Department of Microbiology, Faculty of Medicine, Kuwait University, Kuwait City, Kuwait.
Department of Pharmacology & Therapeutics, Faculty of Pharmacy, Kuwait City, Kuwait.
PLoS One. 2020 Feb 6;15(2):e0228381. doi: 10.1371/journal.pone.0228381. eCollection 2020.
Tuberculosis (TB) is a major health problem of global concern. The control of this disease requires appropriate preventive measures, including vaccines. In TB, T helper (Th)1 cytokines provide protection whereas Th2 and T regulatory (Treg) cytokines contribute to the pathogenesis and Th17 cytokines play a role in both protection and pathogenesis. Previous studies with Mycobacterium tuberculosis-specific proteins have identified seven low molecular weight proteins, PE35, ESXA, ESXB, Rv2346c, Rv2347c, Rv3619c, and Rv3620c, as immunodominant antigens inducing Th1-cell responses in humans following natural infection with M. tuberculosis. The aim of this study was to characterize the cytokine responses induced in mice immunized with these proteins, using various adjuvants and delivery systems, i.e. chemical adjuvants (Alum and IFA), non-pathogenic mycobacteria (M. smegmatis and M. vaccae) and a DNA vaccine plasmid (pUMVC6). The immune responses were monitored by quantifying the marker cytokines secreted by Th1 (IFN-ɣ), Th2 (IL-5), Treg (IL-10), and Th17 (IL-17A) cells. DNA corresponding to pe35, esxa, esxb, rv2346c, rv2347c, rv3619c, and rv3620c genes were cloned into the expression vectors pGES-TH-1, pDE22 and pUMVC6 for expression in Escherichia coli, mycobacteria and eukaryotic cells, respectively. Mice were immunized with the recombinants using different adjuvants and delivery systems, and spleen cells were stimulated in vitro with peptides of immunizing proteins to investigate antigen-specific secretion of Th1 (IFN-ɣ), Th2 (IL-5), Treg (IL-10), and Th17 (IL-17A) cytokines. The results showed that spleen cells, from mice immunized with all antigens, secreted the protective Th1 cytokine IFN-ɣ, except ESXB, with one or more adjuvants and delivery systems. However, only Rv3619c consistently induced Th1-biased responses, without the secretion of significant concentrations of Th2, Th17 and Treg cytokines, with all adjuvants and delivery systems. Rv3619c also induced antigen-specific IgG antibodies in immunized mice.
结核病（TB）是一个全球性的健康问题。控制这种疾病需要采取适当的预防措施，包括疫苗。在结核病中，辅助性 T 细胞（Th）1 细胞因子提供保护，而 Th2 和 T 调节（Treg）细胞因子则有助于发病机制，Th17 细胞因子在保护和发病机制中都发挥作用。以前对结核分枝杆菌特异性蛋白的研究已经确定了七种低分子量蛋白，PE35、ESXA、ESXB、Rv2346c、Rv2347c、Rv3619c 和 Rv3620c，它们是在人类自然感染结核分枝杆菌后诱导 Th1 细胞反应的免疫优势抗原。本研究的目的是用不同的佐剂和传递系统，即化学佐剂（明矾和 IFA）、非致病性分枝杆菌（耻垢分枝杆菌和牛分枝杆菌）和 DNA 疫苗质粒（pUMVC6），对用这些蛋白免疫的小鼠诱导的细胞因子反应进行特征描述。通过定量分析 Th1（IFN-γ）、Th2（IL-5）、Treg（IL-10）和 Th17（IL-17A）细胞分泌的标记细胞因子来监测免疫反应。pe35、esxa、esxb、rv2346c、rv2347c、rv3619c 和 rv3620c 基因的 DNA 分别被克隆到表达载体 pGES-TH-1、pDE22 和 pUMVC6 中，以便在大肠杆菌、分枝杆菌和真核细胞中表达。用不同的佐剂和传递系统对重组蛋白进行免疫，用免疫蛋白的肽体外刺激脾细胞，以研究抗原特异性分泌 Th1（IFN-γ）、Th2（IL-5）、Treg（IL-10）和 Th17（IL-17A）细胞因子。结果表明，除 ESXB 外，用一种或多种佐剂和传递系统免疫的所有抗原的小鼠脾细胞均分泌保护性 Th1 细胞因子 IFN-γ。然而，只有 Rv3619c 在用所有佐剂和传递系统时始终诱导偏向 Th1 的反应，而没有显著浓度的 Th2、Th17 和 Treg 细胞因子的分泌。Rv3619c 还在免疫小鼠中诱导了抗原特异性 IgG 抗体。
