Department of Immunology, Zhongshan School of Medicine, Sun Yat-sen University, 74 Zhongshan 2nd Road, Guangzhou, Guangdong Province 510080, People' s Republic of China.
Vaccine. 2010 Sep 24;28(41):6666-74. doi: 10.1016/j.vaccine.2010.08.013. Epub 2010 Aug 13.
Cytotoxic CD8(+) T lymphocytes (CTLs) play an important role in antiviral immunity. Several human HLA-A0201 restricted CTL epitopes of severe acute respiratory syndrome (SARS) spike (S) protein have been identified in HLA-A0201 transgenic (Tg) mice, but the mechanisms and properties of immune responses are still not well understood. In this study, HLA-A0201 Tg mice were primed intramuscularly with SARS S DNA and boosted subcutaneously with HLA-A0201 restricted peptides. The lymphocytes from draining lymph nodes, spleens and lungs were stimulated with the cognate peptides. Three different methods (ELISA, ELISPOT and FACS) were used to evaluate the immune responses during short and long periods of time after immunization. Results showed that peptide-specific CD8(+) T cells secreted IFN-γ, TNF-α and IL-2 and expressed CD107a/b on cell surface. IFN-γ(+)CD8(+) T cells and CD107a/b(+)CD8(+) T cells distributed throughout the lymphoid and non-lymphoid tissues, but the frequency of peptide-specific CD8(+) T cells was higher in lungs than in spleens and lymph nodes. The phenotype of the CD8(+) T cells was characterized based on the expression of IFN-γ. Most of the HLA-A0201 restricted peptide-specific CD8(+) T cells represented a memory subset with CD45RB(high) and CD62L(low). Taken together, these data demonstrate that immunization with SARS S DNA and HLA-A0201 restricted peptides can elicit antigen-specific CD8(+) T cell immune responses which may have a significant implication in the long-term protection. We provide novel information in cellular immune responses of SARS S antigen-specific CD8(+) T cells, which are important in the development of vaccine against SARS-CoV infection.
细胞毒性 CD8(+) T 淋巴细胞 (CTL) 在抗病毒免疫中发挥重要作用。在 HLA-A0201 转基因 (Tg) 小鼠中已鉴定出几种严重急性呼吸综合征 (SARS) 刺突 (S) 蛋白的人类 HLA-A0201 限制性 CTL 表位,但免疫反应的机制和特性仍未得到很好的理解。在这项研究中,HLA-A0201 Tg 小鼠经肌肉内注射 SARS S DNA 进行初次免疫,然后经皮下注射 HLA-A0201 限制性肽进行加强免疫。用同源肽刺激引流淋巴结、脾脏和肺部的淋巴细胞。使用三种不同的方法(ELISA、ELISPOT 和 FACS)在免疫后短时间和长时间内评估免疫反应。结果表明,肽特异性 CD8(+) T 细胞分泌 IFN-γ、TNF-α 和 IL-2,并在细胞表面表达 CD107a/b。IFN-γ(+)CD8(+) T 细胞和 CD107a/b(+)CD8(+) T 细胞分布在淋巴和非淋巴组织中,但肺部的肽特异性 CD8(+) T 细胞频率高于脾脏和淋巴结。根据 IFN-γ 的表达,对 CD8(+) T 细胞的表型进行了特征描述。大多数 HLA-A0201 限制性肽特异性 CD8(+) T 细胞代表具有 CD45RB(高)和 CD62L(低)的记忆亚群。综上所述,这些数据表明,用 SARS S DNA 和 HLA-A0201 限制性肽免疫可以引发抗原特异性 CD8(+) T 细胞免疫反应,这可能对长期保护具有重要意义。我们提供了 SARS S 抗原特异性 CD8(+) T 细胞细胞免疫反应的新信息,这对于开发针对 SARS-CoV 感染的疫苗很重要。