Alpha hemolysin enhances the immune response by modulating dendritic cell differentiation via ADAM10-Notch signaling

In this study, we used PA0833 a novel protective antigen from Pseudomonas aeruginosa (P. aeruginosa) as the target antigen to evaluate the immune protective effect of the carrier antigen HlaH35A. The transcriptional profiling of bone marrow derived dendritic cells (BMDCs) from mice indicated that HlaH35A predominantly modulates DC maturation, cytokine production, and subsequent T-cell activation. Structural prediction (AlphaFold-Multimer) and fluorescence confocal microscopy confirmed that the specific binding of HlaH35A to ADAM10 enhanced its antigen uptake capacity in dendritic cells. Meanwhile, this interaction between HlaH35A and ADAM10 further activated the downstream Notch signaling transduction in dendritic cells. The HlaH35A-ADM10–Notch axis in cDCs drives their differentiation into type2 cDCs (cDC2s)—particularly the Notch2-dependent cDC2—rather than involving monocyte-derived dendritic cells. This process promotes Th17 and T follicular helper (Tfh) cell responses in draining lymph nodes, leading to elevated antigen-specific IgG1 titers and robust protection against acute Pseudomonas aeruginosa lung infection. Thus, HlaH35A enhances immune response against acute lung infection by modulating cDC differentiation to amplify Th17 and T follicular helper responses, providing a promising Th17/Tfh-oriented vaccine design strategy.