Nasal immunization with liposome particles containing the antigen PspA (Pneumococcal surface protein A) in the protection against pneumococcal colonization

• Grant number: 23/04825-6
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: September 01, 2023
• End date: August 31, 2024
• Field of knowledge: Biological Sciences - Microbiology - Applied Microbiology
• Principal Investigator: Eliane Namie Miyaji
• Grantee: Maria Luiza do Amaral Lyra Schnorrenberg
• Host Institution: Instituto Butantan. Secretaria da Saúde (São Paulo - Estado). São Paulo , SP, Brazil

Abstract

Infections caused by Streptococcus pneumoniae remain a major public health burden despite the use of polysaccharide conjugate vaccines (PCVs). PCVs led to an impressive reduction in invasive pneumococcal disease (pneumonia with bacteremia, bacteremia, meningitis) caused by serotypes included in the vaccine formulations. An increase both in colonization and invasive disease caused by non-vaccine serotypes was observed though. Furthermore, protection provided by PCVs against non-invasive disease, such as pneumonia without bacteremia and otitis media, is reported to be considerably lower. Thus strategies that induce serotype-independent at low cost are being pursued. Our group has been studying the use of Pneumococcal surface protein A (PspA) as a vaccine antigen. Recently, liposome particles encapsulating two PspA variants (LP PspA) were produced. The particles were spray-dried, forming nanocomposite microparticles carriers (NCMPs). LP/NCMP PspA was used for lung immunization of mice and induced high serum anti-PspA IgG levels and protection against lethal pneumococcal challenge. We now aim at testing LP/NCMP PspA for nasal immunization, analyzing induction of serum IgG, mucosal IgG and IgA and protection against nasopharyngeal colonization.