Department of Microbiology and Immunology, University of Michigan Medical School, Ann Arbor, MI 48109-5620, USA.
Trends Immunol. 2013 Jan;34(1):13-21. doi: 10.1016/j.it.2012.08.002. Epub 2012 Sep 7.
Calreticulin is a calcium-binding chaperone that has several functions in the immune response. In the endoplasmic reticulum (ER), calreticulin facilitates the folding of major histocompatibility complex (MHC) class I molecules and their assembly factor tapasin, thereby influencing antigen presentation to cytotoxic T cells. Although calreticulin is normally ER-resident, it is found at the cell surface of living cancer cells and dying cells. Here, calreticulin promotes cellular phagocytic uptake. In tumor vaccine models, drugs that induce cell surface calreticulin confer enhanced tumor protection in an extracellular calreticulin-dependent manner. Much remains to be understood about the roles of calreticulin in these distinct functions. Further investigations are important towards advancing basic knowledge of glycoprotein-folding pathways, and towards developing new cancer therapeutic strategies.
钙网蛋白是一种钙结合伴侣，在免疫反应中具有多种功能。在内质网（ER）中，钙网蛋白促进主要组织相容性复合体（MHC）I 类分子及其组装因子 tapasin 的折叠，从而影响细胞毒性 T 细胞的抗原呈递。尽管钙网蛋白通常位于 ER 中，但它存在于活癌细胞和死亡细胞的细胞表面。在这里，钙网蛋白促进细胞吞噬作用。在肿瘤疫苗模型中，诱导细胞表面钙网蛋白的药物以细胞外钙网蛋白依赖的方式增强肿瘤保护。钙网蛋白在这些不同功能中的作用仍有许多需要了解。进一步的研究对于推进糖蛋白折叠途径的基础知识以及开发新的癌症治疗策略非常重要。
