丹麦科研人员不久前发现一种新的免疫细胞能协助抵抗癌症。他们正据此研制一种新型癌症疫苗，目前正在进行临床试验。
人体免疫抑制细胞和癌细胞可以产生一种特殊的双加氧酶，来抑制免疫细胞的攻击性，使其缺乏足够攻击力抵抗癌细胞侵袭，甚至还会被癌细胞吞噬。双加氧酶的存在使现有癌症疫苗的有效性大打折扣。
丹麦海莱乌医院癌症免疫治疗中心的研究者在最新一期美国学术刊物《血液》上报告说，他们发现人体免疫系统中存在一种此前未知的细胞，这种细胞可以杀死那些产生双加氧酶的细胞。新发现的细胞在消灭免疫抑制细胞的同时，还能直接攻击癌细胞。
领导这项研究的马斯·哈尔·安德森说，研究小组正在研制一种新型癌症疫苗，通过增加上述抗癌细胞的数量，提高机体免疫系统的攻击力，从而抵抗癌症。海莱乌医院正用新疫苗对一些肺癌患者开展临床试验，目前的治疗效果明显好于常规疗法。
研究小组认为，从原理上说，这种可有效抑制双加氧酶产生的癌症疫苗有望与其他疗法协同治疗多种癌症。（生物谷Bioon.com）
生物谷推荐原文出处：
Blood DOI 10.1182/blood-2010-06-288498
Indoleamine 2,3-dioxygenase specific, cytotoxic T cells as immune regulators
Rikke B?k S?rensen, Sine Reker Hadrup, Inge Marie Svane, Mads Christian Hjorts?, Per thor Straten and Mads Hald Andersen*
Abstract
Indoleamine 2,3-dioxygenase (IDO) is an immunoregulatory enzyme that is implicated in suppressing T-cell immunity in normal and pathological settings. Here, we describe that spontaneous cytotoxic T-cell reactivity against IDO exists not only in cancer patients but also in healthy individuals. We show that the presence of such IDO-specific CD8+ T cells boosted T-cell immunity against viral or tumor-associated antigens by eliminating IDO+ suppressive cells. This had profound effects on the balance between IL-17-producing CD4+ T cells and regulatory T cells. Furthermore, this caused an increase in the production of the pro-inflammatory cytokines IL-6 and TNF- while decreasing the IL-10 production. Finally, the addition of IDO-inducing agents (i.e. the TLR9 ligand CpG, soluble CTLA4 or IFN-) induced IDO-specific T cells among PBMC from cancer patients as well as healthy donors. In the clinical setting, IDO may serve as an important and widely applicable target for immunotherapeutic strategies where IDO play a significant regulatory role. The present describe for the first time effector T cells with a general regulatory function that may play a vital role for the mounting or maintaining of an effective adaptive immune response. We suggest terming such effector T cells "supporter T cells".
