Characterization of the key antigenic components of pertussis vaccine based on outer membrane vesicles.

ORMAZÁBAL M; BARTEL E; GAILLARD ME; BOTTERO D; ERREA A; ZURITA ME; MORENO G; RUMBO M; CASTUMA C; FLORES D; MARTÍN MJ; HOZBOR D

VACCINE

ELSEVIER SCI LTD

Lugar: Amsterdam; Año: 2014

0264-410X

tPertussis has resurged during the last two decades in different countries. In particular in the 2010?2013period large outbreaks were detected in US, Australia, UK and The Netherlands with significant mortalityin infants. The epidemiological situation of pertussis points out the need to develop new vaccines andin this regard we previously developed a new vaccine based on outer membrane vesicles (OMVs) whichhave been shown to be safe and to induce protection in mice. Here we have further investigated theproperties of OMVs vaccines; in particular we studied the contribution of pertussis toxin (PTx) and per-tactin (Prn) in OMVs-mediated protection against pertussis. PTx-deficient OMVs and Prn-deficient OMVswere obtained from defective Bordetella pertussis mutants. The absence of PTx or Prn did compromisethe protective capacity of the OMVs formulated as Tdap vaccine. Whereas the protective efficacy of thePTx-deficient OMVs in mice was comparable to Prn-deficient OMVs, the protective capacity of both ofthem was significantly impaired when it was compared with the wild type OMVs. Interestingly, usingOMVs obtained from a B. pertussis strain which does not express any of the virulence factors but expressesthe avirulent phenotype; we observed that the protective ability of such OMVs was lower than that ofOMVs obtained from virulent B. pertussis phase. However, it was surprising that although the protectivecapacity of avirulent OMVs was lower, they were still protective in the used mice model. These resultsallow us to hypothesize that OMVs from avirulent phase shares protective components with all OMVsassayed. Using an immune proteomic strategy we identified some common components that could playan important role in protection against pertussis.