Augmented antitumor immune responses of HER2-targeted pyroptotic induction by long-lasting recombinant immunopyroptotins
Yuqi Xing,
Feiyu Zhang,
Tian Yang,
Chunhui Yin,
Angang Yang,
Bo Yan,
Jing Zhao
Affiliations
Yuqi Xing
State Key Laboratory of Holistic Integrative Management of Gastrointestinal Cancers and Department of Biochemistry and Molecular Biology, Fourth Military Medical University, Xi'an, 710032, China
Feiyu Zhang
Department of Cardiology, Xijing Hospital, Fourth Military Medical University, Xi'an, 710032, China
Tian Yang
Department of Intensive Care Medicine, Bethune International Peace Hospital, Hebei, 050082, China
Chunhui Yin
State Key Laboratory of Holistic Integrative Management of Gastrointestinal Cancers and Department of Biochemistry and Molecular Biology, Fourth Military Medical University, Xi'an, 710032, China
Angang Yang
State Key Laboratory of Holistic Integrative Management of Gastrointestinal Cancers and Department of Immunology, Fourth Military Medical University, Xi'an, 710032, China; Corresponding author. State Key Laboratory of Holistic Integrative Management of Gastrointestinal Cancers and Department of Immunology, Fourth Military Medical University, Xi'an, No. 169 Changle West Road, Shaanxi 710032, China
Bo Yan
State Key Laboratory of Holistic Integrative Management of Gastrointestinal Cancers and Department of Biochemistry and Molecular Biology, Fourth Military Medical University, Xi'an, 710032, China; Corresponding author. State Key Laboratory of Holistic Integrative Management of Gastrointestinal Cancers and Department of Biochemistry and Molecular Biology, Fourth Military Medical University, Xi'an, No. 169 Changle West Road, Shaanxi 710032, China
Jing Zhao
State Key Laboratory of Holistic Integrative Management of Gastrointestinal Cancers and Department of Biochemistry and Molecular Biology, Fourth Military Medical University, Xi'an, 710032, China; Corresponding author. State Key Laboratory of Holistic Integrative Management of Gastrointestinal Cancers and Department of Biochemistry and Molecular Biology, Fourth Military Medical University, Xi'an, No. 169 Changle West Road, Shaanxi 710032, China
Pyroptosis is a well-documented form of programmed cell death caused by the gasdermin-driven perforation of cell membranes. Selective induction of pyroptosis in tumor cells represents a promising antitumor strategy to enhance the efficacy of immunotherapy. In this study, we established a recombinant protein-based immunopyroptotin strategy that led to the intratumoral induction of pyroptosis for HER2-directed therapy. Long-lasting immunopyroptotins were constructed by sequentially fusing the humanized anti-HER2 single-chain antibody P1h3, albumin-binding peptide (ABD035 or dAb7h8), cathepsin B-cleavable peptide B2, endosome-disruptive peptide E5C3, and active pyroptotic effector gasdermin D-N fragment (GN). After purification, we evaluated the cytotoxicity and antitumor immune responses primarily induced by the immunopyroptotins in HER2-overexpressing breast cancer cells. The resulting ABD035-immunoGN and dAb7h8-immunoGN showed improved in vitro cytotoxicity in HER2-overexpressing cancer cells compared with that in the immunotBid that we previously generated to induce tumor cell apoptosis. The binding of long-lasting immunopyroptotins to albumin increased the half-life by approximately 7-fold in nude mice. The enhanced antitumor efficacy of long-lasting immunopyroptotins was confirmed in both N87 tumor-bearing T cell-deficient mice and 4T1-hHER2 bilateral tumor-bearing immunocompetent mice. Immunopyroptotin treatment elicited systemic antitumor immune responses involving CD8+ T cells and mature dendritic cells and upregulated the expression of proinflammatory cytokines, leading to sustained remission of non-injected distant tumors. This study extends the repertoire of antibody-based therapeutics through the tumor-targeted delivery of a constitutively active pore-forming gasdermin-N fragment, which shows great potential for pyroptosis-based antitumor therapy.
