Constitutive macropinocytosis allows TAP-dependent major histocompatibility complex class I presentation of exogenous soluble antigen by bone marrow-derived dendritic cells
Constitutive macropinocytosis allows TAP-dependent major histocompatibility complex class I presentation of exogenous soluble antigen by bone marrow-derived dendritic cells
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DOI：
10.1002/eji.1830270141
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发表时间：
1997-01-01
影响因子：
5.4
通讯作者：
Watts, C
中科院分区：
文献类型：
--
作者：
Norbury, CC;Chambers, BJ;Watts, C
用粒细胞/巨噬细胞集落刺激因子从小鼠骨髓中扩增出的树突状细胞（Dendriticcells，BMDC）在体内外均具有强的T细胞刺激特性。这已被充分记录为主要组织相容性复合体（MHC）II类限制性反应，最近使用肽负载和蛋白脉冲DC的小鼠过继转移后的CD 8反应。一个尚未解决的问题涉及BMDC的能力，提出外源性抗原的MHC I类分子，一种非常规的模式，MHC I类负载，现在有相当多的证据，特别是在巨噬细胞。在这里，我们表明，BMDC表现出高水平的巨胞饮驱动的组成性膜皱褶活动。高达三分之一的积极ruffling和macropinocytosing BMDC转移到胞质溶胶后，15分钟的脉冲，这表明他们可能能够提出外源性可溶性抗原的MHC I类分子。我们发现，BMDC提出外源性卵清蛋白的T细胞杂交瘤更有效，更迅速，并在较低的外源性抗原浓度比BM巨噬细胞的细胞对细胞的基础上。呈递是TAP依赖性的，布雷菲德菌素A敏感的，并且被蛋白酶体加工的抑制剂阻断，表明使用经典的MHC I类途径。虽然BMDC的外源性抗原的有效介绍发生在没有刺激巨胞饮作用的药物，佛波醇肉豆蔻酸酯乙酸酯（PMA）的治疗增强了BMDC的胞饮作用和MHC I类呈递。最后，PMA刺激的BMDC暴露于外源性卵清蛋白在体外能够引发抗原特异性细胞毒性T淋巴细胞反应后，过继转移在体内。
Dendritic cells expanded from mouse bone marrow (BMDC) with granulocyte/macrophage-colony-stimulating factor have potent T cell-stimulatory properties both in vitro and in vivo. This has been well documented for major histocompatibility complex (MHC) class II-restricted responses, and more recently using peptide-loaded and protein-pulsed DC for CD8 responses following adoptive transfer in mice. An unresolved question concerns the capacity of BMDC to present exogenous antigen on MHC class I molecules, an unconventional mode of MHC class I loading for which there is now considerable evidence, particularly in macrophages. Here, we show that BMDC exhibit high levels of macropinocytosis driven by constitutive membrane ruffling activity. Up to one-third of actively ruffling and macropinocytosing BMDC transferred pinocytosed horseradish peroxidase into the cytosol following a 15-min pulse, suggesting that they might be capable of presenting exogenous soluble antigen on MHC class I molecules. We show that BMDC presented exogenous ovalbumin to a T cell hybridoma more effectively, more rapidly, and at lower exogenous antigen concentrations than BM macrophages on a cell-for-cell basis. Presentation was TAP dependent, brefeldin A sensitive, and blocked by inhibitors of proteasomal processing, demonstrating use of the classical MHC class I pathway. Although effective presentation of exogenous antigen by BMDC occurred in the absence of agents which stimulate macropinocytosis, treatment with phorbol myristate acetate (PMA) enhanced both pinocytosis and MHC class I presentation by BMDC. Finally, PMA-stimulated BMDC exposed to exogenous ovalbumin in vitro were able to prime an antigen-specific cytotoxic T lymphocyte response following adoptive transfer in vivo.