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研究發(fā)現(xiàn)：人記憶T細胞會*保持記憶的相關說明
最近更新時間：2013-7-11
提 供 商：上海士鋒生物科技有限公司資料大小：7.5KB
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記憶殺傷性T細胞（memory killer T cell）是一類特化細胞（specialized cell），是在對特定感染做出免疫應答后產(chǎn)生的。小鼠實驗已表明產(chǎn)生新的記憶T細胞導致舊的記憶T細胞激活和隨后的死亡，這可能是因為小鼠免疫系統(tǒng)只能容納一定數(shù)目的記憶T細胞。
但是人類免疫系通過似乎不受這種空間限制的制約。在對大學生進行的追蹤性研究中，來自美國明尼蘇達大學醫(yī)學院的Kristin Hogquist和同事們發(fā)現(xiàn)愛潑斯坦-巴爾病毒（Epstein-Barr virus, EBV，它是導致傳染性單核細胞增多癥產(chǎn)生的病因）導致的急性感染觸發(fā)其他病毒特異性的記憶T細胞激活。但是這些細胞既不增殖也不會死亡，也就意味著它們的數(shù)目不受時間影響，一直保持不變。
因此，人類記憶T細胞只會隨著時間的增加而不斷堆積。這對免疫應答是否產(chǎn)生有益或者有害影響還有待進一步觀察。
Primary Epstein-Barr virus infection does not erode preexisting CD8+ T cell memory in humans
Oludare A. Odumade, Jennifer A. Knight, David O. Schmeling, David Masopust, Henry H. Balfour Jr., and Kristin A. Hogquist
Acute Epstein-Barr virus （EBV） infection results in an unusually robust CD8+ T cell response in young adults. Based on mouse studies, such a response would be predicted to result in attrition of preexisting memory to heterologous infections like influenza A （Flu） and cytomegalovirus （CMV）. Furthermore, many studies have attempted to define the lymphocytosis that occurs during acute EBV infection in humans, but it is unclear whether bystander T cells contribute to it. To address these issues, we performed a longitudinal prospective study of primary EBV infection in humans. During acute EBV infection, both preexisting CMV- and Flu-specific memory CD8+ T cells showed signs of bystander activation, including up-regulation of granzyme B. However, they generally did not expand, suggesting that the profound CD8+ lymphocytosis associated with acute EBV infection is composed largely of EBV-specific T cells. Importantly, the numbers of CMV- and Flu-specific T cells were comparable before and after acute EBV infection. The data support the concept that, in humans, a robust CD8+ T cell response creates a new memory CD8+ T cell niche without substantially depleting preexisting memory for heterologous infections.