Will Systems Biology Deliver Its Promise and Contribute to the Development of New or Improved Vaccines? Systems Biology Views of Vaccine Innate and Adaptive Immunity.

During the last decade, several high-throughput technologies have been applied to gather deeper understanding on the biological events elicited by vaccination. The main goal of systems biology is to integrate different sources of data and extract biologically meaningful information. This holistic approach has provided new insights on the impact that the innate immune status has on vaccine responsiveness. Other factors like chronic infections, age, microbiome, and metabolism can influence the outcome of vaccination, and systems biology offers unique opportunities to expand our understanding of their role on the immune response. However, a few challenges that still need to be overcome will be discussed.

Identification of new potential vaccine candidates against Chlamydia pneumoniae by multiple screenings.

Chlamydia are intracellular bacteria associated to serious human disease. A vaccine has proved difficult to obtain so far, and current opinions agree that multi-antigen combinations may be required to induce optimal protective responses. In order to identify new potential vaccine candidates, we recently screened the Chlamydia pneumoniae (Cpn) genome and described 53 recombinant proteins which elicited antibodies binding to purified Cpn cells. We now report that six proteins in this group can also induce in vitro neutralizing antibodies. Antibody specificity for the corresponding antigens was assessed by immunoblot analysis of 2DE Cpn protein maps. Furthermore, four of the six in vitro neutralizing antigens (Pmp2, Pmp10, OmpH-like and enolase) could inhibit Cpn dissemination in a hamster model. The results show that these Cpn proteins are immunoaccessible in infectious EBs, and recommend further investigation on their value as vaccine components.