摘要
Conventional type 1 dendritic cells(cDC1)are the essential antigen-presenting DC subset in antitumor immunity.Suppressing B-cell lymphoma 9 and B-cell lymphoma 9-like(BCL9/BCL9L)inhibits tumor growth and boosts immune responses against cancer.However,whether oncogenic BCL9/BCL9L impairs antigen presentation in tumors is still not completely understood.Here,we show that targeting BCL9/BCL9L enhanced antigen presentation by stimulating cDC1 activation and infiltration into tumor.Pharmacological inhibition of BCL9/BCL9L with a novel inhibitor hsBCL9z96 or Bcl9/Bcl9l knockout mice markedly delayed tumor growth and promoted antitumor CD8^(+)T cell responses.Mechanistically,targeting BCL9/BCL9L promoted antigen presentation in tumors.This is due to the increase of cDC1 activation and tumor infiltration by the XCL1-XCR1 axis.Importantly,using single-cell transcriptomics analysis,we found that Bcl9/Bcl9l deficient cDC1 were superior to wild-type(WT)cDC1 at activation and antigen presentation via NF-κB/IRF1 signaling.Together,we demonstrate that targeting BCL9/BCL9L plays a crucial role in cDC1-modulated antigen presentation of tumor-derived antigens,as well as CD8^(+)T cell activation and tumor infiltration.Targeting BCL9/BCL9L to regulate cDC1 function and directly orchestrate a positive feedback loop necessary for optimal antitumor immunity could serve as a potential strategy to counter immune suppression and enhance cancer immunotherapy.
基金
the National Natural Science Foundation of China with grants 81872895 and 82073881 awarded to D.Z.,and 81872915,82073904,and 82011530150 to M.-W.W.
the Shanghai Municipal Education Commission under the Shanghai Top-Level University Capacity Building Program(DGF817029-04 to M.-W.W.)
the Shanghai Science and Technology Commission with grants 18ZR1403900,20430713600,and 18JC1413800 to D.Z
Innovative Drug and Evaluation Innovation Team for Tumor Immunotherapy of Jinan Science and Technology Bureau(No.2020GXRC041 to D.Z.)
funded by the Fudan School of Pharmacy and Minhang Hospital Joint Research Fund(RO-MY201712 to D.Z.)
the Fudan-SIMM Joint Research Fund(FU-SIMM20181010 to D.Z.and D.Y.).
