Identification of linear B epitopes of pertactin of Bordetella pertussisinduced by immunization with whole and acellular vaccine

tPertussis is a serious infectious disease of the respiratory tract caused by the gram-negative bacteria Bor-detella pertussis. There has been a reemergence of this disease within the population of several countriesthat have well established vaccination programs. Analyzes of clinical isolates suggest an antigenic diver-gence between the vaccine-based strains to the circulating strains. Although antibodies against P.69are involved in the observed protective immunity, the sequences recognized as antigenic determinantsin P.133, the precursor for P.69, P.3.4 and P.30, have not be determined. Here, the precise mapping oflinear B-cell epitopes within the predicted P.133 pertactin sequences was accomplished using the SPOT-synthesis of peptide arrays onto cellulose membranes and screening with murine sera generated byvaccination with either the Pertussis cellular (miPc) or Pertussis acellular (miPa) vaccine. A total of 23major epitopes were identified by sera from miPc vaccinated mice, while thirteen were identified bysera from miPa vaccinated mice. Of these epitopes, 12 epitopes were specifically identified by antibodiesproduced in response to the miPc vaccine and two were specific to the miPa vaccine. These epitopeswere distributed throughout the pertactin sequence but a significant number were concentrated to theP.30 Prn segment. An analysis of the epitope correlation homologies indicated that the variations fromthe observed mutations in pertactin would not constitute a problem using these vaccines. In addition,the mapping of epitopes demonstrated a higher number of linear B-cell epitopes immunized with the Pcvaccine than the Pa vaccine