Noninvasive PET tracking of post-transplant gut microbiota in living mice
Noninvasive PET tracking of post-transplant gut microbiota in living mice
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无创 PET 追踪活体小鼠移植后肠道微生物群
DOI：
10.1007/s00259-019-04639-3
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发表时间：
2020
期刊：
影响因子：
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通讯作者：
Zhaofei Liu
中科院分区：
文献类型：
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作者：
Yanpu Wang;Chenran Zhang;Jianhao Lai;Yang Zhao;Dehua Lu;Rui Bao;Xun Feng;Ting Zhang;Zhaofei Liu
目的肠道菌群在决定免疫检查点抑制剂抗肿瘤效果中的作用越来越受到关注，粪便细菌移植已被认为是改善或挽救免疫检查点抑制效果的有前途的策略。然而，移植后体内细菌行为的精确监测技术是有限的。在这项研究中，我们的目的是使用代谢标记和随后的正电子发射断层扫描（PET）成像跟踪肠道细菌的体内行为，负责抗PD-1治疗的疗效在活mice.MethodsThe抗PD-1封锁的抗肿瘤作用进行了测试，在低反应4 T1同基因小鼠模型有或没有粪便移植和有或没有广谱抗生素亚胺培南治疗。对抗PD-1治疗前后4 T1荷瘤小鼠粪便中的16 S rRNA基因扩增子进行高通量测序分析。鉴定出的细菌为脆弱拟杆菌（Bacteroides fragilis，B. fragilis），用64 Cu和荧光染料通过N3的代谢标记随后通过点击化学进行标记。体内PET和B.结果肠道菌群失调降低了抗PD-1治疗的效果，B.脆性灌胃和PD-1阻断有利于挽救抗PD-1治疗的抗肿瘤效果。代谢寡糖工程和双正交点击化学导致了成功的B。用64 Cu和荧光染料标记的fragilis具有高的体外和体内稳定性，并且对活力没有影响。PET成像成功地检测了B.结论通过代谢标记的PET跟踪是一种强大的，非侵入性的工具，用于肠道微生物群的实时跟踪和定量成像。该策略在临床上是可转化的，并且还可以扩展到其他功能细胞的PET跟踪，以指导基于细胞的过继治疗。
PurposeThe role that gut microbiota plays in determining the efficacy of the anti-tumor effect of immune checkpoint inhibitors is gaining increasing attention, and fecal bacterial transplantation has been recognized as a promising strategy for improving or rescuing the effect of immune checkpoint inhibition. However, techniques for the precise monitoring of in vivo bacterial behaviors after transplantation are limited. In this study, we aimed to use metabolic labeling and subsequent positron emission tomography (PET) imaging to track the in vivo behaviors of gut bacteria that are responsible for the efficacy of anti-PD-1 therapy in living mice.MethodsThe antitumor effect of anti-PD-1 blockade was tested in a low-response 4T1 syngeneic mouse model with or without fecal transplantation and with or without broad-spectrum antibiotic imipenem treatment. High-throughput sequencing analyses of 16S rRNA gene amplicons in feces of 4T1 tumor-bearing mice pre- and post-anti-PD-1 treatment were performed. The identified bacteria,Bacteroides fragilis(B. fragilis), were labeled with64Cu and fluorescence dye by the metabolic labeling of N3followed by click chemistry. In vivo PET and optical imaging ofB. fragiliswere performed in mice after oral gavage.ResultsThe disturbance of gut microbiota reduced the efficacy of anti-PD-1 treatment, and the combination ofB. fragilisgavage and PD-1 blockade was beneficial in rescuing the antitumor effect of anti-PD-1 therapy. Metabolic oligosaccharide engineering and biorthogonal click chemistry resulted in successfulB. fragilislabeling with64Cu and fluorescence dye with high in vitro and in vivo stability and no effect on viability. PET imaging successfully detected the in vivo behaviors ofB. fragilisafter transplantation.ConclusionPET tracking by metabolic labeling is a powerful, noninvasive tool for the real-time tracking and quantitative imaging of gut microbiota. This strategy is clinically translatable and may also be extended to the PET tracking of other functional cells to guide cell-based adoptive therapies.