我们以前报道过纳米脉冲治疗(NPT),脉冲功率技术,导致4T1-luc乳腺肿瘤消除和强烈的原位疫苗接种,从而完全保护无肿瘤动物免受第二次活肿瘤攻击。NPT在4T1乳腺癌中主要是免疫抑制性肿瘤微环境(TME)中产生有效的抗肿瘤免疫反应的机制仍未得到解决。在这项研究中,用NPT治疗原位4T1小鼠乳腺肿瘤(100ns,50kV/cm,1000个脉冲,3Hz)。血,脾,脾引流淋巴结,肿瘤在4小时后被采集,8-h,1天,3天,7天,和3个月的治疗后间隔的频率分析,死亡,和各种免疫细胞的功能标志物,以及调节性T细胞(Tregs)的抑制功能。NPT被证实能引发针对乳腺癌的强原位疫苗接种(ISV)并促进急性和长期T细胞记忆。NPT通过大幅减少Tregs,在系统和TME中消除了免疫抑制优势,骨髓来源的抑制细胞(MDSCs),和肿瘤相关巨噬细胞(TAMs)。NPT诱导Tregs和TAMs细胞凋亡。它还在功能上降低了Treg抑制能力,通过激活标记的下调来解释,特别是4-1BB和TGFβ,和表型从主要活化的(CD44+CD62L-)转变为未活化的(CD44-CD62L+)Treg。重要的是,NPT在活化的Tregs和幸免效应CD4+和CD8+T细胞中选择性诱导凋亡。这些变化伴随着CD8CD103组织驻留的记忆T细胞和TAMM1极化的增加。这些发现表明,NPT有效地将TME和次级淋巴系统从免疫抑制状态转换为免疫刺激状态,允许细胞毒性T细胞功能和免疫记忆形成以消除癌细胞并解释NPT原位疫苗接种。
We previously reported that nano-pulse treatment (NPT), a pulsed power technology, resulted in 4T1-luc mammary tumor elimination and a strong in situ vaccination, thereby completely protecting tumor-free animals against a second live tumor challenge. The mechanism whereby NPT mounts effective antitumor immune responses in the 4T1 breast cancer predominantly immunosuppressive tumor microenvironment (TME) remains unanswered. In this study, orthotopic 4T1 mouse breast tumors were treated with NPT (100 ns, 50 kV/cm, 1000 pulses, 3 Hz). Blood, spleen, draining lymph nodes, and tumors were harvested at 4-h, 8-h, 1-day, 3-day, 7-day, and 3-month post-treatment intervals for the analysis of frequencies, death, and functional markers of various immune cells in addition to the suppressor function of regulatory T cells (Tregs). NPT was verified to elicit strong in situ vaccination (ISV) against breast cancer and promote both acute and long-term T cell memory. NPT abolished immunosuppressive dominance systemically and in the TME by substantially reducing Tregs, myeloid-derived suppressor cells (MDSCs), and tumor-associated macrophages (TAMs). NPT induced apoptosis in Tregs and TAMs. It also functionally diminished the Treg suppression capacity, explained by the downregulation of activation markers, particularly 4-1BB and TGFβ, and a phenotypic shift from predominantly activated (CD44+CD62L-) to naïve (CD44-CD62L+) Tregs. Importantly, NPT selectively induced apoptosis in activated Tregs and spared effector CD4+ and CD8+ T cells. These changes were followed by a concomitant rise in CD8+CD103+ tissue-resident memory T cells and TAM M1 polarization. These findings indicate that NPT effectively switches the TME and secondary lymphatic systems from an immunosuppressive to an immunostimulatory state, allowing cytotoxic T cell function and immune memory formation to eliminate cancer cells and account for the NPT in situ vaccination.