The connection of innate and adaptive anti-cancer immunity

[]靶向递送IL-12可能会使这种细胞因子成为一种更安全、更有效的癌症治疗药物。在这里，我们描述了一种新的免疫细胞因子，nhs - IL-12，由两个IL-12分子融合到肿瘤坏死靶向人IgG1 （NHS76）组成。人IgG1片段的加入使得nhs - IL-12的血浆半衰期比重组IL-12更长，并且在体内选择性靶向小鼠肿瘤。利用人外周血单个核细胞（PBMCs）和灵长类动物体内研究进行的体外实验数据表明，免疫细胞在免疫细胞因子处理后产生的ifn - γ减少，这表明与单独使用重组IL-12相比，重组IL-12的毒性有所改善。在三种小鼠肿瘤模型中，nhs - IL-12的抗肿瘤作用均优于重组IL-12。利用免疫细胞亚群消耗抗体、流式细胞术方法、体外细胞毒性和ELISA检测的机制研究都表明，nhs - il -12的抗肿瘤作用主要依赖于CD8+ T细胞，可能是il -12介导的。将nhs - il - 12治疗与癌症疫苗、放疗或化疗相结合，比单独治疗产生更大的抗肿瘤效果。这些临床前研究结果为该免疫细胞因子的临床试验提供了理论依据，无论是作为单一药物还是与疫苗、放疗和化疗联合使用。[]转录因子brachyury是人类癌细胞上皮细胞向间质细胞转化的主要驱动因子。与正常成人组织相比，它在几种人类肿瘤类型中过表达，除了睾丸和甲状腺。过表达与耐药和预后不良有关。先前的研究发现了一个短缘HLA-A2细胞毒性t淋巴细胞表位。本文报道的研究描述了brachyury的一个增强子表位。与天然表位相比，激动剂表位：(a)增强了与MHC I类的结合，(b)增加了短节特异性T细胞的ifn - γ的产生，(c)产生了具有更高水平的perforin和增加增殖的短节特异性T细胞，(d)产生了更熟练地裂解内源性表达天然表位的人癌细胞的T细胞，(e)在HLA-A2转基因小鼠体内获得了更大的短节特异性T细胞应答。这些研究还报道了热杀重组酵母载体的产生，表达编码激动剂表位的全长短链酵母基因。与缺乏激动剂表位的酵母-brachyury（天然）相比，酵母-brachyury（激动剂）增强了brachyury特异性T细胞的激活，有效地裂解了人类癌细胞。这些研究除了为重组酵母-brachyury（激动剂）作为一种潜在的癌症治疗疫苗提供了基本原理之外，还为激动剂在以下方面的使用提供了基本原理：(a)树突状细胞（DC）疫苗，(b)佐剂或脂质体疫苗，(c)重组病毒和/或细菌疫苗，(d)蛋白质/多肽疫苗，(e)过继治疗方案中的体外T细胞激活，以及(f)基因工程靶向T细胞的产生。

[] Targeted delivery of IL-12 might turn this cytokine into a safer, more effective cancer therapeutic. Here we describe a novel immunocytokine, NHS-IL12, consisting of two molecules of IL-12 fused to a tumor necrosis-targeting human IgG1 (NHS76). The addition of the human IgG1 moiety resulted in a longer plasma half-life of NHS-IL12 than recombinant IL-12, and a selective targeting to murine tumors in vivo. Data from both in vitro assays using human peripheral blood mononuclear cells (PBMCs) and in vivo primate studies showed that IFN-gamma production by immune cells is attenuated following treatment with the immunocytokine, suggesting an improved toxicity profile than seen with recombinant IL-12 alone. NHS-IL12 was superior to recombinant IL-12 when evaluated as an anti-tumor agent in three murine tumor models. Mechanistic studies utilizing immune cell subset-depleting antibodies, flow cytometric methods, and in vitro cytotoxicity and ELISA assays all indicated that the anti-tumor effects of NHS-IL12 were primarily CD8+ T cell-dependent and likely IL-12-mediated. Combining NHS-IL12 treatment with a cancer vaccine, radiation, or chemotherapy resulted in greater anti-tumor effects than each individual therapy alone. These preclinical findings provide a rationale for the clinical testing of this immunocytokine, both as a single agent and in combination with vaccines, radiation and chemotherapy. [] The transcription factor brachyury is a major driver of epithelial to mesenchymal transition in human carcinoma cells. It is overexpressed in several human tumor types versus normal adult tissues, except for testes and thyroid. Overexpression is associated with drug resistance and poor prognosis. Previous studies identified a brachyury HLA-A2 cytotoxic T-lymphocyte epitope. The studies reported here describe an enhancer epitope of brachyury. Compared to the native epitope, the agonist epitope: (a) has enhanced binding to MHC class I, (b) increased the IFN-gamma production from brachyury-specific T cells, (c) generated brachyury-specific T cells with greater levels of perforin and increased proliferation, (d) generated T cells more proficient at lysing human carcinoma cells endogenously expressing the native epitope, and (e) achieved greater brachyury-specific T-cell responses in vivo in HLA-A2 transgenic mice. These studies also report the generation of a heat-killed recombinant Saccharomyces cerevisiae (yeast) vector expressing the full-length brachyury gene encoding the agonist epitope. Compared to yeast-brachyury (native) devoid of the agonist epitope, the yeast-brachyury (agonist) enhanced the activation of brachyury-specific T cells, which efficiently lysed human carcinoma cells. In addition to providing the rationale for the recombinant yeast-brachyury (agonist) as a potential vaccine in cancer therapy, these studies also provide the rationale for the use of the agonist in (a) dendritic cell (DC) vaccines, (b) adjuvant or liposomal vaccines, (c) recombinant viral and/or bacterial vaccines, (d) protein/polypeptide vaccines, (e) activation of T cells ex vivo in adoptive therapy protocols, and (f) generation of genetically engineered targeted T cells.