Kradin R L, Xia W, McCarthy K, Schneeberger E E
Department of Pathology, Massachusetts General Hospital, Boston 02114.
Am J Pathol. 1993 Mar;142(3):811-9.
A substantial body of evidence indicates that the primary sensitization of naive T cells to inhaled antigens occurs in the regional lymph nodes, whereas secondary responses may be generated directly within lung tissue. Ia+ pulmonary dendritic cells are widely distributed within the rat lung where they can participate in the induction of the immune response to inhaled antigens. Recently, two subsets of Ia+ pulmonary dendritic cells have been distinguished based on their expression of Fc receptors (FcR), but little is known concerning their abilities to support the responses of naive or sensitized T cells. In order to address this question, pulmonary FcR+/- dendritic cells have been purified from enzymatic digests of Lewis rat lungs, based on their differential binding to heat-aggregated immunoglobulin. The FcR+/- dendritic cell subsets differed with respect to their light microscopic appearance and in their expression of non-specific esterase. Only the FcR+ subset was able to phagocytize latex beads and showed intracellular phagolysosomes by electron microscopy. Both of the FcR+/- subsets rapidly formed clusters with naive (OX-22+) and sensitized (OX-22-) T cells. However, the clusters yielded by the FcR+ subset were substantially smaller, possibly reflecting their diminished surface membrane expression of the intercellular adhesion molecule-1. The FcR+/- subsets were capable of presenting soluble and particulate antigens to OX-22- T cells. FcR+ cells were less effective than FcR- cells in promoting the proliferative response of OX-22+ T cells to concanavalin A and in the primary mixed leukocyte reaction. We conclude that the FcR+/- pulmonary dendritic cells differ in their abilities to support the responses of naive and sensitized T lymphocytes. This observation may have significance for how primary and secondary pulmonary cell-mediated immune responses are generated.
大量证据表明，幼稚T细胞对吸入抗原的初次致敏发生在局部淋巴结，而二次反应可能直接在肺组织内产生。Ia⁺肺树突状细胞广泛分布于大鼠肺内，在那里它们可参与对吸入抗原的免疫反应诱导。最近，根据其Fc受体（FcR）的表达区分出了两个Ia⁺肺树突状细胞亚群，但关于它们支持幼稚或致敏T细胞反应的能力知之甚少。为了解决这个问题，基于肺FcR⁺/⁻树突状细胞与热聚集免疫球蛋白的差异结合，从Lewis大鼠肺的酶消化物中纯化出了这些细胞。FcR⁺/⁻树突状细胞亚群在光学显微镜下的外观及其非特异性酯酶的表达方面存在差异。只有FcR⁺亚群能够吞噬乳胶珠，并且通过电子显微镜显示有细胞内吞噬溶酶体。两个FcR⁺/⁻亚群都能与幼稚（OX - 22⁺）和致敏（OX - 22⁻）T细胞迅速形成簇。然而，FcR⁺亚群形成的簇要小得多，这可能反映了它们细胞间粘附分子 - 1的表面膜表达减少。FcR⁺/⁻亚群能够将可溶性和颗粒性抗原呈递给OX - 22⁻T细胞。在促进OX - 22⁺T细胞对伴刀豆球蛋白A的增殖反应以及在初次混合淋巴细胞反应中，FcR⁺细胞比FcR⁻细胞效果更差。我们得出结论，FcR⁺/⁻肺树突状细胞在支持幼稚和致敏T淋巴细胞反应的能力方面存在差异。这一观察结果可能对原发性和继发性肺细胞介导的免疫反应如何产生具有重要意义。
Zotero 插件