Final Report Summary - FLU-MAL VLP (Chimeric Influenza-VLP used as vaccine platform for presentation of foreign antigens - Application to Malaria antigens) The goal of the FLUMAL-VLP project was to engineer a new antigen delivery system, further used as a tool for vaccine discovery for emerging, chronic disease or polymorphism pathogens. This antigen delivery platform is based on influenza Virus like particles which are known to be efficient immunogens. Its first application, included in this project, is malaria antigen evaluation.This project addresses an infection of global Public Health importance. Malaria infects at least 150 million people worldwide and is responsible for the death of 650 000 to 900 000 person per year. According to programs launched in 2000 to eradicate malaria (Roll Back Malaria, PATH Malaria Vaccine Initiative), childhood immunization remains the best strategy to control malaria and a new generation of malaria vaccine is still an urgent need. Our strategy could allow to answer at the same time all the challenges that malaria vaccine developers are currently facing, ie. (i) target both humoral and cellular immune responses, (ii) present multiple antigens at the same time, and (iii) screen of multiple antigens.The technical work plan envisioned for the project was the following:- Select and optimize the construction of the chimeric influenza-VLP platform to achieve best immunogenicity of the VLP particles.- Select and optimize the best process to achieve high yield production and purity of the chimeric influenza-VLP platform.- Successful application to antigens, in this case malaria liver and blood-stage antigens from P. falciparum and P. yoelii which presents weak immunogenicity when injected as recombinant proteins or peptides.Activities & Results:The achievements of this project are the results of a strong collaboration between the three laboratories experts in their disciplines, Virpath laboratory from French University of Lyon (Influenza virus biology, production and characterization), Canadian laboratory from Mc Gill university (Cell culture processes) and A Star Singaporian laboratory (Immunopathology of malaria parasites).Production and purification methods of influenza-VLPs on mammalian cells were successfully transferred from Canadian partner to French laboratory. On these bases, different processes were compared and optimized in order to select the most efficient steps to achieve best productivity and purity of the FLU VLP material generated.Specific DNA plasmid and baculovirus BacMam were designed and constructed for the development of the best VLP particles platform for antigen delivery. Evaluation of the best VLP composition and influenza strain for the VLP backbone were realized. Based on best constructions, optimal process selected and composition of the influenza VLP, the consortium was allowed to produce lots of influenza VLPs with different productive cells at larger scale. These VLPs will now be used as antigen carrier for development of anti-malaria vaccination strategy design.Malaria antigen target were identified by the A*Star Singapore laboratory partner. Four malaria peptides sequences of 12 AA identified for B-cell and T-cell immune response were selected. Insertion sites were identified on the HA influenza protein. Based on best production and process selected for FLU-VLP production, construct will be realized inserting malaria antigens in selected sites of HA protein and produced as chimeric FLUMAL-VLPs.In parallel, this project aimed to develop specific quantification and characterization strategies of VLP lots. Indeed, basic detection and quantification techniques used for influenza-VLP were transferred from Canadian laboratory to VirPath laboratory but, as the production level are classically quite low, additional quantification techniques were developed in-house or in collaboration. Some new technologies are still under development for a fast and specific detection of influenza-VLP.Although the project was facing some challenges, and did not yet achieved all the milestones planned, most of the foreseen steps were achieved and the consortium remain active with the plan to produce a first lot of FLU-MAL VLP vaccine candidate to be tested in pre-clinical trials within a year.Moreover, VLP technology is one of the most promising approaches for vaccine development field. This is why, several pharmaceutical industries, have dedicated efforts to accelerate the development of VLP-based products and clinical trials are now ongoing for a large range of targets, with either enveloped or non-enveloped VLPs. Consequently, more than proposing a new vaccine platform, this project also aimed to develop additional knowledge and expertise within the European academic research, to further support the characterization, the quantification, and the development of such type of vaccines.As measureable results, at this stage of the project, three scientific publications are in preparation; one scientific review on current stage of production and purification processes development for influenza-VLP, one publication on the comparative study of influenza VLPs production on insect and human cell platform and one publication on HPLC quantification of Virus-Like Particles. Additionally, such project allowed strengthening the international network between French and Canadian or Singaporean research centres allowing the emergence of other on-going projects and potential future collaborations.
