Afshar Davoud, Moghadam Solmaz Ohadian, Dehkordi Farhad Safarpoor, Ranjbar Reza, Hasanzadeh Amir
Department of Microbiology, School of Medicine, Zanjan University of Medical Sciences, Zanjan, Iran.
Uro Oncology Research Center, Tehran University of Medical Sciences, Tehran, Iran.
Iran J Microbiol. 2020 Aug;12(4):338-342. doi: 10.18502/ijm.v12i4.3938.
causes many lethal infections. Due to its reduced sensitivity to commonly used antibiotics, development of new strategies against pneumococcal infections seems to be necessary. We aimed to investigate immunodominant antigens in culture supernatant in order to develop novel targets for pneumococcal vaccines.
In this study ATCC49619 was sub-cultured into BHI broth from overnight culture at 37°C for 4 h. The supernatant proteins were precipitated using acetone precipitation method. A rabbit was intramuscularly immunized with alum adjuvant and 100 μg pneumococcal supernatant proteins, 6 times at 14 days' intervals to produce hyperimmune serum. ELISA assay was performed to determine the antibody level response to pneumococcal secretory proteins. Then dot blot applied for rapid evaluation of hyperimmune serum reactivity to pneumococcus supernatant proteins. The western blot was also used to determine the interaction of supernatant proteins with immunogenic rabbit's hyperimmune-serum.
According to the western blot analysis, the immunodominant protein had 140KDa molecular weight and designated as pneumococcal secretory protein140 (Psp140).
The Psp140 protein in the supernatant of culture is an immunodominant protein and it is likely related to pneumococcal secretory protein or surface exposed protein which released into culture supernatant during bacterial growth.
肺炎链球菌可引发多种致命感染。由于其对常用抗生素的敏感性降低，开发针对肺炎链球菌感染的新策略似乎很有必要。我们旨在研究培养上清液中的免疫显性抗原，以开发新型肺炎球菌疫苗靶点。
在本研究中，将ATCC49619从过夜培养物转接至BHI肉汤中，于37°C培养4小时。使用丙酮沉淀法沉淀上清液中的蛋白质。用明矾佐剂和100μg肺炎球菌上清液蛋白对一只兔子进行肌肉注射免疫，每隔14天免疫1次，共免疫6次，以产生超免疫血清。进行ELISA检测以确定对肺炎球菌分泌蛋白的抗体水平反应。然后采用斑点印迹法快速评估超免疫血清对肺炎球菌上清液蛋白的反应性。还使用蛋白质印迹法确定上清液蛋白与免疫原性兔超免疫血清的相互作用。
根据蛋白质印迹分析，免疫显性蛋白的分子量为140 kDa，命名为肺炎球菌分泌蛋白140（Psp140）。
培养物上清液中的Psp140蛋白是一种免疫显性蛋白，它可能与肺炎球菌分泌蛋白或在细菌生长过程中释放到培养上清液中的表面暴露蛋白有关。
