Comparison of recombinant and native pertactin of Bordetella pertussis

Bordetella pertussis pertactin (Prn) is an important attachment factor and protective immunogen, which serves as a component in most acellular pertussis vaccines (APVs). Here, we over-expressed recombinant Prn (r-Prn) without an affinity tag using an Escherichia coli expression system. Compared to the native Prn (n-Prn) from B. pertussis, the recombinant protein showed a comparable reactivity in Western blotting and ELISA as well as a similar structure as analyzed by circular dichroism, fluorescence spectroscopy and size-exclusion chromatography. Furthermore, parenteral immunization of mice with native or r-Prn produced a similar increase in serum anti-Prn antibodies and similar protective activity following aerosol challenge. Our results indicate that the recombinant protein approach may be useful for developing a potential component of APVs as well as an antigen material which can be used in both clinical epidemiological evaluation and laboratory vaccine evaluation studies. Moreover, these studies also provide further evidence for the role of Prn in pertussis immunity.