Selective increased presentation of type II collagen by leupeptin
Selective increased presentation of type II collagen by leupeptin
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DOI：
10.1093/intimm/9.4.581
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发表时间：
1997-04-01
影响因子：
4.4
通讯作者：
Fournier, C
中科院分区：
文献类型：
--
作者：
ManourySchwartz, B;Chiocchia, G;Fournier, C
II型胶原（CII）是DBA/1（H-2（q））小鼠的致关节炎自身抗原。为了分析I-A（q）分子背景下这种纤维状蛋白的细胞内加工，我们通过将B淋巴瘤（A20和M12）细胞与来自DBA/1小鼠的CII-致敏的脾细胞融合来产生杂交抗原呈递细胞（APC）。通过这些APC向特异性T细胞杂交瘤的CII的有效呈递需要抗原的预先切割和肽的细胞内处理。布雷菲德菌素A对蛋白转运的抑制阻止了油肽向T细胞杂交瘤的呈递，表明CII的细胞内呈递依赖于I-A（q）分子的新合成。与此相反，暴露于蛋白酶抑制剂亮抑酶肽的杂合A淋巴瘤，诱导剂量依赖性增加的CII特异性T细胞反应，同时废除I-A（q）限制的卵清蛋白的介绍。以免疫B细胞为抗原提呈细胞时，亮抑酶肽也有增强作用。相比之下，亮抑酶肽抑制CII肽的巨噬细胞或总脾细胞的介绍。脉冲追踪分析代谢标记的混合APC和免疫沉淀与抗体特异性的II类分子或不变（ii）链显示亮抑酶肽不影响II链加工或形成稳定的II类二聚体。亮抑酶素对油呈递的刺激作用表明亮抑酶素通过干扰参与CII细胞内降解的蛋白酶来保护CII表位。
Type II collagen (CII) is an arthritogenic self antigen in DBA/1 (H-2(q)) mice. To analyze the intracellular processing of this fibrillar protein in the context of I-A(q) molecules, we have generated hybrid antigen-presenting cells (APC) by fusion of B lymphoma (A20 and M12) cells with CII-primed spleen cells from DBA/1 mice. Efficient presentation of CII by these APC to specific T cell hybridomas required prior cleavage of the antigen and intracellular handling of the peptides. Inhibition of protein transport by brefeldin A prevented the presentation of oil peptides to T cell hybridomas, indicating that the intracellular presentation of CII was dependent on neo-synthesis of I-A(q) molecules. In contrast, exposure of hybrid a lymphomas to leupeptin, a protease inhibitor, induced a dose-dependent increase of CII-specific T cell response, while abrogating the I-A(q)-restricted presentation of ovalbumin. The enhancing effect of leupeptin was also observed when immune B cells were used as APC. In contrast, leupeptin inhibited the presentation of CII peptides by macrophages or total spleen cells. Pulse-chase analysis of metabolically labeled hybrid APC and immunoprecipitation with antibodies specific for class II molecules or invariant (ii) chain revealed that leupeptin did not affect the Ii chain processing or the formation of stable class II dimers. The stimulatory effect of leupeptin observed on oil presentation suggests that leupeptin protects CII epitopes by interfering with proteases involved in the intracellular degradation of CII.