Influenza virus protecting RNA : an effective prophylactic and therapeutic antiviral

Another influenza pandemic is inevitable, and new measures to combat this and seasonal influenza are urgently needed. Here we describe a new concept in antivirals based on a defined, naturally occurring defective influenza RNA that has the potential to protect against any influenza A virus in any animal host. This protecting RNA (244 RNA) is incorporated into virions which although non-infectious, deliver the RNA to those cells of the respiratory tract that are naturally targeted by infectious influenza virus. A small intranasal dose of this 244 protecting virus (120 ng) completely protected mice against a simultaneous lethal (10 LD50) challenge with influenza A/WSN (H1N1) virus. 244 virus also protected mice against a strong challenge dose of all other subtypes tested (H2N2, H3N2, H3N8). This prophylactic activity was maintained in the animal for at least 1 week prior to challenge. 244 virus was 10 to 100-fold more active than previously characterised influenza A defective viruses, and the protecting activity was confirmed to reside in the 244 RNA molecule by recovering a protecting virus entirely from cloned cDNA. There was clear therapeutic benefit when protecting 244 virus was administered 24-48 h after lethal challenge, an effect which has not been previously observed with any defective virus. Protecting virus reduced, but did not abolish, replication of challenge virus in mouse lungs during both prophylactic and therapeutic treatments. Protecting virus is a novel antiviral which has the potential to combat influenza infections in humans, particularly when the infecting strain is not known, or is resistant to antiviral drugs

Characterization of the NSP6 protein product of rotavirus gene 11

The 12kDa non-structural protein 6 (NSP6) is the least studied of the rotavirus proteins. In an attempt to further characterize this protein mono-specific antisera was generated using purified protein expressed in E. coli. Pulse/chase radio-labeling of virus infected cells was used to show that it is expressed at a steady but low rate throughout the virus replication cycle. In contrast to the other rotavirus non-structural proteins, NSP6 was found to have a high rate of turnover, being completely degraded within 2h of synthesis. NSP6 tagged with GFP was used to probe the intracellular distribution of the protein, perinuclear aggregates were observed in the cytoplasm of transfected cells. Following virus infection of these transfected cells the aggregates were seen to redistribute to the viroplasms. Consistent with its localization to the site of viral genome replication and packaging, NSP6 was found to be a sequence independent nucleic acid binding protein, with similar affinities for ssRNA and dsRNA

Importance of Hydrogen Bond Contacts between the N Protein and RNA Genome of Vesicular Stomatitis Virus in Encapsidation and RNA Synthesis▿

Vesicular stomatitis virus (VSV) genomic RNA encapsidated by the nucleocapsid (N) protein is the template for transcription and replication by the viral polymerase. We analyzed the 2.9-Å structure of the VSV N protein bound to RNA (T. J. Green, X. Zhang, G. W. Wertz, and M. Luo, Science 313:357-360, 2006) and identified amino acid residues with the potential to interact with RNA via hydrogen bonds. The contributions of these interactions to N protein function were investigated by individually substituting the residues with alanine and assaying the effect of these mutations on N protein expression, on the ability of the N protein to interact with the phosphoprotein (P), and on its ability to encapsidate RNA and generate templates that can support transcription and RNA replication. These studies identified individual amino acids critical for N protein function. Nine nucleotides are associated with each N monomer and contorted into two quasi-helices within the N protein RNA binding cavity. We found that N protein residues that formed hydrogen bond contacts with the nucleotides in quasi-helix 2 were critical to the encapsidation of RNA and the production of templates that can support RNA synthesis. Individual hydrogen bond interactions between the N protein and the nucleotides of quasi-helix 1 were not essential for ribonucleoprotein (RNP) template function. Residue R143 forms a hydrogen bond with nucleotide 9, the nucleotide that extends between N monomers. R143A mutant N protein failed to encapsidate RNA and to support RNA synthesis and suppressed wild-type N protein function. These studies show a direct correlation between viral RNA synthesis and N protein residues structurally positioned to interact with RNA

Baldwin lectures for 1902-1903.

Extract from the deed of trust.--Monotheism and the love of God, by Right Rev. Frederick Burgess.--The personal interpretation of Christianity, by Rev. C. E. Woodcock.--The gospel of God's pardon, by Rev. W. S. Rainsford.--Christianity and education, by Right Rev. T. F. Gailor.--The realizing of God, by Rev. W. D. Maxon.Mode of access: Internet