Seliger Barbara
Institute of Medical Immunology, Martin Luther University Halle-Wittenberg, Halle, Germany.
BioDrugs. 2005;19(6):347-54. doi: 10.2165/00063030-200519060-00002.
During the last decade, increased understanding of the molecular mechanisms responsible for immune activation to protect against challenges by tumor cells has revolutionized the field of immunotherapy research. It has been demonstrated that the dysfunction of the host's immune system represents one of the major mechanisms by which tumors evade immunosurveillance. This is due, for example, to T cell anergy, the existence of regulatory T cells, and systemic defects of dendritic cells derived from tumor patients. In addition, escape from immunosurveillance can also be linked to tumor-related factors, including secretion of immunosuppressive cytokines, resistance to apoptosis, and deficient expression of immunomodulatory molecules and major histocompatibility complex (MHC) class I antigens possibly due to immunoselection. Both host- and tumor-related mechanisms can lead to a failure to mount a proper anti-tumor-specific immune response, and these are frequently key factors in limiting the success of cancer immunotherapy.
在过去十年中，人们对机体免疫激活以抵御肿瘤细胞攻击的分子机制有了更深入的了解，这彻底改变了免疫治疗研究领域。已经证明，宿主免疫系统功能失调是肿瘤逃避免疫监视的主要机制之一。例如，这是由于T细胞无反应性、调节性T细胞的存在以及肿瘤患者来源的树突状细胞的系统性缺陷。此外，逃避免疫监视还可能与肿瘤相关因素有关，包括免疫抑制细胞因子的分泌、对凋亡的抵抗以及免疫调节分子和主要组织相容性复合体（MHC）I类抗原表达不足，这可能是由于免疫选择所致。宿主和肿瘤相关机制均可导致无法产生适当的抗肿瘤特异性免疫反应，而这些往往是限制癌症免疫治疗成功的关键因素。
