On-demand integrated nano-engager converting cold tumors to hot via increased DNA damage and dual immune checkpoint inhibition

Cancer immunotherapy has become a promising strategy.However,the effectiveness of immunotherapy is restricted in"cold tumors"characterized with insufficient T cells intratumoral infiltration and failed T cells priming.Herein,an on-demand integrated nano-engager(JOT-Lip)was developed to convert cold tumors to hot via"increased DNA damage and dual immune checkpoint inhibition"strategy.JOT-Lip was engineered by co-loading oxaliplatin(Oxa)and JQ1 into liposomes with T-cell immunoglobulin mucin-3 antibodies(Tim-3 mAb)coupled on the liposomal surface by metalloproteinase-2(MMP-2)-sensitive linker.JQ1 inhibited DNA repair to increase DNA damage and immunogenic cell death(ICD)of Oxa,thus promoting T cells intratumoral infiltration.In addition,JQ1 inhibited PD-1/PD-L1 pathway,achieving dual immune checkpoint inhibition combining with Tim-3 mAb,thus effectively promoting T cells priming.It is demonstrated that JOT-Lip not only increased DNA damage and promoted the release of damage-associated molecular patterns(DAMPs),but also enhanced T cells intratumoral infiltration and promoted T cell priming,which successfully converted cold tumors to hot and showed significant anti-tumor and anti-metastasis effects.Collectively,our study provides a rational design of an effective combination regimen and an ideal co-delivery system to convert cold tumors to hot,which holds great potential in clinical cancer chemoimmunotherapy.