研究人员鉴别出为新生免疫细胞提供基本生存因子的细胞，新成果于9月在线发表在《自然—免疫学》期刊上。
一种名为T淋巴细胞的血细胞是在胸腺中出生的，它们能反击侵入身体的病毒和其他感染性病菌。在离开胸腺后，这些细胞在身体中巡游以寻找潜在的外来侵略者。然而，这些T细胞的生存却依赖于周期性对淋巴结的造访，它们在这里被名为白细胞介素7的化学信号所“充电”。
多年来，科学家们早已知道白细胞介素7为新生的T细胞提供了生存信号，但他们一直不清楚白细胞介素7究竟是怎样产生的。
Sanjiv Luther和同事在淋巴结和脾脏中鉴别出一种特定的“纤维网状细胞”，发现它们是白细胞介素7的来源。这些细胞所产生的化学信号能引导T细胞走向它们，并提供阻止T细胞死亡的白细胞介素7，从而让T细胞能够在身体中巡回，检查入侵的敌人。（科学时报）
原始出处:
Nature Immunology 8, 1255 - 1265 (2007)
Published online: 23 September 2007 | doi:10.1038/ni1513
Fibroblastic reticular cells in lymph nodes regulate the homeostasis of naive T cells
Alexander Link1,4, Tobias K Vogt1,4, Stéphanie Favre1, Mirjam R Britschgi1, Hans Acha-Orbea1, Boris Hinz2, Jason G Cyster3 & Sanjiv A Luther1
Interleukin 7 is essential for the survival of naive T lymphocytes. Despite its importance, its cellular source in the periphery remains poorly defined. Here we report a critical function for lymph node access in T cell homeostasis and identify T zone fibroblastic reticular cells in these organs as the main source of interleukin 7. In vitro, T zone fibroblastic reticular cells were able to prevent the death of naive T lymphocytes but not of B lymphocytes by secreting interleukin 7 and the CCR7 ligand CCL19. Using gene-targeted mice, we demonstrate a nonredundant function for CCL19 in T cell homeostasis. Our data suggest that lymph nodes and T zone fibroblastic reticular cells have a key function in naive CD4+ and CD8+ T cell homeostasis by providing a limited reservoir of survival factors.
Department of Biochemistry, University of Lausanne, 1066 Epalinges, Switzerland.
Laboratory of Cell Biophysics, Ecole Polytechnique Fédérale de Lausanne, 1015 Lausanne, Switzerland.
Howard Hughes Medical Institute and Department of Microbiology and Immunology, University of California San Francisco, San Francisco, California 94143-0414, USA.
These authors contributed equally to this work.
Correspondence to: Sanjiv A Luther1 e-mail: sanjiv.luther@unil.ch
