Müller Melisa Florencia, Sacur Jacinto, Brancher Julia Matias, Vera María Daniela, Arce Lorena, Raya-Tonetti María Fernanda, Kitazawa Haruki, Villena Julio, Vizoso-Pinto María Guadalupe
Infection Biology Laboratory, Instituto Superior de Investigaciones Biológicas (INSIBIO), CONI-CET-UNT, Tucumán, Argentina.
Laboratory of Immunobiotechnology, Reference Centre for Lactobacilli (CERELA-CONICET), Tucumán, Argentina.
Front Microbiol. 2024 Dec 24;15:1512018. doi: 10.3389/fmicb.2024.1512018. eCollection 2024.
The development of a hepatitis E virus (HEV) vaccine is critical, with ORF2 capsid protein as the main target. We previously demonstrated that oral coadministration of recombinant ORF2 with immunomodulatory bacterium-like-particles (IBLP) induces a specific immune response in mice, particularly using IBLP derived from IBL027 (IBLP027), which was effective in eliciting a local humoral response. IBLP are non-live bacteria with adjuvant and carrier properties, serving as a platform for exposing proteins or antigens fused to LysM (lysine motif) domains, protein modules that bind to cell wall polysaccharides like peptidoglycan.
We cloned the most immunogenic domain of ORF2 (O2P2) fused to five LysM domains (LysMO2P2) and displayed this chimeric protein on the surface of IBLP027 to create a prototype vaccine (IBLP027-LysMO2P2). We evaluated its capacity to induce an immune response by immunizing mice with three doses of either the experimental vaccine or the chimeric protein alone, using an oral or a combined schedule with subcutaneous priming followed by oral boosting. Control groups received IBLP027. Sera and small intestine fluid were analyzed for humoral response, while Peyer's patches and spleen immune cells were used for ex vivo stimulation with capsid protein to assess cellular response.
The oral scheme failed to elicit an IgG response, but this was overcome by a subcutaneous priming dose followed by oral boosters, which led to increasing IgG titers in the combined scheme. The highest IgG titers were seen in the vaccine prototype group. Most groups produced significantly higher IgA levels in intestinal fluid, especially in those that received the oral scheme. Cellular response studies showed increased tumor necrosis factor (TNF)-α, interferon (IFN)-γ interleukin (IL)-4, and IL-17 levels in groups receiving the chimeric protein via oral or combined schedules.
Further and continuous research is needed to better understand both the needs and expectations of students and supervisors in different academic realities, including in Veterinary Medicine schools, from which the information available on the subject is scarce.
戊型肝炎病毒（HEV）疫苗的研发至关重要，其主要靶点为ORF2衣壳蛋白。我们之前证明，将重组ORF2与免疫调节细菌样颗粒（IBLP）口服联合给药可在小鼠体内诱导特异性免疫反应，特别是使用源自IBL027（IBLP027）的IBLP，其在引发局部体液反应方面有效。IBLP是具有佐剂和载体特性的非活细菌，可作为一个平台，用于展示与LysM（赖氨酸基序）结构域融合的蛋白质或抗原，LysM是一种与肽聚糖等细胞壁多糖结合的蛋白质模块。
我们克隆了与五个LysM结构域融合的ORF2最具免疫原性的结构域（O2P2）（LysMO2P2），并将这种嵌合蛋白展示在IBLP027表面，以制备一种原型疫苗（IBLP027-LysMO2P2）。我们通过用三剂实验疫苗或单独的嵌合蛋白免疫小鼠，采用口服或皮下初免后口服加强的联合方案，评估其诱导免疫反应的能力。对照组接受IBLP027。分析血清和小肠液以检测体液反应，同时使用派尔集合淋巴结和脾脏免疫细胞用衣壳蛋白进行离体刺激，以评估细胞反应。
口服方案未能引发IgG反应，但皮下初免剂量后再进行口服加强可克服这一问题，这导致联合方案中的IgG滴度增加。在疫苗原型组中观察到最高的IgG滴度。大多数组在肠液中产生了显著更高的IgA水平，尤其是那些接受口服方案的组。细胞反应研究表明，通过口服或联合方案接受嵌合蛋白的组中肿瘤坏死因子（TNF）-α、干扰素（IFN）-γ、白细胞介素（IL）-4和IL-17水平升高。
需要进一步持续研究，以更好地了解不同学术环境下学生和导师的需求与期望，包括兽医学院，目前关于该主题的可用信息稀缺。
