Immune checkpoint blockade(ICB)therapy,which has revolutionized cancer treatment,has been approved for the treatment of triple-negative breast cancer(TNBC).Unfortunately,most patients with TNBC are either not eligible...Immune checkpoint blockade(ICB)therapy,which has revolutionized cancer treatment,has been approved for the treatment of triple-negative breast cancer(TNBC).Unfortunately,most patients with TNBC are either not eligible for treatment or exhibit resistance,resulting in limited overall survival benefits.There is an urgent need to elucidate the mechanisms of resistance and enhance therapeutic efficacy.Here,via CRISPR activation(CRISPRa)screening,we identified family with sequence similarity 114 member A1(FAM114A1)as a key mediator of immune evasion and ICB resistance in TNBC.Mechanistically,FAM114A1 binds p85αto disrupt the p85α/p110αprotein complex,thus activating the PI3K/AKT pathway and simultaneously preventing condensate formation of E2F Transcription Factor 4(E2F4)to promote E2F4-driven Metadherin(MTDH)transcription.Upregulation of these FAM114A1-mediated pathways suppresses tumor antigen presentation and consequently attenuates antitumor immunity in TNBC.Moreover,targeting FAM114A1 improves the therapeutic effectiveness of anti-PD-1 therapy in mouse models,and a FAM114A1-based signature shows strong predictive performance for identifying patients with TNBC who may benefit from ICB.Collectively,our findings not only reveal that FAM114A1 is an immune evasion driver but also highlight it as a promising biomarker and therapeutic target.Our study provides new insights into TNBC immune evasion and outlines a potential avenue to improve the effectiveness of ICB.展开更多
The-1 programmed ribosomal frameshifting(-1 PRF)in severe acute respiratory syndrome coronavirus 2(SARS-CoV-2)is crucial for keeping the balance between pp1a and pp1ab polyproteins.To date,the host factors influencing...The-1 programmed ribosomal frameshifting(-1 PRF)in severe acute respiratory syndrome coronavirus 2(SARS-CoV-2)is crucial for keeping the balance between pp1a and pp1ab polyproteins.To date,the host factors influencing this process remain poorly understood.Using RNA pull-down assays combined with mass spectrometry screening,we discovered five host proteins interacting with-1 PRF RNA,including Stem Loop Binding Protein(SLBP).Our findings revealed that SLBP overexpression enhanced frameshifting and promoted viral replication.Moreover,the interaction between SLBP and-1 PRF RNA was predicted using the PrismNet deep learning tool,which calculated a high binding probability of 0.922.Using Electrophoretic Mobility Shift Assays(EMSAs)and RNA pull down assays,our findings demonstrated SLBP’s direct binding to the SARS-CoV-2 genome,with preferential affinity for the stem loop 3 region of the-1 PRF RNA.Using smFISH assays,we further confirmed their physical colocalization.The role of SLBP in promoting frameshifting was verified using an in vitro translation system.Further investigation showed that SLBP deletions reshaped the host factor pattern around-1 PRF RNA,diminishing interactions with FUBP3 and RPS3A while enhancing RPL10A binding.Together,our findings identify SLBP as a host protein that promotes SARS-CoV-2 frameshifting,highlighting its potential as a druggable target for COVID-19.展开更多
基金supported by grants from the National Natural Science Foundation of China(2021hwyq55 and 82472950 to M.Shen,32270745 to Y.Lu)the Natural Science Foundation of Shanghai(23ZR1466500 to Y.Lu)+1 种基金the Shanghai Municipal Health Commission(2022YQ067 to Y.Lu)supported by the Human Phenome Data Center of Fudan University。
文摘Immune checkpoint blockade(ICB)therapy,which has revolutionized cancer treatment,has been approved for the treatment of triple-negative breast cancer(TNBC).Unfortunately,most patients with TNBC are either not eligible for treatment or exhibit resistance,resulting in limited overall survival benefits.There is an urgent need to elucidate the mechanisms of resistance and enhance therapeutic efficacy.Here,via CRISPR activation(CRISPRa)screening,we identified family with sequence similarity 114 member A1(FAM114A1)as a key mediator of immune evasion and ICB resistance in TNBC.Mechanistically,FAM114A1 binds p85αto disrupt the p85α/p110αprotein complex,thus activating the PI3K/AKT pathway and simultaneously preventing condensate formation of E2F Transcription Factor 4(E2F4)to promote E2F4-driven Metadherin(MTDH)transcription.Upregulation of these FAM114A1-mediated pathways suppresses tumor antigen presentation and consequently attenuates antitumor immunity in TNBC.Moreover,targeting FAM114A1 improves the therapeutic effectiveness of anti-PD-1 therapy in mouse models,and a FAM114A1-based signature shows strong predictive performance for identifying patients with TNBC who may benefit from ICB.Collectively,our findings not only reveal that FAM114A1 is an immune evasion driver but also highlight it as a promising biomarker and therapeutic target.Our study provides new insights into TNBC immune evasion and outlines a potential avenue to improve the effectiveness of ICB.
基金supported by the Major Program of the National Natural Science Foundation of China(No.82394462)the Foundation for Innovative Research Groups of the National Natural Science Foundation of China(82221004)+3 种基金State Key Laboratory Special Fund(2060204)the Yunnan Key R&D Project(202103AQ100001)National Key R&D Program of China(2020YFA0707602,2021YFC230170402,2021YFC0864600,2021YFC0863300)Chinese Academy of Medical Sciences Innovation Fund for Medical Sciences(2023-I2M-2-001,2021-I2M-1-038,2021-I2M-1-039).
文摘The-1 programmed ribosomal frameshifting(-1 PRF)in severe acute respiratory syndrome coronavirus 2(SARS-CoV-2)is crucial for keeping the balance between pp1a and pp1ab polyproteins.To date,the host factors influencing this process remain poorly understood.Using RNA pull-down assays combined with mass spectrometry screening,we discovered five host proteins interacting with-1 PRF RNA,including Stem Loop Binding Protein(SLBP).Our findings revealed that SLBP overexpression enhanced frameshifting and promoted viral replication.Moreover,the interaction between SLBP and-1 PRF RNA was predicted using the PrismNet deep learning tool,which calculated a high binding probability of 0.922.Using Electrophoretic Mobility Shift Assays(EMSAs)and RNA pull down assays,our findings demonstrated SLBP’s direct binding to the SARS-CoV-2 genome,with preferential affinity for the stem loop 3 region of the-1 PRF RNA.Using smFISH assays,we further confirmed their physical colocalization.The role of SLBP in promoting frameshifting was verified using an in vitro translation system.Further investigation showed that SLBP deletions reshaped the host factor pattern around-1 PRF RNA,diminishing interactions with FUBP3 and RPS3A while enhancing RPL10A binding.Together,our findings identify SLBP as a host protein that promotes SARS-CoV-2 frameshifting,highlighting its potential as a druggable target for COVID-19.
