Reiner Steven L
Abramson Family Cancer Research Institute and Department of Medicine, Division of Infectious Diseases, University of Pennsylvania, 421 Curie Blvd., Room 414, Philadelphia, PA, 19104-6160, USA.
Immunol Res. 2008;42(1-3):160-5. doi: 10.1007/s12026-008-8054-9.
A naïve T cell recruited into an immune response receives its critical inductive signals in the lymph node. The selected T cell must then produce cellular progeny empowered with new functions. Differentiated effector cells divide and migrate to infected tissues with an imprint of the instructions delivered to their progenitor. Some progeny of a selected naïve T cell, however, must remain undifferentiated and persist as lymph node-dwelling memory cells to replace and fortify defense should the intruder return. The integration of cell division, differentiation, diversification, and four-dimensional navigation make the clonal burst of a T cell in reaction to microbial invasion an exciting problem of developmental biology, cellular adaptation to environmental cues, and the propagation of signaling pathways through space and time. Epigenetic control of gene expression and an ancient cellular diversification mechanism called asymmetric cell division have recently been proposed to explain how a selected T cell can accomplish its imposing tasks. Future investigations will be directed toward understanding the mechanisms that allow a selected T cell to produce daughter T cells that are different, that are capable of remembering their inductive history, and that fulfill the demand for acute function and regeneration.
被招募参与免疫反应的初始T细胞在淋巴结中接收其关键的诱导信号。然后，被选中的T细胞必须产生具有新功能的细胞后代。分化的效应细胞进行分裂，并带着传递给其祖细胞的指令印记迁移到受感染的组织。然而，被选中的初始T细胞的一些后代必须保持未分化状态，并作为驻留在淋巴结中的记忆细胞持续存在，以便在入侵者再次出现时替代并加强防御。细胞分裂、分化、多样化以及四维导航的整合，使得T细胞对微生物入侵的克隆爆发成为发育生物学、细胞对环境线索的适应以及信号通路在空间和时间上的传播等令人兴奋的问题。最近有人提出，基因表达的表观遗传控制以及一种称为不对称细胞分裂的古老细胞多样化机制，可以解释被选中的T细胞如何完成其艰巨任务。未来的研究将致力于了解使被选中的T细胞产生不同的子代T细胞的机制，这些子代T细胞能够记住其诱导历史，并满足急性功能和再生的需求。
