Regulation of integrin-mediated adhesion and immune response by Rap1 and its downstream effector, p30.

免疫监控需要趋化因子和黏附分子的协调调节来引导免疫细胞迁移。然而，控制免疫细胞高转运能力的关键分子尚不清楚。我们发现RAPL在整合素介导的淋巴细胞和树突状细胞的黏附和迁移中起着不可或缺的作用。RAPL缺陷会导致趋化因子缺陷引发的淋巴细胞黏附和向次级淋巴器官的迁移，导致淋巴滤泡萎缩和边缘带B细胞不足，同时血液中未成熟B细胞增加。此外，脾脏树突状细胞减少，黏附缺陷。皮肤和脾脏树突状细胞在炎性刺激下被激活后，既不能迁移到引流淋巴结，也不能迁移到脾的白髓。因此，RAPL是一种至关重要的免疫细胞运输调节因子，对免疫监控至关重要。

Immunosurveillance requires the coordinated regulation of chemokines and adhesion molecules to guide immune cell migration. However, the critical molecule to govern high trafficking capability of immune cells is not clear. We showed that RAPL plays indispensable roles in integrin-mediated adhesion and migration of lymphocytes and dendritic cells. RAPL deficiency causes defective chemokine-triggered lymphocyte adhesion and migration to secondary lymphoid organs, resulting in atrophic lymphoid follicles and deficient marginal zone B cells, concomitant with increased immature B cells in the blood. Furthermore, splenic dendritic cells were diminished and defective in adhesion. Upon activation with inflammatory stimuli, skin and splenic dendritic cells failed to migrate into either the draining lymph nodes or the white pulp of the spleen. Thus, RAPL is a crucial immune cell trafficking regulator essential for immunosurveillance.