Bacillus Calmette-Guérin (BCG) vaccine is the live attenuated vaccine form of Mycobacterium bovis used to prevent tuberculosis and other mycobacterial infections. Now, using zebrafish “avatars,” a model developed by the Cancer Development and Innate Immune Evasion lab at the Champalimaud Foundation (CF), researchers demonstrate that the vaccine may be used to help destroy bladder cancer cells..

卡介苗（BCG）是牛分枝杆菌的减毒活疫苗，用于预防结核病和其他分枝杆菌感染。现在，研究人员使用斑马鱼“化身”（一种由Champalimaud基金会（CF）癌症发展和先天免疫逃避实验室开发的模型）证明，该疫苗可能用于帮助破坏膀胱癌细胞。。

The findings are published in the journal Disease Models and Mechanisms in an article entitled “Macrophages directly kill bladder cancer cells through TNF signaling in an early response to BCG therapy,” and led by Rita Fior, Mayra Martínez-López—a former PhD student at the lab now working at the Universidad de las Américas in Quito, Ecuador..

这一发现发表在《疾病模型与机制》杂志上，发表在一篇题为“巨噬细胞通过TNF信号直接杀死膀胱癌细胞，对卡介苗治疗有早期反应”的文章中，由Rita Fior、Mayra Martínez-López领导，Mayra Martínez-López是该实验室的前博士生，目前在厄瓜多尔基多的拉斯美洲大学工作。。

“The Bacillus Calmette–Guérin (BCG) vaccine is the oldest cancer immunotherapeutic agent in use,” the researchers wrote. “Despite its effectiveness, its initial mechanisms of action remain largely unknown. Here, we elucidate the earliest cellular mechanisms involved in BCG-induced tumor clearance. We developed a fast preclinical in vivo assay to visualize in real time and at single-cell resolution the initial interactions among bladder cancer cells, BCG and innate immunity using the zebrafish xenograft model.

研究人员写道：“卡介苗（BCG）是目前使用的最古老的癌症免疫治疗剂。”。“尽管其有效性，但其最初的作用机制在很大程度上仍然未知。在这里，我们阐明了卡介苗诱导的肿瘤清除所涉及的最早的细胞机制。我们开发了一种快速的临床前体内测定方法，以实时和单细胞分辨率可视化使用斑马鱼异种移植模型的膀胱癌细胞，卡介苗和先天免疫之间的初始相互作用。

We show that BCG induced the recruitment and polarization of macrophages towards a pro-inflammatory phenotype, accompanied by induction of the inflammatory cytokines tnfa, il1b and il6 in the tumor microenvironment.”.

我们显示卡介苗诱导巨噬细胞向促炎表型的募集和极化，伴随着肿瘤微环境中炎性细胞因子TNFα，il1b和il6的诱导。”。

The idea behind zebrafish Avatars (zAvatars), which are still an experimental model, is to take tumor cells from a cancer patient and inject them into zebrafish embryos. The tumors will then grow inside the embryos, effectively turning them into Avatars of that specific cancer patient. The various treatment options available for that patient can then be tested on the zAvatars, and, in a matter of days rather than several weeks, or even months, that it takes using the traditional testing in mice, it will be possible to determine the best treatment for that patient..

斑马鱼化身（zavatar）仍然是一个实验模型，其背后的想法是从癌症患者身上提取肿瘤细胞，并将其注射到斑马鱼胚胎中。然后肿瘤会在胚胎内生长，有效地将它们变成特定癌症患者的化身。然后可以在Zavatar上测试该患者可用的各种治疗方案，并且在几天而不是几周甚至几个月的时间内，使用传统的小鼠测试就可以确定该患者的最佳治疗方案。。

Fior had a new idea for applying the model. “When I joined Rita’s lab, as a PhD student” (in 2019), Martínez-López recalls, “we were discussing several projects I could undertake, and Rita mentioned that the BCG vaccine was being used in bladder cancer patients.” Martínez-López remembered getting the BCG against tuberculosis when she was a child in South America, and had later worked on the disease.

Fior有一个应用该模型的新想法。Martínez-López回忆道：“当我作为一名博士生加入Rita的实验室时（2019年），“我们正在讨论我可以承担的几个项目，Rita提到BCG疫苗正在膀胱癌患者中使用。”Martínez-López记得她小时候在南美洲接受过抗结核病的BCG治疗，后来就开始研究这种疾病。

“But it was the first time I heard of the TB vaccine as a cancer treatment”, she points out..

她指出：“但这是我第一次听说结核病疫苗可以治疗癌症。”。。

“BCG immunotherapy is still rather empirically used” says Martínez-López. “However, since it works for many people, it has become a gold standard treatment. Surprisingly, it is a very effective immunotherapy, even when compared to so many fancy immunotherapies that are being developed.”

Martínez-López说：“卡介苗免疫疗法仍然是经验性使用的”。“然而，由于它对许多人有效，它已成为金标准疗法。令人惊讶的是，它是一种非常有效的免疫疗法，即使与正在开发的许多花式免疫疗法相比也是如此。”

The treatment consists of instilling the BCG vaccine directly into the bladder. When the treatment works, the 15-year survival rate for patients with so-called “non-muscle-invasive” (early-stage) bladder cancer is 60% to 70%. However, in 30% to 50% of the cases, bladder tumours are unresponsive to BCG treatment.

治疗包括将卡介苗直接注入膀胱。当治疗有效时，所谓的“非肌肉浸润性”（早期）膀胱癌患者的15年生存率为60%至70%。然而，在30%至50%的病例中，膀胱肿瘤对卡介苗治疗无反应。

In these cases, the whole bladder has to be removed..

在这种情况下，必须切除整个膀胱。。

Until now, the way the BCG vaccine works as an immunomodulator to clear bladder tumors was not fully known.

到目前为止，卡介苗作为免疫调节剂清除膀胱肿瘤的方式尚不完全清楚。

The team’s idea was that immune cells, and in particular macrophages resident in the bladder, were involved. And they were able to determine what happens right after BCG is injected into zebrafish Avatars. To do this, they used so-called light sheet microscopy and confocal imaging, which allowed them to see the macrophages interacting with the tumour cells, at single cell resolution and in real time..

该团队的想法是免疫细胞，特别是膀胱中的巨噬细胞参与其中。他们能够确定卡介苗注射到斑马鱼化身后会发生什么。为此，他们使用了所谓的光片显微镜和共聚焦成像，这使他们能够以单细胞分辨率实时观察巨噬细胞与肿瘤细胞的相互作用。。

The researchers further showed that, when macrophages were depleted in the zAvatar, the anti-tumor effects of the BCG vaccine were completely blocked, suggesting that macrophages are crucial for the initial anti-tumor response.

研究人员进一步表明，当巨噬细胞在zAvatar中耗尽时，卡介苗的抗肿瘤作用被完全阻断，这表明巨噬细胞对于最初的抗肿瘤反应至关重要。

“What Mayra saw”, says Rita Fior, “was that if you inject BCG, you have a marked increase of the amount of macrophages going into the tumor.”

Rita Fior说：“Mayra看到的是，如果注射卡介苗，进入肿瘤的巨噬细胞数量会明显增加。”

“Not only did we unravel the mechanisms involved in the first steps of the vaccine’s anti-tumoral action, we also demonstrated that the zebrafish Avatar model is a powerful preclinical tool for drug discovery in oncology”, concluded Martínez-López.

Martínez-López总结道：“我们不仅揭示了疫苗抗肿瘤作用的第一步所涉及的机制，还证明了斑马鱼化身模型是肿瘤学药物发现的强大临床前工具。”。

NewsBladder cancerImmunotherapyMacrophagesTuberculosis vaccineZebrafish

新膀胱癌免疫治疗大噬菌体疫苗斑马鱼