Sallard Erwan, Zhang Wenli, Chilakamarri Nikita, Farzanehkari Setareh, Seuthe Inga Marte Charlott, Ehrhardt Anja, Aydin Malik
Virology and Microbiology, Center for Biomedical Education and Research (ZBAF), School of Medicine, Faculty of Health, Witten/Herdecke University, Witten, Germany.
Laboratory of Experimental Pediatric Pneumology and Allergology, Faculty of Health, Witten/Herdecke University, Witten, Germany.
Front Immunol. 2025 Jun 11;16:1579896. doi: 10.3389/fimmu.2025.1579896. eCollection 2025.
The development of mucosal adenovirus (Ad) vaccine vectors is considered one of the next frontiers to protect vulnerable patients from respiratory and gastrointestinal pathogens. An efficient delivery to or through the oral cavity necessitates a thorough understanding of Ad interactions with saliva for oral, buccal or sublingual vaccine delivery, which could additionally prove instrumental in the containment of natural Ad infections but remains unexplored. Therefore, we investigated the influence of saliva on Ad infectivity, emphasizing its intrinsic antiviral role against particular Ad types in various epithelial cell cultures.
A saliva pool was created from healthy donors (=16) and incubated with ChAdOx1 or human Ads from 20 different types prior to infection of human immortalized epithelial cells. All human Ads used were replication-competent and expressed a GLN cassette containing a green-fluorescent protein, nano-luciferase, and neomycin resistance. Loss-of-function experiments were conducted by immunoprecipitation or enzymatic digestion of specific saliva components to decipher related mechanisms.
Temporal and inter-individual variability in saliva samples were observed, validating the use of a saliva pool to represent the population. Saliva strongly influenced Ad infectivity, in general through inhibiting species B types and enhancing species D and E Ads, that include the vaccine vector platforms Ad26 and ChAdOx1. Interestingly, Ad20 presented the highest infectivity enhancement, as well as superior to average salivary mucus crossing rates. Furthermore, saliva immunoglobulins and human neutrophil peptides marginally influenced the Ad infectivity, while sialic acid inhibited all tested Ad types.
Saliva may have a protective role against infection by certain types of Ads. This discovery highlights a potential limitation in the efficacy of next-generation oral Ad vaccine vectors. Consequently, our study underscores the importance of identifying and utilizing saliva-resistant Ad vectors to optimize Ad-based vaccination strategies.
黏膜腺病毒（Ad）疫苗载体的研发被认为是保护易感患者免受呼吸道和胃肠道病原体感染的下一个前沿领域之一。要实现通过口腔有效递送疫苗，需要深入了解腺病毒与唾液在口服、颊部或舌下疫苗递送中的相互作用，这对于控制腺病毒自然感染可能也有帮助，但目前尚未得到充分研究。因此，我们研究了唾液对腺病毒感染性的影响，重点关注其在各种上皮细胞培养物中对特定腺病毒类型的内在抗病毒作用。
从16名健康供体采集唾液样本混合成唾液池，在感染人永生化上皮细胞之前，将其与ChAdOx1或20种不同类型的人腺病毒进行孵育。所有使用的人腺病毒均具有复制能力，并表达一个包含绿色荧光蛋白、纳米荧光素酶和新霉素抗性的GLN盒。通过免疫沉淀或特定唾液成分的酶消化进行功能丧失实验，以阐明相关机制。
观察到唾液样本存在时间和个体间的差异，验证了使用唾液池来代表总体人群的合理性。唾液对腺病毒感染性有显著影响，总体上通过抑制B种腺病毒类型并增强D种和E种腺病毒的感染性，其中包括疫苗载体平台Ad26和ChAdOx1。有趣的是，Ad20表现出最高的感染性增强，以及高于平均水平的唾液黏液穿透率。此外，唾液免疫球蛋白和人中性粒细胞肽对腺病毒感染性的影响较小，而唾液酸抑制了所有测试的腺病毒类型。
唾液可能对某些类型的腺病毒感染具有保护作用。这一发现凸显了下一代口服腺病毒疫苗载体效力的潜在局限性。因此，我们的研究强调了识别和利用抗唾液腺病毒载体以优化基于腺病毒的疫苗接种策略的重要性。
