Bhimani Saloni, Canas Jorge J, Enslow Samantha M, Mulcare Ryan, Ferraro Mariola J
Department of Microbiology and Cell Science, Institute of Food and Agricultural Sciences, University of Florida, Gainesville, FL, United States.
The Department of Molecular Genetics and Microbiology, College of Medicine, University of Florida, Gainesville, FL, United States.
Front Immunol. 2025 Aug 15;16:1628756. doi: 10.3389/fimmu.2025.1628756. eCollection 2025.
is a leading cause of foodborne illness in the United States and worldwide. This enteric pathogen deploys various mechanisms to evade the intestinal mucosal barrier to enhance its survival and further infect systemic tissues. Commercially available vaccines against are currently restricted to the serovar Typhi, while none are currently approved for non-typhoidal (NTS) serovars, which are becoming increasingly resistant to antibiotics. Due to the lack of effective vaccines against NTS infections, novel oral vaccination strategies have garnered significant interest, owing to their protective abilities at the susceptible sites of infection. We previously reported that mice immunized intranasally with small extracellular vesicles (sEVs) derived from infected macrophages protect mice against lethal challenge. In the present study, we used an oral route of administration of sEVs to determine their protective abilities Remarkably, orally administered sEVs from infected macrophages conferred significant host protection, marked by improved survival post-challenge and reduction in tissue bacterial burdens. Additionally, immunized mice exhibited robust serological responses, including elevated levels of both whole- and OmpA-specific IgG antibodies. Collectively, these findings show the potential of orally delivered sEVs as a promising, cell-free vaccine platform for protection against salmonellosis.
在美国和全球范围内，是食源性疾病的主要病因。这种肠道病原体采用多种机制来逃避肠道黏膜屏障，以提高其存活率并进一步感染全身组织。目前针对的市售疫苗仅限于伤寒血清型，而目前尚无针对非伤寒血清型（NTS）的疫苗获得批准，这些血清型对抗生素的耐药性正在增加。由于缺乏针对NTS感染的有效疫苗，新型口服疫苗策略因其在感染易感部位的保护能力而备受关注。我们之前报道过，用来自感染巨噬细胞的小细胞外囊泡（sEVs）经鼻内免疫小鼠可保护小鼠免受致死性攻击。在本研究中，我们采用口服途径给予sEVs以确定其保护能力。值得注意的是，经口服给予来自感染巨噬细胞的sEVs可赋予宿主显著的保护作用，表现为攻击后存活率提高和组织细菌载量降低。此外，免疫小鼠表现出强烈的血清学反应，包括全特异性和OmpA特异性IgG抗体水平升高。总的来说，这些发现表明口服sEVs作为一种有前景的无细胞疫苗平台用于预防沙门氏菌病的潜力。
