/beta, and subsequently triggering adaptive T cell-mediated immunity by differentiating into DCs. IPCs constitute a critical link between innate and adaptive immunity.

ISGF-<em>3</em> is an <em>interferon</em>-dependent positive-acting transcription factor that is cytoplasmically activated, possibly through direct interaction with the <em>interferon</em> receptor. The factor has been purified, its component proteins have been separated, and its peptide sequences have been obtained. From the sequences, degenerate oligonucleotide probes were constructed to screen for cDNA clones. Sequencing of the selected clones shows that the 91- and 84-kDa components represent two forms of a previously unknown (to our knowledge) protein. Several antibodies raised against these proteins prove that they indeed do encode protein components of ISGF-<em>3</em>. This work provides reagents to explore the modification of this cytoplasmically activated transcription factor.

Inflammation is mediated by a variety of soluble factors, including a group of secreted polypeptides known as cytokines. Inflammatory cytokines can be divided into two groups: those involved in acute inflammation and those responsible for chronic inflammation. This review describes the role played in acute inflammation by IL-1, TNF-<em>alpha</em>, IL-6, IL-11, IL-8 and other chemokines, G-CSF, and GM-CSF. It also describes the involvement of cytokines in chronic inflammation. This latter group can be subdivided into cytokines mediating humoral responses such as IL-4, IL-5, IL-6, IL-7, and IL-1<em>3</em>, and those mediating cellular responses such as IL-1, IL-2, IL-<em>3</em>, IL-4, IL-7, IL-9, IL-10, IL-12, <em>interferons</em>, transforming growth factor-beta, and tumor necrosis factor <em>alpha</em> and beta. Some cytokines, such as IL-1, significantly contribute to both acute and chronic inflammation. This review also summarizes features of the cell-surface receptors that mediate the inflammatory effects of the described cytokines.

In the past few years, inflammation has emerged as a major driving force of atherosclerotic lesion development. It is now well-established that from early lesion to vulnerable plaque formation, numerous cellular and molecular inflammatory components participate in the disease process. The most prominent cells that invade in evolving lesions are monocyte-derived macrophages and T-lymphocytes. Both cell types produce a wide array of soluble inflammatory mediators (cytokines, chemokines) which are critically important in the initiation and perpetuation of the disease. This review summarizes the currently available information from mouse studies on the contribution of a specified group of cytokines expressed in atherosclerotic lesions, viz. interleukins (IL-1, IL-2, IL-<em>3</em>, IL-4, IL-5, IL-6, IL-10, IL-12, IL-18, IL-20) and macrophage-associated cytokines [tumour necrosis factor-<em>alpha</em> (TNF-<em>alpha</em>); macrophage migration inhibitory factor (MIF); <em>interferon</em>-gamma (IFN-gamma); colony stimulating factors G-CSF,-M-CSF,-GM-CSF) to atherogenesis. Emphasis is put on the consistency of the effects of these cytokines, i.e. inasmuch an effect depends on the experimental approach applied (overexpression/deletion, strain, gender, dietary conditions, and disease stage). An important outcome of this survey is (i) that only for a few cytokines there is sufficient consistent data allowing classifying them as typically proatherogenic (IL-1, IL-12, IL-18, MIF, IFN-gamma, TNF-<em>alpha</em>, and M-CSF) or antiatherogenic (IL-10) and (ii) that some cytokines (IL-4, IL-6 and GM-CSF) can exert pro- or anti-atherogenic effects depending on the experimental conditions. This knowledge can be used for improved early detection, prevention and treatment of atherosclerosis.

Wild-type human respiratory syncytial virus (HRSV) is a poor inducer of <em>alpha</em>/beta <em>interferons</em> (IFN-<em>alpha</em>/beta). However, recombinant HRSV lacking the NS1 and NS2 genes (Delta NS1/2) induced high levels of IFN-<em>alpha</em> and -beta in human pulmonary epithelial cells (A549) as well as in macrophages derived from primary human peripheral blood monocytes. Results with NS1 and NS2 single- and double-gene-deletion viruses indicated that the two proteins function independently as well as coordinately to achieve the full inhibitory effect, with NS1 having a greater independent role. The relative contributions of the individual NS proteins were the converse of that recently described for bovine RSV (J. F. Valarcher, J. Furze, S. Wyld, R. Cook, K. K. Conzelmann, and G. Taylor, J. Virol. 77:8426-84<em>3</em>9, 200<em>3</em>). This pattern of inhibition by HRSV NS1 and NS2 also extended to the newly described antiviral cytokines IFN-lambda 1, -2 and -<em>3</em>.

BACKGROUND

Inflammatory cytokines are implicated in the pathophysiology of depression. In rodents, systemically administered inflammatory cytokines induce depression-like behavior. Similarly in humans, therapeutic interferon-alpha induces clinical depression in a third of patients. Conversely, patients with depression also show elevated pro-inflammatory cytokines.

OBJECTIVE

To determine the neural mechanisms underlying inflammation-associated mood change and modulatory effects on circuits involved in mood homeostasis and affective processing.

METHODS

In a double-blind, randomized crossover study, 16 healthy male volunteers received typhoid vaccination or saline (placebo) injection in two experimental sessions. Mood questionnaires were completed at baseline and at 2 and 3 hours. Two hours after injection, participants performed an implicit emotional face perception task during functional magnetic resonance imaging. Analyses focused on neurobiological correlates of inflammation-associated mood change and affective processing within regions responsive to emotional expressions and implicated in the etiology of depression.

RESULTS

Typhoid but not placebo injection produced an inflammatory response indexed by increased circulating interleukin-6 and significant mood reduction at 3 hours. Inflammation-associated mood deterioration correlated with enhanced activity within subgenual anterior cingulate cortex (sACC) (a region implicated in the etiology of depression) during emotional face processing. Furthermore, inflammation-associated mood change reduced connectivity of sACC to amygdala, medial prefrontal cortex, nucleus accumbens, and superior temporal sulcus, which was modulated by peripheral interleukin-6.

CONCLUSIONS

Inflammation-associated mood deterioration is reflected in changes in sACC activity and functional connectivity during evoked responses to emotional stimuli. Peripheral cytokines modulate this mood-dependent sACC connectivity, suggesting a common pathophysiological basis for major depressive disorder and sickness-associated mood change and depression.

Plasmacytoid dendritic cell (P-DC) precursors in peripheral blood produce large amounts of <em>interferon</em> (IFN)-<em>alpha</em>/beta when triggered by viruses. However, when incubated with interleukin-<em>3</em> and CD40 ligand, the same precursors differentiate into mature DCs that stimulate naïve CD4(+) T cells to produce Th2 cytokines. We recently reported that P-DCs accumulate in nasal mucosa of experimentally induced allergic rhinitis, supporting a role for this DC subset in Th2-dominated inflammation. Here we examined whether P-DCs accumulate in cutaneous lesions of lupus erythematosus (LE), a disorder associated with increased IFN-<em>alpha</em>/beta production. Our results showed that P-DCs were present in 14 out of 15 tissue specimens of cutaneous LE lesions, but not in normal skin. Importantly, the density of P-DCs in affected skin correlated well (r(s) = 0.79,P < 0.0005) with the high number of cells expressing the IFN-<em>alpha</em>/beta-inducible protein MxA, suggesting that P-DCs produce IFN-<em>alpha</em>/beta locally. Accumulation of P-DCs coincided also with the expression of L-selectin ligand peripheral lymph node addressin on dermal vascular endothelium, adding further support to the notion that these adhesion molecules are important in P-DC extravasation to peripheral tissue sites. Together, our findings suggested that P-DCs are an important source of IFN-<em>alpha</em>/beta in cutaneous LE lesions and may therefore be of pathogenic importance.

The induction of <em>interferon</em> (IFN) genes by viruses or double-stranded RNA (dsRNA) requires the assembly of a complex set of transcription factors on responsive DNA elements of IFN gene promoters. One of the factors necessary for regulating IFN-beta gene transcription is nuclear factor NF-kappa B, the activation of which is triggered by dsRNA. It has previously been suggested that the dsRNA-activated p68 protein kinase (PKR) may act as an inducer-receptor, transducing the signal from dsRNA to NF-kappa B through phosphorylation of the inhibitor I kappa B. We present direct evidence that PKR can phosphorylate I kappa B-<em>alpha</em> (MAD-<em>3</em>) and activate NF-kappa B DNA binding activity in vitro. We further show that dsRNA induces an unusual phosphorylated form of I kappa B-<em>alpha</em>. The expression of a transdominant mutant PKR is able to perturb the dsRNA-mediated signaling pathway in vivo, suggesting a role for this kinase in IFN-beta gene induction.

The Ebola virus (EBOV) VP<em>3</em>5 protein blocks the virus-induced phosphorylation and activation of <em>interferon</em> regulatory factor <em>3</em> (IRF-<em>3</em>), a transcription factor critical for the induction of <em>alpha</em>/beta <em>interferon</em> (IFN-<em>alpha</em>/beta) expression. However, the mechanism(s) by which this blockage occurs remains incompletely defined. We now provide evidence that VP<em>3</em>5 possesses double-stranded RNA (dsRNA)-binding activity. Specifically, VP<em>3</em>5 bound to poly(rI) . poly(rC)-coated Sepharose beads but not control beads. In contrast, two VP<em>3</em>5 point mutants, R<em>3</em>12A and K<em>3</em>09A, were found to be greatly impaired in their dsRNA-binding activity. Competition assays showed that VP<em>3</em>5 interacted specifically with poly(rI) . poly(rC), poly(rA) . poly(rU), or in vitro-transcribed dsRNAs derived from EBOV sequences, and not with single-stranded RNAs (ssRNAs) or double-stranded DNA. We then screened wild-type and mutant VP<em>3</em>5s for their ability to target different components of the signaling pathways that activate IRF-<em>3</em>. These experiments indicate that VP<em>3</em>5 blocks activation of IRF-<em>3</em> induced by overexpression of RIG-I, a cellular helicase recently implicated in the activation of IRF-<em>3</em> by either virus or dsRNA. Interestingly, the VP<em>3</em>5 mutants impaired for dsRNA binding have a decreased but measurable IFN antagonist activity in these assays. Additionally, wild-type and dsRNA-binding-mutant VP<em>3</em>5s were found to have equivalent abilities to inhibit activation of the IFN-beta promoter induced by overexpression of IPS-1, a recently identified signaling molecule downstream of RIG-I, or by overexpression of the IRF-<em>3</em> kinases IKKepsilon and TBK-1. These data support the hypothesis that dsRNA binding may contribute to VP<em>3</em>5 IFN antagonist function. However, additional mechanisms of inhibition, at a point proximal to the IRF-<em>3</em> kinases, most likely also exist.

C.B-17 severe combined immune deficient (SCID) mice, which lack functional B and T lymphocytes, allow xenografts and, therefore, can be used to study the biology of human malignancies. Two different human B cell lymphoma cell lines, SU-DHL-4 and OCI-Ly8, which both harbor the t(14;18) chromosomal translocation, were injected into C.B-17 SCID mice. Mice injected intravenously or intraperitoneally developed tumors and died in a dose-dependent manner. The presence of tumor cells in various murine tissues could be demonstrated by a clonogenic tumor assay, staining of frozen sections with a monoclonal antibody (mAb) against a human B cell antigen (CD19), and with the polymerase chain reaction technique. A protocol using cytotoxic effector cells was developed and used to selectively deplete the tumor cells from bone marrow. These cells were developed by growing peripheral blood mononuclear cells in the presence of <em>interferon</em> gamma (IFN-gamma), anti-CD<em>3</em> mAb, and interleukin 2 (IL-2). The timing of IFN-gamma treatment was critical and optimal if IFN-gamma was added before IL-2 treatment. The cells that were stimulated by IFN-gamma, followed by IL-2, could be expanded by treatment with a mAb directed against CD<em>3</em>. These cells could be further activated by IL-1, but not by tumor necrosis factor <em>alpha</em>. With this protocol, a tumor cell kill of <em>3</em> logs was obtained as measured by a clonogenic assay. Interestingly, despite their high cytotoxic activity against lymphoma cells, these cells had little toxicity against a subset of normal human hematopoietic precursor cells (granulocyte/macrophage colony-forming units). These cells were further tested by treating murine bone marrow contaminated with the human lymphoma cell line SU-DHL-4, and injecting these cells into SCID mice to assay for tumor growth in vivo. The animals injected with bone marrow contaminated with SU-DHL-4 cells had enhanced survival if the bone marrow was treated with the cytokine-induced killer cells before infusion. The SCID mouse provides a useful in vivo model for evaluation of new therapeutic approaches for lymphoma treatment. The cytokine-induced killer cells generated as described here could have an important impact on bone marrow purging for autologous bone marrow transplantation as well as for adoptive immunotherapy.

The signal transduction pathway through which <em>interferon</em>-<em>alpha</em> (IFN <em>alpha</em>) stimulates transcription of a defined set of genes involves activation of DNA-binding factors specific for the IFN <em>alpha</em>-stimulated response element (ISRE). IFN-stimulated gene factor-<em>3</em> (ISGF<em>3</em>), the positive regulator of transcription, was derived in response to IFN <em>alpha</em> treatment from preexisting protein components that were activated first in the cell cytoplasm prior to appearance in the nucleus. Nuclear translocation of ISGF<em>3</em> required several minutes and could be inhibited by NaF. Formation of active ISGF<em>3</em> was mimicked in vitro by mixing cytoplasmic extracts from IFN <em>alpha</em>-stimulated cells with extracts of cells treated to contain high amounts of the unactivated factor. Active ISGF<em>3</em> was found to be formed from association of two latent polypeptide precursors that were distinguished biochemically by differential sensitivity to N-ethyl maleimide. One precursor was modified in response to IFN <em>alpha</em> occupation of its cell-surface receptor, thus enabling association with the second subunit. The resulting complex then was competent for nuclear translocation and binding to ISRE. Cytoplasmically localized transcription factor precursors thus serve as second messengers to translate directly an extracellular signal into specific transcriptional activity in the nucleus.

Rift Valley fever virus (RVFV) is an important cause of epizootics and epidemics in Africa and a potential agent of bioterrorism. A better understanding of the factors that govern RVFV virulence and pathogenicity is required, given the urgent need for antiviral therapies and safe vaccines. We have previously shown that RVFV strains with mutations in the NSs gene are excellent inducers of <em>alpha</em>/beta <em>interferon</em> (IFN-<em>alpha</em>/beta) and are highly attenuated in mice. Here, we demonstrate that NSs is sufficient to block IFN-beta gene expression at the transcriptional level. In cells transiently expressing NSs, IFN-beta transcripts were not inducible by viral infection or by transfection of poly(I:C). NSs with anti-IFN activity accumulated in the nucleus. In contrast, mutant forms of NSs that had lost their IFN-inhibiting activity remained in the cytoplasm, indicating that nuclear localization plays a role. IFN synthesis is regulated by specific transcription factors, including <em>interferon</em> regulatory factor (IRF-<em>3</em>), NF-kappaB, and AP-1. In the presence of NSs, IRF-<em>3</em> was still activated and moved to the nucleus. Likewise, NF-kappaB and AP-1 were activated normally, as shown in electrophoretic mobility shift assays. Moreover, NSs was found to inhibit transcriptional activity of a constitutive promoter, in agreement with recent findings showing that NSs targets the basal cellular transcription factor TFIIH. The present results suggest that NSs, unlike other viral IFN antagonists, does not inhibit IFN-specific transcription factors but blocks IFN gene expression at a subsequent step.

A link between dietary fructose intake, gut-derived endotoxemia, and nonalcoholic fatty liver disease (NAFLD) has been suggested by the results of human and animal studies. To further investigate the role of gut-derived endotoxin in the onset of fructose-induced NAFLD, Toll-like receptor (TLR-) 4-mutant (C<em>3</em>H/HeJ) mice and wildtype (C<em>3</em>H/HouJ) mice were either fed plain water or water enriched with <em>3</em>0% fructose for 8 weeks. Hepatic steatosis, plasma alanine aminotransferase (ALT), and markers of insulin resistance as well as portal endotoxin levels were determined. Hepatic levels of myeloid differentiation factor 88 (MyD88), <em>interferon</em> regulatory factor (IRF) <em>3</em> and 7, and tumor necrosis factor <em>alpha</em> (TNF<em>alpha</em>) as well as markers of lipid peroxidation were assessed. Chronic intake of <em>3</em>0% fructose solution caused a significant increase in hepatic steatosis and plasma ALT levels in wildtype animals in comparison to water controls. In fructose-fed TLR-4 mutant mice, hepatic triglyceride accumulation was significantly reduced by approximately 40% in comparison to fructose-fed wildtype mice and plasma ALT levels were at the level of water-fed controls. No difference in portal endotoxin concentration between fructose-fed wildtype and TLR-4-mutant animals was detected. In contrast, hepatic lipid peroxidation, MyD88, and TNF<em>alpha</em> levels were significantly decreased in fructose-fed TLR-4-mutant mice in comparison to fructose-fed wildtype mice, whereas IRF<em>3</em> and IRF7 expression remained unchanged. Markers of insulin resistance (e.g., plasma TNF<em>alpha</em>, retinol binding protein 4, and hepatic phospho-AKT) were only altered in fructose-fed wildtype animals.

CONCLUSIONS

Taken together, these data further support the hypothesis that in mice the onset of fructose-induced NAFLD is associated with intestinal bacterial overgrowth and increased intestinal permeability, subsequently leading to an endotoxin-dependent activation of hepatic Kupffer cells.

The Toll-like receptor 4 (TLR4) that recognizes endotoxin, a trigger of inflammation in alcoholic liver disease (ALD), activates two signaling pathways utilizing different adapter molecules: the common TLR adapter, myeloid differentiation factor 88 (MyD88), or Toll/interleukin immune-response-domain-containing adaptor inducing <em>interferon</em> (IFN)-beta. The MyD88 pathway induces proinflammatory cytokine activation, a critical mediator of ALD. Here we evaluated the role of MyD88 in alcohol-induced liver injury in wild-type, TLR2-deficient, TLR4-deficient, or MyD88-deficient (knockout [KO]) mice after administration of the Lieber-De-Carli diet (4.5% volume/volume ethanol) or an isocaloric liquid control diet for 5 weeks. Alcohol feeding resulted in a significant increase in serum alanine aminotransferase levels, liver steatosis and triglyceride levels suggesting liver damage in WT, TLR2-KO, and MyD88-KO but not in TLR4-KO mice. Expression of inflammatory mediators (tumor necrosis factor-<em>alpha</em> and interleukin-6) and TLR4 coreceptors (CD14 and MD2) was significantly higher in livers of alcohol-fed WT, TLR2-KO, or MyD88-KO, but not in TLR4-KO mice, compared to controls. Reactive oxygen radicals produced by cytochrome P450 and the nicotinamide adenine dinucleotide phosphate complexes contribute to alcoholic liver damage. Alcohol feeding-induced expression and activation of cytochrome P450 and the nicotinamide adenine dinucleotide phosphate complex were prevented by TLR4-deficiency but not by MyD88-deficiency. Liver expression of <em>interferon</em> regulatory factor <em>3</em> (IRF<em>3</em>), a MyD88-independent signaling molecule, was not affected by chronic alcohol treatment in whole livers of WT mice or in any of the KO mice. However, the induction of IRF7, an IRF<em>3</em>-inducible gene, was found in Kupffer cells of alcohol-fed WT mice. Alcohol feeding also induced nuclear factor-kappaB activation in a TLR4-dependent MyD88-independent manner.

CONCLUSIONS

While TLR4 deficiency was protective, MyD88 deficiency failed to prevent alcohol-induced liver damage and inflammation. These results suggest that the common TLR adapter, MyD88, is dispensable in TLR4-mediated liver injury in ALD.

OBJECTIVE

To determine whether alpha-interferon is effective in terminating viral replication and in eradicating the carrier state in patients with chronic hepatitis B virus (HBV) infection.

METHODS

Randomized controlled studies published in the English literature between January 1966 and June 1992 were identified through a MEDLINE computer search.

METHODS

Fifteen randomized controlled studies with a total of 837 adult chronic HBV carriers who were positive for hepatitis B surface antigen (HBsAg) and hepatitis B e antigen (HBeAg) were identified. Studies were included if patients were treated for at least 3 months and followed for at least 6 months after cessation of therapy.

RESULTS

Overall, the loss of HBsAg occurred 6% more often in interferon-treated patients than the natural seroconversion seen in controls (7.8% compared with 1.8%, P = 0.001), and the loss of viral replication occurred approximately 20% more often in treated patients than in controls (33% compared with 12% for loss of HBeAg and 37% compared with 17% for the loss of HBV DNA, P = 0.0001) if patients received interferon for 3 to 6 months and were followed for 6 to 12 months. Interferon also had a significant treatment effect on the development of antibodies to HBsAg (anti-HBs), antibodies to HBeAg (anti-HBe), and on the normalization of alanine aminotransferase levels.

CONCLUSIONS

Alpha-interferon is effective in terminating viral replication and in eradicating the carrier state in patients with chronic HBV infection who are HBeAg positive when these patients are treated for 3 to 6 months and followed for 6 to 12 months after cessation of therapy. Follow-up studies are required to determine whether interferon reduces the risk for developing cirrhosis or hepatocellular carcinoma.

Interleukin-28A (IL-28A), IL-28B and IL-29 are a family of class II cytokines that stimulate antiviral responses through a heterodimeric receptor that is distinct from the type I <em>interferon</em> (IFN) receptor. To better understand how this newly described family of cytokines regulates the antiviral state, we compared various cellular responses elicited by IL-29 and IFN-<em>alpha</em>. Here we show that these cytokines stimulate similar patterns of signal transducer and activator of transcription 1 (STAT-1), -2, -<em>3</em>, and -5 phosphorylation and nearly identical patterns of gene expression when analyzed in two distinct cell types by microarray analysis. Interestingly, the IL-29 receptor is preferentially expressed on primary hepatocytes within normal liver and pegylated forms of IL-29 and IFN-<em>alpha</em> induced equivalent 2'5' oligoadenylate synthetase (OAS) and MX1 gene expression in this cell type. Pegylated IL-29 also produced a significant reduction in human hepatitis B and hepatitis C viral load in vitro and reduced the cytopathic effect caused by the fully replicating flavivirus, West Nile virus. In conclusion, IL-29 and IFN-<em>alpha</em> stimulate identical antiviral responses despite their utilization of different receptors. This fact, combined with significant receptor expression in hepatitis virus-infected livers, suggests that IL-29 may have therapeutic value against chronic viral hepatitis in human patients.

Protection against West Nile virus (WNV) infection requires rapid viral sensing and the generation of an <em>interferon</em> (IFN) response. Mice lacking IFN regulatory factor <em>3</em> (IRF-<em>3</em>) show increased vulnerability to WNV infection with enhanced viral replication and blunted IFN-stimulated gene (ISG) responses. IRF-<em>3</em> functions downstream of several viral sensors, including Toll-like receptor <em>3</em> (TLR<em>3</em>), RIG-I, and MDA5. Cell culture studies suggest that host recognizes WNV in part, through the cytoplasmic helicase RIG-I and to a lesser extent, MDA5, both of which activate ISG expression through IRF-<em>3</em>. However, the role of TLR<em>3</em> in vivo in recognizing viral RNA and activating antiviral defense pathways has remained controversial. We show here that an absence of TLR<em>3</em> enhances WNV mortality in mice and increases viral burden in the brain. Compared to congenic wild-type controls, TLR<em>3</em>(-/-) mice showed relatively modest changes in peripheral viral loads. Consistent with this, little difference in multistep viral growth kinetics or IFN-<em>alpha</em>/beta induction was observed between wild-type and TLR<em>3</em>(-/-) fibroblasts, macrophages, and dendritic cells. In contrast, a deficiency of TLR<em>3</em> was associated with enhanced viral replication in primary cortical neuron cultures and greater WNV infection in central nervous system neurons after intracranial inoculation. Taken together, our data suggest that TLR<em>3</em> serves a protective role against WNV in part, by restricting replication in neurons.

A number of recent studies testify that calcitriol alone or in combination with corticosteroids exerts strong immune modulatory activity. As a new approach, we evaluated the protolerogenic potential of calcitriol and dexamethasone in acute T helper (Th)1-mediated colitis in mice. A rectal enema of trinitrobenzene sulfonic acid (TNBS) (100 mg/kg) was applied to BALB/c mice. Calcitriol and/or dexamethasone were administered i.p. from days 0 to <em>3</em> or <em>3</em> to 5 following the instillation of the haptenating agent. Assessment of colitis severity was performed daily. Colon tissue was analyzed macroscopically and microscopically, and myeloperoxidase activity, as well as cytokine levels [tumor necrosis factor-<em>alpha</em>, <em>interferon</em>-gamma, interleukin (IL)-12p70, IL-1beta, IL-10, IL-4] were determined by enzyme-linked immunosorbent assay, T-bet, GATA family of transcription factors <em>3</em>, a Th2 master regulator (GATA<em>3</em>), Foxp<em>3</em>, cytotoxic T-lymphocyte-associated antigen 4 (CTLA4), IL-2<em>3</em>p19 and IL-17 expression by immunoblot analysis. The combination of the steroids most effectively reduced the clinical and histopathologic severity of TNBS colitis. Th1-related parameters were down-regulated, whereas Th2 markers like IL-4 and GATA<em>3</em> were up-regulated. Apart from known steroid effects, calcitriol in particular promoted regulatory T cell profiles as indicated by a marked increase of IL-10, TGFbeta, FoxP<em>3</em>, and CTLA4. Furthermore, analysis of dendritic cell mediators responsible for a proinflammatory differentiation of T cells revealed a significant reduction of IL-12p70 and IL2<em>3</em>p19 as well as IL-6 and IL-17. Thus, our data support a rationale for a steroid-sparing, clinical application of calcitriol derivatives in inflammatory bowel disease. Furthermore they suggest that early markers of inflammatory dendritic cell and Th17 differentiation qualify as new target molecules for both calcitriol and highly selective immune-modulating vitamin D analogs.

The PML gene of acute promyelocytic leukaemia (APL) encodes a cell growth and tumour suppressor, however, the mechanisms by which PML suppresses tumorigenesis are poorly understood. We show here that Pml is required for Fas- and caspase-dependent DNA-damage-induced apoptosis. We also found that Pml is essential for induction of programmed cell death by Fas, tumour necrosis factor <em>alpha</em> (TNF), ceramide and type I and II <em>interferons</em> (IFNs). As a result, Pml-/- mice and cells are protected from the lethal effects of ionizing radiation and anti-Fas antibody. Pml is required for caspase 1 and caspase <em>3</em> activation upon exposure to these stimuli. The PML-RAR <em>alpha</em> fusion protein of APL renders haemopoietic progenitor cells resistant to Fas-, TNF- and IFN-induced apoptosis with a lack of caspase <em>3</em> activation, thus acting as a Pml dominant-negative product. These results demonstrate that Pml is a mediator of multiple apoptotic signals, and implicate inhibition of apoptosis in the pathogenesis of APL.

OBJECTIVE

An open-label, phase II study to evaluate progression-free survival (PFS), overall best response, adverse events (AEs), and patient-reported outcomes with sorafenib versus interferon alfa-2a (IFN-alpha-2a) in patients with untreated, advanced renal cancer.

METHODS

A total of 189 patients were randomly assigned to oral sorafenib 400 mg twice daily or to subcutaneous IFN-alpha-2a 9 million U three times weekly (period 1). Sorafenib patients who progressed were dose-escalated to 600 mg twice daily; IFN-alpha-2a patients who progressed were switched to sorafenib 400 mg twice daily (period 2).

RESULTS

In period 1 PFS was similar for sorafenib-treated (n = 97; 5.7 months) and IFN-alpha-2a-treated patients (n = 92; 5.6 months); more sorafenib-treated patients had tumor shrinkage (68.2% v 39.0%). Common drug-related AEs (Grades>> or = 3) for sorafenib were hand-foot skin reaction (11.3%), diarrhea (6.2%), and rash/desquamation (6.2%); for IFN-alpha-2a, these were fatigue (10.0%), nausea (3.3%), flu-like syndrome (2.2%), and anorexia (2.2%). Sorafenib-treated patients reported fewer symptoms, better quality of life (QOL), and greater treatment satisfaction. In period 2, 41.9% of patients who received sorafenib 600 mg twice daily (n = 43) experienced tumor reduction (median PFS, 3.6 months). After the switch to sorafenib 400 mg twice daily, tumors were reduced in 76.2% of 50 patients (median PFS, 5.3 months). AEs were mostly grade 1 to 2; no increase in AEs of grades>> or = 3 occurred after sorafenib dose escalation.

CONCLUSIONS

In this study, sorafenib resulted in similar PFS as IFN-alpha-2a in patients with untreated RCC. However, sorafenib-treated patients experienced greater rates of tumor size reduction, better QOL, and improved tolerability. Both dose escalation of sorafenib after progression and a switch to sorafenib after progression on IFN-alpha-2a resulted in clinical benefit.

In humans, the type I <em>interferon</em> (IFN) family consists of 1<em>3</em> IFN-<em>alpha</em> subtypes, IFN-beta and IFN-omicron the newly discovered IFN-like family consists of IFN-lambda1, -lambda2 and -lambda<em>3</em>. We have investigated the expression of type I and lambda IFN genes following virus infections or Toll-like receptor (TLR) triggering in monocyte-derived DC (MDDC) and plasmacytoid DC (pDC). We found that all IFN-<em>alpha</em>, -beta, -omicron and -lambda subtypes are expressed in influenza-virus-infected MDDC or pDC. Conversely, differential type I IFN gene transcription was induced in MDDC and pDC stimulated by specific TLR agonists. TLR-9 stimulation by CpG DNA induced the expression of all IFN-<em>alpha</em>, -beta, -omicron and -lambda subtypes in pDC, whereas TLR-4 stimulation by LPS, or TLR-<em>3</em> stimulation by poly I:C, induced only IFN-beta and IFN-lambda gene expression in MDDC. The expression pattern of IFN regulatory factor (IRF)-5 and IRF-7 in MDDC and pDC was also determined. IRF-5 was constitutively expressed in the two DC subsets whereas IRF-7 was constitutive in pDC but its expression was induced along MDDC maturation. Overall, our data indicate that the coordinated expression of IFN-lambda with IFN-beta would be of crucial importance for the maturation of DC.

BACKGROUND

Preoperative portal vein embolization (PVE) is used clinically to prevent postoperative liver insufficiency. The current study examined the impact of portal vein embolization on liver resection.

METHODS

A comprehensive Medline search to identify all registered literature in the English language on portal vein embolization. Meta-analysis was performed to assess the result of PVE and its impact on major liver resection.

RESULTS

A total of 75 publications met the search criteria but only <em>3</em>7 provided data sufficiently enough for analysis involving 1088 patients. The overall morbidity rate for PVE was 2.2% without mortality. Four weeks following PVE, 85% patients underwent the planned hepatectomy (n = 9<em>3</em>0). Twenty-three patients had transient liver failure following resection after PVE (2.5%) but 7 patients developed acute liver failure and died (0.8%). The reason for nonresection following PVE (n = 158, 15%) included inadequate hypertrophy of remnant liver (n = 18), severe progression of liver metastasis (n = 4<em>3</em>), extrahepatic spread (n = <em>3</em>5), refusal to surgery (n = 1), poor general condition (n = 1), altered treatment to transcatheter artery embolization or chemotherapy (n = 24), complete remission after treatment with <em>3</em> cycles of fluoracil and <em>interferon</em> <em>alpha</em> in a patient with hepatocellular carcinoma (n = 1), incomplete pre- or postembolization scanning (n = 8). Of those who underwent laparotomy without resection, (n = 27) reasons included intraoperative finding of peritoneal dissemination (n = 15), portal node metastasis (n = 2), severe invasion of the tumor to the hepatic artery and portal vein (n = 1), and gross tumoral extension precluding curative resection (n = 9). Two techniques were used for portal vein embolization: percutaneous transhepatic portal embolization, (PTPE) and transileocolic portal embolization, (TIPE). The increase in remnant liver volume was much greater in PTPE than TIPE group (11.9% vs. 9.7%; P = 0.00001). However, the proportion of patients who underwent resection following PVE was 97% in TIPE and 88% PTPE, respectively (P = <0.00001). Although there was no significant difference in patients who had major complications post-PVE, the rate for minor complications was significantly higher among patients who had PTPE (5<em>3</em>.6% vs. 0%, P = <0.0001).

CONCLUSIONS

PVE is a safe and effective procedure in inducing liver hypertrophy to prevent postresection liver failure due to insufficient liver remnant.