Katoh Hiroshi, Watanabe Masahiko
Department of Surgery, Kitasato University School of Medicine, 1-15-1 Kitasato, Minami-ku, Sagamihara, Kanagawa 252-0374, Japan.
Mediators Inflamm. 2015;2015:159269. doi: 10.1155/2015/159269. Epub 2015 May 19.
Development of solid cancer depends on escape from host immunosurveillance. Various types of immune cells contribute to tumor-induced immune suppression, including tumor associated macrophages, regulatory T cells, type 2 NKT cells, and myeloid-derived suppressor cells (MDSCs). Growing body of evidences shows that MDSCs play pivotal roles among these immunosuppressive cells in multiple steps of cancer progression. MDSCs are immature myeloid cells that arise from myeloid progenitor cells and comprise a heterogeneous immune cell population. MDSCs are characterized by the ability to suppress both adaptive and innate immunities mainly through direct inhibition of the cytotoxic functions of T cells and NK cells. In clinical settings, the number of circulating MDSCs is associated with clinical stages and response to treatment in several cancers. Moreover, MDSCs are reported to contribute to chemoresistant phenotype. Collectively, targeting MDSCs could potentially provide a rationale for novel treatment strategies in cancer. This review summarizes recent understandings of MDSCs in cancer and discusses promissing clinical approaches in cancer patients.
实体癌的发展依赖于逃避免疫监视。多种类型的免疫细胞参与肿瘤诱导的免疫抑制，包括肿瘤相关巨噬细胞、调节性T细胞、2型自然杀伤T细胞和髓源性抑制细胞（MDSCs）。越来越多的证据表明，MDSCs在这些免疫抑制细胞中，在癌症进展的多个步骤中发挥关键作用。MDSCs是起源于髓系祖细胞的未成熟髓系细胞，构成一个异质性免疫细胞群体。MDSCs的特征是主要通过直接抑制T细胞和NK细胞的细胞毒性功能来抑制适应性免疫和固有免疫。在临床环境中，循环MDSCs的数量与几种癌症的临床分期和治疗反应相关。此外，据报道MDSCs会导致化疗耐药表型。总的来说，靶向MDSCs可能为癌症的新型治疗策略提供理论依据。这篇综述总结了目前对癌症中MDSCs的认识，并讨论了癌症患者中前景广阔的临床方法。
