Immunity：推翻免疫记忆经典理论

　　

生物通报道，德国Charité – University医学院临床免疫学系等处的研究人员在《Immunity》杂志上发表文章Professional Memory CD4+ T Lymphocytes Preferentially Reside and Rest in the Bone Marrow，解析免疫记忆性的新进展。

 

据介绍，这一研究成果堪称可以推翻经典的免疫记忆模型理论。经典的免疫记忆学理论认为，记忆细胞在身体内周游循环，而新的研究发现记忆性T细胞其实定居在骨髓中舒适的微环境中，等待下一次抵抗感染的机会。

 

一名未参与这一研究的学者，瑞士生物医学研究所的研究者Antonio Lanzaveccia表示，这些数据令人兴奋。这些数据可以解释两种定居在不同地域的记忆性细胞的关系。

 

以往研究人员发现记忆性B细胞（生产抗体的细胞）定居在骨髓中。长期以来研究者认为免疫记忆细胞来自于激活的效应T细胞，这些T细胞在体内循环，直到同样的抗原再次刺激它们。因此，人们很容易在外周分离到记忆性T细胞，但是却很少接触到骨髓中的记忆性T细胞。因为要获得骨髓相对要艰难些。

 

德国的这一组研究人员发现，记忆性T细胞其实更喜欢定居在骨髓中，并在骨髓中保持良好的活性随时应对感染，在骨髓中，记忆性T细胞的微环境为表达IL-7的基地细胞微环境。

 

（生物通 小茜）

生物通推荐原文检索：Professional Memory CD4+ T Lymphocytes Preferentially Reside and Rest in the Bone Marrow

Koji Tokoyoda1,,,Sandra Zehentmeier1,Ahmed N. Hegazy1,2,Inka Albrecht1,Joachim R. Grün1,Max Löhning1,2andAndreas Radbruch1

 

1 Deutsches Rheuma-Forschungszentrum (DRFZ), Charitéplatz 1, Berlin 10117, Germany

2 Experimental Immunology, Department of Rheumatology and Clinical Immunology, Charité - University Medicine Berlin, Charitéplatz 1, Berlin 10117, Germany

【Summary】

CD4+ T lymphocytes are key to immunological memory. Here we show that in the memory phase of specific immune responses, most of the memory CD4+ T lymphocytes had relocated into the bone marrow (BM) within 38 weeks after their generationa process involving integrin 2. Antigen-specific memory CD4+ T lymphocytes highly expressed Ly-6C, unlike most splenic CD44hiCD62L CD4+ T lymphocytes. In adult mice, more than 80% of Ly-6ChiCD44hiCD62L memory CD4+ T lymphocytes were in the BM. In the BM, they associated to IL-7-expressing VCAM-1+ stroma cells. Gene expression and proliferation were downregulated, indicating a resting state. Upon challenge with antigen, they rapidly expressed cytokines and CD154 and efficiently induced the production of high-affinity antibodies by B lymphocytes. Thus, in the memory phase of immunity, memory helper Tcells are maintained in BM as resting but highly reactive cells in survival niches defined by IL-7-expressing stroma cells.