Influence of Pneumococcal Surface Protein A (PspA) on the bactericidal effect of Lactoferrin on S. pneumoniae

• Grant number: 11/20245-2
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: December 01, 2011
• End date: November 30, 2012
• Field of knowledge: Biological Sciences - Microbiology - Applied Microbiology
• Principal Investigator: Michelle Darrieux Sampaio Bertoncini
• Grantee: Greiciely André de Oliveira
• Host Institution: Universidade São Francisco (USF). Campus Bragança Paulista. Bragança Paulista , SP, Brazil

Abstract

Streptococcus pneumoniae is a major cause of pneumonia, sepsis, meningitis and middle year infections, which affect mostly children under the age of five and immnunocompromised individuals.The currently available vaccines against this pathogen are based on polysaccharides, alone or conjugated to Carrier proteins, and present limited coverage due to the high diversity in capsular types among pneumococcal strains. Several pneumococcal proteins have been investigated as potential vaccine candidates against pneumococcal infections, with promising results. Pneumococcal surface protein A (PspA) is na exposed virulence factor capable of interacting with components of the innate immune system, preventing bacterial clearance. Lactoferrin is na important component of the innate immunity present in milk, mucosal and inflammatory secretions, which presents bactericidal, bacteriostatic and immunomodulatory effects. The presence of PspA, however, partially protects pneumococci against lactoferrin's bactericidal effects. So, the present work aims at studying the susceptibility of pneumococcus to lactoferrin, as well as the role of anti-PspA antibodies and recombinant proteins in the interaction between lactoferin and the bacterium.