Laboratorio VacSal, Instituto de Biotecnología y Biología Molecular (IBBM), Facultad de Ciencias Exactas, Universidad Nacional de La Plata, CCT-CONICET La Plata, La Plata, Argentina.
Instituto de Biotecnología y Biología Molecular (IBBM), Facultad de Ciencias Exactas, Universidad Nacional de La Plata, CCT-CONICET La Plata, La Plata, Argentina.
Front Immunol. 2021 Sep 15;12:730434. doi: 10.3389/fimmu.2021.730434. eCollection 2021.
Outer membrane vesicles (OMV) derived from the etiologic agent of the resurgent disease called pertussis-are safe and effective in preventing bacterial colonization in the lungs of immunized mice. Vaccine formulations containing those OMV are capable of inducing a mixed Th1/Th2/Th17 profile, but even more interestingly, they may induce a tissue-resident memory immune response. This immune response is recommended for the new generation of pertussis-vaccines that must be developed to overcome the weaknesses of current commercial acellular vaccines (second-generation of pertussis vaccine). The third-generation of pertussis vaccine should also deal with infections caused by bacteria that currently circulate in the population and are phenotypically and genotypically different [in particular those deficient in the expression of pertactin antigen, PRN(-)] from those that circulated in the past. Here we evaluated the protective capacity of OMV derived from bacteria grown in biofilm, since it was observed that, by difference with older culture collection vaccine strains, circulating clinical isolates possess higher capacity for this lifestyle. Therefore, we performed studies with a clinical isolate with good biofilm-forming capacity. Biofilm lifestyle was confirmed by both scanning electron microscopy and proteomics. While scanning electron microscopy revealed typical biofilm structures in these cultures, BipA, fimbria, and other adhesins described as typical of the biofilm lifestyle were overexpressed in the biofilm culture in comparison with planktonic culture. OMV derived from biofilm (OMVbiof) or planktonic lifestyle (OMVplank) were used to formulate vaccines to compare their immunogenicity and protective capacities against infection with PRN(+) or PRN(-) clinical isolates. Using the mouse protection model, we detected that OMVbiof-vaccine was more immunogenic than OMVplank-vaccine in terms of both specific antibody titers and quality, since OMVbiof-vaccine induced antibodies with higher avidity. Moreover, when OMV were administered at suboptimal quantity for protection, OMVbiof-vaccine exhibited a significantly adequate and higher protective capacity against PRN(+) or PRN(-) than OMVplank-vaccine. Our findings indicate that the vaccine based on biofilm-derived OMV induces high protection also against pertactin-deficient strains, with a robust immune response.
从重新出现的百日咳疾病病原体中提取的外膜囊泡（OMV）在免疫接种的小鼠肺部预防细菌定植方面是安全且有效的。含有这些 OMV 的疫苗制剂能够诱导混合 Th1/Th2/Th17 表型，但更有趣的是，它们可能诱导组织驻留记忆免疫反应。这种免疫反应被推荐用于新一代的百日咳疫苗，这些疫苗必须开发出来以克服当前非细胞性疫苗（第二代百日咳疫苗）的弱点。第三代百日咳疫苗还应应对目前在人群中流行的、表型和基因型与过去不同的细菌感染（特别是那些缺乏 pertactin 抗原表达的细菌，PRN(-)）。在这里，我们评估了源自生物膜中生长的细菌的 OMV 的保护能力，因为观察到与较旧的培养物疫苗株不同，目前流行的临床分离株具有更高的这种生活方式能力。因此，我们使用具有良好生物膜形成能力的临床分离株进行了研究。通过扫描电子显微镜和蛋白质组学证实了生物膜生活方式。虽然扫描电子显微镜显示这些培养物中存在典型的生物膜结构，但与浮游培养物相比，在生物膜培养物中过度表达了 BipA、纤毛和其他被描述为生物膜生活方式典型的粘附素。源自生物膜（OMVbiof）或浮游生活方式（OMVplank）的 OMV 用于配制疫苗，以比较它们针对 PRN(+)或 PRN(-)临床分离株感染的免疫原性和保护能力。使用小鼠保护模型，我们发现 OMVbiof-疫苗在特异性抗体滴度和质量方面比 OMVplank-疫苗更具免疫原性，因为 OMVbiof-疫苗诱导的抗体具有更高的亲和力。此外，当以亚最佳保护量给予 OMV 时，OMVbiof-疫苗对 PRN(+)或 PRN(-)的保护能力明显更充足且更高。我们的研究结果表明，基于生物膜衍生的 OMV 的疫苗可诱导针对 pertactin 缺失株的高保护作用，并产生强大的免疫反应。
