Functional expression of the alpha 2-macroglobulin receptor CD91 in salivary gland epithelial cells
Functional expression of the alpha 2-macroglobulin receptor CD91 in salivary gland epithelial cells
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DOI：
10.1016/j.jaut.2009.06.004
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发表时间：
2009-09-01
影响因子：
12.8
通讯作者：
Tzioufas, Athanasios G.
中科院分区：
文献类型：
--
作者：
Bourazopoulou, Efi;Kapsogeorgou, Efstathia K.;Tzioufas, Athanasios G.
CD 91分子是α 2-巨球蛋白、热休克蛋白和钙网蛋白的多功能受体。CD 91参与了由这些蛋白质陪伴的肽向MHC分子的交叉呈递，从而引发抗原特异性免疫应答。因此，CD 91被认为是先天性和获得性免疫应答的主要调节因子。在此，我们表明，CD 91分子表达的人唾液腺上皮细胞（SGEC），在小唾液腺活检组织（n = 21），以及通过分析人类长期培养的非肿瘤性SGEC线（n = 11）和肿瘤性HSG细胞系的免疫组化研究所示。在这些细胞系中，通过RT-PCR、流式细胞术和共聚焦显微镜评估CD 91表达。标准内化测定显示，HSG和SGEC能够结合并内化CD 91配体α 2-巨球蛋白。这种内化是特异性的，如使用未标记的α 2-巨球蛋白和针对人CD 91受体的阻断抗体的抑制研究所证实的。总之，我们的研究结果表明，SGEC功能性表达CD 91受体，这表明该途径可能参与SGEC中外源性抗原的呈递。(C)2009爱思唯尔有限公司保留所有权利。
CD91 molecule is a multifunctional receptor of alpha 2-macroglobulin, heat-shock proteins and calreticulin. CD91 has been implicated in cross-presentation of peptides chaperoned by these proteins to MHC molecules, thus eliciting antigen-specific immune responses. Hence, CD91 is considered as a major regulator of innate and acquired immune responses. Herein, we show that CD91 molecules are expressed by human salivary gland epithelial cells (SGEC), as indicated by immunohistochemical studies in minor salivary gland biopsy tissues (n = 21) as well as by the analyses of human long-term cultured nonneoplastic SGEC lines (n = 11) and the neoplastic HSG cell line. In these cell lines CD91 expression was evaluated by RT-PCR, flow cytometry and confocal microscopy. Standard internalization assays revealed that HSG and SGECs are capable to bind and internalize the CD91 ligand alpha 2-macroglobulin. This internalization is specific, as attested by inhibition studies using unlabeled alpha 2-macroglobulin and a blocking antibody against human CD91 receptor. Conclusively, our findings indicate that SGEC functionally express CD91 receptor, suggesting that this pathway might be involved in the presentation of exogenous antigens in SGEC. (C) 2009 Elsevier Ltd. All rights reserved.