Natural development of antibodies to pneumococcal proteins PsaA, PspA and Ply in relation to pneumococcal contacts
Dr Helena Kayhty
- Start Date:
01 January 2001
National Public Health Institute, Helsinki, Finland
Pneumococcus is an important agent in meningitis and other invasive infections. Pneumococcal conjugate vaccines are efficacious against systemic and local pneumococcal infections but there could be problems in their introduction into world-wide use. Several pneumococcal proteins (e.g. PspA, PsaA and pneumolysin) have been identified as promising vaccine candidates but very little is known about the role of antibodies to these proteins in humans.
We have so far shown that even small children develop antibodies to these proteins and that the development is related to pneumococcal contacts. Clear protein specific differences were evident; PsaA antibodies were already seen at 6 weeks of age while development of anti-PspA antibodies seemed to happen much later in life. Now we propose to study further the reasons for and consequences of these differences. Furthermore, we want to determine the functional activity of naturally induced anti-PspA, -PsaA and -Ply. We will use serum material from two carefully planned studies that follow pneumococcal contacts and antibody development in several (up to 10) consecutive samples. Antibodies to Pnc proteins are measured by EIA by using recombinant E. coli PspA, PsaA and pneumolysin. The functional activity of antibodies will be measured by hemolysis inhibition micro assay (pneumolysin) and opsonophagocytosis assay (PsaA and PspA). The results of this study will be important for understanding the role of antipneumococcal protein antibodies in defence against pneumococcal infection and are thus fundamental for pneumococcal protein vaccine development.
Results from this study have been published in a scientific journal as follows:
Holmlund E, Quiambao B, Ollgren J, Nohynek H, Kayhty H.
Development of natural antibodies to pneumococcal surface protein A, pneumococcal surface adhesin A and pneumolysin in Filipino pregnant women and their infants in relation to pneumococcal carriage.
Vaccine 2006 Jan 9;24(1):57-65.