Role of antibodies against PspA and PspC variants in the protection against Streptococcus pneumoniae

• Grant number: 18/25165-6
• Support Opportunities: Regular Research Grants
• Start date: April 01, 2019
• End date: July 31, 2021
• Field of knowledge: Biological Sciences - Microbiology - Applied Microbiology
• Principal Investigator: Eliane Namie Miyaji
• Grantee: Eliane Namie Miyaji
• Host Institution: Instituto Butantan. Secretaria da Saúde (São Paulo - Estado). São Paulo , SP, Brazil

Abstract

Streptococcus pneumoniae is an important human pathogen, causing diseases such as otitis media, sinusitis, pneumonia, bacteremia and meningitis. The polysaccharide conjugate vaccines are based on the induction of antibodies against the capsular polysaccharide and are very efficient in preventing invasive disease in children. Substitution by non-vaccine serotypes in colonization of the nasopharynx and in disease has taken place after introduction of these vaccines though. Elderly individuals are especially affected, showing high incidence of pneumococcal pneumonia. It is not known whether a lower immune response to specific pneumococcal antigens is correlated with this higher susceptibility. Previous work has shown evidence that lower antibody levels against PspA (Pneumococcal surface protein A) and PspC (Pneumococcal surface protein C) would correlate with increase in colonization. Both antigens show variability among pneumococcal isolates. PspA has been classified in 6 clades, whereas PspC has 11 groups. In this project, antibody levels against different variants of PspA and PspC will be evaluated in serum samples from individuals with more than 50 years of age and compared with levels from young adults. IgG anti-PspA and anti-PspC will be purified from intravenous immunoglobulin preparations (IVIg) and used in experiments to evaluate passive protection of mice against colonization and lethal challenge models. The possible association between lower antibody levels against different PspA and PspC variants with the increase in susceptibility to pneumococcal colonization and infection would support the use of these antigens as vaccines. (AU)

Scientific publications

(References retrieved automatically from Web of Science and SciELO through information on FAPESP grants and their corresponding numbers as mentioned in the publications by the authors)

OLIVEIRA, GIULIANA S.; OLIVEIRA, MARIA LEONOR S.; MIYAJI, ELIANE N.; RODRIGUES, TASSON C.. Pneumococcal Vaccines: Past Findings, Present Work, and Future Strategies. VACCINES, v. 9, n. 11, NOV 2021. (17/26090-7, 18/25165-6, 19/15961-2, 19/06190-2, 21/04996-0)

ARAUJO, ADRIANO P.; COLICHIO, GABRIELA B. C.; OLIVEIRA, MARIA LEONOR S.; GERMAN, ESTHER; NIKOLAOU, ELISSAVET; CHEN, TAO; ADLER, HUGH; FERREIRA, DANIELA M.; MIYAJI, ELIANE N.. Serum levels of anti-PspA and anti-PspC IgG decrease with age and do not correlate with susceptibility to experimental human pneumococcal colonization. PLoS One, v. 16, n. 2, FEB 12 2021. (18/25165-6)