Modified vaccinia virus Ankara induces Toll-like receptor-independent type I interferon responses

Modified vaccinia virus Ankara (MVA) is a highly attenuated vaccinia virus strain undergoing clinical evaluation as a replication-deficient vaccine vector against various infections and tumor diseases. To analyze the basis of its high immunogenicity, we investigated the mechanism of how MVA induces type I interferon (IFN) responses. MVA stimulation of bone marrow-derived dendritic cells (DC) showed that plasmacytoid DC were main alpha IFN (IFN-alpha) producers that were triggered independently of productive infection, viral replication, or intermediate and late viral gene expression. Increased IFN-alpha levels were induced upon treatment with mildly UV-irradiated MVA, suggesting that a virus-encoded immune modulator(s) interfered with the host cytokine response. Mice devoid of Toll-like receptor 9 (TLR9), the receptor for double-stranded DNA, mounted normal IFN-alpha responses upon MVA treatment. Furthermore, mice devoid of the adaptors of TLR signaling MyD88 and TRIF and mice deficient in protein kinase R (PKR) showed IFN-alpha responses that were only slightly reduced compared to those of wild-type mice. MVA-induced IFN-alpha responses were critically dependent on autocrine/paracrine triggering of the IFN-alpha/beta receptor and were independent of IFN-beta, thus involving "one-half" of a positive-feedback loop. In conclusion, MVA-mediated type I IFN secretion was primarily triggered by non-TLR molecules, was independent of virus propagation, and critically involved IFN feedback stimulation. These data provide the basis to further improve MVA as a vaccine vector.     

Comparison of augmentation of human natural killer cell cytotoxicity by interferon-alpha subtypes

The capacity of 3 interferon-alpha (IFN-alpha) subtypes, alpha 1, alpha 2 and alpha 4, to augment human natural killer cytotoxicity after exposure in vitro was shown to be dose-dependent and to differ according to subtype. With 10(2) IU/ml, the lowest IFN concentration used, stimulation of NK activity by IFN-alpha 2 was consistently and significantly greater than by IFN-alpha 4 or IFN-alpha 1. An IFN-alpha analogue in which arginine and lysine residues 121 and 122 were replaced by 2 leucines was generated by site-directed in vitro mutagenesis of the IFN-alpha 4 gene; at equivalent concentrations of antiviral activity, this analogue was 10-fold less effective in NK stimulation. There was a lack of correlation between NK-stimulatory and other activities of the IFN-alpha subtypes and the mutant, suggesting that different biological activities may be mediated by different regions of the IFN-alpha molecule.     

Expressions of VEGF and its receptors in rat corpus luteum during interferon alpha administration in early and pseudopregnancy

It is accepted that angiogenesis plays an important role in the development of the corpus luteum (CL) and is probably necessary for normal lutein cell function. A number of drugs currently being tested in clinical trials as possible angiogenesis inhibitors were not originally developed with the intention of suppressing tumor angiogenesis. Interferon alpha (IFN-alpha) is one of the notable examples of such 'accidental angiogenesis inhibitors' and daily administration of IFN-alpha is known to suppress tumor growth, tumor vascularization, and down-regulation of various growth factors. We investigated the effects of IFN-alpha treatment on the expression of vascular endothelial growth factor (VEGF), and its receptors KDR and Flt-1, and CD34 in CL during the first week of pseudopregnancy and pregnancy in hormonally induced rat ovaries by immunohistochemistry and Western blot techniques. Basal body temperatures of the drug-treated rats, as an indicator of treatment effect, were determined daily and were increased significantly when compared to controls (38.03 +/- 0.18 vs. 36.6 +/- 0.1 degrees C), respectively. The effect of IFN-alpha treatment was minimal when the entire week was evaluated, however, the expression of VEGF decreased at 3rd, 5th, and 7th days of both pregnancy and pseudopregnancy, when compared to the 1st day, whereas there was not a such alteration in the untreated rats regarding these days. The daily subcutaneous administrations of 672.500 U IFN-alpha2b had minimal effects on the expressions of VEGF, and its two receptors KDR and Flt-1 in either pregnant or pseudopregnant corpora lutea utilizing HSCORE.     

In vivo destruction of tumor tissue by cryoablation can induce inhibition of secondary tumor growth: an experimental study

BACKGROUND: Cryoablation has been used successfully for the local treatment of several cancers. Besides local destruction, a systemic antitumor response has been postulated after cryoablation of tumor tissue. In this study we evaluate the possible systemic antitumor response induced by cryodestruction of tumor tissue in two mouse tumor models. METHODS: Mice received two subcutaneously placed tumor implants (thigh and flank) of the nonimmunogenic mouse colon tumor cell line, colon 26-B. After 7 days, the thigh implant was treated by cryoablation or excision and the effect on secondary tumor growth was determined by volume measurement of the nontreated flank tumor. Cytokine (IL-1alpha and TNF-alpha) levels in plasma were measured after treatment. Similar experiments were performed in nude mice using a human melanoma cell line (MV3). Moreover, in this model the effect of cryoablation on development of spontaneous lung metastases was evaluated. RESULTS: In the colon 26-B tumor model treatment of primary tumor implants by cryoablation resulted in a significant inhibition of secondary tumor growth compared to animals treated by surgical excision (P < 0.01). Six hours after treatment, plasma levels of IL-1alpha and TNF-alpha were higher after cryoablation than after excision (P < 0.01). Also in the nude mice model cryoablation resulted in inhibition of secondary tumor growth, though not significant. Mice treated by cryoablation showed significantly less lung metastases compared to those treated by excision (P = 0.03). CONCLUSIONS: Cryoablation of tumor tissue can result in inhibition of secondary and metastatic tumor growth. A cytokine response induced by cryoablation of tumor tissue may attribute to this feature.     

Human macrophages, but not dendritic cells, are activated and produce alpha/beta interferons in response to Mopeia virus infection

Lassa virus (LV) and Mopeia virus (MV) are closely related members of the Arenavirus genus, sharing 75% amino acid sequence identity. However, LV causes hemorrhagic fever in humans and nonhuman primates, whereas MV cannot induce disease. We have previously shown that antigen-presenting cells (APC)-macrophages (MP) and dendritic cells (DC)-sustain high replication rates of LV but are not activated, suggesting that they play a role in the immunosuppression observed in severe cases of Lassa fever. Here, we infected human APC with MV and analyzed the cellular responses induced. MV infection was productive in MP and even more so in DC. Apoptosis was not induced in either cell type. Moreover, unlike DC, MP were early and strongly activated in response to MV, as shown by the increased surface expression of CD86, CD80, CD54, CD40, and HLA-abc and by the production of mRNA encoding alpha interferon (IFN-alpha), IFN-beta, tumor necrosis factor alpha and interleukin-6. In addition, MV-infected MP produced less of the virus than DC, which was related to the fact that these cells secreted IFN-alpha. Thus, the strong activation of MP is probably a major event in the control of MV infection and may be involved in the induction of an adaptive immune response in infected hosts. These results may explain the difference in pathogenicity between LV and MV.     

Regulation of thyrotropin biosynthesis. Discordant effect of thyroid hormone on alpha and beta subunit mRNA levels

We have studied the regulation of the biosynthesis of thyrotropin (TSH) and its alpha and beta subunits by thyroid hormone in thyrotropic tumors carried in hypothyroid mice. Treatment with 3,5,3'-triiodo-L-thyronine (T3) (20 micrograms/100 g, body weight) daily for 4 or 10 days reduced serum TSH to 3 and 0.3% of control, respectively. Serum levels of free alpha subunit were reduced to 60 and 11% of control at 4 days and 10 days, respectively, and serum free TSH-beta was undetectable at both time points. There was no significant decrease in tumor TSH content after 4 days of treatment and, after 10 days, TSH content was reduced to 15% of control levels. There was no significant effect of T3 on tumor alpha subunit levels at either 4 or 10 days. In contrast, tumor TSH-beta content was markedly reduced after 4 days and 10 days of T3 treatment, to 29 and 10% of control levels, respectively. Translation of tumor poly(A) mRNA in a rabbit reticulocyte lysate system showed that thyroid hormone decreased translatable TSH-beta mRNA to undetectable levels at both 4 and 10 days, whereas translatable alpha mRNA was reduced strikingly only at 10 days in one of two tumors. RNA blot hybridization with 32P-labeled plasmid probes containing alpha or TSH-beta cDNAs showed that TSH-beta mRNA was reduced to less than 10% of control after both 4 and 10 days of T3 treatment, whereas, again, alpha mRNA was only reduced in one of two tumors at 10 days. Our data thus show that thyroid hormone affects alpha and TSH-beta mRNA and protein levels discordantly and suggest that regulation of TSH biosynthesis may occur predominantly at the level of TSH-beta mRNA.     

Cytostatic product(s) released by activated macrophages, unrelated to interleukin 1, tumor necrosis factor alpha, and interferon-alpha/beta

Murine peritoneal macrophages activated for cytotoxicity by trehalose dimycolate in vivo and lipopolysaccharide in vitro released cytostatic factor(s) against EMT6 target cells, in 8-hr conditioned medium (CM). The cytostatic factor(s) completely blocked DNA synthesis by EMT6 cells within 16 hr. Other cell lines are less sensitive (P815 and R-L929) or resistant (KB and HT29) to the cytostatic effect of CM. The anti-proliferative activity of CM had a MW greater than 10,000 Da, as judged by ultrafiltration. It was destroyed by proteases and strongly inhibited by P815 cell product(s). Conditioned media from nonactivated macrophages were not cytostatic against EMT6 cells. No relationship was found between cytostatic factor(s) in CM and interleukin 1 (IL-1), tumor necrosis factor alpha (TNF-alpha), and interferon-alpha/beta (IFN-alpha/beta): the growth of EMT6 cells was unaffected by Hu.r.IL-is and Hu.r.TNF-alpha and was only slightly inhibited by IFN-alpha/beta. Furthermore, cytostatic CM contained low levels of TNF and IFN activities. Finally, antibodies raised against murine IFN-alpha/beta had no effect on the cytostatic activity of CM.     

Human immunodeficiency virus type 1 activates plasmacytoid dendritic cells and concomitantly induces the bystander maturation of myeloid dendritic cells

In this study, we analyzed the phenotypic and physiological consequences of the interaction of plasmacytoid dendritic cells (pDCs) with human immunodeficiency virus type 1 (HIV-1). pDCs are one cellular target of HIV-1 and respond to the virus by producing alpha/beta interferon (IFN-alpha/beta) and chemokines. The outcome of this interaction, notably on the function of bystander myeloid DC (CD11c+ DCs), remains unclear. We therefore evaluated the effects of HIV-1 exposure on these two DC subsets under various conditions. Blood-purified pDCs and CD11c+ DCs were exposed in vitro to HIV-1, after which maturation markers, cytokine production, migratory capacity, and CD4 T-cell stimulatory capacity were analyzed. pDCs exposed to different strains of infectious or even chemically inactivated, nonreplicating HIV-1 strongly upregulated the expression of maturation markers, such as CD83 and functional CCR7, analogous to exposure to R-848, a synthetic agonist of toll-like receptor-7 and -8. In addition, HIV-1-activated pDCs produced cytokines (IFN-alpha and tumor necrosis factor alpha), migrated in response to CCL19 and, in coculture, matured CD11c+ DCs, which are not directly activated by HIV. pDCs also acquired the ability to stimulate na?ve CD4+ T cells, albeit less efficiently than CD11c+ DCs. This HIV-1-induced maturation of both DC subsets may explain their disappearance from the blood of patients with high viral loads and may have important consequences on HIV-1 cellular transmission and HIV-1-specific T-cell responses.     

Cellular damage and altered carbohydrate expression in P815 tumor cells induced by direct electric current: an in vitro analysis

Treatment with direct electric current (DC) can inhibit tumor growth in several systems. To evaluate the cellular reactions generated by this treatment, we stimulated mouse mastocytoma P815 cells with DC and examined their viability and ultrastructural characteristics, as well as the effect of DC on surface carbohydrate expression. DC treatment affected cell viability and caused marked alterations in vital structures of P815 cells. Alterations varied depending on the duration of stimulation and polarity of electrode. Anodic and cathodic treatments caused decrease in cell viability, although the latter was more effective in generating cell lysis. DC stimulation also induced changes such as membrane damage, alterations in cell shape and chromatin organization, mitochondrial swelling and condensation, cytoplasmic swelling, and matrix rarefaction. Stimulation of P815 cells without contact with electrodes produced no alterations, suggesting that this contact might be essential for the occurrence of the cellular modifications. DC treatment also altered the membrane distribution of anionic sites of P815 cells, as well as the surface carbohydrate exposition, involving a diminished binding of Concanavalin A to the cell surface after cathodic stimulation, and an increased binding of sialic acid- and fucose-specific lectins after anodic treatment. In this work we describe important cellular targets for the action of DC, which may contribute to the understanding of the mechanisms by which DC supresses several kinds of tumors.     

Prophylactic alpha interferon treatment increases the therapeutic index of oncolytic vesicular stomatitis virus virotherapy for advanced hepatocellular carcinoma in immune-competent rats

Vesicular stomatitis virus (VSV) is a negative-strand RNA virus with intrinsic oncolytic specificity due to substantially attenuated antiviral responses in many tumors. We have recently reported that recombinant VSV vector can be used as an effective oncolytic agent to safely treat multifocal hepatocellular carcinoma (HCC) in the livers of immune-competent rats via hepatic artery infusion. When administered at doses above the maximum tolerated dose (MTD), however, the animals suffered from neurotoxicity and/or acute lethal hepatotoxicity. Since VSV is extremely sensitive to the antiviral actions of alpha/beta interferon (IFN-alpha/beta) in normal cells, we tested if prophylactic treatment with rat IFN-alpha would enhance VSV safety without compromising treatment efficacy in tumor-bearing rats. We found that VSV retained its replication potential in human and rat HCC cells after preincubation with relatively high doses of rat and human IFN-alpha in vitro, and its MTD in tumor-bearing rats treated systemically with rat IFN-alpha at 66 IU/g body weight (BW), equivalent to a human IFN-alpha dose that is currently prescribed for patients with viral hepatitis, was elevated by more than 1/2 log unit. Furthermore, we demonstrate that intratumoral replication of VSV was not attenuated by administration of 66 IU/g BW rat IFN-alpha, as tumor response and survival advantage in VSV-treated rats in the presence or absence of rat IFN-alpha were equivalent. The results suggest that prophylactic rat IFN-alpha treatment elevates the therapeutic index of hepatic arterial VSV therapy for multifocal HCC in rats. Since human IFN-alpha is currently in clinical use, its prophylactic application should be considered in future clinical translational protocols for VSV-mediated oncolytic virotherapy as a novel therapeutic modality in patients with advanced HCC, as well as other types of cancer.     

Sindbis virus translation is inhibited by a PKR/RNase L-independent effector induced by alpha/beta interferon priming of dendritic cells

The tropism of Sindbis virus (SB) for cells of the dendritic cell (DC) lineage and the virulence of SB in vivo are largely determined by the efficacy of alpha/beta interferon (IFN-alpha/beta)-mediated antiviral responses. These responses are essentially intact in the absence of PKR and/or RNase L (K. D. Ryman, L. J. White, R. E. Johnston, and W. B. Klimstra, Viral Immunol. 15:53-76, 2002). In the present studies, we investigated the nature of antiviral effects and identity of antiviral effectors primed by IFN-alpha/beta treatment of bone marrow-derived DCs (BMDCs) generated from mice deficient in PKR and RNase L (TD). IFN-alpha/beta priming exerted significant antiviral activity at very early stages of SB replication and most likely inhibited the initial translation of infecting genomes. The early effect targeted cap-dependent translation as protein synthesis from an SB-like and a simple RNA were inhibited by interferon treatment, but an encephalomyocarditis virus internal ribosome entry site-driven element exhibited no inhibition. Phosphorylation of the alpha subunit of eukaryotic translation initiation factor 2 was defective after virus infection of TD cells, suggesting other mechanisms of translation inhibition. To identify components of these alternative antiviral pathway(s), we have compared global gene regulation in BMDCs derived from normal 129 Sv/Ev, IFNAR1-/-, and TD mice following infection with SB or treatment with IFN-alpha/beta. Candidate effectors of alternative antiviral pathways were those genes induced by virus infection or IFN-alpha/beta treatment in 129 Sv/Ev and TD-derived BMDC but not in virus-infected or IFN-alpha/beta-treated IFNAR1-/- cells. Statistical analyses of gene array data identified 44 genes that met these criteria which are discussed.     

In vivo and in vitro induction of 2'-5' oligoadenylate synthetase by interferon-alpha in nodular non-Hodgkin's lymphoma and correlations with the clinical response

We investigated the correlations between the in vivo-in vitro induction of 2'-5' oligoadenylate synthetase (2-5A synthetase) by IFN-alpha in cells isolated from patients with low-grade nodular non-Hodgkin's lymphoma (NHL) and subsequent clinical responses of these patients to IFN-alpha therapy. Eleven patients were treated daily with 9 x 10(6) U of IFN-alpha 2a in a phase II trial. After an eight week treatment, four patients achieved complete remission, one a partial response, one a minor response, and five failed to respond. Basal levels of 2-5A synthetase in lymph node tumor B cells and peripheral blood mononuclear cells (PBMC) isolated before therapy differed from patient to patient and were significantly lower than in PBMC from healthy donors (P less than 0.03). In vivo single injections of 9 x 10(6) U IFN-alpha 2a induced the 2-5A synthetase in PBMC from all patients to various degrees without quantitative relation to the clinical responses. Injection of a tenfold lower dose resulted in effects of similar extent in most cases. In vitro, IFN-alpha 2a induced the 2-5A synthetase in lymph node tumor B cells isolated before therapy, and the degree of induction was significantly higher in patients who proved to respond to therapy than in patients who displayed no or minor responses (P less than 0.013). This indicates that, in nodular NHL, the 2-5A synthetase assay may have some predictive value for responsiveness to IFN-alpha therapy.     

Alpha/beta interferon protects against lethal West Nile virus infection by restricting cellular tropism and enhancing neuronal survival

West Nile virus (WNV) is a mosquito-borne flavivirus that is neurotropic in humans, birds, and other animals. While adaptive immunity plays an important role in preventing WNV spread to the central nervous system (CNS), little is known about how alpha/beta interferon (IFN-alpha/beta) protects against peripheral and CNS infection. In this study, we examine the virulence and tropism of WNV in IFN-alpha/beta receptor-deficient (IFN- alpha/betaR-/-) mice and primary neuronal cultures. IFN-alpha/betaR-/- mice were acutely susceptible to WNV infection through subcutaneous inoculation, with 100% mortality and a mean time to death (MTD) of 4.6 +/- 0.7 and 3.8+/- 0.5 days after infection with 10(0) and 10(2) PFU, respectively. In contrast, congenic wild-type 129Sv/Ev mice infected with 10(2) PFU showed 62% mortality and a MTD of 11.9 +/- 1.9 days. IFN-alpha/betaR-/- mice developed high viral loads by day 3 after infection in nearly all tissues assayed, including many that were not infected in wild-type mice. IFN-alpha/betaR-/- mice also demonstrated altered cellular tropism, with increased infection in macrophages, B cells, and T cells in the spleen. Additionally, treatment of primary wild-type neurons in vitro with IFN-beta either before or after infection increased neuronal survival independent of its effect on WNV replication. Collectively, our data suggest that IFN-alpha/beta controls WNV infection by restricting tropism and viral burden and by preventing death of infected neurons.     

Effects of progesterone and oestradiol-17 beta on oxytocin-induced release of prostaglandin F-2 alpha in heifers

Seven bilaterally ovariectomized heifers were used in 4 experiments and received: (1) saline injections, as control; (2) one injection of oestradiol (3 mg; i.v.); (3) two i.v. injections of oxytocin (100 i.u.) 6 h apart; or (4) one oestradiol injection 30 min after the first oxytocin injection and a second oxytocin injection 6 h later. All experiments were performed without progesterone and then after 7, 14 and 21 days of progesterone treatment. Frequent blood samples were taken for 1 h before and 7 h after the first injection of oxytocin or oestradiol for the measurement of 13,14-dihydro-15-keto-PGF-2 alpha (PGFM) by radioimmunoassay. After 7, 14 and 21 days of progesterone priming, oestradiol caused a significant increase (P less than 0.001) in plasma PGFM after 6 h but not before. After 7, 14 and 21 days of progesterone, there was a significant increase (P less than 0.005) in PGFM after the first oxytocin injection and a similar increase following the second. The oxytocin-induced increase in PGFM after 14 and 21 days of progesterone was significantly higher (P less than 0.001) 6 h after oestradiol injection than before the oestradiol injection. There was no significant effect of oestradiol on the response to oxytocin in animals that received no progesterone or in those animals that received progesterone for only 7 days. These results show that, under the influence of progesterone, oestradiol enhances the oxytocin-induced release of PGF-2 alpha, and suggest a possible synergistic action of these hormones for the induction of luteolysis in heifers.     

Localization of prostaglandin F2 alpha inhibition of lipoprotein use by bovine luteal cells.

Prostaglandin F2 alpha (PGF2 alpha) inhibits lipoprotein-stimulated progesterone production by bovine luteal cells in vitro and the objective of this study was to localize the site of action of PGF2 alpha. Cultured bovine luteal cells were treated with PGF2 alpha for seven days, and then with either lipoproteins or 25-hydroxycholesterol in the presence of aminoglutethimide (which inhibits cholesterol side-chain cleavage) for the final 48 h. The effects of PGF2 alpha on progesterone production, cellular cholesterol content, mitochondrial cholesterol content and cholesterol side-chain cleavage activity were determined. As expected, PGF2 alpha inhibited (P less than 0.05) lipoprotein-stimulated progesterone production. However, PGF2 alpha did not inhibit low-density lipoprotein-stimulated, or high density lipoprotein-stimulated, increases in cellular cholesterol (P less than 0.05) or inhibit lipoprotein-induced increases in mitochondrial cholesterol content (P less than 0.05). Additionally, cholesterol content of mitochondria increased (P less than 0.05) in the presence of PGF2 alpha alone. To determine if the PGF2 alpha-induced inhibition of steroidogenesis occurred at, or after, the side-chain cleavage reaction, we treated cells with the readily diffusable sterol, 25-hydroxycholesterol. Prostaglandin F2 alpha did not inhibit 25-hydroxycholesterol-stimulated progesterone production (P less than 0.05). Prostaglandin F2 alpha may therefore exert its luteolytic effect at a site after cholesterol transport to the mitochondria but before cholesterol side-chain cleavage.     

Targeting IFN-alpha to B cell lymphoma by a tumor-specific antibody elicits potent antitumor activities

IFN-alpha, a cytokine crucial for the innate immune response, also demonstrates antitumor activity. However, use of IFN-alpha as an anticancer drug is hampered by its short half-life and toxicity. One approach to improving IFN-alpha's therapeutic index is to increase its half-life and tumor localization by fusing it to a tumor-specific Ab. In the present study, we constructed a fusion protein consisting of anti-HER2/neu-IgG3 and IFN-alpha (anti-HER2/neu-IgG3-IFN-alpha) and investigated its effect on a murine B cell lymphoma, 38C13, expressing human HER2/neu. Anti-HER2/neu-IgG3-IFN-alpha exhibited potent inhibition of 38C13/HER2 tumor growth in vivo. Administration of three daily 1-microg doses of anti-HER2/neu-IgG3-IFN-alpha beginning 1 day after tumor challenge resulted in 88% of the mice remaining tumor free. Remarkably, anti-HER2/neu-IgG3-IFN-alpha demonstrated potent activity against established 38C13/HER2 tumors, with complete tumor remission observed in 38% of the mice treated with three daily doses of 5 microg of the fusion protein (p = 0.0001). Ab-mediated targeting of IFN-alpha induced growth arrest and apoptosis of lymphoma cells contributing to the antitumor effect. The fusion protein also had a longer in vivo half-life than rIFN-alpha. These results suggest that IFN-alpha Ab fusion proteins may be effective in the treatment of B cell lymphoma.     

Gene expression and antiviral activity of alpha/beta interferons and interleukin-29 in virus-infected human myeloid dendritic cells

Dendritic cells (DCs) respond to microbial infections by undergoing phenotypic maturation and by producing multiple cytokines. In the present study, we analyzed the ability of influenza A and Sendai viruses to induce DC maturation and activate tumor necrosis factor alpha (TNF-alpha), alpha/beta interferon (IFN-alpha/beta), and IFN-like interleukin-28A/B (IFN-lambda2/3) and IL-29 (IFN-lambda1) gene expression in human monocyte-derived myeloid DCs (mDC). The ability of influenza A virus to induce mDC maturation or enhance the expression of TNF-alpha, IFN-alpha/beta, interleukin-28 (IL-28), and IL-29 genes was limited, whereas Sendai virus efficiently induced mDC maturation and enhanced cytokine gene expression. Influenza A virus-induced expression of TNF-alpha, IFN-alpha, IFN-beta, IL-28, and IL-29 genes was, however, dramatically enhanced when cells were pretreated with IFN-alpha. IFN-alpha priming led to increased expression of Toll-like receptor 3 (TLR3), TLR7, TLR8, MyD88, TRIF, and IFN regulatory factor 7 (IRF7) genes and enhanced influenza-induced phosphorylation and DNA binding of IRF3. Influenza A virus also enhanced the binding of NF-kappaB to the respective NF-kappaB elements of the promoters of IFN-beta and IL-29 genes. In mDC IL-29 induced MxA protein expression and possessed antiviral activity against influenza A virus, although this activity was lower than that of IFN-alpha or IFN-beta. Our results show that in human mDCs viruses can readily induce the expression of IL-28 and IL-29 genes whose gene products are likely to contribute to the host antiviral response.     

Effect of oxytocin on plasma concentrations of 13,14-dihydro-15-keto-prostaglandin F2 alpha during the oestrous cycle and early pregnancy in the goat.

The effect of subcutaneous oxytocin on plasma concentrations of 13,14-dihydro-15-keto-prostaglandin (PG) F2 alpha (PGFM) was examined in the goat at various periods during the oestrous cycle and early pregnancy. 100 i.u. oxytocin was administered daily for 4 day, the dose being divided and given at 0900 and 2100 h; PGFM concentrations were assessed after the first treatment of each day. On days 3-6 (oestrus, day 0) PGFM concentrations increased significantly (P less than 0.001) within 15 minutes and both non-pregnant and mated goats exhibited oestrus behaviour by day 7. Significant (P less than 0.01) increases in PGFM were also produced on days 7-10, in both non-pregnant and pregnant goats, but the responses diminished from day 7 to day 10; only one goat (non-pregnant) came into oestrus. There was a marked difference in response between groups, however, during days 12-15. In non-pregnant goats significant (P less than 0.05) increases in PGFM were detected on days 13-15, but in pregnant animals oxytocin was without effect. Similarly, oxytocin did not increase PGFM concentrations on days 17-20 of pregnancy. However, uterine responsiveness reappeared in pregnant goats with significant (P less than 0.01) increases in PGFM on days 24 and 25.