差异效应途径调节针对疟原虫伯氏疟原虫和约氏疟原虫孢子的记忆 CD8 T 细胞免疫。
Differential effector pathways regulate memory CD8 T cell immunity against Plasmodium berghei versus P. yoelii sporozoites.
机构信息
Department of Microbiology, University of Iowa, Iowa City, IA 52242, USA.
出版信息
J Immunol. 2010 Mar 1;184(5):2528-38. doi: 10.4049/jimmunol.0903529. Epub 2010 Jan 22.
Malaria results in >1,000,000 deaths per year worldwide. Although no licensed vaccine exists, much effort is currently focused on subunit vaccines that elicit CD8 T cell responses directed against Plasmodium parasite liver stage Ags. Multiple immune-effector molecules play a role in antimicrobial immunity mediated by memory CD8 T cells, including IFN-gamma, perforin, TRAIL, Fas ligand, and TNF-alpha. However, it is not known which pathways are required for memory CD8 T cell-mediated immunity against liver stage Plasmodium infection. In this study, we used a novel immunization strategy to generate memory CD8 T cells in the BALB/c mouse model of P. berghei or P. yoelii sporozoite infection to examine the role of immune-effector molecules in resistance to the liver stage infection. Our studies reveal that endogenous memory CD8 T cell-mediated protection against both parasite species is, in part, dependent on IFN-gamma, whereas perforin was only critical in protection against P. yoelii. We further show that neutralization of TNF-alpha in immunized mice markedly reduces memory CD8 T cell-mediated protection against both parasite species. Thus, our studies identify IFN-gamma and TNF-alpha as important components of the noncytolytic pathways that underlie memory CD8 T cell-mediated immunity against liver stage Plasmodium infection. Our studies also show that the effector pathways that memory CD8 T cells use to eliminate liver stage infection are, in part, Plasmodium species specific.
疟疾每年导致全球超过 100 万人死亡。虽然没有许可的疫苗,但目前仍在努力研究亚单位疫苗,这些疫苗能引发针对疟原虫肝期抗原的 CD8 T 细胞反应。多种免疫效应分子在记忆 CD8 T 细胞介导的抗微生物免疫中发挥作用,包括 IFN-γ、穿孔素、TRAIL、Fas 配体和 TNF-α。然而,尚不清楚记忆 CD8 T 细胞介导的抗肝期疟原虫感染所需的途径是什么。在这项研究中,我们使用一种新的免疫策略在 P. berghei 或 P. yoelii 孢子感染的 BALB/c 小鼠模型中产生记忆 CD8 T 细胞,以研究免疫效应分子在抵抗肝期感染中的作用。我们的研究表明,内源性记忆 CD8 T 细胞对两种寄生虫的保护部分依赖于 IFN-γ,而穿孔素仅对 P. yoelii 的保护至关重要。我们进一步表明,在免疫小鼠中中和 TNF-α 会显著降低记忆 CD8 T 细胞对两种寄生虫的保护作用。因此,我们的研究确定 IFN-γ和 TNF-α是记忆 CD8 T 细胞介导的抗肝期疟原虫感染中非细胞毒性途径的重要组成部分。我们的研究还表明,记忆 CD8 T 细胞用于消除肝期感染的效应途径部分是寄生虫特异性的。