Evaluation of PspA (Pneumococcal surface protein A) and PspC (Pneumococcal surface protein C) as antigens for the development of vaccines against Streptococcus pneumoniae

• Grant number: 07/05138-0
• Support Opportunities: Regular Research Grants
• Start date: May 01, 2008
• End date: April 30, 2010
• Field of knowledge: Biological Sciences - Biochemistry - Molecular Biology
• 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 the causative agent of life threatening diseases such as meningitis, pneumonia, bacteremia and sepsis, and also of common respiratory tract infections such as otitis media and sinusitis. The vaccines currently available are based on the antibody response against the capsular polysaccharide, but factors, such as the high cost of the vaccine prescribed for children, hinder their use by the public health system. An alternative to broaden coverage in a low cost vaccine is the identification of protective protein antigens common to all pneumococcal isolates.We propose the study of PspA (Pneumococcal surface protein A) and PspC (Pneumococcal surface protein C), which are virulence factors involved in invasive infection and colonization, respectively. PspA will be analyzed in immunization experiments using recombinant protein with adjuvants that induce a balanced Th1/Th2 response, which was previously shown by our group to be more appropriate in experiments using DNA vaccines. Immunization will be performed subcutaneously and the systemic response will be evaluated in an intraperitoneal challenge model. PspC will be administered intranasally as DNA vaccine using chitosan microspheres as vehicle and the induction of a mucosal immune response will be evaluated. The analysis of both antigens would thus cover different stages of pneumococcal infection. (AU)