殺傷性Ｔ細(xì)胞是一種重要的免疫細(xì)胞,，能夠破壞被病毒感染或癌變的細(xì)胞,，日本專家在25日的《自然·免疫學(xué)》雜志網(wǎng)絡(luò)版上發(fā)表報(bào)告說(shuō),，他們發(fā)現(xiàn)了殺傷性Ｔ細(xì)胞是如何確定出擊時(shí)機(jī)的。
殺傷性Ｔ細(xì)胞是白細(xì)胞的一種,，它們擔(dān)負(fù)著向出現(xiàn)異常的細(xì)胞內(nèi)注入分解酶,，破壞這些異常細(xì)胞的任務(wù)，但殺傷性Ｔ細(xì)胞發(fā)揮這種功能的具體機(jī)制一直不明,。
日本德島大學(xué)教授安友康二等人發(fā)現(xiàn),，當(dāng)其他一些免疫細(xì)胞首先感覺(jué)到某細(xì)胞出現(xiàn)異常時(shí)，這些免疫細(xì)胞便分泌出特殊物質(zhì),。這些物質(zhì)與殺傷性Ｔ細(xì)胞表面的Notch2分子結(jié)合后,，殺傷性Ｔ細(xì)胞就會(huì)對(duì)異常細(xì)胞展開(kāi)攻擊,。老鼠實(shí)驗(yàn)證實(shí),，如果其他免疫細(xì)胞不能分泌上述特殊物質(zhì)，或者該物質(zhì)與Notch2分子不能結(jié)合,，它們的免疫功能就會(huì)減弱,，這樣的老鼠感染病毒后的死亡率也要高于正常老鼠。
日本研究人員指出,，如果能依靠藥物控制殺傷性Ｔ細(xì)胞的出擊時(shí)機(jī),，或許能幫助治療癌癥和某些病毒性傳染病。（生物谷Bioon.com）
生物谷推薦原始出處：
Nature Immunology Published online: 24 August 2008 | doi:10.1038/ni.1649
Notch2 integrates signaling by the transcription factors RBP-J and CREB1 to promote T cell cytotoxicity
Yoichi Maekawa, Yoshiaki Minato, Chieko Ishifune, Takeshi Kurihara, Akiko Kitamura, Hidefumi Kojima, Hideo Yagita, Mamiko Sakata-Yanagimoto, Toshiki Saito, Ichiro Taniuchi, Shigeru Chiba, Saburo Sone & Koji Yasutomo
The acquisition of cytotoxic effector function by CD8+ T cells is crucial for the control of intracellular infection and tumor invasion. However, it remains unclear which signaling pathways are required for the differentiation of CD8+ cytotoxic T lymphocytes. We show here that Notch2-deficient T cells had impaired differentiation into cytotoxic T lymphocytes. In addition, dendritic cells with lower expression of the Notch ligand Delta-like 1 induced the differentiation of cytotoxic T lymphocytes less efficiently. We found that the intracellular domain of Notch2 interacted with a phosphorylated form of the transcription factor CREB1, and together these proteins bound the transcriptional coactivator p300 to form a complex on the promoter of the gene encoding granzyme B. Our results suggest that the highly regulated, dynamic control of T cell cytotoxicity depends on the integration of Notch2 and CREB1 signals.
