ABSTRACT Checkpoint blockade therapies targeting PD‐L1 have revolutionized cancer immunotherapy, yet their efficacy is constrained by systemic immune toxicity and inadequate immune infiltration in certain tumor types. Here, we introduce a synergistic gene‐silencing nanosystem based on a target‐selective Pistol ribozyme (PS473) encapsulated within a manganese‐based, pH‐responsive metal–organic framework (NKMOF‐101‐Mn). The engineered PS473 exhibited high cleavage efficiency toward GU‐rich PD‐L1 mRNA motifs and was further activated by Mn 2 + cofactors. NKMOF‐101‐Mn not only protects the ribozyme from nuclease degradation but also enables localized Mn 2 + release to increase catalytic activity and innate immune signaling under the acidic tumor microenvironment. In vitro, PS473@NKMOF‐101‐Mn markedly suppressed PD‐L1 expression and promoted macrophage activation. In the B16F10 melanoma model, this system achieved over 90% tumor inhibition, enhanced immune cell infiltration and activation, and exhibited minimal systemic toxicity. Transcriptomic profiling further revealed the upregulation of immune‐related pathways, supporting a synergistic mechanism of gene silencing and immune activation. Overall, this study established a ribozyme‐directed immunotherapeutic platform with strong potential for precision cancer therapy via checkpoint modulation and immune reprogramming.
Zhao et al. (Tue,) studied this question.