Changes in the Expression of Proteins Associated with Neurodegeneration in the Brains of Mice after Infection with Influenza A Virus with Wild Type and Truncated NS1.

Influenza type A virus (IAV) infection is a major cause of morbidity and mortality during influenza epidemics. Recently, a specific link between IAV infection and neurodegenerative disease progression has been established. The non-structural NS1 protein of IAV regulates viral replication during infection and antagonizes host antiviral responses, contributing to influenza virulence.

Hypoxia alters the immune response in mouse peritoneal macrophages infected with influenza a virus with truncated NS1 protein.

Macrophages are the most abundant cells in infected tissue and are involved in the clearing infection, and immunomodulation of the innate and adaptive immune response. NS80 virus of influenza A virus, which encodes only the first 80 aa of the NS1 protein, suppresses the immune host response and is associated with enhanced pathogenicity. Hypoxia promotes infiltration of peritoneal macrophages into the adipose tissue and production of cytokines.

Pandemics of the 21st Century: The Risk Factor for Obese People.

The number of obese adults and children is increasing worldwide, with obesity now being a global epidemic. Around 2.8 million people die annually from clinical overweight or obesity.

Chemokine-binding proteins encoded by herpesviruses.

To establish infection, a wide variety of pathogens, including viruses, have evolved a number of strategies to avoid immune elimination. Viruses have acquired and optimized molecules that interact with the host chemokine network in order to disrupt immune surveillance and defense of vertebrates, helping to promote cell entry, facilitating dissemination of infected cells, and evasion the immune response. Viral immunomodulators include ligands, chemokine receptors and chemokine-binding proteins (vCKBPs) functioning as either cell surface receptor mimics, ligand mimics, or secreted chemokine-binding proteins.

T cells and their function in the immune response to viruses.

The development of CD4+ T helper cells is determined by the set of transcription factors and the genes these transcription factors transcribe. In this review, we describe the basic nature of Th1, Th2, Th9, Th17, T-follicular helper (Tfh), gamma delta (γδ) T cells, and T-regulatory (Treg) cells subsets, their master regulator transcription factors and their corresponding signature cytokine production profiles. Cellular immunity plays important role during virus infection.

Influenza A virus lacking the effector and C terminal domains of NS1 protein induces cytokines associated with high pathogenicity in mice.

Non-structural NS1 protein of influenza A virus counters host antiviral defences by antagonizing the interferon response. The C-terminal effector domain suppresses the host response and is associated with the pathogenicity of the virus.  To better understand the regulatory role of the C-terminal domain, we used reverse genetics system to generate NS1-truncated virus (NS80) and compared the cytokine profiles in the lungs of mice infected with the NS80 mutant and with the control virus A/WSN/33 (WSN).

Comparison of cytokine profiles induced by nonlethal and lethal doses of influenza A virus in mice.

Influenza viruses are among the most common human pathogens and are responsible for causing extensive seasonal morbidity and mortality. To investigate the immunological factors associated with severe influenza infection, the immune responses in mice infected with nonlethal (LD0) doses of A/PR/8/34 (H1N1) influenza virus were compared with those of mice infected with a lethal dose (LD100) of the virus. The virus titer and activation of retinoic acid-inducible gene (RIG)-I-like receptor signaling pathways were similar in the mice infected with LD0 and LD100 at 2 days post-infection; however, mice infected with LD100 exhibited a greater abundance of cytokines and a more diverse cytokine profile.

Conserved methionine 165 of matrix protein contributes to the nuclear import and is essential for influenza A virus replication.

Background: The influenza matrix protein (M1) layer under the viral membrane plays multiple roles in virus assembly and infection. N-domain and C-domain are connected by a loop region, which consists of conserved RQMV motif.

Methods: The function of the highly conserve RQMV motif in the influenza virus life cycle was investigated by site-directed mutagenesis and by rescuing mutant viruses by reverse genetics.

Comparison of transcriptional profiles of interferons, CXCL10 and RIG-1 in influenza infected A549 cells stimulated with exogenous interferons.

Type I and type III interferons (IFNs) are induced by viral infection. It was concluded that these IFN species are identical in regulation and biological functions. However, these two systems differ in the tissue expression of their receptors and their transcriptional regulation is fundamentally different as well as cellular signaling pathways that drive expression of each IFN.

Cytokines Induced During Influenza Virus Infection.

Influenza A virus is one of the major human pathogens. The influenza infection can pass out without any subclinical symptoms or infestation can appear in upper respiratory tract as well as in lower respiratory tract where it can result in lethal outcome. Both innate and adaptive immune responses are activated shortly after infection providing protection against infection.

Transforming Activity of Murine Herpesvirus 68 Putative Growth Factor Is Related to the Ability to Change Cytoskeletal Structure.

Murine herpesvirus 68 (MHV-68) can transform cells in vitro and in vivo. We investigated putative murine herpesvirus growth factors (MHGFs) obtained by the separation of cell-free media from MHV-68-transformed cells on an FPLC Sephadex G15 column. The transforming activity of the MHGFA fraction was related to depolymerization of actin, disruption of the microtubule network, and punctate-reticular changes of the Golgi.

Nest ecology of blood parasites in the European roller and its ectoparasitic carnid fly.

Haemosporidian parasites are considered the most important vector-borne parasites. However, vector identity and ecology is unknown for most such host-vector-parasite systems. In this study, we employ microscopic and molecular analyses to examine haemosporidian prevalence in a migratory, cavity-nesting bird, European roller Coracias garrulus, and its nidicolous blood-feeding ectoparasite Carnus hemapterus.

Protective efficacy of IFN-ω AND IFN-λs against influenza viruses in induced A549 cells.

The interferon system represents one of the components of the first line defence against influenza virus infection. Interferon omega (IFN-ω) is antigenetically different from IFN-α and IFN-β and can affect patients who are resistant to these IFNs. To improve the biological characterization of IFN-ω, we compared its activity with those of type I and type III IFNs in induced A549 cells.

Induction of interferon lambda in influenza a virus infected cells treated with shRNAs against M1 transcript.

RNA interference (RNAi) represents a form of post-transcriptional gene silencing mediated by small interfering RNAs (siRNA) and provides a powerful tool to specifically inhibit viral infection. To investigate therapeutic capacity of siRNAs targeting M gene, six vectors with U1-short hairpin RNA (shRNA) expression system were prepared and tested in infected cells and animals. In infected cells, three of six shRNAs targeting M1 gene significantly (P <0,01) reduced the virus titer to 66%, 45% or 21%, respectively.

Antiviral Effect of Interferon Lambda Against Lymphocytic Choriomeningitis Virus.

Lambda interferons inhibit replication of many viruses, but their role in the inhibition of lymphocytic choriomeningitis virus (LCMV) infection remains unclear. In this study, we examined the antiviral effects of interferon (IFN)-λ2 and IFN-λ3 against LCMV in A549 cells. We found that IFN-λ2 is a more potent inhibitor of LCMV strain MX compared with IFN-λ3, whereas both cytokines have similar antiviral effects against an immunosuppressive variant of LCMV, clone-13.

Murine gammaherpesvirus (MHV-68) transforms cultured cells in vitro.

Human dermal fibroblasts and mouse NIH/3T3 cells acquired the transformed phenotype ('criss-cross' pattern of growth) after infection with ultraviolet-irradiated murine gammaherpesvirus (MuHV-4 strain 68; MHV-68). These cells with changed phenotype could be serially cultured for 5-6 passages (35-40 days), and then they entered into crisis and most of them died. In a small number of cultures, however, foci of newly transformed cells appeared from which two stable cell lines were derived.

Synergic and antagonistic effect of small hairpin RNAs targeting the NS gene of the influenza A virus in cells and mice.

In the present study, we demonstrate the effect of individual and mixtures of shRNAs targeting the NS gene to treat an established infection of influenza A virus (IAV). We prepared 10 shRNAs targeting the NS gene of the IAV, and these shRNAs were tested individually or in mixtures 16h after infection. Our results revealed: (i) shRNA targeting the NS1 transcript decreased the virus titre up to 21% (P<0.

Interferons lambda, new cytokines with antiviral activity.

Interferons (IFNs) are key cytokines in the establishment of a multifaceted antiviral response. Three distinct types of IFNs are now recognized (type I, type II, and type III) based on their receptor usage, structural features and biological activities. Although all IFNs are important mediators of antiviral protection, their roles in antiviral defence vary.

Role and application of RNA interference in replication of influenza viruses.

Unlabelled: RNA interference (RNAi) is a naturally occurring endogenous biological post-transcriptional cellular mechanism that regulates RNA expression. Small interfering RNAs (siRNAs), mediators of RNAi, are short (19-26nt), double-stranded RNA duplexes that inhibit gene expression by inducing sequence-specific degradation of homologous messenger RNA (mRNA). Influenza virus infection is a major public health problem, causing hundreds of thousands of deaths worldwide each year.

Overview of measles and mumps vaccine: origin, present, and future of vaccine production.

Measles and mumps are common viral childhood diseases that can cause serious complications. Vaccination remains the most efficient way to control the spread of these viruses. The manufacturing capability for viral vaccines produced in embryonated hen eggs and conventional/classical cell substrates, such as chicken embryo fibroblast or primary dog kidney cell substrates, is no longer sufficient.

Molecular detection of murine herpesvirus 68 in ticks feeding on free-living reptiles.

The MHV-68 (designed as Murid herpesvirus 4 (MuHV 4) strain 68) isolated from two rodents, Myodes glareolus and Apodemus flavicollis, is considered as a natural pathogen of free-living murid rodents. Recently, the detection of MHV antibodies in the blood of animals living in the same biotope as MHV-infected mice has suggested that ticks may have a role in the transmission of this pathogen. Ixodes ricinus is one the most abundant tick species in Europe known to transmit multiple pathogens causing human and animal diseases.

Influenza A virus replication is inhibited in IFN-λ2 and IFN-λ3 transfected or stimulated cells.

Interferons lambda (IFN-λ) are the most recently defined members of the class III cytokine family. To investigate whether IFN-λ2 and IFN-λ3 displayed antiviral activity against influenza A virus (IAV), a number of cell lines induced with IFNs - as well as two established cell lines (A549-IFN-λ2 and A549-IFN-λ3) - were infected with IAV. Our results indicate that IFN-λ2 has statistically significant antiviral activity in A549-IFN-λ2 (P=0.

Human immunodeficiency virus 1 Vpu protein does not affect the conversion of influenza A virus hemagglutinin to its low-pH conformation in an acidic trans-Golgi compartment.

The 81-aa Vpu protein of Human immunodeficiency virus 1 (HIV-1) is a structural analogue of the M2 protein of influenza A virus (IAV). Expression of Vpu in Xenopus oocytes has showed that it can form a voltage-activated ion channel permeable to Na+ and K+ ions (Ewart et al., 1996).

Determination of hemagglutinin and neuraminidase subtypes of avian influenza A viruses in urban pigeons by a new nested RT-PCR.

The prevalence of avian influenza viruses (AIVs) together with determination of hemagglutinin (HA) and neuraminidase (NA) subtypes were studied in urban pigeons using a new nested RT-PCR. Both oropharyngeal and cloacal swabs from birds were collected. Altogether, screening of all samples revealed that 12% of oropharyngeal and 20% of cloacal samples were positive for AIVs.