Gut Microbiota Modulation through Akkermansia spp. Supplementation Increases CAR T-cell Potency

Area of Science:

• Microbiology
• Immunology
• Oncology

Background:

• Gut microbiome dysbiosis is linked to cancer treatment outcomes.
• The role of specific gut bacteria in CAR-T cell therapy efficacy remains under investigation.

Purpose of the Study:

• To investigate the clinical relevance of gut microbiome composition and function in anti-CD19 CAR-T cell therapy.
• To explore the mechanistic link between Akkermansia species, host metabolism, and CAR-T cell activity.

Main Methods:

• Analysis of gut microbiome taxonomic and metabolic profiles in B cell lymphoma patients undergoing CAR-T therapy.
• Preclinical syngeneic tumor model studies involving Akkermansia massiliensis supplementation.
• Genetic manipulation of CAR-T cells to assess the role of the aryl hydrocarbon receptor (Ahr).

Main Results:

• CAR-T therapy induced intestinal dysbiosis, characterized by reduced bacterial richness and Akkermansia species, correlating with therapy resistance.
• Oral Akkermansia supplementation enhanced CAR-T cell infiltration, improved CD4/CD8 ratios, promoted Tc1 polarization, and increased indole metabolite production.
• The therapeutic benefits of Akkermansia were dependent on CAR-T cell expression of the aryl hydrocarbon receptor (Ahr), with indole metabolites alone being insufficient.

Conclusions:

• Akkermansia species play a crucial role in the efficacy of anti-CD19 CAR-T cell therapy.
• Targeting the gut microbiome, specifically Akkermansia deficiency, represents a potential strategy to enhance CAR-T cell therapy outcomes.
• The Ahr pathway is a key mediator of Akkermansia-driven improvements in CAR-T cell function.