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

Abstract

Pertussis is a serious infectious disease of the respiratory tract caused by the gram-negative bacteria Bordetella pertussis. There has been a reemergence of this disease within the population of several countries that have well established vaccination programs. Analyzes of clinical isolates suggest an antigenic divergence between the vaccine-based strains to the circulating strains. Although antibodies against P.69 are involved in the observed protective immunity, the sequences recognized as antigenic determinants in P.133, the precursor for P.69, P.3.4 and P.30, have not be determined. Here, the precise mapping of linear 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 by vaccination with either the Pertussis cellular (miPc) or Pertussis acellular (miPa) vaccine. A total of 23 major epitopes were identified by sera from miPc vaccinated mice, while thirteen were identified by sera from miPa vaccinated mice. Of these epitopes, 12 epitopes were specifically identified by antibodies produced in response to the miPc vaccine and two were specific to the miPa vaccine. These epitopes were distributed throughout the pertactin sequence but a significant number were concentrated to the P.30 Prn segment. An analysis of the epitope correlation homologies indicated that the variations from the 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 Pc vaccine than the Pa vaccine.

Epitope Mapping of the Diphtheria Toxin and Development of an ELISA-Specific Diagnostic Assay

“…To obtain mice sera, thirty-eight NIH Swiss mice (12-16 g) were immunized as described previously [50] with wDTP vaccine reconstituted with saline and 2 IU (defined by the Brazilian National Immunization Program) administered in 0.5 ml with an interval of 21 days. Sera were collected one week after the last inoculation and stored at -20 •C.…”

“…Chemiluminescent signals were detected on an Odyssey FC (LI-COR Bioscience) using the same conditions described previously [50] with minor modifications. Briefly, a digital image file was generated at a resolution of 5 MP and the signal intensities quantified using the TotalLab TL100 (v 2009, Nonlinear Dynamics, USA) software.…”

Preventive and Protective Properties of Pertussis Vaccines: Current Situation and Future Challenges

“…Additionally, using refined techniques of peptide microarray, it has been demonstrated that qualitative differences within the humoral response of individuals vaccinated with wPV and aPVs exist. Using a microarray technique, it was shown that animals immunized with wPV recognize qualitatively a major number of B epitopes in the PTx than mice immunized with aPV [49]. Another study using a similar approach compared the recognition pattern of sera from children immunized with different pertussis vaccines (17 B. pertussis proteins) and concluded that 11% of the individuals displayed a private humoral response [50].…”

New approaches to understanding the immune response to vaccination and infection

“…Peptide arrays were successfully used in the identification of specific epitopes on Toxoplasma gondii antigens, leading to an improvement in the serological diagnosis of toxoplasmosis [110]; to study the antibody diversity against linear HIV-1 sequences in HIV-1-infected humans and HIV-1-vaccinated humans [111]; to profile the pre-existing antibody repertoire to the seasonal influenza vaccine thus enabling to distinguish immune from pre-immune samples in young and older donors [6, 112, 113]; in Valley Fever patients [114]; to identify linear B epitopes of pertactin of Bordetella pertussis induced by immunization with whole and acellular vaccine in mice [115]; and to identify strain-specific B-cell epitopes in Trypanosoma cruzi [102]. More recently photolithography was used to synthesize arrays (Intel arrays) that contained every possible overlapping peptide within a linear protein sequence covering the N-terminal tail of human histone H2B individuals with SLE [116].…”