Intertwining DNA-RNA nanocapsules loaded with tumor neoantigens as synergistic nanovaccines for cancer immunotherapy

TLDR

Nanomedicines that co‑deliver DNA, RNA, and peptide therapeutics are highly desirable yet remain underdeveloped for cancer theranostics. The study reports self‑assembled intertwining DNA‑RNA nanocapsules that co‑deliver CpG, shRNA, and tumor neoantigens to antigen‑presenting cells in lymph nodes to stimulate cancer immunotherapy. The nanovaccines were fabricated by concurrent rolling circle replication and transcription to generate CpG and shRNA, self‑assembly into microflowers, PEG‑grafted cationic polypeptide shrinking into iDR‑NCs, and loading of neoantigen, and CpG and shRNA synergistically activate APCs for sustained antigen presentation. iDR‑NC/neoantigen nanovaccines induced eight‑fold higher neoantigen‑specific peripheral CD8+ T cells, promoted T cell memory, and markedly inhibited colorectal tumor progression, demonstrating the potential of iDR‑NCs as triple‑co‑delivery immunotherapeutic nanovaccines.

Abstract

Nanomedicines that co-deliver DNA, RNA, and peptide therapeutics are highly desirable yet remain underdeveloped for cancer theranostics. Herein, we report self-assembled intertwining DNA-RNA nanocapsules (iDR-NCs) that efficiently delivered synergistic DNA CpG and short hairpin RNA (shRNA) adjuvants, as well as tumor-specific peptide neoantigens into antigen presenting cells (APCs) in lymph nodes for cancer immunotherapy. These nanovaccines were prepared by (1) producing tandem CpG and shRNA via concurrent rolling circle replication and rolling circle transcription, (2) self-assembling CpG and shRNA into DNA-RNA microflowers, (3) shrinking microflowers into iDR-NCs using PEG-grafted cationic polypeptides, and (4) physically loading neoantigen into iDR-NCs. CpG and shRNA in iDR-NCs synergistically activate APCs for sustained antigen presentation. Remarkably, iDR-NC/neoantigen nanovaccines elicit 8-fold more frequent neoantigen-specific peripheral CD8+ T cells than CpG, induce T cell memory, and significantly inhibit the progression of neoantigen-specific colorectal tumors. Collectively, iDR-NCs represent potential DNA/RNA/peptide triple-co-delivery nanocarriers and synergistic tumor immunotherapeutic nanovaccines.