Medical Genetics Laboratory, Faculty of Medicine and Health Sciences, Universiti Putra Malaysia, Serdang, Selangor, Malaysia.
Department of Companion Animal and Surgery, Faculty of Veterinary Medicine, Universiti Putra Malaysia, Serdang, Selangor, Malaysia.
J Med Microbiol. 2022 May;71(5). doi: 10.1099/jmm.0.001536.
Cholera is an acute enteric infection caused by , particularly in areas lacking access to clean water. Despite the global effort to improve water quality in these regions, the burden of cholera in recent years has not yet declined. Interest has therefore extended in the use of bicistronic DNA vaccine encoding and genes of as a potential vaccine. The potential of a bicistronic DNA vaccine, pVAX- has not been determined and . The goal of present study was to evaluate expression and potential of pVAX- vaccine against . The pVAX- was transiently transfected into mammalian COS-7 cells, and the expression was assessed using fluorescence and Western blot analyses. Next, the vaccine was encapsulated into sodium alginate using water-in-oil emulsification and evaluated for its efficiency in different pH conditions. Subsequently, oral vaccination using en(pVAX-) was performed . The animals were challenged with O1 El Tor after 2 weeks of vaccination using the Removable Intestinal Tie-Adult Rabbit Diarrhoea (RITARD) model. Following the infection challenge, the rabbits were monitored for evidence of symptoms, and analysed for systemic cytokine expression level (TNF-α, IFN-γ, IL-6 and IL-10) using quantitative real-time polymerase chain reaction. The expression of pVAX- was successfully verified via fluorescence and Western blot analyses. Meanwhile, analysis demonstrated that the en(pVAX-) was able to protect the RITARD model against infection due to a lack of evidence on the clinical manifestations of cholera following bacterial challenge. Furthermore, the bicistronic group showed an upregulation of systemic IFN-γ and IL-10 following 12 days of vaccination, though not significant, suggesting the possible activation of both T-helper 1 and 2 types of response. However, upon bacterial challenge, the gene expression of all cytokines did not change. Our findings suggest that the bicistronic plasmid DNA vaccine, pVAX-, showed a potential role in inducing immune response against cholera through upregulation of gene and protein expression as well as cytokine gene expression, particularly IFN-γ and IL-10.
霍乱是一种由 引起的急性肠道感染，特别是在缺乏清洁水的地区。尽管全球努力改善这些地区的水质，但近年来霍乱的负担尚未下降。因此，人们对使用编码 和 基因的双顺反子 DNA 疫苗作为潜在疫苗产生了兴趣。双顺反子 DNA 疫苗 pVAX- 的潜力尚未得到确定。本研究的目的是评估 pVAX- 疫苗对 的 表达和潜力。使用荧光和 Western blot 分析评估 pVAX- 在哺乳动物 COS-7 细胞中的瞬时转染和 表达。接下来，使用水包油乳液将疫苗包封在海藻酸钠中，并评估其在不同 pH 条件下的效率。随后，通过口服接种 en(pVAX-)。在使用可移动肠道结扎-成年兔腹泻（RITARD）模型接种 2 周后，用 O1 El Tor 对动物进行感染挑战。感染挑战后，监测兔子是否出现症状，并通过定量实时聚合酶链反应分析系统细胞因子表达水平（TNF-α、IFN-γ、IL-6 和 IL-10）。通过荧光和 Western blot 分析成功验证了 pVAX- 的表达。同时，分析表明，由于在细菌攻击后缺乏霍乱临床表现的证据，en(pVAX-)能够保护 RITARD 模型免受 感染。此外，双顺反子组在接种后 12 天表现出系统 IFN-γ和 IL-10 的上调，尽管不显著，但表明可能激活了辅助性 T 细胞 1 和 2 两种类型的反应。然而，在细菌攻击后，所有细胞因子的基因表达都没有改变。我们的研究结果表明，双顺反子质粒 DNA 疫苗 pVAX- 通过上调 基因和蛋白表达以及细胞因子基因表达，特别是 IFN-γ 和 IL-10，在诱导针对霍乱的免疫反应方面显示出潜在作用。
