Chicken infectious anemia (CIA) is a poultry disease that causes huge economic losses in the poultry industry worldwide. Commercially available CIA vaccines are derived from wild-type chicken anemia viruses (CAVs) by serial passage in cells or chicken embryos. However, these vaccinal viruses are not completely attenuated; therefore, they can be transmitted vertically and horizontally, and may induce clinical symptoms in young birds. In this study, we sought to eliminate these issues by developing a subunit vaccine exploiting the CAV structural proteins, engineering recombinant baculovirus-infected Spodoptera frugiperda (Sf9) cells that contained both the viral protein 1 (VP1) and VP2 of CAV. Moreover, we produced single-chain chicken interleukin-12 (chIL-12) in the same system, to serve as an adjuvant. The recombinant VP1 was recognized by chicken anti-CAV polyclonal antibodies in Western blotting and immunofluorescence assays, and the bioactivity of the recombinant chIL-12 was confirmed by stimulating interferon-γ (IFN-γ) secretion in chicken splenocytes. Furthermore, the ability of the recombinant VP1 to generate self-assembling virus-like particles (VLPs) was confirmed by transmission electron microscopy. Specific pathogen-free (SPF) chickens inoculated with VLPs and co-administered the recombinant chIL-12 induced high CAV-specific antibodies and cell-mediated immunity. Taken together, the VLPs produced by the baculovirus expression system have the potential to be a safe and effective CIA vaccine. Finally, we demonstrated the utility of recombinant chIL-12 as an adjuvant for poultry vaccine development.

Avian influenza virus (AIV) can cause severe diseases in poultry worldwide. H6N1 AIV was the dominant enzootic subtype in 1985 in the chicken farms of Taiwan until the initial outbreak of a low pathogenic avian influenza (LPAI) H5N2 virus in 2003; thereafter, this and other LPAIs have been sporadically detected. In 2015, the outbreak of three novel H5Nx viruses of highly pathogenic avian influenza (HPAI) emerged and devastated Taiwanese chicken and waterfowl industries. The mechanism of variation in pathogenicity among these viruses is unclear; but, in light of the many biological functions of viral non-structural protein 1 (NS1), including interferon (IFN) antagonist and host range determinant, we hypothesized that NS genetic diversity contributes to AIV pathogenesis. To determine the impact of NS1 variants on viral infection dynamics, we established a reverse genetics system with the genetic backbone of the enzootic Taiwanese H6N1 for generation of reassortant AIVs carrying exogenous NS segments of three different Taiwanese H5N2 strains. We observed distinct cellular distributions of NS1 among the reassortant viruses. Moreover, exchange of the NS segment significantly influenced growth kinetics and induction of cytokines [IFN-α, IFN-β, and tumor necrosis factor alpha (TNF-α)] in an NS1-and host-specific manner. The impact of NS1 variants on viral replication appears related to their synergic effects on viral RNA-dependent RNA polymerase activity and IFN response. With these approaches, we revealed that NS1 is a key factor responsible for the diverse characteristics of AIVs in Taiwan.

A polymer blend system F81–x :SY x based on poly­(9,9-dioctylfluorene) (F8) from the family of polyfluorenes (PFO) and a poly­(para-phenylenevinylene) (PPV) derivative superyellow (SY) shows highly efficient energy transfer from F8 host to SY guest molecules. This has been realized due to a strong overlap between F8 photoemission and SY photoabsorption spectra and negligibly low self-absorption. The steady-state and time-correlated spectroscopic measurements show an increased photoluminescence quantum efficiency (PLQE) and lifetime (τ) of SY, with an opposite trend of decreasing PLQE and τ of F8 excitons with increasing SY concentration, suggesting the Förster resonance energy transfer (FRET) to be the main decay pathway in the proposed system. The systematic study of the exciton dynamics shows a complete energy transfer at 10% of SY in the F8 host matrix and a Förster radius of ∼6.3 nm. The polymer blend system exhibits low laser and amplified spontaneous emission thresholds. An ultrahigh efficiency (27 cd·A–1) in F81–x :SY x based light emitting diodes (LED) has been realized due to the intrinsic property of a well-balanced charge transport within the emissive layer. The dual pathway, that is, the efficient energy transfer between the blended molecules via resonance energy transfer, and the charge-traps-assisted balanced transport makes the system promising for achieving highly efficient devices and a potential candidate for lasing applications.

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