Journal Articles

A genome‑wide screen in E. coli reveals metabolic adaptations that enhance intratumoral fitness and bacterial cancer therapy efficacy

Spotlight 

Utilizing a high-throughput barcoded KO screen targeting all non-essential E. coli genes, Chen et al. identified that KO of non-glucose phosphotransferase system genes enhanced intratumoral fitness and tumor colonization by increasing glucose avidity. A quadruple-mutant, tumor-avid E. coli strain (Ec-TA) outcompeted and displaced wild-type E. coli from pre-colonized tumors, demonstrated tumor specificity and a favorable safety profile, and increased delivery of an IFNγ payload upon intravenous administration. Ec-TA-IFNγ enhanced intratumoral IFNγ and effector T cell responses, and reduced tumor burden across colorectal tumor models.

Contributed by Ute Burkhardt

Utilizing a high-throughput barcoded KO screen targeting all non-essential E. coli genes, Chen et al. identified that KO of non-glucose phosphotransferase system genes enhanced intratumoral fitness and tumor colonization by increasing glucose avidity. A quadruple-mutant, tumor-avid E. coli strain (Ec-TA) outcompeted and displaced wild-type E. coli from pre-colonized tumors, demonstrated tumor specificity and a favorable safety profile, and increased delivery of an IFNγ payload upon intravenous administration. Ec-TA-IFNγ enhanced intratumoral IFNγ and effector T cell responses, and reduced tumor burden across colorectal tumor models.

Contributed by Ute Burkhardt

ABSTRACT: Despite decades of investigation, the fundamental molecular and cellular principles that enable bacteria to thrive within the tumor microenvironment have yet to be defined. Here, through a genome‑wide functional screen, we identify the bacterial genes and pathways that govern intratumoral fitness. Targeted deletion of nonglucose phosphotransferase systems to align bacterial metabolic preference with tumor metabolite availability promotes bacterial intratumoral fitness. Integrating multiple metabolic adaptations into a single tumor‑avid Escherichia coli strain (Ec‑TA) results in increased tumor colonization, not only after intratumoral delivery but also after intravenous delivery, leading to increased anti‑tumor efficacy when using Ec‑TA engineered to deliver an encoded immunostimulatory payload. Furthermore, Ec‑TA displaces wild‑type bacteria from pre‑colonized tumors when administered systemically, underscoring its potential for locally delivering therapeutics in the presence of resident tumor microbes. These data demonstrate that adapting bacteria to the unique characteristics of the tumor metabolic microenvironment can drive the development of safer and more effective chassis for next‑generation bacterial cancer therapies.

Author Info: (1) Department of Microbiology & Immunology, Columbia University, New York, NY, USA. Herbert Irving Comprehensive Cancer Center, Vagelos College of Physicians and Surgeons, Columbi

Author Info: (1) Department of Microbiology & Immunology, Columbia University, New York, NY, USA. Herbert Irving Comprehensive Cancer Center, Vagelos College of Physicians and Surgeons, Columbia University, New York, NY, USA. (2) Department of Microbiology & Immunology, Columbia University, New York, NY, USA. Herbert Irving Comprehensive Cancer Center, Vagelos College of Physicians and Surgeons, Columbia University, New York, NY, USA. (3) Department of Microbiology & Immunology, Columbia University, New York, NY, USA. (4) Department of Microbiology & Immunology, Columbia University, New York, NY, USA. (5) Department of Microbiology & Immunology, Columbia University, New York, NY, USA. (6) Herbert Irving Comprehensive Cancer Center, Vagelos College of Physicians and Surgeons, Columbia University, New York, NY, USA. Division of Digestive and Liver Diseases, Department of Medicine, Vagelos College of Physicians and Surgeons, Columbia University Irving Medical Center, New York, NY, USA. (7) Herbert Irving Comprehensive Cancer Center, Vagelos College of Physicians and Surgeons, Columbia University, New York, NY, USA. Division of Digestive and Liver Diseases, Department of Medicine, Vagelos College of Physicians and Surgeons, Columbia University Irving Medical Center, New York, NY, USA. (8) Department of Biological Sciences, Columbia University, New York, NY, USA. (9) Department of Microbiology & Immunology, Columbia University, New York, NY, USA. Herbert Irving Comprehensive Cancer Center, Vagelos College of Physicians and Surgeons, Columbia University, New York, NY, USA. (10) Department of Microbiology & Immunology, Columbia University, New York, NY, USA. (11) Department of Microbiology & Immunology, Columbia University, New York, NY, USA. (12) Department of Biological Sciences, Department of Chemistry, and Department of Pathology and Cell Biology, Herbert Irving Comprehensive Cancer Center, Irving Institute for Cancer Dynamics, Digestive and Liver Disease Research Center, Columbia University, New York, NY, USA. (13) Department of Environmental Science and Technology, Faculty of Engineering, Shinshu University, Nagano, Japan. (14) Herbert Irving Comprehensive Cancer Center, Vagelos College of Physicians and Surgeons, Columbia University, New York, NY, USA. Department of Biomedical Engineering, Columbia University, New York, NY, USA. Data Science Institute, Columbia University, New York, NY, USA. (15) Department of Microbiology & Immunology, Columbia University, New York, NY, USA. na2697@cumc.columbia.edu. Herbert Irving Comprehensive Cancer Center, Vagelos College of Physicians and Surgeons, Columbia University, New York, NY, USA. na2697@cumc.columbia.edu.

Tumor-to-dendritic cell reprogramming induces immunogenic lymphoid structures across cancers Featured  

Ascic, Chatelain, et al. investigated TLSs initiated in various tumor models after PIB-transduction of tumor cells into cDC1s. Immunogenic TLSs formed in tumors and were associated with improved outcomes, immune memory, and, in some cases, synergized with ICB. TLS formation was dependent on T and B cells, and on MHC-I and CD40 signaling.

Ascic, Chatelain, et al. investigated TLSs initiated in various tumor models after PIB-transduction of tumor cells into cDC1s. Immunogenic TLSs formed in tumors and were associated with improved outcomes, immune memory, and, in some cases, synergized with ICB. TLS formation was dependent on T and B cells, and on MHC-I and CD40 signaling.

ABSTRACT: Tertiary lymphoid structures (TLSs) in tumors are associated with improved responses to immunotherapy. Here, we examined the impact of type 1 conventional dendritic cells (cDC1s) in TLS formation. Reprogrammed tumor cells into cDC1-like cells remodeled the tumor microenvironment and induced immunogenic TLSs (imgTLSs) across melanoma, colon, bladder, breast, and pancreatic cancer models with distinct genetic backgrounds. cDC1-like cells activated lymphotoxin, TNF, and interferon programs and engaged early with T cells through MHC class I and CD40 signaling to induce imgTLSs containing BCL6(+) germinal centers, independently of endogenous cDC1s. Intratumoral positioning shaped distinct cDC1-like cell states, with DC-LAMP(+) CCR7(+) migratory cDC1s nucleating niches enriched in CD4(+), CD8(+) T cells, and B cells in mouse and human tumors. ImgTLSs sustained B and T cell responses and promoted systemic immunity through expansion of shared clonotypes in distant, untreated tumors. Our findings outline the spatial organization, signaling programs and interactions of cDC1-like cells that initiate intratumoral lymphoid structures and establish cellular reprogramming as a strategy toward overcoming resistance to immunotherapy.

Author Info: (1) Division of Immuno-Oncology, Lund Stem Cell Center, Lund University, Lund, Sweden; Wallenberg Centre for Molecular Medicine, Lund University, Lund, Sweden; Science for Life Lab

Author Info: (1) Division of Immuno-Oncology, Lund Stem Cell Center, Lund University, Lund, Sweden; Wallenberg Centre for Molecular Medicine, Lund University, Lund, Sweden; Science for Life Laboratory (SciLifeLab), Lund University, Lund, Sweden. (2) Division of Immuno-Oncology, Lund Stem Cell Center, Lund University, Lund, Sweden; Wallenberg Centre for Molecular Medicine, Lund University, Lund, Sweden; Science for Life Laboratory (SciLifeLab), Lund University, Lund, Sweden. (3) Division of Immuno-Oncology, Lund Stem Cell Center, Lund University, Lund, Sweden; Wallenberg Centre for Molecular Medicine, Lund University, Lund, Sweden; Science for Life Laboratory (SciLifeLab), Lund University, Lund, Sweden. (4) Division of Immuno-Oncology, Lund Stem Cell Center, Lund University, Lund, Sweden; Wallenberg Centre for Molecular Medicine, Lund University, Lund, Sweden; Science for Life Laboratory (SciLifeLab), Lund University, Lund, Sweden. (5) Division of Immuno-Oncology, Lund Stem Cell Center, Lund University, Lund, Sweden; Wallenberg Centre for Molecular Medicine, Lund University, Lund, Sweden; Science for Life Laboratory (SciLifeLab), Lund University, Lund, Sweden; State Key Laboratory of Systems Medicine for Cancer, Shanghai Cancer Institute, Renji Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China. (6) Division of Immuno-Oncology, Lund Stem Cell Center, Lund University, Lund, Sweden; Wallenberg Centre for Molecular Medicine, Lund University, Lund, Sweden; Science for Life Laboratory (SciLifeLab), Lund University, Lund, Sweden. (7) Division of Immuno-Oncology, Lund Stem Cell Center, Lund University, Lund, Sweden; Wallenberg Centre for Molecular Medicine, Lund University, Lund, Sweden; Science for Life Laboratory (SciLifeLab), Lund University, Lund, Sweden. (8) Division of Immuno-Oncology, Lund Stem Cell Center, Lund University, Lund, Sweden; Wallenberg Centre for Molecular Medicine, Lund University, Lund, Sweden; Science for Life Laboratory (SciLifeLab), Lund University, Lund, Sweden. (9) Division of Immuno-Oncology, Lund Stem Cell Center, Lund University, Lund, Sweden; Wallenberg Centre for Molecular Medicine, Lund University, Lund, Sweden; Science for Life Laboratory (SciLifeLab), Lund University, Lund, Sweden. (10) Division of Immuno-Oncology, Lund Stem Cell Center, Lund University, Lund, Sweden; Wallenberg Centre for Molecular Medicine, Lund University, Lund, Sweden; Science for Life Laboratory (SciLifeLab), Lund University, Lund, Sweden. (11) Division of Immuno-Oncology, Lund Stem Cell Center, Lund University, Lund, Sweden; Wallenberg Centre for Molecular Medicine, Lund University, Lund, Sweden; Science for Life Laboratory (SciLifeLab), Lund University, Lund, Sweden. (12) Department of Clinical Sciences, Division of Oncology and Pathology, Lund University Cancer Center, Lund University, Lund, Sweden. (13) Department of Clinical Sciences, Division of Oncology and Pathology, Lund University Cancer Center, Lund University, Lund, Sweden. (14) Department of Clinical Sciences, Division of Oncology and Pathology, Lund University Cancer Center, Lund University, Lund, Sweden; Asgard Therapeutics AB, Medicon Village, Lund, Sweden. (15) Asgard Therapeutics AB, Medicon Village, Lund, Sweden. (16) Asgard Therapeutics AB, Medicon Village, Lund, Sweden. (17) Division of Immuno-Oncology, Lund Stem Cell Center, Lund University, Lund, Sweden; Wallenberg Centre for Molecular Medicine, Lund University, Lund, Sweden; Science for Life Laboratory (SciLifeLab), Lund University, Lund, Sweden. (18) Department of Clinical Sciences, Lund University, SkŒne university hospital, Lund, Sweden. (19) Department of Clinical Sciences, Lund University, SkŒne university hospital, Lund, Sweden. (20) Department of Clinical Sciences, Lund University, SkŒne university hospital, Lund, Sweden. (21) Asgard Therapeutics AB, Medicon Village, Lund, Sweden. (22) Department of Clinical Sciences, Division of Oncology and Pathology, Lund University Cancer Center, Lund University, Lund, Sweden. (23) Division of Immuno-Oncology, Lund Stem Cell Center, Lund University, Lund, Sweden; Wallenberg Centre for Molecular Medicine, Lund University, Lund, Sweden; Science for Life Laboratory (SciLifeLab), Lund University, Lund, Sweden. (24) Division of Immuno-Oncology, Lund Stem Cell Center, Lund University, Lund, Sweden; Wallenberg Centre for Molecular Medicine, Lund University, Lund, Sweden; Science for Life Laboratory (SciLifeLab), Lund University, Lund, Sweden; Asgard Therapeutics AB, Medicon Village, Lund, Sweden; CNC - Centre for Neuroscience and Cell Biology, University of Coimbra, Largo Marqus do Pombal, Coimbra, Portugal; CiBB - Centre for Innovative Biomedicine and Biotechnology, University of Coimbra, Coimbra, Portugal. Electronic address: filipe.pereira@med.lu.se.

Targeting MDA5 induces immunogenic cell death and promotes anti-tumor immunity

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Niu and Cheng et al. found that the RNA sensor MDA5 promoted tumor immune evasion by suppressing the unfolded protein response and the release of DAMPs associated with immunogenic cell death (ICD). Targeting MDA5 in murine tumors enhanced ICD as well as DC antigen uptake and cross-talk with T cells, resulting in increased T cell activation, tumor infiltration, effector functions, and memory. MDA5 depletion also primed the ASK1-JNK/P38 pathway in tumors, increasing vulnerability to TNFα and IFNγ. In patient data, MDA5 was upregulated in cancer, and high pre-treatment MDA5 predicted poor survival and resistance to ICB across multiple cancers.

Contributed by Lauren Hitchings

Niu and Cheng et al. found that the RNA sensor MDA5 promoted tumor immune evasion by suppressing the unfolded protein response and the release of DAMPs associated with immunogenic cell death (ICD). Targeting MDA5 in murine tumors enhanced ICD as well as DC antigen uptake and cross-talk with T cells, resulting in increased T cell activation, tumor infiltration, effector functions, and memory. MDA5 depletion also primed the ASK1-JNK/P38 pathway in tumors, increasing vulnerability to TNFα and IFNγ. In patient data, MDA5 was upregulated in cancer, and high pre-treatment MDA5 predicted poor survival and resistance to ICB across multiple cancers.

Contributed by Lauren Hitchings

ABSTRACT: Identifying targets to enhance tumor immunity is an urgent need. Although nucleic acid sensors play critical roles in promoting tumor immune clearance, their exceptionally low mutation rate in cancers suggests potential unexplored roles in tumor progression. Here, we demonstrate that the RNA sensor melanoma differentiation-associated protein 5 (MDA5) promotes immune evasion, and its high expression is strongly predictive of poor survival and resistance to immune checkpoint blockade (ICB) therapy in patients. Targeting MDA5 reshapes the tumor microenvironment, strengthening immune memory responses and enhancing effector CD8⁺ T cell activity in preclinical models in female mice. Mechanistically, MDA5 deficiency triggers unfolded protein response driven immunogenic cell death through induction of damage-associated molecular patterns, leading to enhanced dendritic cell-mediated antigen engulfment and T cell activation. Additionally, MDA5 loss primes the ASK1-JNK/P38 signaling pathway, sensitizing tumor cells to TNF-α/IFN-γ, further amplifying this process. Consequently, targeting MDA5 enhances the efficacy of ICB therapy across multiple cancer types, positioning it as a promising therapeutic target.

Author Info: Guangdong Provincial Key laboratory of Colorectal and Pelvic Floor Disease, The Sixth Affiliated Hospital, Sun Yat-sen University, Guangzhou, 510655, China Zhitong Niu, Bing Cheng,

Author Info: Guangdong Provincial Key laboratory of Colorectal and Pelvic Floor Disease, The Sixth Affiliated Hospital, Sun Yat-sen University, Guangzhou, 510655, China Zhitong Niu, Bing Cheng, Yue Jiang, Yingzhen Weng, Qian Xiao, Chaoying Wei, Qiufeng Liu, Jinxin Chen, Xiaojian Wu & Wenyu WangGuangdong Institute of Gastroenterology, The Sixth Affiliated Hospital, Sun Yat-sen University, Guangzhou, 510655, China Zhitong Niu, Bing Cheng, Yue Jiang, Yingzhen Weng, Qian Xiao, Chaoying Wei, Qiufeng Liu, Jinxin Chen, Xiaojian Wu & Wenyu WangBiomedical Innovation Center, The Sixth Affiliated Hospital, Sun Yat-sen University, Guangzhou, 510655, China Zhitong Niu, Bing Cheng, Yue Jiang, Yingzhen Weng, Qian Xiao, Guojie Long, Chaoying Wei, Qiufeng Liu, Jinxin Chen, Xiaofeng Wen, Yufeng Chen, Yan Huang, Weidong Pan, Xiaojian Wu & Wenyu WangDepartment of General Surgery, The Sixth Affiliated Hospital, Sun Yat-sen University, Guangzhou, 510655, China Guojie Long, Xiaofeng Wen, Yufeng Chen, Weidong Pan & Xiaojian WuThe First Affiliated Hospital of Jinan University, Guangzhou, 510630, China Panpan WangDepartment of Pathology, The Sixth Affiliated Hospital, Sun Yat-sen University, Guangzhou, 510655, China Yan HuangState Key Laboratory of Oncology in South China, Guangdong Provincial Clinical Research Center for Cancer, Sun Yat-sen University Cancer Center, Guangzhou, 510060, China Jing TanLaboratory of Cancer Epigenome, Division of Medical Sciences, National Cancer Centre Singapore, Singapore, 168583, Singapore Jing TanHainan Academy of Medical Science, Hainan Medical University, Haikou, 571199, China Jing TanPharmacy college, Jinan University, Guangzhou, 510632, China Ronghua ZhangCancer research institute, Jinan University, Guangzhou, 510632, China Ronghua ZhangGenome Institute of Singapore, Agency for Science, Technology and Research (A*STAR), Biopolis, 138672, Singapore Qiang YuDepartment of Physiology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, 117597, Singapore Qiang YuCancer and Stem Cell Biology, Duke-NUS Medical School, Singapore, 169857, Singapore Qiang Yu

Cullin-5 RING E3 ligase limits CD8⁺ T-cell persistence and effector responses during chronic antigen stimulation

Featured  

Two recent back-to-back publications by Bachl et al. and Saco et al. used CRISPR-Cas9 knockout screens in primary human T cells exposed to repetitive antigen challenge and uncovered the enrichment of Cullin-RING Ligase 5 (CRL5) complex members over time with chronic antigen exposure. Knockouts of CRL5 components resulted in maintenance of antitumor effector function and delayed dysfunction. KO of these components in CAR-T or TCR-T cells improved tumor control in mice.

Two recent back-to-back publications by Bachl et al. and Saco et al. used CRISPR-Cas9 knockout screens in primary human T cells exposed to repetitive antigen challenge and uncovered the enrichment of Cullin-RING Ligase 5 (CRL5) complex members over time with chronic antigen exposure. Knockouts of CRL5 components resulted in maintenance of antitumor effector function and delayed dysfunction. KO of these components in CAR-T or TCR-T cells improved tumor control in mice.

ABSTRACT: T-cell exhaustion limits durable antitumor responses and remains a barrier to adoptive cell therapies (ACT) in solid tumors. To identify regulators of T-cell persistence, we performed genome-wide CRISPR knockout screens in primary human CD8_ T cells expressing an NY-ESO-1-specific T-cell receptor and subjected them to repeated tumor cell rechallenge. These screens revealed enrichment of single-guide RNAs targeting components of Cullin-RING E3 ligases, particularly Cullin-5 (CRL5) assemblies comprising CUL5, RNF7, and ARIH2. Disruption of CRL5 genes in T cells preserved cytotoxic activity and enhanced cytokine production while sustaining effector-associated transcriptional programs and suppressing exhaustion-related signatures. Pharmacologic inhibition of cullin neddylation with the NEDD8-activating enzyme inhibitor MLN4924 recapitulated CRL5 loss and enhanced T-cell effector function in vitro. In a human melanoma xenograft model, ACT with CRL5-deficient T cells improved tumor control. Together, these findings identify CRL5 as a negative regulator of T-cell fitness and a potential therapeutic target to enhance ACT durability in solid tumors.

Author Info: (1) University of California, Los Angeles Los Angeles, CA United States. ROR: https://ror.org/046rm7j60 (2) University of California, Los Angeles LA, CA United States. ROR: https:/

Author Info: (1) University of California, Los Angeles Los Angeles, CA United States. ROR: https://ror.org/046rm7j60 (2) University of California, Los Angeles LA, CA United States. ROR: https://ror.org/046rm7j60 (3) University of California, Los Angeles Los Angeles, CA United States. ROR: https://ror.org/046rm7j60 (4) Gladstone Institutes San Francisco, California United States. ROR: https://ror.org/038321296 (5) Gladstone Institutes San Francisco, California United States. ROR: https://ror.org/038321296 (6) University of California, San Francisco San Francisco, CA United States. ROR: https://ror.org/043mz5j54 (7) University of California, Los Angeles Los Angeles, CA United States. ROR: https://ror.org/046rm7j60 (8) University of California, Los Angeles Los Angeles, CA United States. ROR: https://ror.org/046rm7j60 (9) University of California, Los Angeles Los Angeles, CA United States. ROR: https://ror.org/046rm7j60 (10) University of California, Los Angeles Los Angeles, CA United States. ROR: https://ror.org/046rm7j60 (11) Dana-Farber Cancer Institute Boston United States. ROR: https://ror.org/02jzgtq86 (12) Max Planck Institute of Biochemistry Martinsried Germany. ROR: https://ror.org/04py35477 (13) University of California, Los Angeles Los Angeles, CA United States. ROR: https://ror.org/046rm7j60 (14) University of California, San Francisco San Francisco, CA United States. ROR: https://ror.org/043mz5j54 (15) University of California, Los Angeles Los Angeles, CA United States. ROR: https://ror.org/046rm7j60 (16) University of California, Los Angeles Los Angeles, CA United States. ROR: https://ror.org/046rm7j60

Disruption of the CRL5 ubiquitin ligase complex enhances engineered T-cell persistence under chronic tumor antigen exposure Featured  

Two recent back-to-back publications by Bachl et al. and Saco et al. used CRISPR-Cas9 knockout screens in primary human T cells exposed to repetitive antigen challenge and uncovered the enrichment of Cullin-RING Ligase 5 (CRL5) complex members over time with chronic antigen exposure. Knockouts of CRL5 components resulted in maintenance of antitumor effector function and delayed dysfunction. KO of these components in CAR-T or TCR-T cells improved tumor control in mice.

Two recent back-to-back publications by Bachl et al. and Saco et al. used CRISPR-Cas9 knockout screens in primary human T cells exposed to repetitive antigen challenge and uncovered the enrichment of Cullin-RING Ligase 5 (CRL5) complex members over time with chronic antigen exposure. Knockouts of CRL5 components resulted in maintenance of antitumor effector function and delayed dysfunction. KO of these components in CAR-T or TCR-T cells improved tumor control in mice.

ABSTRACT: Engineered T-cell therapies are limited by progressive dysfunction under chronic tumor antigen exposure, and genetic perturbation of negative regulators has emerged as a promising strategy to sustain effector activity. We reanalyzed a genome-wide CRISPR knockout screen in primary human T cells under repetitive tumor stimulation; protein-protein interaction mapping revealed seven members of the Cullin-RING Ligase 5 (CRL5) complex as an enriched hit cluster. Knockout of any of these members (CUL5, ARIH2, RNF7, UBE2F, UBE2L3, CISH, DCUN1D3) enhanced tumor serial killing, and CUL5, the complex scaffold, emerged as the strongest target. CUL5 knockout T cells exhibited sustained cytotoxicity, elevated effector cytokine production, and fewer exhaustion marker-positive cells while retaining antigen specificity and cytokine dependence. Quantitative ubiquitylation proteomics in resting, and acutely and chronically stimulated T cells mapped CRL5-dependent candidate substrates beyond the canonical JAK/STAT axis, including nutrient transporters, receptor trafficking proteins, and TCR signaling components. The benefit of CUL5 knockout extended across CARs targeting CD19, BCMA, and HER2 with different costimulatory domains, and to 1XX-modified CAR and HLA-independent TCR architectures. Combining CUL5 ablation with a tumor-induced IL-2 circuit produced tumor control across nine rounds of repetitive stimulation, whereas either modification alone eventually failed. In vivo, CUL5 knockout BCMA CAR T cells were enriched in the bone marrow following repeated tumor rechallenge and exhibited enhanced ex vivo cytotoxicity after nearly 90 days in tumor-bearing mice. These findings position CUL5 perturbation as a strategy to improve T-cell persistence and the efficacy of adoptive cell therapies, potentially with engineered cytokine support.

Author Info: (1) Gladstone Institutes San Francisco, California United States. ROR: https://ror.org/038321296 (2) Gladstone Institutes San Francisco, California United States. ROR: https://ror.

Author Info: (1) Gladstone Institutes San Francisco, California United States. ROR: https://ror.org/038321296 (2) Gladstone Institutes San Francisco, California United States. ROR: https://ror.org/038321296 (3) H™pital Saint-Louis Paris France. ROR: https://ror.org/049am9t04 (4) University of California San Francisco Medical Center United States. ROR: https://ror.org/01t8svj65 (5) University of California, San Francisco San Francisco, CA United States. ROR: https://ror.org/043mz5j54 (6) University of California, San Francisco San Francisco, CA United States. ROR: https://ror.org/043mz5j54 (7) University of California, San Francisco San Francisco, CA United States. ROR: https://ror.org/043mz5j54 (8) Gladstone Institutes United States. ROR: https://ror.org/038321296 (9) University of California, San Francisco San Francisco, CA United States. ROR: https://ror.org/043mz5j54 (10) University of California, San Francisco San Francisco, CA United States. ROR: https://ror.org/043mz5j54 (11) University of California, San Francisco San Francisco, CA United States. ROR: https://ror.org/043mz5j54 (12) University of California, San Francisco San Francisco, CA United States. ROR: https://ror.org/043mz5j54 (13) UCSF San Francisco, CA United States. (14) Tango Therapeutics (United States) Boston, Massachusetts United States. ROR: https://ror.org/003x6t567 (15) University of California, San Francisco San Francisco, California United States. ROR: https://ror.org/043mz5j54 (16) University of California, San Francisco San Francisco, California United States. ROR: https://ror.org/043mz5j54 (17) University of California, San Francisco San Francisco, CA United States. ROR: https://ror.org/043mz5j54 (18) University of California, San Francisco United States. ROR: https://ror.org/043mz5j54 (19) Gladstone Institutes San Francisco, California United States. ROR: https://ror.org/038321296 (20) UCSF San Francisco, CA United States. (21) University of California, San Francisco San Francisco, CA United States. ROR: https://ror.org/043mz5j54

Propionate promotes MHC class I antigen presentation and anti-tumor immunity Spotlight 

Li et al. found that dietary supplementation with the short-chain fatty acid propionate could be used to stabilize and maintain expression of MHC-I in tumor cells by binding to the E3 ligase STUB1, blocking the K30 and N34 residues, and thus the direct interactions that would lead to STUB1-mediated polyubiquitination and lysosomal degradation of MHC-I. In mice, dietary propionate increased MHC-I on tumor cells, resulting in enhanced CD8+ T cell-mediated antitumor immunity and IFNγ production, which further increased tumor MHC-I. Propionate also improved the efficacy of anti-PD-1, as did the propionate-producing probiotic A. muciniphila.

Contributed by Lauren Hitchings

Li et al. found that dietary supplementation with the short-chain fatty acid propionate could be used to stabilize and maintain expression of MHC-I in tumor cells by binding to the E3 ligase STUB1, blocking the K30 and N34 residues, and thus the direct interactions that would lead to STUB1-mediated polyubiquitination and lysosomal degradation of MHC-I. In mice, dietary propionate increased MHC-I on tumor cells, resulting in enhanced CD8+ T cell-mediated antitumor immunity and IFNγ production, which further increased tumor MHC-I. Propionate also improved the efficacy of anti-PD-1, as did the propionate-producing probiotic A. muciniphila.

Contributed by Lauren Hitchings

ABSTRACT: Defective tumor antigen presentation promotes immune evasion and resistance to immune checkpoint blockade. Here, we identified the short-chain fatty acid propionate as a potent enhancer of major histocompatibility complex class I (MHC class I) antigen presentation. Propionate stabilizes MHC class I on tumor cells, promotes CD8(+) T cell infiltration and activation, and suppresses tumor growth. Mechanistically, the E3 ubiquitin (Ub) ligase STUB1 directly interacts with human leukocyte antigen (HLA)-A to mediate K168/K170 polyubiquitination and subsequent degradation. Propionate directly binds STUB1 through hydrogen bonds involving K30 and N34, residues that overlap with the MHC class I-binding interface. This interaction blocks STUB1-mediated MHC class I polyubiquitination, thereby stabilizing MHC class I, enhancing T cell receptor (TCR) engagement and T cell activation, and restraining tumor growth. Importantly, propionate or the propionate-producing probiotic Akkermansia muciniphila markedly enhanced anti-PD-1 efficacy. These findings uncover a non-metabolic moonlighting function of short-chain fatty acids in regulating tumor immunity and provide a rationale for leveraging dietary propionate or propionate-producing probiotics to enhance immune checkpoint therapy.

Author Info: (1) Zhejiang Key Laboratory of Pancreatic Disease, The First Affiliated Hospital, Zhejiang Key Laboratory of Frontier Medical Research on Cancer Metabolism, and Institute of Transl

Author Info: (1) Zhejiang Key Laboratory of Pancreatic Disease, The First Affiliated Hospital, Zhejiang Key Laboratory of Frontier Medical Research on Cancer Metabolism, and Institute of Translational Medicine, Zhejiang University School of Medicine, Hangzhou, Zhejiang 310029, China; Institute of Fundamental and Transdisciplinary Research, Zhejiang University Cancer Center, Zhejiang University, Hangzhou, Zhejiang 310029, China; The Center for Translational Research, The Second Affiliated Hospital and Institute of Translational Medicine, Zhejiang University, Hangzhou, Zhejiang 310029, China. (2) Department of Gastroenterology, Songjiang Research Institute, Shanghai Key Laboratory of Emotions and Affective Disorders, Songjiang Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai 201600, China. Electronic address: dongguo@shsmu.edu.cn. (3) Zhejiang Key Laboratory of Pancreatic Disease, The First Affiliated Hospital, Zhejiang Key Laboratory of Frontier Medical Research on Cancer Metabolism, and Institute of Translational Medicine, Zhejiang University School of Medicine, Hangzhou, Zhejiang 310029, China; Institute of Fundamental and Transdisciplinary Research, Zhejiang University Cancer Center, Zhejiang University, Hangzhou, Zhejiang 310029, China; The Center for Translational Research, The Second Affiliated Hospital and Institute of Translational Medicine, Zhejiang University, Hangzhou, Zhejiang 310029, China. (4) Department of General Surgery, Pancreatic Disease Center, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200025, China. (5) Zhejiang Key Laboratory of Pancreatic Disease, The First Affiliated Hospital, Zhejiang Key Laboratory of Frontier Medical Research on Cancer Metabolism, and Institute of Translational Medicine, Zhejiang University School of Medicine, Hangzhou, Zhejiang 310029, China. (6) Zhejiang Key Laboratory of Pancreatic Disease, The First Affiliated Hospital, Zhejiang Key Laboratory of Frontier Medical Research on Cancer Metabolism, and Institute of Translational Medicine, Zhejiang University School of Medicine, Hangzhou, Zhejiang 310029, China; Institute of Fundamental and Transdisciplinary Research, Zhejiang University Cancer Center, Zhejiang University, Hangzhou, Zhejiang 310029, China; The Center for Translational Research, The Second Affiliated Hospital and Institute of Translational Medicine, Zhejiang University, Hangzhou, Zhejiang 310029, China. (7) Department of Hepatobiliary and Pancreatic Surgery, The Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang 310029, China. (8) Zhejiang Key Laboratory of Pancreatic Disease, The First Affiliated Hospital, Zhejiang Key Laboratory of Frontier Medical Research on Cancer Metabolism, and Institute of Translational Medicine, Zhejiang University School of Medicine, Hangzhou, Zhejiang 310029, China; Institute of Fundamental and Transdisciplinary Research, Zhejiang University Cancer Center, Zhejiang University, Hangzhou, Zhejiang 310029, China; The Center for Translational Research, The Second Affiliated Hospital and Institute of Translational Medicine, Zhejiang University, Hangzhou, Zhejiang 310029, China. (9) Zhejiang Key Laboratory of Pancreatic Disease, The First Affiliated Hospital, Zhejiang Key Laboratory of Frontier Medical Research on Cancer Metabolism, and Institute of Translational Medicine, Zhejiang University School of Medicine, Hangzhou, Zhejiang 310029, China; Institute of Fundamental and Transdisciplinary Research, Zhejiang University Cancer Center, Zhejiang University, Hangzhou, Zhejiang 310029, China; The Center for Translational Research, The Second Affiliated Hospital and Institute of Translational Medicine, Zhejiang University, Hangzhou, Zhejiang 310029, China. (10) Zhejiang Key Laboratory of Pancreatic Disease, The First Affiliated Hospital, Zhejiang Key Laboratory of Frontier Medical Research on Cancer Metabolism, and Institute of Translational Medicine, Zhejiang University School of Medicine, Hangzhou, Zhejiang 310029, China; Institute of Fundamental and Transdisciplinary Research, Zhejiang University Cancer Center, Zhejiang University, Hangzhou, Zhejiang 310029, China; The Center for Translational Research, The Second Affiliated Hospital and Institute of Translational Medicine, Zhejiang University, Hangzhou, Zhejiang 310029, China. (11) Zhejiang Key Laboratory of Pancreatic Disease, The First Affiliated Hospital, Zhejiang Key Laboratory of Frontier Medical Research on Cancer Metabolism, and Institute of Translational Medicine, Zhejiang University School of Medicine, Hangzhou, Zhejiang 310029, China; Institute of Fundamental and Transdisciplinary Research, Zhejiang University Cancer Center, Zhejiang University, Hangzhou, Zhejiang 310029, China; The Center for Translational Research, The Second Affiliated Hospital and Institute of Translational Medicine, Zhejiang University, Hangzhou, Zhejiang 310029, China. (12) Zhejiang Key Laboratory of Pancreatic Disease, The First Affiliated Hospital, Zhejiang Key Laboratory of Frontier Medical Research on Cancer Metabolism, and Institute of Translational Medicine, Zhejiang University School of Medicine, Hangzhou, Zhejiang 310029, China; Institute of Fundamental and Transdisciplinary Research, Zhejiang University Cancer Center, Zhejiang University, Hangzhou, Zhejiang 310029, China; The Center for Translational Research, The Second Affiliated Hospital and Institute of Translational Medicine, Zhejiang University, Hangzhou, Zhejiang 310029, China. (13) Zhejiang Key Laboratory of Pancreatic Disease, The First Affiliated Hospital, Zhejiang Key Laboratory of Frontier Medical Research on Cancer Metabolism, and Institute of Translational Medicine, Zhejiang University School of Medicine, Hangzhou, Zhejiang 310029, China; Institute of Fundamental and Transdisciplinary Research, Zhejiang University Cancer Center, Zhejiang University, Hangzhou, Zhejiang 310029, China; The Center for Translational Research, The Second Affiliated Hospital and Institute of Translational Medicine, Zhejiang University, Hangzhou, Zhejiang 310029, China. (14) Key Laboratory of Cancer Prevention and Intervention, China National Ministry of Education, Zhejiang Provincial Clinical Research Center for Cancer, Department of Medical Oncology, The Second Affiliated Hospital, Zhejiang University School of Medicine, Cancer Center, Zhejiang University, Hangzhou, Zhejiang 310058, China. (15) Zhejiang Key Laboratory of Pancreatic Disease, The First Affiliated Hospital, Zhejiang Key Laboratory of Frontier Medical Research on Cancer Metabolism, and Institute of Translational Medicine, Zhejiang University School of Medicine, Hangzhou, Zhejiang 310029, China; Institute of Fundamental and Transdisciplinary Research, Zhejiang University Cancer Center, Zhejiang University, Hangzhou, Zhejiang 310029, China; The Center for Translational Research, The Second Affiliated Hospital and Institute of Translational Medicine, Zhejiang University, Hangzhou, Zhejiang 310029, China. (16) Zhejiang Key Laboratory of Pancreatic Disease, The First Affiliated Hospital, Zhejiang Key Laboratory of Frontier Medical Research on Cancer Metabolism, and Institute of Translational Medicine, Zhejiang University School of Medicine, Hangzhou, Zhejiang 310029, China. (17) Zhejiang Key Laboratory of Pancreatic Disease, The First Affiliated Hospital, Zhejiang Key Laboratory of Frontier Medical Research on Cancer Metabolism, and Institute of Translational Medicine, Zhejiang University School of Medicine, Hangzhou, Zhejiang 310029, China; Institute of Fundamental and Transdisciplinary Research, Zhejiang University Cancer Center, Zhejiang University, Hangzhou, Zhejiang 310029, China; The Center for Translational Research, The Second Affiliated Hospital and Institute of Translational Medicine, Zhejiang University, Hangzhou, Zhejiang 310029, China. (18) Center for Regeneration and Aging Medicine, The Fourth Affiliated Hospital of School of Medicine, International School of Medicine, International Institutes of Medicine, Zhejiang University, Yiwu, Zhejiang 322000, China. (19) Key Laboratory of Cancer Prevention and Intervention, China National Ministry of Education, Zhejiang Provincial Clinical Research Center for Cancer, Department of Medical Oncology, The Second Affiliated Hospital, Zhejiang University School of Medicine, Cancer Center, Zhejiang University, Hangzhou, Zhejiang 310058, China. (20) Zhejiang Key Laboratory of Pancreatic Disease, The First Affiliated Hospital, Zhejiang Key Laboratory of Frontier Medical Research on Cancer Metabolism, and Institute of Translational Medicine, Zhejiang University School of Medicine, Hangzhou, Zhejiang 310029, China; Institute of Fundamental and Transdisciplinary Research, Zhejiang University Cancer Center, Zhejiang University, Hangzhou, Zhejiang 310029, China; The Center for Translational Research, The Second Affiliated Hospital and Institute of Translational Medicine, Zhejiang University, Hangzhou, Zhejiang 310029, China. (21) Department of Hepatobiliary and Pancreatic Surgery, The Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang 310029, China. Electronic address: wam@zju.edu.cn. (22) Department of Hepatobiliary and Pancreatic Surgery, The Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang 310029, China. Electronic address: dingyuan@zju.edu.cn. (23) Zhejiang Key Laboratory of Pancreatic Disease, The First Affiliated Hospital, Zhejiang Key Laboratory of Frontier Medical Research on Cancer Metabolism, and Institute of Translational Medicine, Zhejiang University School of Medicine, Hangzhou, Zhejiang 310029, China; Institute of Fundamental and Transdisciplinary Research, Zhejiang University Cancer Center, Zhejiang University, Hangzhou, Zhejiang 310029, China; The Center for Translational Research, The Second Affiliated Hospital and Institute of Translational Medicine, Zhejiang University, Hangzhou, Zhejiang 310029, China. Electronic address: zhiminlu@zju.edu.cn.

Perforin triggers iron-induced mitochondrial damage to drive ferroptosis and anti-tumor immunity Spotlight 

Bell et al. discovered a previously unrecognized, granzyme-independent function of perforin (Prf1) in CTLs and NK cells that showed that Prf1 can directly kill tumor cells via ferroptosis. Mechanistically, Prf1 induced transferrin receptor (CD71) endocytosis, leading to increased cellular iron uptake. Via endosomal–mitochondrial contacts, this subsequently elevated mitochondrial iron and lipid peroxidation, and tumor cell ferroptosis. In murine studies, dietary iron supplementation potentiated antitumor immunity in a Prf1-dependent manner, while in patients with cancer, higher Prf1 expression correlated with longer survival and improved responses to ICB.

Contributed by Katherine Turner

Bell et al. discovered a previously unrecognized, granzyme-independent function of perforin (Prf1) in CTLs and NK cells that showed that Prf1 can directly kill tumor cells via ferroptosis. Mechanistically, Prf1 induced transferrin receptor (CD71) endocytosis, leading to increased cellular iron uptake. Via endosomal–mitochondrial contacts, this subsequently elevated mitochondrial iron and lipid peroxidation, and tumor cell ferroptosis. In murine studies, dietary iron supplementation potentiated antitumor immunity in a Prf1-dependent manner, while in patients with cancer, higher Prf1 expression correlated with longer survival and improved responses to ICB.

Contributed by Katherine Turner

ABSTRACT: Cytotoxic CD8(+) T cells and natural killer cells are critical effectors of anti-tumor immunity. Cytotoxic lymphocytes eliminate tumor cells by releasing perforin (Prf1), a pore-forming protein that enables granzymes (Gzms) to enter target cells and trigger both caspase-dependent and -independent cell death. Here, we uncover a previously unrecognized, Gzm-independent function of Prf1. We find that Prf1 directly induces tumoral ferroptosis, an iron- and lipid-dependent form of cell death. Mechanistically, Prf1-mediated pore formation drives endocytosis of the transferrin receptor, which increases cellular iron uptake. Prf1 promotes the formation of endosomal-mitochondrial contacts, which leads to mitochondrial iron accumulation, mitochondrial dysfunction, and tumor cell ferroptosis. Dietary iron supplementation suppresses tumor progression in murine tumor models in a Prf1-dependent manner. Higher Prf1 expression correlates with improved survival and enhanced response to immune checkpoint blockade in patients with cancer. These findings define a Gzm-independent function of Prf1 as a direct executioner of cancer cell death through ferroptosis.

Author Info: (1) Department of Surgery, University of Michigan School of Medicine, Ann Arbor, MI, USA; Center of Excellence for Cancer Immunology and Immunotherapy, University of Michigan Rogel

Author Info: (1) Department of Surgery, University of Michigan School of Medicine, Ann Arbor, MI, USA; Center of Excellence for Cancer Immunology and Immunotherapy, University of Michigan Rogel Cancer Center, Ann Arbor, MI, USA. (2) Department of Molecular and Cellular Physiology, Albany Medical College, Albany, NY, USA. (3) Department of Surgery, University of Michigan School of Medicine, Ann Arbor, MI, USA; Center of Excellence for Cancer Immunology and Immunotherapy, University of Michigan Rogel Cancer Center, Ann Arbor, MI, USA; Graduate Program in Immunology, University of Michigan, Ann Arbor, MI, USA. (4) Department of Surgery, University of Michigan School of Medicine, Ann Arbor, MI, USA; Center of Excellence for Cancer Immunology and Immunotherapy, University of Michigan Rogel Cancer Center, Ann Arbor, MI, USA. (5) Department of Computational Medicine and Bioinformatics, University of Michigan, Ann Arbor, MI, USA. (6) Department of Molecular & Physiology, University of Michigan, Ann Arbor, MI, USA. (7) Program in Cellular and Molecular Medicine, Boston Children's Hospital and Department of Pediatrics, Harvard Medical School, Boston, MA 02115, USA. (8) Program in Cellular and Molecular Medicine, Boston Children's Hospital and Department of Pediatrics, Harvard Medical School, Boston, MA 02115, USA. (9) Department of Computational Medicine and Bioinformatics, University of Michigan, Ann Arbor, MI, USA. (10) Department of Surgery, University of Michigan School of Medicine, Ann Arbor, MI, USA; Center of Excellence for Cancer Immunology and Immunotherapy, University of Michigan Rogel Cancer Center, Ann Arbor, MI, USA. (11) Department of Surgery, University of Michigan School of Medicine, Ann Arbor, MI, USA; Center of Excellence for Cancer Immunology and Immunotherapy, University of Michigan Rogel Cancer Center, Ann Arbor, MI, USA. (12) Department of Molecular & Physiology, University of Michigan, Ann Arbor, MI, USA. (13) Department of Molecular & Physiology, University of Michigan, Ann Arbor, MI, USA. (14) Program in Cellular and Molecular Medicine, Boston Children's Hospital and Department of Pediatrics, Harvard Medical School, Boston, MA 02115, USA. (15) Cancer Immunology Program, Peter MacCallum Cancer Centre, Melbourne, VIC, Australia. (16) Department of Surgery, University of Michigan School of Medicine, Ann Arbor, MI, USA; Center of Excellence for Cancer Immunology and Immunotherapy, University of Michigan Rogel Cancer Center, Ann Arbor, MI, USA. (17) Department of Surgery, University of Michigan School of Medicine, Ann Arbor, MI, USA; Center of Excellence for Cancer Immunology and Immunotherapy, University of Michigan Rogel Cancer Center, Ann Arbor, MI, USA. (18) Department of Surgery, University of Michigan School of Medicine, Ann Arbor, MI, USA; Center of Excellence for Cancer Immunology and Immunotherapy, University of Michigan Rogel Cancer Center, Ann Arbor, MI, USA; Graduate Program in Immunology, University of Michigan, Ann Arbor, MI, USA. (19) Department of Surgery, University of Michigan School of Medicine, Ann Arbor, MI, USA; Center of Excellence for Cancer Immunology and Immunotherapy, University of Michigan Rogel Cancer Center, Ann Arbor, MI, USA; Graduate Program in Immunology, University of Michigan, Ann Arbor, MI, USA. (20) Department of Surgery, University of Michigan School of Medicine, Ann Arbor, MI, USA. (21) Department of Surgery, University of Michigan School of Medicine, Ann Arbor, MI, USA. (22) Department of Surgery, University of Michigan School of Medicine, Ann Arbor, MI, USA. (23) Cayman Chemical, Ann Arbor, MI, USA. (24) Cayman Chemical, Ann Arbor, MI, USA. (25) Department of Molecular & Physiology, University of Michigan, Ann Arbor, MI, USA; Department of Internal Medicine, Division of Gastroenterology, University of Michigan, Ann Arbor, MI, USA. (26) Department of Surgery, University of Michigan School of Medicine, Ann Arbor, MI, USA; Center of Excellence for Cancer Immunology and Immunotherapy, University of Michigan Rogel Cancer Center, Ann Arbor, MI, USA; Graduate Program in Immunology, University of Michigan, Ann Arbor, MI, USA. Electronic address: ilonak@umich.edu. (27) Cancer Immunology Program, Peter MacCallum Cancer Centre, Melbourne, VIC, Australia. (28) Department of Molecular and Cellular Physiology, Albany Medical College, Albany, NY, USA. Electronic address: barrosm@amc.edu. (29) Program in Cellular and Molecular Medicine, Boston Children's Hospital and Department of Pediatrics, Harvard Medical School, Boston, MA 02115, USA. Electronic address: judy.lieberman@childrens.harvard.edu. (30) Department of Surgery, University of Michigan School of Medicine, Ann Arbor, MI, USA; Center of Excellence for Cancer Immunology and Immunotherapy, University of Michigan Rogel Cancer Center, Ann Arbor, MI, USA; Graduate Program in Immunology, University of Michigan, Ann Arbor, MI, USA. Electronic address: wzou@umich.edu.

XIAP inhibition augments personalized neoantigen vaccine-driven antitumor immunity in orthotopic hepatocellular carcinoma Spotlight 

Zheng et al. showed that in human HCC, XIAP is markedly upregulated and inversely correlated with CD8+ T cell tumor infiltration and RFS. Treatment of orthotopic HCC mouse models with the SMAC mimetic Birinapant boosted MHC-­I expression, reduced PD-­L1 levels, induced short-term immune cell tumor infiltration and mediated modest antitumor effects. Birinapant combined with personalized NeoVAC therapy expanded less exhausted, cytotoxic, neoantigen-­specific CD8+ Tem cells, promoted DC antigen presentation, and shifted TAMs toward a pro-­inflammatory phenotype to safely stimulate potent tumor control, immune memory, and protection against metastases.

Contributed by Paula Hochman

Zheng et al. showed that in human HCC, XIAP is markedly upregulated and inversely correlated with CD8+ T cell tumor infiltration and RFS. Treatment of orthotopic HCC mouse models with the SMAC mimetic Birinapant boosted MHC-­I expression, reduced PD-­L1 levels, induced short-term immune cell tumor infiltration and mediated modest antitumor effects. Birinapant combined with personalized NeoVAC therapy expanded less exhausted, cytotoxic, neoantigen-­specific CD8+ Tem cells, promoted DC antigen presentation, and shifted TAMs toward a pro-­inflammatory phenotype to safely stimulate potent tumor control, immune memory, and protection against metastases.

Contributed by Paula Hochman

BACKGROUND: Personalized neoantigen vaccines offer a rational immunotherapeutic strategy for hepatocellular carcinoma (HCC), but their efficacy is limited by insufficient tumor immunogenicity and an immunosuppressive tumor microenvironment. Tumor-intrinsic factors that constrain vaccine-induced immune responses in HCC are not well defined. X-linked inhibitor of apoptosis protein (XIAP) is frequently overexpressed in HCC and has been linked to immune evasion, raising the possibility that targeting XIAP may improve the effectiveness of neoantigen-based vaccination. METHODS: XIAP expression is examined in human HCC specimens using transcriptomic analysis and multiplex immunofluorescence. A personalized neoantigen vaccine (NeoVAC) is generated and evaluated in combination with Birinapant, a clinically investigated second mitochondria-derived activator of caspases (SMAC) mimetic, and IAP antagonist, in orthotopic HCC and KPC-OVA-ICC mouse models. Antitumor efficacy is assessed by bioluminescence imaging and survival analysis. Immune landscapes are characterized by flow cytometry, immunohistochemistry, multiplex immunofluorescence, and single-cell RNA sequencing. Neoantigen-specific immune responses are further assessed using functional assays. RESULTS: XIAP is markedly upregulated in human HCC and inversely associates with intratumoral CD8+T_cell infiltration and recurrence-free survival. Birinapant treatment increases major histocompatibility complex class I (MHC-I) expression, reduces PD-L1 levels, and facilitates immune-cell infiltration, but only has modest antitumor effects as monotherapy. In contrast, combining Birinapant with NeoVAC substantially improves tumor control. A notable proportion of treated mice achieves complete tumor regression, accompanied by durable protection against tumor rechallenge and metastatic dissemination. These effects are associated with the expansion of neoantigen-specific Ly6C(+)CD8(+) T cells exhibiting effector-memory features, strong cytotoxic capacity, and limited exhaustion, together with enhanced dendritic-cell antigen presentation and a shift of tumor-associated macrophages toward a pro-inflammatory M1-like phenotype. CONCLUSIONS: These data identify XIAP expression as a clinical correlate of an immune-refractory HCC phenotype and show that pharmacological IAP antagonism with Birinapant enhances tumor immunogenicity and supports antigen-specific T-cell immunity. The findings provide a preclinical rationale for combining the SMAC mimetic Birinapant with neoantigen vaccine-based immunotherapy in HCC.

Author Info: (1) The United Innovation of Mengchao Hepatobiliary Technology Key Laboratory of Fujian Province, Mengchao Hepatobiliary Hospital of Fujian Medical University, Fuzhou, China. (2) T

Author Info: (1) The United Innovation of Mengchao Hepatobiliary Technology Key Laboratory of Fujian Province, Mengchao Hepatobiliary Hospital of Fujian Medical University, Fuzhou, China. (2) The United Innovation of Mengchao Hepatobiliary Technology Key Laboratory of Fujian Province, Mengchao Hepatobiliary Hospital of Fujian Medical University, Fuzhou, China. (3) The United Innovation of Mengchao Hepatobiliary Technology Key Laboratory of Fujian Province, Mengchao Hepatobiliary Hospital of Fujian Medical University, Fuzhou, China. (4) The United Innovation of Mengchao Hepatobiliary Technology Key Laboratory of Fujian Province, Mengchao Hepatobiliary Hospital of Fujian Medical University, Fuzhou, China. Department of Hepatopancreatobiliary Surgery, First Affiliated Hospital of Fujian Medical University, Fuzhou, China. (5) Fujian Key Laboratory of Integrative Medicine on Geriatrics, Fujian University of Traditional Chinese Medicine, Fuzhou, China. (6) The United Innovation of Mengchao Hepatobiliary Technology Key Laboratory of Fujian Province, Mengchao Hepatobiliary Hospital of Fujian Medical University, Fuzhou, China. (7) The United Innovation of Mengchao Hepatobiliary Technology Key Laboratory of Fujian Province, Mengchao Hepatobiliary Hospital of Fujian Medical University, Fuzhou, China. (8) The United Innovation of Mengchao Hepatobiliary Technology Key Laboratory of Fujian Province, Mengchao Hepatobiliary Hospital of Fujian Medical University, Fuzhou, China. (9) The United Innovation of Mengchao Hepatobiliary Technology Key Laboratory of Fujian Province, Mengchao Hepatobiliary Hospital of Fujian Medical University, Fuzhou, China. (10) The United Innovation of Mengchao Hepatobiliary Technology Key Laboratory of Fujian Province, Mengchao Hepatobiliary Hospital of Fujian Medical University, Fuzhou, China. (11) The United Innovation of Mengchao Hepatobiliary Technology Key Laboratory of Fujian Province, Mengchao Hepatobiliary Hospital of Fujian Medical University, Fuzhou, China. (12) The United Innovation of Mengchao Hepatobiliary Technology Key Laboratory of Fujian Province, Mengchao Hepatobiliary Hospital of Fujian Medical University, Fuzhou, China. (13) The United Innovation of Mengchao Hepatobiliary Technology Key Laboratory of Fujian Province, Mengchao Hepatobiliary Hospital of Fujian Medical University, Fuzhou, China. (14) The United Innovation of Mengchao Hepatobiliary Technology Key Laboratory of Fujian Province, Mengchao Hepatobiliary Hospital of Fujian Medical University, Fuzhou, China. (15) The United Innovation of Mengchao Hepatobiliary Technology Key Laboratory of Fujian Province, Mengchao Hepatobiliary Hospital of Fujian Medical University, Fuzhou, China. (16) The United Innovation of Mengchao Hepatobiliary Technology Key Laboratory of Fujian Province, Mengchao Hepatobiliary Hospital of Fujian Medical University, Fuzhou, China. (17) The United Innovation of Mengchao Hepatobiliary Technology Key Laboratory of Fujian Province, Mengchao Hepatobiliary Hospital of Fujian Medical University, Fuzhou, China xiaoloong.liu@gmail.com lamp197311@126.com caizhixiong1985@163.com. (18) The United Innovation of Mengchao Hepatobiliary Technology Key Laboratory of Fujian Province, Mengchao Hepatobiliary Hospital of Fujian Medical University, Fuzhou, China xiaoloong.liu@gmail.com lamp197311@126.com caizhixiong1985@163.com. Department of Hepatopancreatobiliary Surgery, First Affiliated Hospital of Fujian Medical University, Fuzhou, China. (19) The United Innovation of Mengchao Hepatobiliary Technology Key Laboratory of Fujian Province, Mengchao Hepatobiliary Hospital of Fujian Medical University, Fuzhou, China xiaoloong.liu@gmail.com lamp197311@126.com caizhixiong1985@163.com.

Orally delivered metabolically reprogrammed probiotics for cascade-activated antitumor immunity in colorectal cancer Spotlight 

Wang and Chen et al. designed an oral, metabolically engineered bacterial platform (EHC) based on the probiotic E. coli strain Nissle 1917 that selectively targeted CRC cells and induced ferroptosis via depletion of intratumoral cysteine and glutathione, thus enhancing immunogenic cell death and remodeling the immunosuppressive TIME. In vivo, oral EHC suppressed orthotopic CRC tumor growth, inhibited metastatic progression, and synergized with anti-PD-1. Immune profiling revealed robust systemic and gut mucosal activation, increased numbers of mature dendritic cells, CD4+ and CD8+ T cells, and pro-inflammatory macrophages.

Contributed by Katherine Turner

Wang and Chen et al. designed an oral, metabolically engineered bacterial platform (EHC) based on the probiotic E. coli strain Nissle 1917 that selectively targeted CRC cells and induced ferroptosis via depletion of intratumoral cysteine and glutathione, thus enhancing immunogenic cell death and remodeling the immunosuppressive TIME. In vivo, oral EHC suppressed orthotopic CRC tumor growth, inhibited metastatic progression, and synergized with anti-PD-1. Immune profiling revealed robust systemic and gut mucosal activation, increased numbers of mature dendritic cells, CD4+ and CD8+ T cells, and pro-inflammatory macrophages.

Contributed by Katherine Turner

ABSTRACT: Immunotherapy for colorectal cancer (CRC) remains limited due to the inherently low tumor immunogenicity and the profoundly immunosuppressive tumor microenvironment (TME). Herein, capitalizing on the metabolic traits and anatomical accessibility of CRC, we propose a broadly applicable oral strategy based on metabolically engineered bacteria (EcN-HlpA-CGL [EHC]) for CRC immunotherapy. Mechanistically, cystathionine γ-lyase expressed by EHC disrupts redox homeostasis, triggering ferroptosis in CRC cells and thereby enhancing tumor immunogenicity. Concurrently, the intrinsic adjuvant activity of the bacteria amplifies the cancer-immunity cycle driven by immunogenic cell death and remodels the immunosuppressive TME. In vivo studies demonstrate that this orally delivered engineered bacterial platform not only suppresses the growth of orthotopic CRC tumors but also inhibits metastatic progression, indicating the induction of a potent systemic immune response. Immune profiling confirms robust systemic and gut mucosal immune activation following oral administration. Collectively, this oral metabolically engineered bacterial platform is precisely tailored to the features of CRC and offers a safe and effective immunotherapeutic strategy for this malignancy.

Author Info: (1) Engineering Research Center of Molecular & Neuroimaging, Ministry of Education, School of Life Science and Technology, Xidian University, Xi'an 710126, P.R. China. (2) Engineer

Author Info: (1) Engineering Research Center of Molecular & Neuroimaging, Ministry of Education, School of Life Science and Technology, Xidian University, Xi'an 710126, P.R. China. (2) Engineering Research Center of Molecular & Neuroimaging, Ministry of Education, School of Life Science and Technology, Xidian University, Xi'an 710126, P.R. China. Electronic address: chenyang@xidian.edu.cn. (3) Engineering Research Center of Molecular & Neuroimaging, Ministry of Education, School of Life Science and Technology, Xidian University, Xi'an 710126, P.R. China. (4) Engineering Research Center of Molecular & Neuroimaging, Ministry of Education, School of Life Science and Technology, Xidian University, Xi'an 710126, P.R. China. (5) Engineering Research Center of Molecular & Neuroimaging, Ministry of Education, School of Life Science and Technology, Xidian University, Xi'an 710126, P.R. China. (6) Engineering Research Center of Molecular & Neuroimaging, Ministry of Education, School of Life Science and Technology, Xidian University, Xi'an 710126, P.R. China. (7) Engineering Research Center of Molecular & Neuroimaging, Ministry of Education, School of Life Science and Technology, Xidian University, Xi'an 710126, P.R. China. (8) Engineering Research Center of Molecular & Neuroimaging, Ministry of Education, School of Life Science and Technology, Xidian University, Xi'an 710126, P.R. China. (9) Engineering Research Center of Molecular & Neuroimaging, Ministry of Education, School of Life Science and Technology, Xidian University, Xi'an 710126, P.R. China. Electronic address: chenzhuang@xidian.edu.cn. (10) Research Center of Nano Technology and Application Engineering, The First Dongguan Affiliated Hospital, School of Pharmacy, Guangdong Medical University, Dongguan 523808, P.R. China. Electronic address: wsyt132@163.com. (11) Engineering Research Center of Molecular & Neuroimaging, Ministry of Education, School of Life Science and Technology, Xidian University, Xi'an 710126, P.R. China. Electronic address: qiaochaoqiang@xidian.edu.cn. (12) Engineering Research Center of Molecular & Neuroimaging, Ministry of Education, School of Life Science and Technology, Xidian University, Xi'an 710126, P.R. China. Electronic address: wangzl@xidian.edu.cn.

Rapid CAR-T manufacturing with low-intensity priming enhances CAR-T cell fitness and limits inflammatory programming in a phase 1 study Featured  

Yang and Li et al. developed a 2-day protocol called PrimeCAR in which T cells were primed ex vivo with low-intensity soluble anti-CD3 in combination with IL-7 and IL-21. Compared to a longer conventional CAR T cell manufacturing protocol, PrimeCAR T cell manufacturing yielded less activated, less differentiated CAR T cell products that maintained strong cytotoxicity, while limiting inflammatory cytokine signaling and associated toxicities. PrimeCAR T cells showed promising results for maintaining efficacy while limiting toxicity in two phase 1 trials in patients with either B-ALL or B-NHL.

Yang and Li et al. developed a 2-day protocol called PrimeCAR in which T cells were primed ex vivo with low-intensity soluble anti-CD3 in combination with IL-7 and IL-21. Compared to a longer conventional CAR T cell manufacturing protocol, PrimeCAR T cell manufacturing yielded less activated, less differentiated CAR T cell products that maintained strong cytotoxicity, while limiting inflammatory cytokine signaling and associated toxicities. PrimeCAR T cells showed promising results for maintaining efficacy while limiting toxicity in two phase 1 trials in patients with either B-ALL or B-NHL.

ABSTRACT: Conventional chimeric antigen receptor (CAR)-T manufacturing requires prolonged ex vivo activation and expansion, which may compromise T cell fitness and promote inflammatory differentiation. Here, we developed PrimeCAR, a 2-day manufacturing strategy combining low-intensity anti-CD3 priming with IL-7 and IL-21. Compared with conventionally manufactured CAR-T cells, PrimeCAR products exhibited a distinct transcriptional state characterized by preserved stemness-associated programs and a PrimeCAR-enriched primed naive T cell (Tn)-like state. Following antigen stimulation, PrimeCAR cells preferentially engaged proliferative programs while limiting exhaustion-associated regulators and inflammatory mediators. Functionally, PrimeCAR cells demonstrated enhanced expansion, persistence, and durable antitumor activity in xenograft models. In investigator-initiated phase I studies of relapsed or refractory B cell acute lymphoblastic leukemia and B cell non-Hodgkin lymphoma, PrimeCAR showed encouraging clinical activity with a favorable safety profile. Together, these findings demonstrate that rapid manufacturing with controlled early T cell priming selectively restrains inflammatory programming while preserving CAR-T cell fitness, providing a practical strategy for improving CAR-T manufacturing and therapeutic performance.

Author Info: (1) Chongqing Key Laboratory of Gene and Cell Therapy, Chongqing 400039, China; Chongqing Precision Biotech Co., Ltd., Chongqing 400039, China. Electronic address: yangzhi@precisio

Author Info: (1) Chongqing Key Laboratory of Gene and Cell Therapy, Chongqing 400039, China; Chongqing Precision Biotech Co., Ltd., Chongqing 400039, China. Electronic address: yangzhi@precision-biotech.com. (2) 920th Hospital of Joint Logistics Support Force of People's Liberationsi Army of China, Kunming 650100, Yunnan, China. (3) Chongqing Key Laboratory of Gene and Cell Therapy, Chongqing 400039, China; Chongqing Precision Biotech Co., Ltd., Chongqing 400039, China. (4) Chongqing Key Laboratory of Gene and Cell Therapy, Chongqing 400039, China; Chongqing Precision Biotech Co., Ltd., Chongqing 400039, China. (5) Chongqing Key Laboratory of Gene and Cell Therapy, Chongqing 400039, China; Chongqing Precision Biotech Co., Ltd., Chongqing 400039, China. (6) 920th Hospital of Joint Logistics Support Force of People's Liberationsi Army of China, Kunming 650100, Yunnan, China. (7) 920th Hospital of Joint Logistics Support Force of People's Liberationsi Army of China, Kunming 650100, Yunnan, China. (8) 920th Hospital of Joint Logistics Support Force of People's Liberationsi Army of China, Kunming 650100, Yunnan, China. (9) Chongqing Key Laboratory of Gene and Cell Therapy, Chongqing 400039, China; Chongqing Precision Biotech Co., Ltd., Chongqing 400039, China. (10) 920th Hospital of Joint Logistics Support Force of People's Liberationsi Army of China, Kunming 650100, Yunnan, China. (11) 920th Hospital of Joint Logistics Support Force of People's Liberationsi Army of China, Kunming 650100, Yunnan, China. (12) Chongqing Key Laboratory of Gene and Cell Therapy, Chongqing 400039, China; Chongqing Precision Biotech Co., Ltd., Chongqing 400039, China. (13) Chongqing Key Laboratory of Gene and Cell Therapy, Chongqing 400039, China; Chongqing Precision Biotech Co., Ltd., Chongqing 400039, China. (14) Chongqing Key Laboratory of Gene and Cell Therapy, Chongqing 400039, China; Chongqing Precision Biotech Co., Ltd., Chongqing 400039, China. (15) Chongqing Key Laboratory of Gene and Cell Therapy, Chongqing 400039, China; Chongqing Precision Biotech Co., Ltd., Chongqing 400039, China. (16) Chongqing Key Laboratory of Gene and Cell Therapy, Chongqing 400039, China; Chongqing Precision Biotech Co., Ltd., Chongqing 400039, China. (17) 920th Hospital of Joint Logistics Support Force of People's Liberationsi Army of China, Kunming 650100, Yunnan, China. (18) 920th Hospital of Joint Logistics Support Force of People's Liberationsi Army of China, Kunming 650100, Yunnan, China. (19) 920th Hospital of Joint Logistics Support Force of People's Liberationsi Army of China, Kunming 650100, Yunnan, China. Electronic address: sanbin1011@163.com. (20) Chongqing Key Laboratory of Gene and Cell Therapy, Chongqing 400039, China; Chongqing Precision Biotech Co., Ltd., Chongqing 400039, China. Electronic address: cqian8634@gmail.com.

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