Ueno Tomoo, Hara Kyoko, Willis Melissa Swope, Malin Mark A, Höpken Uta E, Gray Daniel H D, Matsushima Kouji, Lipp Martin, Springer Timothy A, Boyd Richard L, Yoshie Osamu, Takahama Yousuke
Division of Experimental Immunology, Institute for Genome Research, The University of Tokushima and Laboratory of Immune System Development, RIKEN Research Center for Allergy and Immunology, 3-18-15 Kuramoto, 770-8503, Tokushima, Japan.
Immunity. 2002 Feb;16(2):205-18. doi: 10.1016/s1074-7613(02)00267-4.
Most T lymphocytes are generated within the thymus. It is unclear, however, how newly generated T cells relocate out of the thymus to the circulation. The present study shows that a CC chemokine CCL19 attracts mature T cells out of the fetal thymus organ culture. Another CC chemokine CCL21, which shares CCR7 with CCL19 but has a unique C-terminal extension containing positively charged amino acids, failed to show involvement in thymic emigration. Neonatal appearance of circulating T cells was defective in CCL19-neutralized mice as well as in CCR7-deficient mice but not in CCL21-neutralized mice. In the thymus, CCL19 is predominantly localized in the medulla including endothelial venules. These results indicate a CCL19- and CCR7-dependent pathway of thymic emigration, which represents a major pathway of neonatal T cell export.
大多数T淋巴细胞在胸腺内产生。然而，新产生的T细胞如何从胸腺迁移至循环系统尚不清楚。本研究表明，CC趋化因子CCL19可吸引成熟T细胞从胎儿胸腺器官培养物中迁出。另一种CC趋化因子CCL21与CCL19共用CCR7，但具有包含带正电荷氨基酸的独特C末端延伸，未显示参与胸腺输出。在CCL19中和的小鼠以及CCR7缺陷的小鼠中循环T细胞的新生期出现存在缺陷，但在CCL21中和的小鼠中则不然。在胸腺中，CCL19主要定位于包括内皮小静脉在内的髓质。这些结果表明存在一条依赖CCL19和CCR7的胸腺输出途径，这代表了新生T细胞输出的主要途径。
