MicroRNA-based strategy to mitigate the risk of gain-of-function influenza studies.

Recent gain-of-function studies in influenza A virus H5N1 strains revealed that as few as three-amino-acid changes in the hemagglutinin protein confer the capacity for viral transmission between ferrets. As transmission between ferrets is considered a surrogate indicator of transmissibility between humans, these studies raised concerns about the risks of gain-of-function influenza A virus research. Here we present an approach to strengthen the biosafety of gain-of-function influenza experiments.

Influenza A virus utilizes suboptimal splicing to coordinate the timing of infection.

Influenza A virus is unique as an RNA virus in that it replicates in the nucleus and undergoes splicing. With only ten major proteins, the virus must gain nuclear access, replicate, assemble progeny virions in the cytoplasm, and then egress. In an effort to elucidate the coordination of these events, we manipulated the transcript levels from the bicistronic nonstructural segment that encodes the spliced virus product responsible for genomic nuclear export.

Hematopoietic-specific targeting of influenza A virus reveals replication requirements for induction of antiviral immune responses.

A coordinated innate and adaptive immune response, orchestrated by antigen presenting cells (APCs), is required for effective clearance of influenza A virus (IAV). Although IAV primarily infects epithelial cells of the upper respiratory tract, APCs are also susceptible. To determine if virus transcription in these cells is required to generate protective innate and adaptive immune responses, we engineered IAV to be selectively attenuated in cells of hematopoietic origin.

Engineered RNA viral synthesis of microRNAs.

MicroRNAs (miRNAs) are short noncoding RNAs that exert posttranscriptional gene silencing and regulate gene expression. In addition to the hundreds of conserved cellular miRNAs that have been identified, miRNAs of viral origin have been isolated and found to modulate both the viral life cycle and the cellular transcriptome. Thus far, detection of virus-derived miRNAs has been largely limited to DNA viruses, suggesting that RNA viruses may be unable to exploit this aspect of transcriptional regulation.

MicroRNA-mediated species-specific attenuation of influenza A virus.

Influenza A virus leads to yearly epidemics and sporadic pandemics. Present prophylactic strategies focus on egg-grown, live, attenuated influenza vaccines (LAIVs), in which attenuation is generated by conferring temperature sensitivity onto the virus. Here we describe an alternative approach to attenuating influenza A virus based on microRNA-mediated gene silencing.

Recombinant Newcastle disease virus as a vaccine vector for cancer therapy.

Naturally occurring strains of Newcastle disease virus (NDV) are currently being investigated in multiple clinical trials for oncolytic cancer therapy in the United States and abroad. We have previously reported, for the first time, the development of recombinant NDVs designed for enhanced cancer therapeutic efficacy. Specifically, we have shown that NDV engineered to express interleukin-2 (IL-2) generates a robust therapeutic response associated with increased tumor-specific T-cell infiltration after intratumoral administration in mice.

Use of reverse genetics to enhance the oncolytic properties of Newcastle disease virus.

Naturally occurring strains of Newcastle disease virus (NDV) have shown oncolytic therapeutic efficacy in preclinical studies and are currently in clinical trials. Here, we have evaluated the possibility to enhance the cancer therapeutic potential of NDV by means of reverse genetics. Mice bearing s.

Multiple functions of the IKK-related kinase IKKepsilon in interferon-mediated antiviral immunity.

IKKepsilon is an IKK (inhibitor of nuclear factor kappaBkinase)-related kinase implicated in virus induction of interferon-beta (IFNbeta). We report that, although mice lacking IKKepsilon produce normal amounts of IFNbeta, they are hypersusceptible to viral infection because of a defect in the IFN signaling pathway. Specifically, a subset of type I IFN-stimulated genes are not activated in the absence of IKKepsilon because the interferon-stimulated gene factor 3 complex (ISGF3) does not bind to promoter elements of the affected genes.