Mazo I B, Gutierrez-Ramos J C, Frenette P S, Hynes R O, Wagner D D, von Andrian U H
The Center for Blood Research, Harvard Medical School, Boston, Massachusetts 02115, USA.
J Exp Med. 1998 Aug 3;188(3):465-74. doi: 10.1084/jem.188.3.465.
We have used intravital microscopy to study physiologically perfused microvessels in murine bone marrow (BM). BM sinusoids and venules, but not adjacent bone vessels, supported rolling interactions of hematopoietic progenitor cells. Rolling did not involve L-selectin, but was partially reduced in wild-type mice treated with antibodies to P- or E-selectin and in mice that were deficient in these two selectins. Selectin-independent rolling was mediated by alpha4 integrins, which interacted with endothelial vascular cell adhesion molecule (VCAM)-1. Parallel contribution of the endothelial selectins and VCAM-1 is not known to direct blood cell trafficking to other noninflamed tissues. This combination of constitutively expressed adhesion molecules may thus constitute a BM-specific recruitment pathway for progenitor cells analogous to the vascular addressins that direct selective lymphocyte homing to lymphoid organs.
我们利用活体显微镜技术研究了小鼠骨髓（BM）中生理灌注的微血管。骨髓血窦和小静脉而非相邻的骨血管支持造血祖细胞的滚动相互作用。滚动不涉及L-选择素，但在用抗P-或E-选择素抗体处理的野生型小鼠以及这两种选择素缺陷的小鼠中，滚动部分减少。非选择素依赖性滚动由α4整合素介导，α4整合素与内皮血管细胞黏附分子（VCAM）-1相互作用。目前尚不清楚内皮选择素和VCAM-1的平行作用是否直接将血细胞运输到其他非炎症组织。因此，这种组成性表达的黏附分子组合可能构成祖细胞的一种骨髓特异性募集途径，类似于引导选择性淋巴细胞归巢至淋巴器官的血管地址素。
