最近，许多努力已经为使用重组细菌毒素治疗癌症而进行，并且该策略已在各种癌症的临床试验中得到应用。治疗性DNA癌症疫苗现在被认为是一种激活免疫系统抵抗癌症的有前途策略。癌症疫苗可以诱导针对肿瘤的特异性和持久性免疫反应。本研究旨在评估SEB DNA疫苗作为新的抗肿瘤候选药物对小鼠乳腺肿瘤的抗肿瘤效能。为了确定SEB构成对抑制小鼠体内肿瘤细胞生长的影响，将合成的SEB基因，随后转化密码子优化和嵌入剪切位点，亚克隆到表达载体中。然后，注射SEB构成物、SEB和PBS到小鼠中。接种疫苗后，在小鼠右侧侧腹皮下注射4T1癌细胞。然后，采用ELISA方法评估IL-4和IFN-γ的细胞因子水平以评估抗肿瘤活性。评估脾淋巴细胞增殖，肿瘤大小和存活时间。与其他组相比，SEB-Vac组的IFN-γ浓度显著增加。DNA疫苗组中的IL-4产生没有与对照组相比显著变化。与PBS对照组相比，接受SEB构成物小鼠组中的淋巴细胞增殖显著增加（p<0.001）。虽然肿瘤大小显著降低（p<0.001），但观察到接受重组构成物的动物模型中的肿瘤组织坏死显著增加（p<0.01）以及存活时间显著增加。设计的SEB基因构成物可以成为乳腺癌的新模型疫苗，因为它可以有效诱导坏死并产生特异性免疫反应。这种结构不会伤害正常细胞，比化疗和放射治疗更安全。它的缓慢和长期释放温和地刺激免疫系统和细胞记忆。它可以作为诱导凋亡和抗肿瘤免疫的新模型应用于治疗癌症。©2023作者，独家授权Springer Nature Switzerland AG。

Recently, many efforts have been made to treat cancer using recombinant bacterial toxins and this strategy has been used in clinical trials of various cancers. Therapeutic DNA cancer vaccines are now considered as a promising strategy to activate the immune system against cancer. Cancer vaccines could induce specific and long-lasting immune responses against tumors. This study aimed to evaluate the antitumor potency of the SEB DNA vaccine as a new antitumor candidate against breast tumors in vivo. To determine the effect of the SEB construct on inhibiting tumor cell growth in vivo, the synthetic SEB gene, subsequent codon optimization, and embedding the cleavage sites were sub-cloned to an expression vector. Then, SEB construct, SEB, and PBS were injected into the mice. After being vaccinated, 4T1 cancer cells were injected subcutaneously into the right flank of mice. Then, the cytokine levels of IL-4 and IFN-γ were estimated by the ELISA method to evaluate the antitumor activity. The spleen lymphocyte proliferation, tumor size, and survival time were assessed. The concentration of IFN-γ in the SEB-Vac group showed a significant increase compared to other groups. The production of IL-4 in the group that received the DNA vaccine did not change significantly compared to the control group. The lymphocyte proliferation increased significantly in the mice group that received SEB construct than PBS control group (p < 0.001). While there was a meaningful decrease in tumor size (p < 0.001), a significant increase in tumor tissue necrosis (p < 0.01) and also in survival time of the animal model receiving the recombinant construct was observed. The designed SEB gene construct can be a new model vaccine for breast cancer because it effectively induces necrosis and produces specific immune responses. This structure does not hurt normal cells and is a safer treatment than chemotherapy and radiation therapy. Its slow and long-term release gently stimulates the immune system and cellular memory. It could be applied as a new model for inducing apoptosis and antitumor immunity to treat cancer.© 2023. The Author(s), under exclusive licence to Springer Nature Switzerland AG.