We have shown previously that expression library immunization is viable alternative approach to induce protective immunity against Neisseria meningitidis serogroup B. In this study we report that few rounds of library screening allow identification of protective pools of defined antigens. A previously reported protective meningococcal library (L8, with 600 clones) was screened and two sub-libraries of 95 clones each were selected based on the induction of bactericidal and protective antibodies in BALB/c mice. After sequence analysis of each clone within these sub-libraries, we identified a pool of 20 individual antigens that induced protective immune responses in mice against N. meningitidis infection, and the observed protection was associated with the induction of bactericidal antibodies. Our studies demonstrate for the first time that ELI combined with sequence analysis is a powerful and efficient tool for identification of candidate antigens for use in a meningococcal vaccine.
Bibliographical noteFunding Information:
We are grateful to Sergio Sifontes at Finlay Institute for providing facilities for experimental work with animals, especially on the establishment of the mice protection model. Research at the Health Protection Agency was funded by the UK Department of Health.
- Expression library
- Genomic immunization
- Neisseria meningitidis