Outer Membrane Vesicles from Bordetella pertussis triggers inflammasome canonical and non-canonical activation

ERIKA GUIMARAES; SERGIO COSTA OLIVEIRA; MARCO TULIO GOMES; DANIELA F HOZBOR; MAIA L ELIZAGARAY; MARTÍN RUMBO; GRISELDA N MORENO

Guarujá

Simposio; Keystone Symposia: "Why So Many Ways to Die? Apoptosis, Necroptosis, Pyroptosis and Beyond (T3)"; 2019

Keystone

The resurgence of pertussis in different countries has urged the development of new vaccines that could overcome the weakness of current vaccines. We have characterized a vaccine candidate based on outer membrane vesicles derived from Bordetella pertussis (OMVsBp). The OMVsBp has shown to be safe and able to induce protection, mixed Th1/Th17/Th2 profile, lung resident memory CD4 T cells, and a robust antibody response in the murine model. Recent advances have shown the interplay between the inflammasome activation and the adaptive immune response. This pathway could determine T cell polarization to a Th17 protective profile. Inflammasome activation can be via caspase1 (canonical) or caspase 1/11 (non-canonical: based on intracellular sensing of LPS/LOS). We evaluated inflammasome activation triggered by OMVsBp using Bone Marrow Derived Macrophages (BMDM) from C57BL/6, Casp11-, Casp1/11-, GSDMD-, GBPchr3- and NLRP3- mice. The BMDM were stimulated with 400ng of OMVsBp, free BpLOS or transfected BpLOS. Levels of cytokine IL-1β was measured in culture supernatant by ELISA. We observed a significantly (p≤0.001) decrease in IL-1β secretion in all cultures from KOs mice under OMVsBp stimulation, showing a dependence on canonical and non-canonical pathways of inflammasome activation. For the BpL0S transfection, we saw the same but less dependence on GBPchr3- (p≤0.01), suggesting a role of these proteins to allow LPS recognition by innate receptors. There is no IL-1β secretion in culture medium for free BpLPS stimulation. We tested IL-1α secretion in culture media as a measure of GSDMD pore formation and found a dependence on Casp11 and GSDMD (p≤0.001) unlike with NLRP3-, confirming data on the field where IL-1α depends on Casp11/GSDMD. These results show that our vaccine candidate activates both inflammasome pathways. This might be one of the mechanisms from the innate immune system that orchestrates the adaptive immune response responsible of the protective capacity of our vaccine.