A New Master Donor Virus for the Development of Live-Attenuated Influenza B Virus Vaccines

Abstract

Influenza B viruses (IBV) circulate annually, with young children, the elderly and immunocompromised individuals being at high risk. Yearly vaccinations are recommended to protect against seasonally influenza viruses, including IBV. Live attenuated influenza vaccines (LAIV) provide the unique opportunity for direct exposure to the antigenically variable surface glycoproteins as well as the more conserved internal components. Ideally, LAIV Master Donor Viruses (MDV) should accurately reflect seasonal influenza strains. Unfortunately, the continuous evolution of IBV have led to significant changes in conserved epitopes compared to the IBV MDV based on B/Ann Arbor/1/1966 strain. Here, we propose a recent influenza B/Brisbane/60/2008 as an efficacious MDV alternative, as its internal viral proteins more accurately reflect those of circulating IBV strains. We introduced the mutations responsible for the temperature sensitive (ts), cold adapted (ca) and attenuated (att) phenotype of B/Ann Arbor/1/1966 MDV LAIV into B/Brisbane/60/2008 to generate a new MDV LAIV. In vitro and in vivo analysis demonstrated that the mutations responsible of the ts, ca, and att phenotype of B/Ann Arbor/1/1966 MDV LAIV were able to infer the same phenotype to B/Brisbane/60/2008, demonstrating its potential as a new MDV for the development of LAIV to protect against contemporary IBV strains.

Development of a Mouse Model to Explore CD4 T Cell Specificity, Phenotype, and Recruitment to the Lung after Influenza B Infection

“…However, these viruses are now understood to cause significant morbidity and mortality, particularly in children, accounting for almost 25% of influenza infections each year and over 50% of influenza-related deaths in children (reviewed in [39,41,42,98]). For these reasons, there is increasing attention to influenza B vaccines, which have become quadrivalent in recent years to the two different lineages of influenza B that tend to co-circulate [99,100], as well as the development of novel vaccine candidates for influenza B [101][102][103] and novel therapeutic reagents [104][105][106]. The studies here are important for future clinical studies relevant to human disease.…”

“…Often, the first step in developing novel vaccines and anti-viral reagents is the establishment of preclinical mouse models that allow rapid and well-controlled analyses of efficacy. There have been a number of recent studies of this type [43,[101][102][103][104][105][106][107][108][109]. However, there have been limited analyses of the impact on the antigen-specific adaptive responses and in particular CD4 T cell responses, which are the critical regulators of both B cell and CD8 T cell immunity.…”

Silencing Transcription from an Influenza Reverse Genetics Plasmid in E. coli Enhances Gene Stability

“…Influenza A virus (IAV) RG systems have been instrumental for addressing key questions about the viral life cycle, virus evolution, and for developing new influenza vaccine strategies. − The first systems involved the transfection of twelve or sixteen plasmids into mammalian cells; ,− eight human RNA polymerase I (Pol I) promoter-driven plasmids for transcribing the eight negative-sense viral RNA (vRNA) gene segments and eight or four RNA polymerase II (Pol II) promoter-driven plasmids for transcribing either all the viral mRNAs or only the mRNAs encoding for the nucleoprotein (NP) and the three polymerase subunits. These initial plasmids were modified further to create an elegant bidirectional (ambisense) construct that can efficiently generate IAVs from eight plasmids. , In this system, each pHW plasmid contains one IAV gene segment flanked by a Pol I and a Pol II promoter resulting in the transcription of both vRNAs and mRNAs from all eight gene segments following co-transfection into 293T cells.…”