Division of Molecular Pharmaceutics, School of Pharmacy, University of North Carolina, Chapel Hill, NC 27599, USA.
Cytokine. 2010 Dec;52(3):238-44. doi: 10.1016/j.cyto.2010.08.010. Epub 2010 Sep 24.
Bryostatin-1 (Bryo-1), a PKC modulator, was previously shown to activate monocytes and lymphocytes to produce cytokines. In this report, we investigated the adjuvanticity of Bryo-1 both in vitro and in vivo. First, Bryo-1 was found to induce the release of CCL2 and CCL3 from mouse bone marrow-derived dendritic cells (BMDC) in a dose-dependent manner. As little as 0.1nM Bryo-I induced release of chemokines from BMDC and the maximal induction could be achieved at 5-10nM. Both PKC and ERK inhibitors attenuated the release of CCL2 and CCL3. Consistently, Western blot indicated that Bryo-I activated ERK in a dose- and time-dependent manner. Experiments with the NF-κB inhibitor, MG-132, demonstrated that NF-κB was involved in the induction of CCL2 but not CCL3. Because chemokines have been demonstrated to have profound effects on immune reactions by regulating the trafficking of DC and other lymphocytes into lymphoid organs, Bryo-I was tested as an adjuvant in an E7 peptide (MHC class I-restricted peptide epitope derived from human papillomavirus (HPV) 16 E7 protein)-based cancer vaccine. Mice immunized by s.c. injection with Bryo-I/E7 had enlarged draining lymph nodes and showed an antigen specific T-cell response demonstrated by the release of IFN-γ from isolated splenocytes and in vivo CTL activity. Finally, immunization with Bryo-I/E7 totally prevented the E7-expressing TC-1 tumor growth in mice. In conclusion, for the first time, we demonstrated that Bryo-I induced chemokine release from dendritic cell and was an effective adjuvant for peptide cancer vaccine.
Bryostatin-1（Bryo-1），一种蛋白激酶 C 调节剂，先前已被证明可激活单核细胞和淋巴细胞产生细胞因子。在本报告中，我们研究了 Bryo-1 在体外和体内的佐剂作用。首先，我们发现 Bryo-1 以剂量依赖性方式诱导小鼠骨髓来源树突状细胞（BMDC）释放 CCL2 和 CCL3。低至 0.1nM 的 Bryo-1 即可诱导 BMDC 释放趋化因子，而 5-10nM 时可达到最大诱导效果。PKC 和 ERK 抑制剂均可减弱 CCL2 和 CCL3 的释放。Western blot 结果一致表明，Bryo-1 以剂量和时间依赖性方式激活 ERK。使用 NF-κB 抑制剂 MG-132 的实验表明，NF-κB 参与了 CCL2 的诱导，但不参与 CCL3 的诱导。由于趋化因子已被证明通过调节树突状细胞和其他淋巴细胞向淋巴器官的迁移对免疫反应产生深远影响，因此我们将 Bryo-1 作为 E7 肽（源自人乳头瘤病毒（HPV）16 E7 蛋白的 MHC I 限制性肽表位）基于癌症疫苗的佐剂进行了测试。通过皮下注射 Bryo-1/E7 免疫的小鼠引流淋巴结增大，并通过从分离的脾细胞释放 IFN-γ和体内 CTL 活性证明了针对抗原的 T 细胞反应。最后，用 Bryo-1/E7 免疫完全阻止了表达 E7 的 TC-1 肿瘤在小鼠中的生长。总之，我们首次证明 Bryo-1 诱导树突状细胞释放趋化因子，并可作为有效的肽类癌症疫苗佐剂。
