Gong J L, McCarthy K M, Telford J, Tamatani T, Miyasaka M, Schneeberger E E
Department of Pathology, Massachusetts General Hospital, Boston 02114.
J Exp Med. 1992 Mar 1;175(3):797-807. doi: 10.1084/jem.175.3.797.
Dendritic cells (DC), in general, and pulmonary DC, in particular, are a heterogeneous population of cells, their phenotype and function being dependent on their anatomic location, their state of activation, and the regulatory effect of locally secreted cytokines. Using a novel microdissection technique, the epithelium from the trachea and entire airway system was harvested, and the contained DC isolated at greater than 90% purity. The phenotype and function of these airway DC (ADC) was compared to DC isolated, at greater than 90% purity, from the parenchyma of the same lung. In contrast to lung DC (LDC), ADC did not express intercellular adhesion molecule 1 (ICAM-1) in situ, the amount of immune associated antigen (Ia) expressed was less (as determined by immunoperoxidase staining and immunopanning), and greater than 50% of ADC displayed Fc receptors (FcR). The majority of LDC were ICAM-1+, less than 5% expressed FcR, and all were intensely Ia+. Airway DC were most numerous in tracheal epithelium, but they were also present in small numbers in the epithelium of the most distal airways. Their numbers increased in all segments of the tracheobronchial epithelium in response to the administration of IFN-gamma. ADC were consistently more effective than LDC in presenting soluble (hen egg lysozyme) and particulate (heat-killed Listeria monocytogenes) antigens to antigen-sensitized T cells. By contrast, LDC were significantly more efficient in stimulating the proliferation of nonsensitized T cells in an autologous mixed leukocyte reaction. These data suggest that in normal animals, intraepithelial DC of airways share many attributes with Langerhans cells of the skin. Interstitial LDC, by contrast, reside in an environment where they may be exposed to a different set of regulatory factors and where they have progressed to a more advanced stage of differentiation than ADC. Both groups of DC are, however, heterogeneous, reflecting the continuous turnover that these cells undergo in the lung.
一般来说，树突状细胞（DC），尤其是肺树突状细胞，是一类异质性细胞群体，其表型和功能取决于它们的解剖位置、激活状态以及局部分泌细胞因子的调节作用。采用一种新型显微切割技术，采集气管和整个气道系统的上皮组织，并以大于90%的纯度分离其中所含的DC。将这些气道DC（ADC）的表型和功能与从同一肺实质中以大于90%的纯度分离得到的DC进行比较。与肺DC（LDC）相比，ADC在原位不表达细胞间黏附分子1（ICAM-1），表达的免疫相关抗原（Ia）量较少（通过免疫过氧化物酶染色和免疫淘选测定），且超过50%的ADC显示有Fc受体（FcR）。大多数LDC为ICAM-1阳性，少于5%表达FcR，且全部强烈表达Ia。气道DC在气管上皮中数量最多，但在最远端气道的上皮中也有少量存在。给予γ干扰素后，气管支气管上皮各节段中的DC数量均增加。在将可溶性（鸡卵溶菌酶）和颗粒性（热灭活单核细胞增生李斯特菌）抗原呈递给抗原致敏T细胞方面，ADC始终比LDC更有效。相比之下，在自体混合淋巴细胞反应中，LDC在刺激未致敏T细胞增殖方面效率显著更高。这些数据表明，在正常动物中，气道上皮内DC与皮肤的朗格汉斯细胞有许多共同特征。相比之下，间质LDC所处的环境可能使其接触到不同的一组调节因子，且它们已发展到比ADC更高级的分化阶段。然而，这两组DC都是异质性的，反映了这些细胞在肺中持续更新的过程。
