The biotherapeutic Clostridium butyricum MIYAIRI 588 strain potentiates enterotropism of Rorγt⁺Treg and PD-1 blockade efficacy

ABSTRACT

Immune checkpoint inhibitors (ICI) have been positioned as a standard of care for patients with advanced non-small-cell lung carcinomas (NSCLC). A pilot clinical trial has reflected optimistic association between supplementation with Clostridium butyricum MIYAIRI 588 (CBM588) and ICI efficacy in NSCLC. However, it remains to be established whether this biotherapeutic strain may be sufficient to heighten the immunogenicity of the tumor draining lymph nodes to overcome resistance to ICI. Herein, we report that supplementation with CBM588 led to an improved responsiveness to antibody targeting programmed cell death protein 1 (aPD-1). This was statistically associated with a significant decrease in α-diversity of gut microbiota from CBM588-treated mice upon PD-1 blockade. At the level of the tumor-draining lymph node, such combination of treatment significantly lowered the frequency of microbiota-modulated subset of regulatory T cells that express Retinoic Orphan Receptor gamma t (Ror$\mathit{\gamma }$t⁺ Treg). Specifically, this strongly immunosuppressive was negatively correlated with the abundance of bacteria that belong to the family of Ruminococcaceae. Accordingly, the colonic expression of both indoleamine 2,3-Dioxygenase 1 (IDO-1) and interleukin-10 (IL-10) were heightened in mice with greater PD-1 blockade efficacy. The CBM588-induced ability to secrete Interleukin-10 of lamina propria mononuclear cells was heightened in tumor bearers when compared with cancer-free mice. Conversely, blockade of interleukin-10 signaling preferentially enhanced the capacity of CD8⁺ T cells to secrete Interferon gamma when being cocultured with CBM588-primed lamina propria mononuclear cells of tumor-bearing mice. Our results demonstrate that CBM588-centered intervention can adequately improve intestinal homeostasis and efficiently overcome resistance to PD-1 blockade in mice.

GRAPHICAL ABSTRACT

KEYWORDS:

• Immune checkpoint inhibitors
• interferon gamma
• interleukin-10
• oncomicrobiotic
• Rorγt⁺T_reg

Acknowledgments

This study was financially supported by Miyarisan Pharmaceutical Co., Ltd., which also provided the CBM588 powder. We thank Ms. Ayaka Minemura and Miyuki Matsuda (Miyarisan Pharmaceutical) for technical assistance. We also thank the staff of PLBS facility (UAR CNRS 2014 - US Inserm 41) for excellent technical instructions and assistance in mice husbandry.

Disclosure statement

A.H., K.O., and M.T. are employee of Miyarisan Pharmaceutical. The other authors declare no competing financial interests.

Author’s contribution

TPDS and OB performed all experiments and analyzed the data. LFP critically contributed to the acquisition, analysis or interpretation of flow cytometry data. KO contributed to the acquisition and analysis of 16S rRNA sequencing data. AH, MT and MC conceived and designed the study. MC wrote the first draft of the manuscript. All authors read and approved the manuscript.

Ethics approval

All animal experiments were approved by the local investigational review board (APAFIS#20990). Animal studies were performed in an accredited establishment (N° B59–350009) according to governmental guidelines N°86/609/CEE.

Data availability statement

All data relevant to the study are included in the article or available as online supplemental information. 16S rRNA data have been deposited to the DNA Data Bank of Japan (accession number DRA017067).

Provenance and peer review

Not commissioned; externally peer reviewed.

Supplementary material

Supplemental data for this article can be accessed online at https://doi.org/10.1080/19490976.2024.2315631

Additional information

Funding

The work was supported by the Miyarisan Pharmaceutical Co. Ltd.