Engineering of the influenza A virus NS1 protein became an attractive approach to the development of influenza vaccine vectors since it can tolerate large inserts of foreign proteins. However, influenza virus vectors expressing long foreign sequences from the NS1 open reading frame (ORF) are usually replication deficient in animals due to the abrogation of their NS1 protein function. In this study, we describe a bicistronic expression strategy based on the insertion of an overlapping UAAUG stop-start codon cassette into the NS gene, allowing the reinitiation of translation of a foreign sequence. Although the expression level of green fluorescent protein (GFP) from the newly created reading frame was significantly lower than that obtained previously from an influenza virus vector expressing GFP from the NS1 ORF, the bicistronic vector appeared to be replication competent in mice and showed outstanding genetic stability. All viral isolates derived from mouse lungs at 10 days postinfection were still capable of expressing GFP in infected cells. Utilizing this bicistronic approach, we constructed another recombinant influenza virus, allowing the secretion of biologically active human interleukin-2 (IL-2). Although this virus also replicated to high titers in mouse lungs, it did not display any mortality rate in infected animals, in contrast to control viruses. Moreover, the IL-2-expressing virus showed an enhanced CD8 ؉ response to viral antigens in mice after a single intranasal immunization. These results indicate that influenza viruses could be engineered for the expression of biologically active molecules such as cytokines for immune modulation purposes.

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Body ideals conveyed by the media and by body comparisons often result in body dissatisfaction, which can cause risky health behaviours and eating disorders, especially in adolescents. We conducted a meta-analytic review of existing school-based interventions designed to enhance media literacy in order to reduce body dissatisfaction and to promote a positive body image. We included controlled trials examining children and adolescents from grade five to nine (age 10–15 years) after a manual search and a comprehensive literature search using PsycINFO, Medline, Web of Science, and CENTRAL. We computed average weighted effect sizes (Hedges’ g) with the help of a random effects model and identified seventeen different programme evaluations with 7392 participants. We found a significantly larger effect on positive body image and media literacy in the intervention compared to control groups. However, heterogeneity was substantial for both outcomes. Results suggest that media literacy interventions have the potential to improve media literacy and reduce body dissatisfaction. Interventions that worked with the principle of induction of cognitive dissonance were the most effective.

Mature protein C of tick-borne encephalitis virus (TBEV) is cleaved from the polyprotein precursor by the viral NS2B/3 protease (NS2B/3pro). We showed previously that replacement of the NS2B/3pro cleavage site at the C terminus of protein C by the foot-and-mouth disease virus (FMDV) 2A StopGo sequence leads to the production of infectious virions. Here, we show that infectious virions can also be produced from a TBEV mutant bearing an inactivated 2A sequence through the expression of the FMDV 3C protease (3Cpro) either in cis or in trans (from a TBEV replicon). Cleavage at the C terminus of protein C depended on the catalytic activity of 3Cpro as well as on the presence of an optimized 3Cpro cleavage site. Passage of the TBEV mutants bearing a 3Cpro cleavage site either in the absence of 3Cpro or in the presence of a catalytically inactive 3Cpro led to the appearance of revertants in which protein C cleavage by NS2B/3pro had been regained. In three different revertants, a cleavage site for NS2B/3pro, namely RR*C, was now present, leading to an elongated protein C. Furthermore, two revertants acquired additional mutations in the C terminus of protein C, eliminating two basic residues. Although these latter mutants showed wild-type levels of early RNA synthesis, their foci were smaller and an accumulation of protein C in the cytoplasm was observed. These findings suggest a role of the positive charge of the C terminus of protein C for budding of the nucleocapsid and further support the notion that TBEV protein C is a multifunctional protein.