Probiotics are natural systems bridging synthetic biology, physical biotechnology, and immunology, initiating innate and adaptive anti-tumor immune activity. We previously constructed an all-in-one engineered food-grade probiotic Lactococcus lactis (FOLactis) which could boost the crosstalk among different immune cells such as dendritic cells (DCs), natural killer cells, and T cells. Herein, considering the limited clinical efficacy of naked personalized neoantigen peptide vaccines, we decorate FOLactis with tumor antigens by employing a Plug-and-Display system comprising membrane-inserted peptides. Intranodal injection of FOLactis coated with neoantigen peptides (Ag-FOLactis) induces robust DCs presentation and neoantigen-specific cellular immunity. Notably, Ag-FOLactis not only triggers a 45-fold rise in the quantity of locally reactive neoantigen-specific T cells but also induces epitope spreading in both subcutaneous and metastatic tumor-bearing models, leading to potent inhibition of tumor growth. These findings imply that Ag-FOLactis represents a powerful platform to rapidly and easily display antigens, facilitating the development of a bio-activated platform for personalized therapy.

肿瘤免疫治疗的新策略发展迅速，已经成为肿瘤治疗最受瞩目的领域。关于如何实现最理想抗肿瘤免疫效果，可采 用“被动”免疫疗法如过继性细胞疗法、基因工程T细胞等直接攻击肿瘤细胞，也可采用“主动”免疫疗法如细胞因子、肿瘤疫苗、 免疫检查点抑制剂等调节并激活免疫系统。原位疫苗以局部瘤内注射的方式， 将“主动”和“被动”免疫科学地结合起来，在直接 抑制肿瘤细胞的同时深度调节和触发机体免疫系统，形成免疫启动-免疫效应-肿瘤细胞死亡-抗原释放导致免疫再启动-免疫再 效应的反复循环，最大限度地发挥抗肿瘤免疫效果。本文就原位疫苗的具体策略、临床前研究和临床试验的进展，以及原位疫苗 的优势、存在问题和应对策略等展开讨论。

OBJECTIVETo observe the effects of electroacupuncture (EA) on inflammatory reaction of acute myocardial ischemia (MI) in mice, and to explore its action mechanism.

METHODSForty adult male C57BL/6 mice were randomly divided into a control group, a sham operation group, a model group and an EA group, 10 mice in each one. The model was established in the model group and EA group by ligating the left anterior descending branch of coronary artery. The mice in the EA group were treated with EA at "Neiguan" (PC 6) with 2 mA of intensity and 2 Hz /100 Hz of frequency; EA was given 30 min per treatment, once a day for totally 5 days. The mice in the control group and model group were treated with immobilization and no EA was given. The mice in the sham operation group were not treated with ligating at the left anterior descending branch of coronary artery, but the remaining procedure was identical to the model group. The electrocardiogram was recorded and △ST was calculated to evaluate the model. TTC and HE staining methods were applied to evaluate the infarct size and pathologic change of myocardial tissue, respectively. Western blot method was applied to test the protein expression levels of tumor necrosis factor-α (TNF-α), nuclear factor-κB p65 (NF-κB p65), interleukin-1β (IL-1β) and interleukin-8 (IL-8).

RESULTSCompared with the sham operation group, the S-T segments in the model group and EA group were increased obviously after modeling (both <0.01), indicating the MI model was established successfully. The TTC and HE staining results indicated, compared with the sham operation group, the model group had larger infarction size (<0.01), more myocardial fibers injury and inflammatory infiltration; compared with the model group, the infarction size of the EA group was significantly reduced (<0.01), and the myocardial fibers injury and inflammatory infiltration were improved. Compared with the control group, the protein expression levels in the sham operation group were similar (all >0.05); compared with the sham operation group, the expression levels of TNF-α, NF-κB p65, IL-1β and IL-8 were significantly increased in the model group (<0.01, <0.05); compared with the model group, the expression levels of TNF-α, NF-κB p65, IL-1β and IL-8 were significantly reduced in the EA group (all <0.05).

CONCLUSIONEA might reduce the protein expression levels of TNF-α, NF-κB p65, IL-1β and IL-8 in cardiac muscle tissue to inhibit inflammatory reaction and achieve myocardial protective effect in mice with acute myocardial ischemia.

Animals ; Electroacupuncture ; Inflammation ; therapy ; Interleukin-1beta ; metabolism ; Interleukin-8 ; metabolism ; Male ; Mice ; Mice, Inbred C57BL ; Myocardial Ischemia ; therapy ; Myocardium ; pathology ; Random Allocation ; Transcription Factor RelA ; metabolism ; Tumor Necrosis Factor-alpha ; metabolism