Aberrant Glycosylation Augments the Immuno-Stimulatory Activities of Soluble Calreticulin.
Aberrant Glycosylation Augments the Immuno-Stimulatory Activities of Soluble Calreticulin.
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异常糖基化增强可溶性钙网蛋白的免疫刺激活性
DOI：
10.3390/molecules23030523
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发表时间：
2018-02-27
期刊：
影响因子：
--
通讯作者：
Gao XM
中科院分区：
文献类型：
--
作者：
Gong FY;Gong Z;Duo CC;Wang J;Hong C;Gao XM
钙网蛋白（Calreticulin，CRT）是一种存在于细胞腔的钙结合糖蛋白，是一种参与肿瘤发生的肿瘤相关抗原，也是多种自身免疫性疾病患者自身抗体的靶向抗原。我们以前已经表明，原核表达的重组鼠CRT（rCRT）表现出强大的刺激活性，对单核细胞/巨噬细胞在体外和有效的免疫原性在体内，这是部分归因于可溶性rCRT的自身寡聚化。然而，即使是从小鼠肝脏中分离的寡聚化形式的天然CRT（nCRT）也比rCRT活性低得多，这与单独的自身寡聚化将向nCRT许可有效的促炎性质的可能性相矛盾。由于rCRT与nCRT的不同之处在于其缺乏糖基化，我们想知道真核表达CRT（eCRT）的异常糖基化是否会显著增强其免疫活性。在本研究中，衣霉素，一种N-糖基转移酶抑制剂，处理CHO细胞（CHO-CRT）稳定表达全长重组小鼠CRT的分泌形式，制备异常糖基化的eCRT（tun-eCRT）。我们的生化和免疫学分析结果表明，CHO-CRT细胞产生的eCRT在糖基化水平、缺乏自身寡聚化、相对较差的免疫原性和较弱的巨噬细胞刺激活性方面与nCRT相似，而tun-eCRT显示糖基化降低，但在小鼠中引起特异性体液反应的能力以及体外巨噬细胞产生TNF-α和一氧化氮的能力大大增强。鉴于蛋白质的异常糖基化是癌细胞的标志，也与人类自身免疫性疾病的发展有关，我们的数据可能为更好地理解CRT等分子糖基化失调在肿瘤发生和自身免疫中的增强作用提供有用的线索。
Calreticulin (CRT), a luminal resident calcium-binding glycoprotein of the cell, is a tumor-associated antigen involved in tumorigenesis and also an autoantigen targeted by autoantibodies found in patients with various autoimmune diseases. We have previously shown that prokaryotically expressed recombinant murine CRT (rCRT) exhibits strong stimulatory activities against monocytes/macrophages in vitro and potent immunogenicity in vivo, which is partially attributable to self-oligomerization of soluble rCRT. However, even in oligomerized form native CRT (nCRT) isolated from mouse liver is much less active than rCRT, arguing against the possibility that self-oligomerization alone would license potent pro-inflammatory properties to nCRT. Since rCRT differs from nCRT in its lack of glycosylation, we wondered if aberrant glycosylation of eukaryotically expressed CRT (eCRT) would significantly enhance its immunological activity. In the present study, tunicamycin, an N-glycosyltransferase inhibitor, was employed to treat CHO cells (CHO-CRT) stably expressing full-length recombinant mouse CRT in secreted form for preparation of aberrantly glycosylated eCRT (tun-eCRT). Our biochemical and immunological analysis results indicate that eCRT produced by CHO-CRT cells is similar to nCRT in terms of glycosylation level, lack of self-oligomerization, relatively poor immunogenicity and weak macrophage-stimulatory activity, while tun-eCRT shows reduced glycosylation yet much enhanced ability to elicit specific humoral responses in mice and TNF-α and nitric oxide production by macrophages in vitro. Given that abberant glycosylation of proteins is a hallmark of cancer cells and also related to the development of autoimmune disorders in humans, our data may provide useful clues for better understanding of potentiating roles of dysregulated glycosylation of molecules such as CRT in tumorigenesis and autoimmunity.
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影响因子：
3.5
作者：
Komatsu, S.;Yamada, E.;Furukawa, K.
通讯作者：
Furukawa, K.
影响因子：
4.1
作者：
Rendón-Huerta, E;Mendoza-Hernández, G;Robles-Flores, M
通讯作者：
Robles-Flores, M
影响因子：
4.6
作者：
Ding, H.;Hong, C.;Zheng, F.
通讯作者：
Zheng, F.
天然钙网蛋白单体和寡聚物的免疫活性差异
影响因子：
3.7
作者：
He MC;Wang J;Wu J;Gong FY;Hong C;Xia Y;Zhang LJ;Bao WR;Gao XM
通讯作者：
Gao XM
影响因子：
4.1
作者：
KHANNA, NC;TOKUDA, M;WAISMAN, DM
通讯作者：
WAISMAN, DM