生物谷：研究人员发现了免疫细胞的新作用，为免疫系统提供了更好的了解。免疫细胞对身体炎症迹象的响应很快。白血细胞（单核白血球）像士兵那样快速奔赴需要它们的地点，沿着血管的内皮进入到组织中与敌人搏斗。Cedric Auffray和他的法国同事发现，一群单核白血球在没有炎症时潜伏在内皮中，它们在毛细管、静脉和动脉的表面站岗放哨，一旦检测到炎症或损坏，它们就成了细胞的紧急反应士兵。这些单核白血球转化为吃掉和消化入侵者的巨噬细胞，直到身体中其它的白血球赶来援助。在另一项免疫系统的研究中，Scott N. Mueller和同事发现，细胞在免疫危机中分泌的“交通警察”小蛋白质--趋化因子(chemokines)—在正在进行的免疫响应中将自己在淋巴结的生产减半并且阻碍T细胞的进入。文章作者得出结论：这种出乎意料的行为也许增强了淋巴结环境产生最优免疫响应的能力。
原始出处：
Science 3 August 2007:
Vol. 317. no. 5838, pp. 666 - 670
DOI: 10.1126/science.1142883
Monitoring of Blood Vessels and Tissues by a Population of Monocytes with Patrolling Behavior
Cedric Auffray,1 Darin Fogg,1 Meriem Garfa,1 Gaelle Elain,1 Olivier Join-Lambert,2,3 Samer Kayal,1,2,3 Sabine Sarnacki,2,3 Ana Cumano,4 Gregoire Lauvau,5 Frederic Geissmann1,2,3*
The cellular immune response to tissue damage and infection requires the recruitment of blood leukocytes. This process is mediated through a classical multistep mechanism, which involves transient rolling on the endothelium and recognition of inflammation followed by extravasation. We have shown, by direct examination of blood monocyte functions in vivo, that a subset of monocytes patrols healthy tissues through long-range crawling on the resting endothelium. This patrolling behavior depended on the integrin LFA-1 and the chemokine receptor CX3CR1 and was required for rapid tissue invasion at the site of an infection by this "resident" monocyte population, which initiated an early immune response and differentiated into macrophages.
1 Institut Nationale de la Santé et de la Recherche Médicale (INSERM) U838, Laboratory of Biology of the Mononuclear Phagocyte System, and Cellular and Molecular imaging core facility, Institut Fédératif de Recherche Necker-Enfants Malades, Paris, France.
2 University Paris-Descartes, Paris, France.
3 Hôpital Necker-Enfants Malades, AP-HP, Paris, France.
4 INSERM U668, Unité de Développement des Lymphocytes, Institut Pasteur, Paris, France.
5 INSERM E03-44, Institut de Pharmacologie Moleculaire et Cellulaire, Nice, France.
* To whom correspondence should be addressed. E-mail: geissmann@necker.fr
