Department of Microbiology, Faculty of Advanced Science and Technology, Tehran Medical Sciences, Islamic Azad University, Tehran, Iran.
Department of Pharmaceutical Biotechnology, Faculty of Pharmacy and Biotechnology Research Center, Tehran University of Medical Sciences, Tehran, Iran.
World J Microbiol Biotechnol. 2022 Nov 19;39(1):16. doi: 10.1007/s11274-022-03455-6.
Methicillin-resistant Staphylococcus aureus (MRSA) is one of the leading causes of hospital-acquired infections worldwide, which is resistant to many antibiotics, resulting in significant mortality in societies. Vaccination is a well-known approach to preventing disease. Autolysin, a surface-associated protein in S. aureus with multiple functions, is a suitable candidate for vaccine development. As a co-adjuvant, selenium nanoparticles (SeNPs) can increase the immune system, presumably resulting in increased vaccine efficacy. The present study evaluated the immunogenicity and defense of recombinant autolysin formulated in SeNPs and Alum adjuvants against MRSA. r-Autolysin was expressed and purified by the Ni-NTA affinity chromatography. SeNPs were synthetically obtained from sodium dioxide, followed by an assessment of shape and size using SEM and DLS. Balb/c mice were injected subcutaneously with 20 mg of r-autolysin formulated in Alum and SeNps adjuvants three times with the proper control group in 2 weeks intervals. Cytokine profile and isotyping ELISA were conducted to determine the type of induced immunity. Opsonophagocytosis tests assessed the functional activity of the vaccine, and the bacterial burden from the infected tissues was determined. Results showed that mice receiving SeNps and r-Autolysin had higher levels of total IgG and isotypes (IgG1 and IgG2a) and increased cytokine levels (IFN-γ, TNF-α, IL-12, and IL-4) as compared with those only receiving autolysin and PBS as a control. More importantly, mice immunized with SeNps and r-Autolysin exhibited a decrease in mortality and bacterial burden compared to the control group. We concluded that SeNps could stimulate immune responses and can be used as an adjuvant element in vaccine formulation.
耐甲氧西林金黄色葡萄球菌（MRSA）是全球导致医院获得性感染的主要原因之一，它对许多抗生素具有耐药性，导致社会死亡率显著增加。疫苗接种是预防疾病的一种众所周知的方法。金黄色葡萄球菌表面相关的多功能蛋白自溶素是疫苗开发的合适候选物。作为一种佐剂，硒纳米粒子（SeNPs）可以增强免疫系统，推测可以提高疫苗的功效。本研究评估了重组自溶素在 SeNPs 和 Alum 佐剂中的免疫原性和防御作用，以对抗 MRSA。r-自溶素通过 Ni-NTA 亲和层析表达和纯化。SeNPs 是通过亚硫酸钠合成的，然后使用 SEM 和 DLS 评估其形状和大小。Balb/c 小鼠在 2 周的间隔内通过皮下注射 20mg 的 Alum 和 SeNps 佐剂中的 r-自溶素三次，并与适当的对照组进行比较。细胞因子谱和分型 ELISA 用于确定诱导免疫的类型。调理吞噬作用试验评估了疫苗的功能活性，并测定了感染组织中的细菌负荷。结果表明，与仅接受自溶素和 PBS 作为对照的小鼠相比，接受 SeNps 和 r-自溶素的小鼠具有更高水平的总 IgG 和同种型（IgG1 和 IgG2a），以及更高水平的细胞因子（IFN-γ、TNF-α、IL-12 和 IL-4）。更重要的是，与对照组相比，用 SeNps 和 r-自溶素免疫的小鼠死亡率和细菌负荷降低。我们得出结论，SeNps 可以刺激免疫反应，并可用作疫苗配方中的佐剂成分。
