Salmonella enteric serovar infections result in high morbidity and mortality worldwide. Cross-protective vaccines are an effective strategy in controlling salmonellosis caused by multiple serotypes. In our previous study, outer membrane vesicles (OMVs) derived from flagellin-deficient Salmonella Typhimurium (S. Typhimurium) were proven effective in mediating cross-protection against infection by multiple Salmonella serotypes; OMVs also exhibit potent adjuvant effects. In this study, we further investigated the adjuvant capacities of flagellin-deficient S. Typhimurium OMVs. Our finding showed that outer membrane proteins (OMPs) in combination with flagellin-deficient S. Typhimurium OMVs could function as adjuvants and invoke stronger humoral, cellular, mucosal, and cross-protective immune responses compared to conventional aluminum (alum). Furthermore, as an adjuvant, OMVs could induce significantly higher cellular immune responses and display enhanced cross-protection for OMPs against wild-type virulent Salmonella Choleraesuis and Salmonella Enteritidis challenge. In summary, OMVs function as a potent adjuvant with the capability of conferring greater cross-protection against infection by multiple Salmonella serotypes, and may be of great value as an effective vaccine adjuvant in enteric diseases.

中文翻译：

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鞭毛蛋白缺乏的外膜囊泡作为佐剂诱导鼠伤寒沙门氏菌外膜蛋白对异源沙门氏菌血清型感染的交叉保护。

沙门氏菌肠血清型感染导致全世界高发病率和高死亡率。交叉保护疫苗是控制由多种血清型引起的沙门氏菌病的有效策略。在我们先前的研究中，已证明源自鞭毛蛋白缺陷型鼠伤寒沙门氏菌（鼠伤寒沙门氏菌）的外膜囊泡可有效介导交叉保护，以抵抗多种沙门氏菌血清型的感染。OMV还表现出有效的佐剂作用。在这项研究中，我们进一步调查了鞭毛蛋白缺陷型鼠伤寒沙门氏菌OMV的佐剂能力。我们的发现表明，与常规铝（铝）相比，外膜蛋白（OMP）与鞭毛蛋白缺陷型鼠伤寒沙门氏菌OMV组合可以起到佐剂的作用，并引起更强的体液，细胞，粘膜和交叉保护性免疫应答。此外，作为佐剂，OMV可以诱导明显更高的细胞免疫反应，并增强针对OMP的交叉保护，以抵抗野生型强毒霍乱沙门氏菌和肠炎沙门氏菌的攻击。综上所述，OMVs具有强大的佐剂功能，能够针对多种沙门氏菌血清型感染提供更大的交叉保护作用，并且在肠道疾病中作为有效的疫苗佐剂具有巨大的价值。