Persistence of Bordetella pertussis as aggregates within nasal tissues of aPV immunized mice prevents recruitment of Siglec-F+ neutrophils and bacterial clearance

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Presentation Time: 08:15 AM - 08:30 AM
Abstract ID: 4679 - B

Presenting Author:
Jesse M Hall , Post-Doctoral Scholar at Ohio State Univ.

Abstract:

Despite global vaccination, pertussis caused by Bordetella pertussis (Bp) is resurging. One explanation for the increased incidence of infections in immunized individuals is the inability of acellular pertussis vaccines (aPV) to clear Bp from the nose. To understand the host and bacterial mechanisms that contribute to Bp persistence, we evaluated bacterial localization and the immune response in the nasal associated tissues (NT) of naïve and immunized mice following Bp challenge. Bp resided in the NT of naïve and aPV-immunized mice as aggregates, while aggregate formation was not observed in mice immunized with a whole cell pertussis vaccine (wPV). CXCL1 was detected in the NT of wPV immunized mice. Siglec-F+ neutrophils, critical for eliminating Bp from the nose, were elicited at higher levels in wPV immunized mice compared to aPV immunized mice. Together, our data suggest that the T_H2 polarized immune response generated by aPV vaccination permitted Bp to persist in the NT by establishing a niche in epithelial tissues that formed a protective barrier to infiltration of immune effectors. In contrast, immune responses generated by wPV, including the neutrophil chemoattractant CXCL1, recruited neutrophils that rapidly eliminated the bacterial burden and prevented establishment of a nasal reservoir. Overall, development of a nasal Bp reservoir and subsequent transmission may be prevented by a modified aPV that elicits a T_H1/T_H17 phenotype generated by wPV.