CD83抑制了内源的March-I依赖的MHCII类无化,内细胞化和降解
Sunil Kaul1, Nelson B Cole1, Joanna Bandola-Simon1
1Experimental Immunology Branch, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892.
概括
E3泛基因酶March-I调节了抗原呈现细胞上的主要基因相容性复合体II类 (MHC-II) 周转率. CD83还抑制了March-I活动,揭示了对免疫反应调节的新见解.
科学领域:
- 免疫学 免疫学 免疫学
- 分子生物学分子生物学
- 细胞生物学 细胞生物学
背景情况:
- 主性基因相容性复合体II类 (MHC-II) 通过抗原呈现细胞 (APC) 向CD4T细胞呈现外源抗原.
- 在E3泛基因酶March-I控制了APC上的表面MHC-II分子的降解和周转.
- 了解MHC-II表达的调节对于适应性免疫至关重要.
研究的目的:
- 在APC中研究E3泛基因酶March-I的蛋白质表达和调节.
- 阐明CD83在调节March-I活动和MHC-II表达中的作用.
- 揭示控制免疫反应中MHC-II循环的分子机制.
主要方法:
- 为蛋白质跟踪生成一个V5表位标记的3月I号小鼠模型.
- 在树突细胞 (DC) 和B细胞中对March-I蛋白表达的定量分析.
- 在DC和B细胞激活时评估March-I mRNA,蛋白质水平和MHC-II无化.
- 调查CD83对March-I依赖的MHC-II无化,内细胞化和DCs中的降解的影响.
主要成果:
- 休息的小鼠脏DC和B细胞表达了低水平的March-I (分别为500和125个分子/细胞).
- 在DC中,March-I蛋白的半衰期很短,在细胞激活时,其表达和MHC-II无化迅速减少.
- 发现CD83可以抑制内源的March-I-依赖的MHC-II无化,内细胞化和老鼠 DCs的降解.
结论:
- 3月-I是MHC-II表面表达周转率的关键调节者,在 APC中,在激活时迅速降解和减少表达.
- CD83在MHC-II的March-I介导调节中发挥抑制作用,影响无处不在和降解.
- 这项研究揭示了March-I和CD83控制MHC-II表达和免疫反应的关键分子机制.
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