Protection of mice from respiratory Sendai virus infections by recombinant vaccinia viruses.

Mechanisms of protection of mice from Sendai virus, which is exclusively pneumotropic and causes a typical respiratory disease, by immunization with recombinant vaccinia viruses (RVVs) were investigated. Although the RVV carrying a hemagglutinin-neuraminidase gene of Sendai virus (Vac-HN) propagated in the noses and lungs of mice by either intranasal (i.n.) or intraperitoneal (i.p.) inoculation, no vaccinia virus antigens were detected in the mucosal layer of upper and lower airways of the i.p.-inoculated mice. The mice immunized i.n. with Vac-HN or Vac-F (the RVV carrying a fusion protein gene of Sendai virus) demonstrated the strong resistance to Sendai virus challenge both in the lung and in the nose, whereas the i.p.-immunized mice showed almost no resistance in the nose but showed a partial resistance in the lung. Titration of Sendai virus-specific antibodies in the nasal wash (NW), bronchoalveolar lavage (BAL), and serum collected from the Vac-F-immunized mice showed that the NW from the i.n.-immunized mice contained immunoglobulin A (IgA) antibodies but no IgG and the BAL from the mice contained both IgA and IgG antibodies. On the other hand, neither IgA nor IgG antibodies were detected in the NW from the i.p.-immunized mice and only IgG antibodies were detected in the BAL, although both i.n.- and i.p.-immunized mice exhibited similar levels of serum IgG, IgA, and neutralizing antibodies. The resistance to Sendai virus in the noses of i.n.-immunized mice could be abrogated by the intranasal instillation of anti-mouse IgA but not of anti-IgG antiserum, while the resistance in the lung was not significantly abrogated by such treatments. These results demonstrate that IgA is a major mediator for the immunity against Sendai virus induced by the RVVs and IgG is a supplementary one, especially in the lung, and that the RVV should be intranasally inoculated to induce an efficient mucosal immunity even if it has a pantropic nature.     

MDCK cell-cultured influenza virus vaccine protects mice from lethal challenge with different influenza viruses

Influenza epidemics are major health concern worldwide. Vaccination is the major strategy to protect the general population from a pandemic. Currently, most influenza vaccines are manufactured using chicken embroynated eggs, but this manufacturing method has potential limitations, and cell-based vaccines offer a number of advantages over the traditional method. We reported here using the scalable bioreactor to produce pandemic influenza virus vaccine in a Madin-Darby canine kidney cell culture system. In the 7.5-L bioreactor, the cell concentration reached to 3.2 × 10(6) cells/mL and the highest virus titers of 256 HAU/50 μL and 1 × 10(7) TCID50/mL. The HA concentration was found to be 11.2 μg/mL. The vaccines produced by the cell-cultured system induced neutralization antibodies, cross-reactive T-cell responses, and were protective in a mouse model against different lethal influenza virus challenge. These data indicate that microcarrier-based cell-cultured influenza virus vaccine manufacture system in scalable bioreactor could be used to produce effective pandemic influenza virus vaccines.     

Replication-competent or attenuated, nonpropagating vesicular stomatitis viruses expressing respiratory syncytial virus (RSV) antigens protect mice against RSV challenge

Foreign glycoproteins expressed in recombinant vesicular stomatitis virus (VSV) can elicit specific and protective immunity in the mouse model. We have previously demonstrated the expression of respiratory syncytial virus (RSV) G (attachment) and F (fusion) glycoprotein genes in recombinant VSV. In this study, we demonstrate the expression of RSV F and G glycoproteins in attenuated, nonpropagating VSVs which lack the VSV G gene (VSVDeltaG) and the incorporation of these RSV proteins into recombinant virions. We also show that intranasal vaccination of mice with nondefective VSV recombinants expressing RSV G (VSV-RSV G) or RSV F (VSV-RSV F) elicited RSV-specific antibodies in serum (by enzyme-linked immunosorbent assay [ELISA]) as well as neutralizing antibodies to RSV and afford complete protection against RSV challenge. In contrast, VSVDeltaG-RSV F induced detectable serum antibodies to RSV by ELISA, but no detectable neutralizing antibodies, yet it still protected from RSV challenge. VSVDeltaG-RSV G failed to induce any detectable serum (by ELISA) or neutralizing antibodies and failed to protect from RSV challenge. The attenuated, nonpropagating VSVDeltaG-RSV F is a particularly attractive candidate for a live attenuated recombinant RSV vaccine.     

Immunosuppression induced in vivo by 15 hydroxyeicosatetoic acid (15 HETE)

We have investigated the in vivo effects of 15 HETE on C57B1/6 (H-2^b) mice injected IP daily with this product. After that the 15 HETE treated animals and the controls were challenged in vivo by DBA/2 (H-2^d) cells.Splenocytes from 15 HETE injected animals were either stimulated in vitro by lectins or cocultivated with DBA/2 irradiated splenocytes. It was observed that the response of splenocytes from in vivo treated animals is weaker than the control's response. The data suggest that 15 HETE induce the generation of suppressor cells.     

Attenuation of inducible respiratory immune responses by oseltamivir treatment in mice infected with influenza A virus

The antiviral neuraminidase inhibitor oseltamivir (OSV) is widely used to suppress viral replication in the treatment of influenza. Here, we report that OSV administration significantly suppressed respiratory mucosal secretory IgA responses with respect to antigen (Ag)-specific antibody (Ab) production and also the induction of Ag-specific IgA Ab-forming cells, but not systemic IgG responses, in weanling mice as a model of pediatric influenza. Neutralizing activities of the airway fluids in oral OSV-treated mice were significantly less than those of sham-treated mice. Our findings suggest the risk of re-infection in patients showing a low mucosal response following OSV treatment.     

Host cellular signaling induced by influenza virus

A wide range of host cellular signal transduction pathways can be stimulated by influenza virus infection. Some of these signal transduction pathways induce the host cell’s innate immune response against influenza virus, while others are essential for efficient influenza virus replication. This review examines the cellular signaling induced by influenza virus infection in host cells, including host pattern recognition receptor (PRR)-related signaling, protein kinase C (PKC), Raf/MEK/ERK and phosphatidylinositol- 3-kinase (PI3K)/Akt signaling, and the corresponding effects on the host cell and/or virus, such as recognition of virus by the host cell, viral absorption and entry, viral ribonucleoprotein (vRNP) export, translation control of cellular and viral proteins, and virus-induced cell apoptosis. Research into influenza virus-induced cell signaling promotes a clearer understanding of influenza virus-host interactions and assists in the identification of novel antiviral targets and antiviral strategies.     

Growth of H5N1 influenza A viruses in the upper respiratory tracts of mice

Highly pathogenic avian H5N1 influenza A viruses have spread throughout Asia, Europe, and Africa, raising serious worldwide concern about their pandemic potential. Although more than 250 people have been infected with these viruses, with a consequent high rate of mortality, the molecular mechanisms responsible for the efficient transmission of H5N1 viruses among humans remain elusive. We used a mouse model to examine the role of the amino acid at position 627 of the PB2 viral protein in efficient replication of H5N1 viruses in the mammalian respiratory tract. Viruses possessing Lys at position 627 of PB2 replicated efficiently in lungs and nasal turbinates, as well as in cells, even at the lower temperature of 33 degrees C. Those viruses possessing Glu at this position replicated less well in nasal turbinates than in lungs, and less well in cells at the lower temperature. These results suggest that Lys at PB2-627 confers to avian H5N1 viruses the advantage of efficient growth in the upper and lower respiratory tracts of mammals. Therefore, efficient viral growth in the upper respiratory tract may provide a platform for the adaptation of avian H5N1 influenza viruses to humans and for efficient person-to-person virus transmission, in the context of changes in other viral properties including specificity for human (sialic acid alpha-2,6-galactose containing) receptors.     

Vulpinic acids inhibit influenza (RNA) viruses but not herpes (DNA) viruses

Three synthetic vulpinic acids inhibited two influenza RNA viruses, type A (Philippine) and B (Paraha), in tissue culture with ID₅₀ values ranging from 3.9 to 15.5 g/ml. They had no activity against a third influenza virus or against two herpes viruses.

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Résumé Trois acides vulpiniques de synthèse inhibent deux virus à DNA de l'influenza, types A (Philippine) et B (Paraha), en culture tissulalre avec des valeurs d'ID₅₀ s'étalant de 3.9 à 15.5 g/ml. Ces acides vulpiniques ne présentent d'activité ni contre un trolalème virus de l'influenza, ni contre deux virus de l'herpes.

     

流感裂解疫苗H3N2-抗H3N2免疫原性复合物滴鼻诱导小鼠黏膜免疫应答的研究

目的研究流感裂解病毒疫苗抗原抗体复合物滴鼻诱生小鼠黏膜免疫应答.方法分别以15μg H3N2、H3N2-CpG、H3N2-鼠抗H3N2及H3N2-PEG滴鼻免疫小鼠,检测肺泡灌洗液抗H3N2 IgA、血清抗H3N2 IgG效价.取免疫小鼠脾细胞,体外抗原刺激,用定量酶联免疫吸附试验(ELISA)检测上清液IFN-γ及IL-4分泌水平.结果H3N2-抗H3N2免疫原性复合物诱生的抗H3N2 IgA效价明显高于H3N2单独免疫组(P＜0.01),而与H3N2-CpG组无显著性差异.此外,复合物诱生的血清抗H3N2也高于H3N2单独免疫组(P＜0.05).H3N2-CpG组诱生的IFN-γ水平明显升高,而其他组之间无明显差异.结论流感病毒血凝素抗原抗体复合物、血凝素抗原加CpG佐剂可以诱生较强的局部黏膜免疫和体液免疫.这两组诱生的IgA效价均明显高于H3N2单独免疫组.另外,H3N2-CpG组小鼠的脾脏细胞经特异性抗原诱导后培养上清液中的IFN-γ水平明显升高.     

Vaccination with inactivated influenza A virus during pregnancy protects neonatal mice against lethal challenge by influenza A viruses representing three subtypes.

A single intraperitoneal injection of pregnant mice with a monovalent Formalin-inactivated influenza A virus vaccine protected their offspring against a lethal challenge dose of the same influenza A virus H3N2, H2N2, and H1N1 subtypes, as well as against challenge with the other two subtypes. Degree of protection was vaccine dose related. Cross-fostering of neonates indicated that protection was conferred by breast milk antibodies. Serum virus-specific neutralizing antibodies in the mothers and neonates correlated with resistance to vaccine virus, but were detected against other subtypes only in a complement enhancement test or when high doses of vaccine were given.     

甲型H1N1流感病毒在季流病毒、禽流感病毒共感染时变异可能性的验证

目的 甲型H1N1流感病毒A/California/7/2009分别与A/Brisbane/10/07和A/ShenZhen/406H/06共感染小型香猪,预测甲流病毒在与季流H3N2病毒/甲流病毒与禽流感病毒共感染时是否会发生变异.方法 分别将A/California/7/2009(CA7)与A/Brisbane/10/07(H3N2),A/California/7/2009与A/Shenzhen/406H/06(H5N1)对5～6月龄小型猪共感染,小型猪经复方氯胺酮0.1 mL/kg麻醉后进行滴鼻感染,感染后第5天安乐死动物,取动物肺组织作病毒测序分析.结果 A/California/7/2009(CA7)与A/Brisbane/10/07(H3N2)共感染后,A/California/7/2009病毒PB1基因993位G→A突变,PA基因1659位G→A突变,没有氨基酸的变异.A/California/7/2009与A/Shenzhen/406H/06(H5N1)共感染后A/California/7/2009病毒PB2基因1711位T→C突变.碱基的突变未引起氨基酸的变异.结论 A/California/7/2009(CA7)与A/Brisbane/10/07(H3N2),A/California/7/2009与A/Shenzhen/406H/06(H5N1)共感染后在猪的体内没有发生病毒重组、变异.