An enzyme-responsive nanoplatform rewires host-microbe tryptophan metabolism for cancer immunotherapy.

An enzyme-responsive nanoplatform enhances microbial indole metabolism and suppresses kynurenine pathway to boost cancer immunotherapy efficacy.

• Why it matters: Imbalanced tryptophan metabolism causes tumor immune tolerance, limiting the success of immunotherapy. Correcting this imbalance could improve treatment outcomes.
• What they did: Researchers developed an oral nanoparticle loaded with tryptophan and coated with an inhibitor, designed for enzyme-responsive release in the large intestine, to modulate host-microbe tryptophan pathways.
• The result: The platform promotes microbial indole derivatives and inhibits the kynurenine pathway, synergistically enhancing antitumor immunity with strong efficacy and biosafety.