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.

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.

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.

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.

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.

Comparison of the activities of BM2 protein and its H19 and W23 mutants of influenza B virus with activities of M2 protein and its H37 and W41 mutants of influenza A virus.

Co-expression of the BM2 protein with pH-sensitive HA reduces the conversion of HA to its low-pH conformation during transport to the cell surface in the same way as human M2 proteins. BM2 protein is capable of increasing vesicular pH by as much as 0.4 pH units.

Stability and function of the influenza A virus M2 ion channel protein is determined by both extracellular and cytoplasmic domains.

A series of M2/NB chimeras were used to investigate the ion channel activity of the IAV M2 protein. Replacing the M2 cytoplasmic domain with the equivalent NB domain (AAB chimera) did not influence ion channel activity, while replacement of N-terminal domains (BAA and BAB chimeras) resulted in loss of activity. Extension of the M2 protein N-terminal domain resulted in full restoration of ion channel activity in BAA chimeras but only partial restoration in BAB.

Prevalence of avian influenza viruses, Borrelia garinii, Mycobacterium avium, and Mycobacterium avium subsp. paratuberculosis in waterfowl and terrestrial birds in Slovakia, 2006.

The prevalence of Borrelia, Mycobacteria and avian influenza virus (AIV) infections, together with the distribution of different AIV subtypes, was studied in migratory waterfowl and terrestrial birds trapped in three localities in Slovakia during 2006. Samples obtained from waterfowl captured in the Senianske Ponds area of Eastern Slovakia showed the highest diversity of AIV isolates. A total of 13 different subtypes were detected in 19 samples from this location (H1N2, H2N2, H3N2, H6N6, H7N6, H9N2, H9N5, H9N6, H10N5, H10N6, H12N6, H13N6, and H16N6).

Using nested RT-PCR analyses to determine the prevalence of avian influenza viruses in passerines in western Slovakia, during summer 2007.

The prevalence of avian influenza virus (AIV), together with the distribution of different AIV subtypes, was studied in migratory waterfowl and terrestrial birds caught in western Slovakia during summer 2007. Both oropharyngeal and cloacal swabs were collected. Screening of samples revealed that 18% of oropharyngeal and 18% of cloacal samples were positive for AIV.

M2 protein-a proton channel of influenza A virus.

Recent outbreaks of highly pathogenic avian influenza A virus infections (H5 and H7 subtypes) in poultry and humans have raised concerns that a new influenza pandemic will occur in near future. Currently, four antivirals have proven efficacy in the treatment and prophylaxis of influenza A infections: two M2 inhibitors (amantadine and rimantadine) and two neuraminidase inhibitors (zanamivir and oseltamivir). Early treatment with antivirals reduces the duration of symptoms and the time to recovery by one to two days.

Evidence that the CM2 protein of influenza C virus can modify the pH of the exocytic pathway of transfected cells.

The 115 residue CM2 protein of influenza C virus is a structural homologue of the M2 protein of influenza A virus. Expression of the CM2 protein in Xenopus oocytes showed that it can form a voltage-activated ion channel permeable to Cl-. To investigate whether the CM2 protein has pH modulating activity comparable to that of the M2 protein, CM2 was co-expressed with a pH-sensitive haemagglutinin (HA) from influenza A virus.

Reconstitution of carbonic anhydrase activity of the cell-surface-binding protein of vaccinia virus.

The N-terminal region of a 32 kDa cell-surface-binding protein, encoded by the D8L gene of vaccinia virus, shows sequence homology to CAs (carbonic anhydrases; EC 4.2.1.

Influence of residue 44 on the activity of the M2 proton channel of influenza A virus.

The influenza A virus M2 proton channel plays a role in two stages of virus replication. The proteins of two closely related strains of the avian H7 subtype of influenza A virus, Rostock and Weybridge, were found to differ in their pH-modulating activities and activation characteristics. Of three amino acid differences at residues 27, 38 and 44 within the membrane-spanning domain, substitution at residue 44 was necessary and sufficient to account for differences in trans-Golgi pH-modulating activity, whereas changes in all three were required to switch the activation characteristics of the Weybridge M2 to those of the Rostock M2.