A Single Vaccination of Chimeric Bivalent Virus-Like Particle Vaccine Confers Protection Against H9N2 and H3N2 Avian Influenza in Commercial Broilers and Allows a Strategy of Differentiating Infected from Vaccinated Animals.

H9N2 and H3N2 are the two most important subtypes of low pathogenic avian influenza viruses (LPAIV) because of their ongoing threat to the global poultry industry and public health. Although commercially available inactivated H9N2 vaccines are widely used in the affected countries, endemic H9N2 avian influenza remains uncontrolled. In addition, there is no available avian H3N2 vaccine. Influenza virus-like particles (VLPs) are one of the most promising vaccine alternatives to traditional egg-based vaccines. In this study, to increase the immunogenic content of VLPs to reduce production costs, we developed chimeric bivalent VLPs (cbVLPs) co-displaying hemagglutinin (HA) and neuraminidase (NA) of H9N2 and H3N2 viruses with the Gag protein of bovine immunodeficiency virus (BIV) as the inner core using the Bac-to-Bac baculovirus expression system. The results showed that a single immunization of chickens with 40µg/0.3mL cbVLPs elicited an effective immune response and provided complete protection against H9N2 and H3N2 viruses. More importantly, cbVLPs with accompanying serological assays can successfully accomplish the strategy of differentiating infected animals from vaccinated animals (DIVA), making virus surveillance easier. Therefore, this cbVLP vaccine candidate would be a promising alternative to conventional vaccines, showing great potential for commercial development.

Activation of Dopamine 4 Receptor Subtype Enhances Gamma Oscillations in Hippocampal Slices of Aged Mice.

Aim: Neural network oscillation at gamma frequency band (γ oscillation, 30-80 Hz) is synchronized synaptic potentials important for higher brain processes and altered in normal aging. Recent studies indicate that activation of dopamine 4 receptor (DR4) enhanced hippocampal γ oscillation of young mice and fully recovered the impaired hippocampal synaptic plasticity of aged mice, we determined whether this receptor is involved in aging-related modulation of hippocampal γ oscillation. Methods: We recorded γ oscillations in the hippocampal CA3 region from young and aged C57bl6 mice and investigated the effects of dopamine and the selective dopamine receptor (DR) agonists on γ oscillation. Results: We first found that γ oscillation power (γ power) was reduced in aged mice compared to young mice, which was restored by exogenous application of dopamine (DA). Second, the selective agonists for different D1- and D2-type dopamine receptors increased γ power in young mice but had little or small effect in aged mice. Third, the D4 receptor (D4R) agonist PD168077 caused a large increase of γ power in aged mice but a small increase in young mice, and its effect is blocked by the highly specific D4R antagonist L-745,870 or largely reduced by a NMDAR antagonist. Fourth, D3R agonist had no effect on γ power of either young or aged mice. Conclusion: This study reveals DR subtype-mediated hippocampal γ oscillations is aging-related and DR4 activation restores the impaired γ oscillations in aged brain, and suggests that D4R is the potential target for the improvement of cognitive deficits related to the aging and aging-related diseases.

Enriched environment combined with fluoxetine ameliorates depression-like behaviors and hippocampal SYP expression in a rat CUS model.

Effects of enriched environment (EE) combined with fluoxetine in a chronic unpredictable stress (CUS) rat model were examined in our study. Thirty male Sprague-Dawley rats were randomly divided into control group, CUS group, CUS+EE group, CUS+fluoxetine group, and CUS+EE+fluoxetine group (n=six per group). Rats in the CUS group were bred under conditions of CUS and separation for 6 weeks; Control group animals were bred in group cages (three rats per cage) under standard laboratory conditions for 6 weeks; Rats in CUS+EE group, CUS+fluoxetine group, and CUS+EE+fluoxetine groups were bred under the conditions of CUS and separation for 6 weeks and had an intervention of EE, an oral gavage of fluoxetine, and an intervention of EE+oral gavage of fluoxetine, respectively, every day for the final 3 weeks. Every rat underwent a behavioral assessment at the beginning of the 1st week, at the end of the 3rd week and at the end of the 6th week. Behavioral assessments included sucrose water consumption, weight measurement, and an open field test (measuring horizontal moving distance, rearing behavior, and defecation). Finally, the level of synaptophysin expressed in the hippocampus was measured with immunohistochemistry. We found that EE, fluoxetine, and EE+fluoxetine all reversed the depression-like behaviors of CUS rats. The effect of EE+fluoxetine appeared to be superior to EE or fluoxetine alone; the expression level of synaptophysin in CA1, CA3, and DG of the hippocampus was decreased in CUS rats, however, exposure to EE, fluoxetine, and EE+fluoxetine all reversed this decrease.

Quetiapine mitigates the ethanol-induced oxidative stress in brain tissue, but not in the liver, of the rat.

Quetiapine, an atypical antipsychotic, has been employed to treat alcoholic patients with comorbid psychopathology. It was shown to scavenge hydroxyl radicals and to protect cultured cells from noxious effects of oxidative stress, a pathophysiological mechanism involved in the toxicity of alcohol. This study compared the redox status of the liver and the brain regions of prefrontal cortex, hippocampus, and cerebellum of rats treated with or without ethanol and quetiapine. Ethanol administration for 1 week induced oxidative stress in the liver and decreased the activity of glutathione peroxidase and total antioxidant capacity (TAC) there. Coadministration of quetiapine did not protect glutathione peroxidase and TAC in the liver against the noxious effect of ethanol, thus was unable to mitigate the ethanol-induced oxidative stress there. The ethanol-induced alteration in the redox status in the prefrontal cortex is mild, whereas the hippocampus and cerebellum are more susceptible to ethanol intoxication. For all the examined brain regions, coadministration of quetiapine exerted effective protection on the antioxidants catalase and total superoxide dismutase and on the TAC, thus completely blocking the ethanol-induced oxidative stress in these brain regions. These protective effects may explain the clinical observations that quetiapine reduced psychiatric symptoms intensity and maintained a good level of tolerability in chronic alcoholism with comorbid psychopathology.