biostudies-literatureUnknownBrangulis KNIAID NIH HHSThe quality of protective immunity plays a critical role in modulating vaccine efficacy, with native antigens often not able to trigger sufficiently strong immune responses for pathogen killing. This warrants creation of structure-based vaccine design, leveraging high-resolution antigen structures for mutagenesis to improve protein stability and efficient immunization strategies. Here, we investigated the mechanisms underlying structure-based vaccine design using CspZ-YA, a vaccine antigen from <i>Borrelia burgdorferi</i>, the bacteria causing Lyme disease (LD), the most common vector-borne disease in the Northern Hemisphere. Compared to wild-type CspZ-YA, we found CspZ-YA_I183Y and CspZ-YA_C187S required lower immunization frequency to protect mice from LD-associated manifestations and bacterial colonization. We observed indistinguishable human and mouse antigenicity between wild-type and mutant CspZ-YA proteins after native infection or active immunization. This supports our newly generated, high-resolution structures of CspZ-YA_I183Y and CspZ-YA_C187S, showing no altered surface epitopes after mutagenesis. However, CspZ-YA_I183Y and CspZ-YA_C187S favored the interactions between helices H and I, consistent with their elevated thermostability. Such findings are further strengthened by increasing ability of protective CspZ-YA monoclonal antibodies in binding to CspZ-YA at a physiological temperature (37°C). Overall, this study demonstrated enhanced intramolecular interactions improved long-term stability of antigens while maintaining protective epitopes, providing a mechanism for structure-based vaccine design. These findings can ultimately be extended to other vaccine antigens against newly emerging pathogens for the improvement of protective immunity.bioRxiv : the preprint server for biology2024.10.23.619738https://www.ebi.ac.uk/biostudies/studies/S-EPMC11565809biostudies-literatureMechanistic insights into structure-based design of a Lyme disease subunit vaccine.PMC11565809R01 AI154542R21 AI144891R01 AI181746R44 AI152954Wang APal UHsieh CLLee JBottazzi MEMalfetano JLin YPMarcinkiewicz ALYang XLiu ZBrangulis KStrych UChen WHChen YLfalseMechanistic insights into structure-based design of a Lyme disease subunit vaccine.The quality of protective immunity plays a critical role in modulating vaccine efficacy, with native antigens often not able to trigger sufficiently strong immune responses for pathogen killing. This warrants creation of structure-based vaccine design, leveraging high-resolution antigen structures for mutagenesis to improve protein stability and efficient immunization strategies. Here, we investigated the mechanisms underlying structure-based vaccine design using CspZ-YA, a vaccine antigen from <i>Borrelia burgdorferi</i>, the bacteria causing Lyme disease (LD), the most common vector-borne disease in the Northern Hemisphere. Compared to wild-type CspZ-YA, we found CspZ-YA_I183Y and CspZ-YA_C187S required lower immunization frequency to protect mice from LD-associated manifestations and bacterial colonization. We observed indistinguishable human and mouse antigenicity between wild-type and mutant CspZ-YA proteins after native infection or active immunization. This supports our newly generated, high-resolution structures of CspZ-YA_I183Y and CspZ-YA_C187S, showing no altered surface epitopes after mutagenesis. However, CspZ-YA_I183Y and CspZ-YA_C187S favored the interactions between helices H and I, consistent with their elevated thermostability. Such findings are further strengthened by increasing ability of protective CspZ-YA monoclonal antibodies in binding to CspZ-YA at a physiological temperature (37°C). Overall, this study demonstrated enhanced intramolecular interactions improved long-term stability of antigens while maintaining protective epitopes, providing a mechanism for structure-based vaccine design. These findings can ultimately be extended to other vaccine antigens against newly emerging pathogens for the improvement of protective immunity.2024-01-01T00:00:00Z2024 Oct2026-05-26T20:09:53.972Z2025-04-21T21:43:46.393ZS-EPMC115658093955403610.1101/2024.10.23.619738