Department of International Health, Immunology and Microbiology, University of Copenhagen, Blegdamsvej 3 , Copenhagen DK-2200, Denmark.
Sci Rep. 2012;2:266. doi: 10.1038/srep00266. Epub 2012 Feb 14.
Because naïve T cells are unable to import cystine due to the absence of cystine transporters, it has been suggested that T cell activation is dependent on cysteine generated by antigen presenting cells. The aim of this study was to determine at which phases during T cell activation exogenous cystine/cysteine is required and how T cells meet this requirement. We found that early activation of T cells is independent of exogenous cystine/cysteine, whereas T cell proliferation is strictly dependent of uptake of exogenous cystine/cysteine. Naïve T cells express no or very low levels of both cystine and cysteine transporters. However, we found that these transporters become strongly up-regulated during T cell activation and provide activated T cells with the required amount of cystine/cysteine needed for T cell proliferation. Thus, T cells are equipped with mechanisms that allow T cell activation and proliferation independently of cysteine generated by antigen presenting cells.
由于幼稚 T 细胞由于缺乏胱氨酸转运体而无法摄取胱氨酸，因此有人提出 T 细胞的激活依赖于抗原呈递细胞产生的半胱氨酸。本研究旨在确定在 T 细胞激活的哪个阶段需要外源性胱氨酸/半胱氨酸，以及 T 细胞如何满足这一需求。我们发现 T 细胞的早期激活不依赖于外源性胱氨酸/半胱氨酸，而 T 细胞的增殖则严格依赖于外源性胱氨酸/半胱氨酸的摄取。幼稚 T 细胞表达的胱氨酸和半胱氨酸转运体很少或没有。然而，我们发现这些转运体在 T 细胞激活过程中被强烈上调，并为激活的 T 细胞提供 T 细胞增殖所需的胱氨酸/半胱氨酸。因此，T 细胞具有允许 T 细胞激活和增殖的机制，而不依赖于抗原呈递细胞产生的半胱氨酸。
