Chyb Maciej, Ferra Bartłomiej Tomasz, Kawka Malwina, Skwarecka Marta, Dziadek Bożena, Gatkowska Justyna
Department of Molecular Microbiology, Institute of Microbiology, Biotechnology and Immunology, Faculty of Biology and Environmental Protection, University of Lodz, Lodz, Poland.
The Bio-Med-Chem Doctoral School of the University of Lodz and Lodz Institutes of the Polish Academy of Sciences, Faculty of Biology and Environmental Protection, University of Lodz, Lodz, Poland.
Front Immunol. 2024 Dec 13;15:1480349. doi: 10.3389/fimmu.2024.1480349. eCollection 2024.
Toxoplasmosis is caused by the opportunistic, cosmopolitan protozoan is one of the most common parasitoses in the world. This parasite can pose a threat to people with immunodeficiency but also to the fetus, since the invasion can lead to miscarriages. Moreover, this parasite can contribute to economic losses in livestock farming. These problems lead to the implementation of new, safe solutions for the development of effective toxoplasmosis immunoprophylaxis.
In this work, newly produced recombinant trivalent chimeric proteins of , based on SAG1-SAG2 recombinant chimeric antigen that differ in one terminal antigenic component, were tested in terms of their ability to induce an effective post-vaccination response. Antigens were tested to assess their ability to elicit APC cells response and further mice of the C3H/HeOuJ strain were immunized using those antigens, to evaluate their immunogenicity and immunoprotective effect . Two weeks after the last dose mice were either sacrificed to assess selected parameters of the immune response or infected with DX strain to determine the degree of protection one month later.
The results of serological tests revealed a high level of serum IgG antibodies specific for the native TLA antigens. TLA-stimulated splenocytes produced cytokines that are important in inhibiting protozoal invasion. Additionally, CD3 CD4 and CD3 CD8 T cell subpopulations of splenocytes were analysed by flow cytometry. One month after experimental infection mice were sacrificed, and their brains were isolated to count tissue cyst. Immunization of mice with recombinant trivalent chimeric proteins of resulted in reduction of tissue cyst burden rates reaching even 74%.
The obtained results demonstrate strong immunogenicity of the studied proteins and will allow to select candidates for further research aimed at increasing the immunoprotective properties of experimental vaccines against toxoplasmosis based on chimeric antigens.
弓形虫病由机会性、世界性分布的原生动物引起，是世界上最常见的寄生虫病之一。这种寄生虫不仅会对免疫功能低下的人构成威胁，还会对胎儿构成威胁，因为其入侵可能导致流产。此外，这种寄生虫会给畜牧业造成经济损失。这些问题促使人们实施新的安全解决方案，以开发有效的弓形虫病免疫预防方法。
在这项研究中，基于SAG1-SAG2重组嵌合抗原（仅在一个末端抗原成分上有所不同）新制备的重组三价嵌合蛋白，就其诱导有效疫苗接种后反应的能力进行了测试。对这些抗原进行测试，以评估其引发抗原呈递细胞（APC）反应的能力，随后使用这些抗原对C3H/HeOuJ品系小鼠进行免疫，以评估其免疫原性和免疫保护效果。在最后一剂疫苗接种两周后，处死小鼠以评估免疫反应的选定参数，或用DX株感染小鼠，以在一个月后确定保护程度。
血清学检测结果显示，针对天然弓形虫速殖子抗原（TLA）的血清IgG抗体水平较高。TLA刺激的脾细胞产生了对抑制原生动物入侵很重要的细胞因子。此外，通过流式细胞术分析了脾细胞的CD3+CD4+和CD3+CD8+T细胞亚群。在实验感染一个月后处死小鼠，并分离其大脑以计数组织囊肿。用弓形虫重组三价嵌合蛋白免疫小鼠，可使组织囊肿负荷率降低，甚至达到74%。
所得结果证明了所研究蛋白具有很强的免疫原性，并将有助于筛选候选物，以开展进一步研究，旨在提高基于弓形虫嵌合抗原的实验性疫苗对弓形虫病的免疫保护特性。
