Production and characterization of liposomal nanoparticles containing pneumococcal protein antigens for pulmonary immunization against pneumococcal pneumonia

• Grant number: 19/10497-6
• Support Opportunities: Scholarships abroad - Research Internship - Doctorate
• Start date: September 04, 2019
• End date: February 28, 2020
• Field of knowledge: Biological Sciences - Microbiology - Applied Microbiology
• Principal Investigator: Eliane Namie Miyaji
• Grantee: Tasson da Costa Rodrigues
• Supervisor: Imran Saleem
• Host Institution: Instituto Butantan. Secretaria da Saúde (São Paulo - Estado). São Paulo , SP, Brazil
• Institution abroad: Liverpool John Moores University (LJMU), England
• Associated to the scholarship: 17/26090-7 - Nanoparticle pulmonary vaccine formulation based on lipossomes containing protein antigens from Streptococcus pneumoniae, BP.DR

Abstract

Streptococcus pneumoniae, or pneumococcus, is a component of human microbiota, but in some cases it can cause serious diseases. Vaccines are the most important way to control pneumococcal infections and there are currently two licensed vaccines based on capsular polysaccharides (PS). The pneumococcal conjugate vaccines (PCVs) led to an impressive decrease in the cases of invasive pneumococcal diseases (IPD) in immunized individuals and herd effect protection in non-immunized people was also observed. On the other hand, an increase in the number of IPD cases caused by serotypes not included in the PCVs was reported. Besides that, PCV effectiveness against non-invasive disease, including non-bacteremic pneumonia, is reported to be lower than against IPD. A new generation of serotype-independent vaccines could improve protection against pneumococcal infections. Pneumococcal surface protein A (PspA) is an important vaccine candidate. PspA shows some sequence diversity and it is classified in family 1 (clades 1 and 2), family 2 (clades 3, 4 and 5) and family 3 (clade 6). Since the majority of strains express PspA from families 1 or 2, a broad-coverage vaccine should include proteins from both families. We propose to develop liposomal nanoparticles (LNP) containing PspA from families 1 and 2 (PspA1 and PspA4Pro) for pulmonary immunization against pneumococcal pneumonia. Recombinant PspA4Pro has already been produced by our group in large quantities with high purity and low endotoxin content. During the first year of the PhD program at Instituto Butantan, the experiments for obtaining PspA1 were initiated and we plan to have the purified protein in the next couple of months. The formulation of LNPs containing PspA1 and PspA4Pro will be incorporated within dry powder microcarrier system, nanocomposite microparticle carriers (LNP/NCMP), suitable for lung delivery via inhalation during the internship in Dr Imran Saleem's laboratory at Liverpool John Moores University. The LNPs will be characterized by determination of mean particle size, polydispersity index and zeta-potential. In vitro studies will determine release kinetics and also protein stability. Cell toxicity,uptake by dendritic cells and upregulation of cell surface markers will be evaluated. Finally, in vitro aerosolization studies will determine deposition of LNP/NCMPs in the different lung compartments. The final goal of the project is to immunize mice with the LNP/NCMPs to evaluate the immune response and protection, which will be done back at Instituto Butantan during the final 20 months of the PhD program. (AU)