Journal Articles

FLT3L-secreting cDC1 in situ vaccination enhances antitumor immunity and synergizes with PD-1 blockade in murine non-small cell lung cancer Spotlight 

Abascal et al. engineered FLT3L-secreting mouse cDC1s that retained APC and phagocytic ability in vitro. In situ vaccination (ISV) with the cDC1s inhibited s.c. tumor growth in multiple syngeneic murine models, including those with driver mutations common in human NSCLC, and increased trafficking of the autologous cDC1s to TdLN and tumor infiltration of T cells. TCGA analysis showed that FLT3L expression in human NSCLC correlated with profiles of B and T cells, activated DCs and HEV-enriched TLS. ISV increased immature TLS formation in the murine TIME and synergized with anti-PD-1 in a NSCLC model to enhance efficacy and induce immune memory.

Contributed by Paula Hochman

Abascal et al. engineered FLT3L-secreting mouse cDC1s that retained APC and phagocytic ability in vitro. In situ vaccination (ISV) with the cDC1s inhibited s.c. tumor growth in multiple syngeneic murine models, including those with driver mutations common in human NSCLC, and increased trafficking of the autologous cDC1s to TdLN and tumor infiltration of T cells. TCGA analysis showed that FLT3L expression in human NSCLC correlated with profiles of B and T cells, activated DCs and HEV-enriched TLS. ISV increased immature TLS formation in the murine TIME and synergized with anti-PD-1 in a NSCLC model to enhance efficacy and induce immune memory.

Contributed by Paula Hochman

BACKGROUND: Non-small cell lung cancer (NSCLC) frequently evades immune surveillance through defective antigen presentation and a suppressive tumor microenvironment (TME), limiting the efficacy of immune checkpoint blockade (ICB). Conventional type 1 dendritic cells (cDC1s) are essential for initiating antitumor CD8(+) T-cell responses; however, their abundance and function are often diminished in NSCLC, contributing to poor outcomes and resistance to immunotherapy. We hypothesized that in situ vaccination (ISV) using gene-modified cDC1s engineered to secrete FMS-like tyrosine kinase 3 ligand (FLT3L) would enhance cDC1 function within the TME, promote antitumor immunity, and improve responses to ICB. METHODS: Syngeneic murine models of NSCLC (Kras(G12D)/P53(-/-)/Lkb1(-/-); Kras(G12D)/P53(-/-) ; and Kras(G12D) ) with varying tumor mutational burden, along with the MC38 model, were used to assess the therapeutic efficacy of FLT3L-cDC1 ISV. Flow cytometry and multiplex immunofluorescence were used to evaluate immune mechanisms of response. To assess translational relevance, immune and tertiary lymphoid structure (TLS) signatures were analyzed in The Cancer Genome Atlas (TCGA) NSCLC datasets, with TLS signatures refined using a retrained xCell2 framework incorporating curated TLS and high endothelial venule (HEV) microdissection datasets. RESULTS: FLT3L-cDC1 ISV remodeled the TME across multiple NSCLC models, inducing T lymphocyte infiltration and expanding cytolytic CD8(+) T cells. FLT3L-cDC1 ISV was associated with increased formation of immature TLS with primary follicle-like features within the TME. TCGA analyses revealed that FLT3L expression correlates with activated DC, T cell, and B cell signatures, as well as HEV-enriched TLS-associated programs. Combination with PD-1 blockade further enhanced the antitumor immunity of FLT3L-cDC1 ISV, resulting in robust local and systemic T-cell activation and the expansion of activated CCR7(+)PD-L1(+) cDC1s and stem-like TCF1(+)PD-1(+) CD8(+) progenitors within the TME. In an LKB1-deficient NSCLC model, FLT3L-cDC1 ISV plus PD-1 blockade induced complete and durable regression in 85% of tumors, leading to long-lasting systemic tumor-specific immune memory, consistent with effective tumor vaccination. CONCLUSIONS: FLT3L-cDC1 ISV represents a rational cytokine-enhanced cellular immunotherapy designed to overcome immunosuppression and restore DC function within the TME, thereby promoting tumor-specific adaptive immune responses and enhancing responsiveness to ICB.

Author Info: (1) Department of Medicine, David Geffen School of Medicine, Los Angeles, California, USA. (2) Department of Medicine, David Geffen School of Medicine, Los Angeles, California, USA

Author Info: (1) Department of Medicine, David Geffen School of Medicine, Los Angeles, California, USA. (2) Department of Medicine, David Geffen School of Medicine, Los Angeles, California, USA. (3) Department of Medicine, David Geffen School of Medicine, Los Angeles, California, USA. VA Greater Los Angeles Healthcare System, Los Angeles, California, USA. (4) Department of Molecular and Medical Pharmacology, David Geffen School of Medicine, Los Angeles, California, USA. (5) Department of Medicine, David Geffen School of Medicine, Los Angeles, California, USA. (6) Department of Medicine, David Geffen School of Medicine, Los Angeles, California, USA. VA Greater Los Angeles Healthcare System, Los Angeles, California, USA. (7) Department of Molecular and Medical Pharmacology, David Geffen School of Medicine, Los Angeles, California, USA. (8) Department of Molecular and Medical Pharmacology, David Geffen School of Medicine, Los Angeles, California, USA. (9) Department of Medicine, David Geffen School of Medicine, Los Angeles, California, USA. (10) UCLA, Los Angeles, California, USA. (11) Department of Medicine, David Geffen School of Medicine, Los Angeles, California, USA. (12) Department of Medicine, David Geffen School of Medicine, Los Angeles, California, USA. (13) Department of Molecular and Medical Pharmacology, David Geffen School of Medicine, Los Angeles, California, USA. (14) Department of Medicine, David Geffen School of Medicine, Los Angeles, California, USA. (15) Department of Medicine, David Geffen School of Medicine, Los Angeles, California, USA. VA Greater Los Angeles Healthcare System, Los Angeles, California, USA. Department of Molecular and Medical Pharmacology, David Geffen School of Medicine, Los Angeles, California, USA. (16) Department of Medicine, David Geffen School of Medicine, Los Angeles, California, USA rsalehirad@mednet.ucla.edu bliu@mednet.ucla.edu. (17) Department of Medicine, David Geffen School of Medicine, Los Angeles, California, USA rsalehirad@mednet.ucla.edu bliu@mednet.ucla.edu. VA Greater Los Angeles Healthcare System, Los Angeles, California, USA.

B cell-derived type I interferon sustains T cell functionality upon strong TCR stimulation during chronic infection Spotlight 

Graça et al. show that B cells are essential for CD8+ T cell effector response during chronic, but not acute, LCMV infection. In chronic infection, splenic B cells sense viruses via TLR7/8-STING pathways and produce IFN-I, which promotes exhausted T cell differentiation and sustain effector function in the spleen, whereas CD8+ T cells in the LN or responding to low antigen load were B cell independent. Loss of B cells or IFN-I signaling impaired exhausted T cell cytokine production (‘tolerized-like’). IRF1 integrates IFN-I signals to promote T cell expansion. Chronic human HBV showed a similar antigen-load-dependent effect observed in the murine LCMV model.

Contributed by Shishir Pant

Graça et al. show that B cells are essential for CD8+ T cell effector response during chronic, but not acute, LCMV infection. In chronic infection, splenic B cells sense viruses via TLR7/8-STING pathways and produce IFN-I, which promotes exhausted T cell differentiation and sustain effector function in the spleen, whereas CD8+ T cells in the LN or responding to low antigen load were B cell independent. Loss of B cells or IFN-I signaling impaired exhausted T cell cytokine production (‘tolerized-like’). IRF1 integrates IFN-I signals to promote T cell expansion. Chronic human HBV showed a similar antigen-load-dependent effect observed in the murine LCMV model.

Contributed by Shishir Pant

ABSTRACT: B cells are highly abundant lymphocytes and central players in humoral immunity. Although T cells are well known to support humoral responses, how B cells influence T cell responses is less understood. Here, we show that B cells are critical for CD8(+) T cell responses to chronic, but not acute, viral infections. In the absence of B cells, T cells responding to chronic infection exhibited severely impaired effector differentiation. This dependency on B cell help was dictated by high antigen loads and strong T cell receptor (TCR) stimulation. Loss of either B cells or interferon-I (IFN-I) signaling led to severe functional deficits in exhausted T cells, implicating B cells as key producers of IFN-I. The IFN-I-dependent T cell response to strong TCR stimulation is mediated, in part, by the transcription factor IRF1. Therefore, during chronic infection, we uncover an important role for B cell-derived IFN-I in modulating T cell responses to strong TCR stimulation.

Author Info: (1) Department of Microbiology and Immunology, the Peter Doherty Institute for Infection and Immunity, University of Melbourne, Melbourne, VIC, Australia. (2) Department of Microbi

Author Info: (1) Department of Microbiology and Immunology, the Peter Doherty Institute for Infection and Immunity, University of Melbourne, Melbourne, VIC, Australia. (2) Department of Microbiology and Immunology, the Peter Doherty Institute for Infection and Immunity, University of Melbourne, Melbourne, VIC, Australia. (3) Department of Microbiology and Immunology, the Peter Doherty Institute for Infection and Immunity, University of Melbourne, Melbourne, VIC, Australia. (4) Institute of Molecular Medicine and Experimental Immunology, University Hospital Bonn, University of Bonn, Venusberg-Campus 1, 53127 Bonn, Germany. (5) Department of Microbiology and Immunology, the Peter Doherty Institute for Infection and Immunity, University of Melbourne, Melbourne, VIC, Australia; Institute of Molecular Medicine and Experimental Immunology, University Hospital Bonn, University of Bonn, Venusberg-Campus 1, 53127 Bonn, Germany. (6) Department of Microbiology and Immunology, the Peter Doherty Institute for Infection and Immunity, University of Melbourne, Melbourne, VIC, Australia. (7) Department of Microbiology and Immunology, the Peter Doherty Institute for Infection and Immunity, University of Melbourne, Melbourne, VIC, Australia. (8) Department of Microbiology and Immunology, the Peter Doherty Institute for Infection and Immunity, University of Melbourne, Melbourne, VIC, Australia. (9) Department of Microbiology and Immunology, the Peter Doherty Institute for Infection and Immunity, University of Melbourne, Melbourne, VIC, Australia. (10) Institute for Immunology, University Hospital Heidelberg, Heidelberg, Germany. (11) Department of Microbiology and Immunology, the Peter Doherty Institute for Infection and Immunity, University of Melbourne, Melbourne, VIC, Australia. (12) Department of Microbiology and Immunology, the Peter Doherty Institute for Infection and Immunity, University of Melbourne, Melbourne, VIC, Australia. (13) Centre for Innate Immunity and Infectious Diseases, Hudson Institute of Medical Research, Clayton, VIC, Australia; Department of Molecular and Translational Science, Monash University, Clayton, VIC, Australia. (14) Centre for Innate Immunity and Infectious Diseases, Hudson Institute of Medical Research, Clayton, VIC, Australia; Department of Molecular and Translational Science, Monash University, Clayton, VIC, Australia. (15) Institute for Immunology, University Hospital Heidelberg, Heidelberg, Germany. (16) Department of Medicine II (Gastroenterology, Hepatology, Endocrinology, and Infectious Diseases), Medical Center, University of Freiburg, Baden-WŸrttemberg, Germany. (17) Department of Medicine II (Gastroenterology, Hepatology, Endocrinology, and Infectious Diseases), Medical Center, University of Freiburg, Baden-WŸrttemberg, Germany. (18) Department of Microbiology and Immunology, the Peter Doherty Institute for Infection and Immunity, University of Melbourne, Melbourne, VIC, Australia. (19) Institute of Molecular Medicine and Experimental Immunology, University Hospital Bonn, University of Bonn, Venusberg-Campus 1, 53127 Bonn, Germany. (20) Computational Sciences Initiative (CSI), the Peter Doherty Institute for Infection and Immunity, University of Melbourne, Melbourne, VIC, Australia. (21) Department of Microbiology and Immunology, the Peter Doherty Institute for Infection and Immunity, University of Melbourne, Melbourne, VIC, Australia. (22) Department of Microbiology and Immunology, the Peter Doherty Institute for Infection and Immunity, University of Melbourne, Melbourne, VIC, Australia. Electronic address: yannick.alexandre@unimelb.edu.au. (23) Department of Microbiology and Immunology, the Peter Doherty Institute for Infection and Immunity, University of Melbourne, Melbourne, VIC, Australia. Electronic address: daniel.utzschneider@unimelb.edu.au.

IL-2 mutein promotes antigen-specific transplant acceptance in mice through expansion of ST2(+) regulatory T cells Spotlight 

Focused on improving transplantation tolerance, Ganchiku et al. evaluated a long-lived, high-affinity receptor binding IL-2 mutein (mIL-2) in multiple solid organ transplantation models. mIL-2 therapy (with transient co-stimulation blockade) significantly improved long-term allograft survival in an Ag-specific manner, which persisted after cessation of treatment. Allograft survival was accompanied by Treg activation, decreased effector T cell activation, and reduced donor specific antibody levels. mIL-2-mediated allograft survival depended on expansion of highly active and suppressive tissue ST2+ Tregs and was abrogated in Treg-specific ST2 KO graft recipients.

Contributed by Katherine Turner

Focused on improving transplantation tolerance, Ganchiku et al. evaluated a long-lived, high-affinity receptor binding IL-2 mutein (mIL-2) in multiple solid organ transplantation models. mIL-2 therapy (with transient co-stimulation blockade) significantly improved long-term allograft survival in an Ag-specific manner, which persisted after cessation of treatment. Allograft survival was accompanied by Treg activation, decreased effector T cell activation, and reduced donor specific antibody levels. mIL-2-mediated allograft survival depended on expansion of highly active and suppressive tissue ST2+ Tregs and was abrogated in Treg-specific ST2 KO graft recipients.

Contributed by Katherine Turner

ABSTRACT: Although transplantation is the preferred treatment for end-stage organ disease, long-term outcomes are limited by immunosuppressive drug toxicity and immune-mediated injury. Selective in vivo expansion of regulatory T cells (Tregs) using interleukin-2 (IL-2) analogs has emerged as a strategy to induce antigen-specific transplant tolerance with fewer side effects. Herein, we investigate the therapeutic efficacy of an IL-2 mutein molecule (mIL-2) with enhanced receptor specificity and extended half-life in murine models of solid organ transplantation. mIL-2 therapy significantly improves allograft survival in an antigen-specific manner, accompanied by increased Treg activation, decreased effector T cell activation and reduced donor-specific antibody production. Transcriptional profiling reveals expansion of Tregs expressing the suppression of tumorigenicity 2 (ST2) Tregs with heightened activation status and suppressive function. Accordingly, the mIL-2-induced long-term allograft survival is abrogated in Treg-specific ST2 knockout graft recipients, underscoring the critical role of ST2(+) Tregs. These findings identify mIL-2 as an approach to promote long-term transplant tolerance while reducing reliance on conventional immunosuppression.

Author Info: (1) Center for Transplantation Sciences, Department of Surgery, Massachusetts General Hospital, Harvard Medical School, Charlestown, MA, USA. Department of Gastroenterological Surg

Author Info: (1) Center for Transplantation Sciences, Department of Surgery, Massachusetts General Hospital, Harvard Medical School, Charlestown, MA, USA. Department of Gastroenterological Surgery I, Graduate School of Medicine, Hokkaido University, Hokkaido, Japan. (2) Center for Transplantation Sciences, Department of Surgery, Massachusetts General Hospital, Harvard Medical School, Charlestown, MA, USA. (3) Center for Transplantation Sciences, Department of Surgery, Massachusetts General Hospital, Harvard Medical School, Charlestown, MA, USA. (4) Center for Transplantation Sciences, Department of Surgery, Massachusetts General Hospital, Harvard Medical School, Charlestown, MA, USA. (5) Center for Transplantation Sciences, Department of Surgery, Massachusetts General Hospital, Harvard Medical School, Charlestown, MA, USA. (6) Center for Transplantation Sciences, Department of Surgery, Massachusetts General Hospital, Harvard Medical School, Charlestown, MA, USA. (7) Center for Immunology & Inflammatory Diseases, Massachusetts General Hospital, Harvard Medical School, Charlestown, MA, USA. Division of Pulmonary and Critical Care Medicine, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA. (8) Center for Immunology & Inflammatory Diseases, Massachusetts General Hospital, Harvard Medical School, Charlestown, MA, USA. Division of Rheumatology, Allergy & Immunology, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA. (9) Visterra, Inc., Waltham, MA, USA. (10) Visterra, Inc., Waltham, MA, USA. (11) Center for Transplantation Sciences, Department of Surgery, Massachusetts General Hospital, Harvard Medical School, Charlestown, MA, USA. (12) Center for Transplantation Sciences, Department of Surgery, Massachusetts General Hospital, Harvard Medical School, Charlestown, MA, USA. (13) Center for Transplantation Sciences, Department of Surgery, Massachusetts General Hospital, Harvard Medical School, Charlestown, MA, USA. (14) Center for Transplantation Sciences, Department of Surgery, Massachusetts General Hospital, Harvard Medical School, Charlestown, MA, USA. LRIELLA@mgh.harvard.edu. Nephrology Division, Department of Medicine, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA. LRIELLA@mgh.harvard.edu.

TIGIT-targeted IL-12 fusion protein engages NK and CD8+ T cells for potent tumor immunotherapy

Spotlight 

To mitigate systemic IL-12 activation, Tang et al. generated T-12, a fusion protein linking IL-12 to an anti-TIGIT scFv that blocks TIGIT binding to its inhibitory receptor. Compared to wild-type IL-12, T-12 selectively localized to tumor sites and activated intratumoral NK and CD8+ T cells (both highly expressing TIGIT) to promote NK cell proliferation and reprogram CD8+ T cells toward a proliferative, memory-like effector phenotype. T-12 exhibited an MTD ~100X higher than wild-type IL-12, suppressed tumor growth in multiple mouse models (including immunologically “cold”/anti-PD-1 resistant), and reduced metastatic lesions to promote survival by mechanisms requiring both NK and CD8+ T cells.

Contributed by Paula Hochman

To mitigate systemic IL-12 activation, Tang et al. generated T-12, a fusion protein linking IL-12 to an anti-TIGIT scFv that blocks TIGIT binding to its inhibitory receptor. Compared to wild-type IL-12, T-12 selectively localized to tumor sites and activated intratumoral NK and CD8+ T cells (both highly expressing TIGIT) to promote NK cell proliferation and reprogram CD8+ T cells toward a proliferative, memory-like effector phenotype. T-12 exhibited an MTD ~100X higher than wild-type IL-12, suppressed tumor growth in multiple mouse models (including immunologically “cold”/anti-PD-1 resistant), and reduced metastatic lesions to promote survival by mechanisms requiring both NK and CD8+ T cells.

Contributed by Paula Hochman

ABSTRACT: The limitation of wild-type interleukin-12 (IL-12) in its clinical application lies in its systemic activation, which results in severe toxicities. Here, we develop a fusion protein named _TIGIT-IL12 (T-12), which fuses the 13G6 (_TIGIT) antibody scFv fragment in tandem with IL-12. T-12 can selectively localize to the tumor site and concurrently target intratumoral natural killer (NK) and CD8(+) T cells in vivo. T-12 demonstrated exceptional efficacy in reducing tumor burden across multiple tumor models in mice, dependent on NK and CD8(+) T cells. T-12 preferentially activates tumor-infiltrating NK and CD8(+) T cells over their peripheral counterparts, in contrast to wild-type IL-12. Compared with wild-type IL-12, T-12 exhibits greater safety upon systemic administration while treating tumor-bearing models, and the maximal tolerance dosage was elevated by up to about 100-fold. T-12 exhibits potent therapeutic efficacy in checkpoint-insensitive tumor models and metastatic tumor models. These findings underscore the potential of the T-12 fusion protein as a strategy in immunotherapy.

Author Info: (1) State Key Laboratory of Immune Response and Immunotherapy, Institute of Immunology, School of Basic Medical Sciences, Center for Advanced Interdisciplinary Science and Biomedic

Author Info: (1) State Key Laboratory of Immune Response and Immunotherapy, Institute of Immunology, School of Basic Medical Sciences, Center for Advanced Interdisciplinary Science and Biomedicine of IHM, The First Affiliated Hospital of USTC, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei 230027, China. (2) CAS Key Laboratory of Quantitative Engineering Biology, Shenzhen Institute of Synthetic Biology, Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences, Shenzhen 518055, China; Center for Genomic and Personalized Medicine, Guangxi key Laboratory for Genomic and Personalized Medicine, Guangxi Collaborative Innovation Center for Genomic and Personalized Medicine, The First Affiliated Hospital of Guangxi Medical University, Guangxi Medical University, Nanning 530021, Guangxi, China. (3) CAS Key Laboratory of Quantitative Engineering Biology, Shenzhen Institute of Synthetic Biology, Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences, Shenzhen 518055, China. (4) CAS Key Laboratory of Quantitative Engineering Biology, Shenzhen Institute of Synthetic Biology, Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences, Shenzhen 518055, China. (5) State Key Laboratory of Immune Response and Immunotherapy, Institute of Immunology, School of Basic Medical Sciences, Center for Advanced Interdisciplinary Science and Biomedicine of IHM, The First Affiliated Hospital of USTC, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei 230027, China. (6) State Key Laboratory of Immune Response and Immunotherapy, Institute of Immunology, School of Basic Medical Sciences, Center for Advanced Interdisciplinary Science and Biomedicine of IHM, The First Affiliated Hospital of USTC, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei 230027, China. (7) State Key Laboratory of Immune Response and Immunotherapy, Institute of Immunology, School of Basic Medical Sciences, Center for Advanced Interdisciplinary Science and Biomedicine of IHM, The First Affiliated Hospital of USTC, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei 230027, China; Hefei TG ImmunoPharma Corporation Limited, Hefei, China. (8) State Key Laboratory of Immune Response and Immunotherapy, Institute of Immunology, School of Basic Medical Sciences, Center for Advanced Interdisciplinary Science and Biomedicine of IHM, The First Affiliated Hospital of USTC, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei 230027, China. Electronic address: mahongdi@ustc.edu.cn. (9) State Key Laboratory of Immune Response and Immunotherapy, Institute of Immunology, School of Basic Medical Sciences, Center for Advanced Interdisciplinary Science and Biomedicine of IHM, The First Affiliated Hospital of USTC, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei 230027, China; CAS Key Laboratory of Quantitative Engineering Biology, Shenzhen Institute of Synthetic Biology, Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences, Shenzhen 518055, China; Hefei TG ImmunoPharma Corporation Limited, Hefei, China. Electronic address: tzg@ustc.edu.cn. (10) Department of Immunology, School of Basic Medical Sciences, and Department of Oncology, Shanghai Medical College, Fudan University, Shanghai 200032, China; Department of Medical Oncology, Fudan University Shanghai Cancer Center, Shanghai 200032, China; Hefei TG ImmunoPharma Corporation Limited, Hefei, China. Electronic address: haoyusun@ustc.edu.cn. (11) State Key Laboratory of Immune Response and Immunotherapy, Institute of Immunology, School of Basic Medical Sciences, Center for Advanced Interdisciplinary Science and Biomedicine of IHM, The First Affiliated Hospital of USTC, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei 230027, China; CAS Key Laboratory of Quantitative Engineering Biology, Shenzhen Institute of Synthetic Biology, Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences, Shenzhen 518055, China; Hefei TG ImmunoPharma Corporation Limited, Hefei, China. Electronic address: ustczxh@ustc.edu.cn.

FAP-CD40 and PD1-IL2v combination therapy reprograms immunologically cold tumors through de novo intratumoral T cell-dendritic cell clusters Spotlight 

In a KPC tumor model, Nguyen et al. combined a FAP-targeted CD40 agonist (FAP-CD40; localizes CD40 stimulation to the TME) and PD1–IL-2v (targets a mutated IL-2 to PD-1+ T cells and not Tregs). FAP-CD40 alone activated TME cDC1s, which migrated to tdLNs. Combination therapy expanded TME T cells and increased CD4+/CD8+/cDC1 clustering and therapeutic efficacy (dependent on both CD4+ and CD8+ T cells) compared to monotherapies. FTY720 blockade of LN egress did not preclude clustering or efficacy, suggesting activation of TME T cells. Combination therapy boosted TME T cell Th1 gene expression, TNFα/IFNγ production, and Nur77 promoter activity.

Contributed by Alex Najibi

In a KPC tumor model, Nguyen et al. combined a FAP-targeted CD40 agonist (FAP-CD40; localizes CD40 stimulation to the TME) and PD1–IL-2v (targets a mutated IL-2 to PD-1+ T cells and not Tregs). FAP-CD40 alone activated TME cDC1s, which migrated to tdLNs. Combination therapy expanded TME T cells and increased CD4+/CD8+/cDC1 clustering and therapeutic efficacy (dependent on both CD4+ and CD8+ T cells) compared to monotherapies. FTY720 blockade of LN egress did not preclude clustering or efficacy, suggesting activation of TME T cells. Combination therapy boosted TME T cell Th1 gene expression, TNFα/IFNγ production, and Nur77 promoter activity.

Contributed by Alex Najibi

BACKGROUND: Pancreatic ductal adenocarcinoma (PDAC) remains a major challenge for immunotherapy due to its immunologically cold tumor nature, characterized by poor T cell infiltration and a highly suppressive tumor microenvironment. Here, we propose a novel strategy, combining fibroblast activation protein (FAP)-CD40 to activate dendritic cells (DCs) in the tumor microenvironment and programmed cell death protein-1 (PD1)-interleukin 2v (IL2v) to promote the expansion and differentiation of tumor-infiltrating T cells. We hypothesize that this combination will synergistically enhance both T cell priming and expansion directly within pancreatic 4662 KPC tumors, which recapitulate the immunologically cold features of human PDAC. METHODS: Immune cell distribution and abundance following FAP-CD40/PD1-IL2v monotherapy or combination therapy were analyzed using multiplexed confocal imaging (3D immune phenotyping). FTY720 studies assessed the contribution of lymph node priming in treatment efficacy, while CD4+/CD8+ T cell depletion experiments identified the roles of these subsets in combination therapy. T cell functionality was further assessed through ex vivo restimulation assays and single-cell RNA sequencing. RESULTS: Combination therapy induced dense intratumoral clusters of CD4(+) and CD8(+) T cells, colocalized with type 1 conventional DCs, termed as T cell-DC clusters (TDCs). These TDCs were strongly associated with tumor regression, which required both CD4(+) and CD8(+) T cells. Furthermore, T cells from combination-treated tumors showed enhanced functionality, with increased tumor necrosis factor-alpha and interferon-gamma production compared with monotherapy groups. Single-cell RNA sequencing revealed polarization of CD4(+) T cells toward a T helper cell 1 phenotype in combination-treated tumors. CONCLUSION: The combination of FAP-CD40 and PD1-IL2v offers a promising strategy for treating poorly infiltrated, cold tumors. By driving T cell infiltration, promoting de novo TDC formation and orchestrating local antitumor immunity, this strategy provides a foundation for future therapies targeting immunotherapy-resistant tumors.

Author Info: (1) Roche Pharma Research and Early Development, Roche Innovation Center Zurich, Schlieren, Switzerland. (2) Roche Pharma Research and Early Development, Roche Innovation Center Ba

Author Info: (1) Roche Pharma Research and Early Development, Roche Innovation Center Zurich, Schlieren, Switzerland. (2) Roche Pharma Research and Early Development, Roche Innovation Center Basel, Basel, Switzerland. (3) Roche Pharma Research and Early Development, Roche Innovation Center Zurich, Schlieren, Switzerland. (4) Roche Pharma Research and Early Development, Roche Innovation Center Zurich, Schlieren, Switzerland. (5) Roche Pharma Research and Early Development, Roche Innovation Center Zurich, Schlieren, Switzerland. (6) Roche Pharma Research and Early Development, Roche Innovation Center Basel, Basel, Switzerland. (7) Roche Pharma Research and Early Development, Roche Innovation Center Zurich, Schlieren, Switzerland. (8) Roche Pharma Research and Early Development, Roche Innovation Center Basel, Basel, Switzerland. (9) Roche Pharma Research and Early Development, Roche Innovation Center Zurich, Schlieren, Switzerland. (10) Roche Pharma Research and Early Development, Roche Innovation Center Zurich, Schlieren, Switzerland. (11) Institute of Experimental Immunology, UniversitŠt ZŸrich, ZŸrich, Switzerland. Department of Immunology, Heidelberg University Medical Faculty Mannheim, Mannheim, Germany. (12) Roche Pharma Research and Early Development, Roche Innovation Center Zurich, Schlieren, Switzerland. (13) Roche Pharma Research and Early Development, Roche Innovation Center Basel, Basel, Switzerland leo.kunz@roche.com.

Targeting CCR1 remodels the tumor microenvironment and relieves immune suppression in pancreatic cancer Featured  

Evaluating the role of CCR1 in pancreatic cancer, Zhang et al. used KC and KPC mouse tumor models, and found while elimination of CCR1 did not limit tumor formation, it delayed progression of active disease, resulting in prolonged survival. CCR1 was mainly expressed by macrophages and granulocytes, but its deletion induced TIME remodeling that affected fibroblasts and increased CD8+ T cell accumulation, but not activation. CCR1 inhibition showed synergy in combination with targeting of other immunosuppressive mechanisms, though there was still room to improve antitumor efficacy in this highly resistant tumor setting.

Evaluating the role of CCR1 in pancreatic cancer, Zhang et al. used KC and KPC mouse tumor models, and found while elimination of CCR1 did not limit tumor formation, it delayed progression of active disease, resulting in prolonged survival. CCR1 was mainly expressed by macrophages and granulocytes, but its deletion induced TIME remodeling that affected fibroblasts and increased CD8+ T cell accumulation, but not activation. CCR1 inhibition showed synergy in combination with targeting of other immunosuppressive mechanisms, though there was still room to improve antitumor efficacy in this highly resistant tumor setting.

ABSTRACT: A hallmark of pancreatic cancer is an extensive fibroinflammatory stroma. Myeloid cells, including abundant macrophages, are a prevalent cellular component of the pancreatic cancer microenvironment and a key driver of immunosuppression. Identifying mechanisms of myeloid-cell driven immunosuppression is thus key to developing therapeutic approaches. Harnessing single-cell RNA sequencing data from human and murine tumors, we determined that tumor infiltrating myeloid cells (including macrophages and granulocytes) have elevated expression of C-C motif chemokine receptor 1 (CCR1). To determine the functional role of CCR1, we generated oncogenic KRAS based genetically engineered mouse models of pancreatic cancer, with or without addition of a mutant form of the tumor suppressor Trp53 (KC and KPC, respectively), lacking CCR1 expression. CCR1 inactivation did not affect formation of early lesions, but delayed progression to cancer and resulted in prolonged survival. In these mice, macrophages lacking CCR1 had reduced expression of the immunosuppressive marker Arginase 1. Loss of CCR1 also profoundly shifted the prevalent fibroblast population, inducing a pancreatic stellate cell-like phenotype. In two independent syngeneic orthotopic models, ablation or pharmacologic inhibition of CCR1 reduced tumor growth and increased CD8+ T cell cytotoxic activity, sensitizing tumors to immunotherapy. Our data show that CCR1-expressing myeloid cells promote pancreatic cancer growth through modulation of the immune microenvironment and fibroblasts, indicating that CCR1 might be a suitable target for combination therapy.

Author Info: (1) University of Michigan-Ann Arbor Ann Arbor, MI United States. ROR: https://ror.org/00jmfr291 (2) University of Michigan-Ann Arbor Ann Arbor, MI United States. (3) University of

Author Info: (1) University of Michigan-Ann Arbor Ann Arbor, MI United States. ROR: https://ror.org/00jmfr291 (2) University of Michigan-Ann Arbor Ann Arbor, MI United States. (3) University of Michigan-Ann Arbor Ann Arbor, Michigan United States. ROR: https://ror.org/00jmfr291 (4) University of Michigan Medical Schooligan United States. (5) University of Michigan-Ann Arbor Ann Arbor, Michigan United States. ROR: https://ror.org/00jmfr291 (6) University of Michigan-Ann Arbor Ann Arbor, Michigan United States. ROR: https://ror.org/00jmfr291 (7) University of Michigan-Ann Arbor Ann Arbor, MI United States. ROR: https://ror.org/00jmfr291 (8) University of Michigan-Ann Arbor Ann Arbor, MI United States. ROR: https://ror.org/00jmfr291 (9) University of Michigan-Ann Arbor Ann Arbor, MI United States. ROR: https://ror.org/00jmfr291 (10) University of Michigan-Ann Arbor Ann Arbor, MI United States. ROR: https://ror.org/00jmfr291 (11) University of Michigan-Ann Arbor Ann Arbor United States. ROR: https://ror.org/00jmfr291 (12) University of Michigan-Ann Arbor United States. ROR: https://ror.org/00jmfr291 (13) University of Maryland, Baltimore Baltimore United States. ROR: https://ror.org/04rq5mt64 (14) University of Michigan-Ann Arbor Ann Arbor, Michigan United States. ROR: https://ror.org/00jmfr291 (15) University of Michigan-Ann Arbor Ann Arbor United States. ROR: https://ror.org/00jmfr291 (16) University of Michigan-Ann Arbor United States. ROR: https://ror.org/00jmfr291 (17) University of Michigan-Ann Arbor United States. ROR: https://ror.org/00jmfr291 (18) University of Michigan-Ann Arbor Ann Arbor, Michigan United States. ROR: https://ror.org/00jmfr291 (19) University of Michigan-Ann Arbor United States. ROR: https://ror.org/00jmfr291 (20) University of Michigan-Ann Arbor Ann Arbor, Michigan United States. ROR: https://ror.org/00jmfr291 (21) University of Michigan-Ann Arbor Ann Arbor, Michigan United States. ROR: https://ror.org/00jmfr291 (22) University of Michigan-Ann Arbor Ann Arbor, Michigan United States. ROR: https://ror.org/00jmfr291 (23) University of Michigan-Ann Arbor Ann Arbor United States. ROR: https://ror.org/00jmfr291 (24) University of Michigan-Ann Arbor United States. ROR: https://ror.org/00jmfr291 (25) Cornell University Ithaca United States. ROR: https://ror.org/05bnh6r87 (26) University of Michigan-Ann Arbor Ann Arbor, MI United States. ROR: https://ror.org/00jmfr291 (27) University of Michigan-Ann Arbor Ann Arbor, MI United States. ROR: https://ror.org/00jmfr291 (28) University of Michigan-Ann Arbor Ann Arbor, Michigan United States. ROR: https://ror.org/00jmfr291 (29) University of Michigan-Ann Arbor Ann Arbor, MI United States. ROR: https://ror.org/00jmfr291 (30) University of Michigan-Ann Arbor Ann Arbor, MI United States. ROR: https://ror.org/00jmfr291 (31) Cedars-Sinai Medical Center Los Angeles, CA United States. ROR: https://ror.org/02pammg90 (32) University of Michigan-Ann Arbor Ann Arbor, MI United States. ROR: https://ror.org/00jmfr291 (33) University of Michigan-Ann Arbor Ann Arbor, MI United States. ROR: https://ror.org/00jmfr291

Pembrolizumab plus high-dose IL-2 in advanced clear cell renal cell carcinoma: six-year survival outcomes and molecular signatures from a phase 2 trial Spotlight 

In a phase 2 clinical trial of a short-course regimen (median 7 months) of pembrolizumab (anti-PD-1) plus high-dose IL-2 in patients with advanced ccRCC, Johnson et al. reported that at a median follow-up of over 6 years, the ORR was 73%, with 42% CRs and a 92% DCR. Median OS was over 84 months, and median PFS was 19.3 months. Patients were able to remain off treatment for a median of 23.8 months, with 42% of patients off treatment at 5 years. Potential biomarkers for durable clinical benefit included elevated CD16+ NK cells, enhanced innate immunity, reduced PD-1+ T cells, and patterns of IL-2-induced immune remodeling.

Contributed by Lauren Hitchings

In a phase 2 clinical trial of a short-course regimen (median 7 months) of pembrolizumab (anti-PD-1) plus high-dose IL-2 in patients with advanced ccRCC, Johnson et al. reported that at a median follow-up of over 6 years, the ORR was 73%, with 42% CRs and a 92% DCR. Median OS was over 84 months, and median PFS was 19.3 months. Patients were able to remain off treatment for a median of 23.8 months, with 42% of patients off treatment at 5 years. Potential biomarkers for durable clinical benefit included elevated CD16+ NK cells, enhanced innate immunity, reduced PD-1+ T cells, and patterns of IL-2-induced immune remodeling.

Contributed by Lauren Hitchings

ABSTRACT: Prolonged or indefinite systemic therapy remains standard for advanced clear cell renal cell carcinoma (ccRCC), often resulting in cumulative toxicities and treatment burden. We conducted a single-arm phase 2 trial (ClinicalTrials.gov identifier: NCT02964078) of a fixed-duration regimen of anti-PD1 pembrolizumab plus high-dose interleukin-2 in treatment-naive advanced ccRCC. Primary objectives of safety and response were previously reported. The study met its primary endpoint with an overall response rate exceeding the pre-specified threshold of 45%. Here we report long-term follow-up (median follow-up of 76.4 months) including overall response, progression-free survival, treatment-free interval, and correlative analysis. Among 26 patients treated, the objective response rate was 73%, with complete responses in 42% of patients. Median overall survival was >84 months with a 5-year restricted mean survival time of 48.6 months. Median progression-free survival was 19.3 months, and median treatment-free interval was 23.8 months. 42% of patients remained treatment-free at the 5-year timepoint. No grade 5 adverse events occurred, and no patients with durable disease control experienced persistent grade ≥2 toxicities. Correlative analyses identified exploratory immune patterns associated with durable benefit, including enrichment of CD16⁺ natural killer cells, suppression of PD-1⁺ T-cell frequencies, and coordinated chemokine, complement, and PKC/TGF-β pathway activation.

Author Info: (1) Department of Genitourinary Oncology, H. Lee Moffitt Cancer Center, Tampa, FL, USA. (2) USF Health Morsani College of Medicine, Tampa, FL, USA. (3) Department of Genitourinary

Author Info: (1) Department of Genitourinary Oncology, H. Lee Moffitt Cancer Center, Tampa, FL, USA. (2) USF Health Morsani College of Medicine, Tampa, FL, USA. (3) Department of Genitourinary Oncology, H. Lee Moffitt Cancer Center, Tampa, FL, USA. (4) Department of Biostatistics and Bioinformatics, H. Lee Moffitt Cancer Center, Tampa, FL, USA. (5) Department of Biostatistics and Bioinformatics, H. Lee Moffitt Cancer Center, Tampa, FL, USA. (6) Department of Genitourinary Oncology, H. Lee Moffitt Cancer Center, Tampa, FL, USA. (7) Department of Genitourinary Oncology, H. Lee Moffitt Cancer Center, Tampa, FL, USA. (8) Department of Genitourinary Oncology, H. Lee Moffitt Cancer Center, Tampa, FL, USA. (9) Department of Genitourinary Oncology, H. Lee Moffitt Cancer Center, Tampa, FL, USA. (10) Department of Genitourinary Oncology, Weill Cornell Medicine, New York, NY, USA. (11) Department of Genitourinary Oncology, H. Lee Moffitt Cancer Center, Tampa, FL, USA. (12) Department of Biostatistics and Bioinformatics, H. Lee Moffitt Cancer Center, Tampa, FL, USA. (13) Department of Anatomic Pathology, H. Lee Moffitt Cancer Center, Tampa, FL, USA. (14) Immune Monitoring Core, H. Lee Moffitt Cancer Center, Tampa, FL, USA. (15) Department of Biostatistics and Bioinformatics, H. Lee Moffitt Cancer Center, Tampa, FL, USA. (16) Department of Biostatistics and Bioinformatics, H. Lee Moffitt Cancer Center, Tampa, FL, USA. (17) Department of Biostatistics and Bioinformatics, H. Lee Moffitt Cancer Center, Tampa, FL, USA. (18) Department of Pharmacy, H. Lee Moffitt Cancer Center, Tampa, FL, USA. (19) Department of Genitourinary Oncology, H. Lee Moffitt Cancer Center, Tampa, FL, USA. (20) Department of Genitourinary Oncology, H. Lee Moffitt Cancer Center, Tampa, FL, USA. (21) Department of Biostatistics and Bioinformatics, H. Lee Moffitt Cancer Center, Tampa, FL, USA. (22) Department of Genitourinary Oncology, H. Lee Moffitt Cancer Center, Tampa, FL, USA. (23) USF Health Morsani College of Medicine, Tampa, FL, USA. Tampa General Hospital Cancer Institute, Tampa, FL, USA. (24) Department of Genitourinary Oncology, Orlando Health Cancer Institute, Orlando, FL, USA. Jad.Chahoud@orlandohealth.com.

In vivo reprogramming of cytotoxic effector CD8+ T cells via fractalkine-conjugated mRNA-LNP

Spotlight 

Corrigan et al. developed and tested mRNA lipid nanoparticles (mRNA-LNP) conjugated with fractalkine (CX3CL1) and found that they were able to specifically target CX3CR1+ cells – primarily effector T cells and NK cells – inducing transient expression of the payload mRNA. Administration of fraktalkine-conjugated mRNA-LNPs could be used to induce secretion of IL-2 or cell membrane expression of CD62L in target cells in vivo, with detectable expression of payload expression in up to 95% and 100% of Teff in the peripheral blood of mice and rhesus macaques, respectively. CD62L expression may have enabled lymph node trafficking of CX3CR1+ Teff cells.

Contributed by Lauren Hitchings

Corrigan et al. developed and tested mRNA lipid nanoparticles (mRNA-LNP) conjugated with fractalkine (CX3CL1) and found that they were able to specifically target CX3CR1+ cells – primarily effector T cells and NK cells – inducing transient expression of the payload mRNA. Administration of fraktalkine-conjugated mRNA-LNPs could be used to induce secretion of IL-2 or cell membrane expression of CD62L in target cells in vivo, with detectable expression of payload expression in up to 95% and 100% of Teff in the peripheral blood of mice and rhesus macaques, respectively. CD62L expression may have enabled lymph node trafficking of CX3CR1+ Teff cells.

Contributed by Lauren Hitchings

ABSTRACT: Selective in vivo reprogramming of cytotoxic effector CD8 T (Teff) cells holds tremendous promise as a therapeutic tool but has not yet been accomplished. Here, we demonstrate that fractalkine-conjugated mRNA lipid nanoparticles (mRNA-LNPs) can specifically target and deliver mRNA to CX3CR1+ Teff cells in vitro and in vivo. In mice, fractalkine-conjugated mRNA-LNPs targeted up to 95% of blood and splenic Teff cells. In addition, delivery of IL-2-encoding mRNA and human CD62L-encoding mRNA to mouse Teff cells enabled robust exogenous IL-2 secretion and CD62L expression. In rhesus macaques, fractalkine-conjugated mRNA-LNPs targeted up to ~100% of peripheral blood Teff cells, and delivery of human CD62L-encoding mRNA enabled cell-surface human CD62L expression on peripheral blood Teff cells and detection of human CD62L+ Teff cells in lymphoid tissue. Collectively, these data demonstrate the potential of natural receptor ligand-based targeting of mRNA-LNPs for rapid, efficient, and transient in vivo modification of Teff cells.

Author Info: 1Department of Microbiology, University of Pennsylvania, Philadelphia, PA, USA. 2Institute for Immunology and Immune Health, Perelman School of Medicine, University of Pennsylvania

Author Info: 1Department of Microbiology, University of Pennsylvania, Philadelphia, PA, USA. 2Institute for Immunology and Immune Health, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA. 3Department of Systems Pharmacology and Translational Therapeutics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA. 4Parker Institute for Cancer Immunotherapy, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA. 5Division of Microbiology and Immunology, Emory National Primate Research Center, Emory University, Atlanta, GA, USA. 6Department of Medicine, University of Pennsylvania, Philadelphia, PA, USA. 7Department of Pathology and Laboratory Medicine, University of Pennsylvania, Philadelphia, PA, USA. 8Division of Animal Resources, Emory National Primate Research Center, Emory University, Atlanta, GA, USA. 9Acuitas Therapeutics, Vancouver, Canada. 10Vaccine and Immunotherapy Center, Wistar Institute, Philadelphia, PA, USA. 11Department of Pathology and Laboratory Medicine, Emory University School of Medicine, Atlanta, GA, USA. 12Center for AIDS Research, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA.

Targeted TNF Potentiates the Activity of Bispecific T-cell Engagers in Solid Tumors by Turning Cold Tumors Hot Spotlight 

As colorectal cancer immunotherapy has shown limited success, Thorhallsdottir et al. developed a dual-modality approach. L19-TNF, a TNF-based fusion protein directed to pan-tumor stromal extradomain B of fibronectin (to induce intratumoral inflammation) was combined with a CEA-targeted CD3-based T cell engager (CEAxCD3 TCE) to promote CD8+ T cell proliferation and antigen-specific cytotoxicity. In two immunocompetent models, L19-TNF plus CEAxCD3 resulted in >50% CRs, prolonged survival, and durable memory, with a tolerable safety profile. Mechanistically, the combination revealed enhanced TCE extravasation and TIME remodeling.

Contributed by Katherine Turner

As colorectal cancer immunotherapy has shown limited success, Thorhallsdottir et al. developed a dual-modality approach. L19-TNF, a TNF-based fusion protein directed to pan-tumor stromal extradomain B of fibronectin (to induce intratumoral inflammation) was combined with a CEA-targeted CD3-based T cell engager (CEAxCD3 TCE) to promote CD8+ T cell proliferation and antigen-specific cytotoxicity. In two immunocompetent models, L19-TNF plus CEAxCD3 resulted in >50% CRs, prolonged survival, and durable memory, with a tolerable safety profile. Mechanistically, the combination revealed enhanced TCE extravasation and TIME remodeling.

Contributed by Katherine Turner

ABSTRACT: Colorectal cancer remains a major global health burden and an area of urgent unmet medical need. Immunotherapy has shown limited success in colorectal cancer as most patients present with an immune-excluded, "cold" tumor microenvironment (TME). In this study, we report a dual-modality approach to treating colorectal cancer by combining the tumor necrosis factor (TNF)-based fusion protein directed to the extradomain B (EDB) of fibronectin, L19-TNF, which induces localized intratumoral inflammation and facilitates T-cell infiltration, with a CD3-based bispecific T-cell engager (TCE) targeting carcinoembryonic antigen (CEA), which mediates antigen-specific cytotoxicity. Together, these agents aim to remodel the TME, convert "cold" tumors into inflamed "hot" lesions, and broaden the therapeutic reach of immunotherapy in colorectal cancer. Immunohistochemistry confirmed coexpression of CEA and EDB across microsatellite-stable and -instable tumors. In vitro, L19-TNF in combination with a CEAxCD3 TCE significantly enhanced tumor cell killing and CD8+ T-cell proliferation. In vivo, the combination induced complete tumor regression in most animals, prolonged survival, and conferred durable protection against tumor rechallenge. Furthermore, mechanistic analyses revealed enhanced TCE extravasation, upregulated intercellular adhesion molecule 1 expression, and increased CD8+ T-cell infiltration, indicating vascular modulation and remodeling of the TME toward an inflamed "hot" phenotype. These findings confirm that targeted delivery of TNF to the TME can effectively enhance the activity of immunotherapeutic agents, such as T cell-redirecting therapies, in challenging tumor settings.

Author Info: (1) Philochem AG, Otelfingen, Switzerland. Swiss Federal Institute of Technology, ETH ZŸrich, Zurich, Switzerland. ROR: https://ror.org/05a28rw58 (2) Philochem AG, Otelfingen, Swit

Author Info: (1) Philochem AG, Otelfingen, Switzerland. Swiss Federal Institute of Technology, ETH ZŸrich, Zurich, Switzerland. ROR: https://ror.org/05a28rw58 (2) Philochem AG, Otelfingen, Switzerland. (3) University of Pisa , Pisa, Italy. ROR: https://ror.org/03ad39j10 (4) University of Pisa , Pisa, Italy. ROR: https://ror.org/03ad39j10 (5) Philochem AG, Otelfingen, Switzerland. (6) Philochem AG, Otelfingen, Switzerland. (7) Philochem AG, Otelfingen, Switzerland. Swiss Federal Institute of Technology, ETH ZŸrich, Zurich, Switzerland. ROR: https://ror.org/05a28rw58 (8) Philochem AG, Otelfingen, Switzerland. (9) Philochem AG, Otelfingen, Switzerland. Philogen SpA, Siena, Italy. (10) Philochem AG, Otelfingen, Switzerland. Swiss Federal Institute of Technology, ETH ZŸrich, Zurich, Switzerland. ROR: https://ror.org/05a28rw58 Philogen SpA, Siena, Italy. (11) Philochem AG, Otelfingen, Switzerland.

Developing a multimodal therapy for glioblastoma using oncolytic virus delivering CD19 and EGFRvIII antigens and bi-specific CARs

Spotlight 

Li et al. engineered an oncolytic vaccinia virus that expressed truncated CD19 and EGFRvIII on GBM cells (OVDual) and a bispecific CD19/EGFRvIII CAR-T (BiCAR-T). BiCAR-T cells effectively targeted OVDual-infected GBM cells in vitro, and intratumoral OVDual plus BiCAR-T reduced tumor burden in the xenograft model of GBM. Oncolytic vaccinia virus encoding mIL-15 and mIL-21 (OVmIL15/21) further enhanced CAR expansion, persistence, and cytotoxicity. Human pluripotent stem cell-derived (off-the-shelf) BiCAR-NK cells combined with OVDual and OVmIL15/21 showed similar antigen-specific cytotoxicity and in vivo efficacy, limiting immune escape.

Contributed by Shishir Pant

Li et al. engineered an oncolytic vaccinia virus that expressed truncated CD19 and EGFRvIII on GBM cells (OVDual) and a bispecific CD19/EGFRvIII CAR-T (BiCAR-T). BiCAR-T cells effectively targeted OVDual-infected GBM cells in vitro, and intratumoral OVDual plus BiCAR-T reduced tumor burden in the xenograft model of GBM. Oncolytic vaccinia virus encoding mIL-15 and mIL-21 (OVmIL15/21) further enhanced CAR expansion, persistence, and cytotoxicity. Human pluripotent stem cell-derived (off-the-shelf) BiCAR-NK cells combined with OVDual and OVmIL15/21 showed similar antigen-specific cytotoxicity and in vivo efficacy, limiting immune escape.

Contributed by Shishir Pant

ABSTRACT: Glioblastoma is the most aggressive primary brain tumor with no cure, largely because of tumor heterogeneity and immunosuppressive tumor microenvironment. Chimeric antigen receptor (CAR)-T cell therapy is highly effective in blood cancers but exhibits limited efficacy in glioblastoma due to heterogeneous tumor antigen expression, antigen loss and poor persistence of tumor-targeting immune cells in glioblastoma. Here we show a multimodal immunotherapy strategy that integrates engineered immune cells with oncolytic viruses to overcome these barriers. We have developed bispecific CAR-T and CAR-NK cells in combination with oncolytic virus that delivers two tumor antigens to glioblastoma cells for effective CAR targeting. Moreover, oncolytic virus armed with membrane-bound interleukin-15 and interleukin-21 enhances immune cell expansion/persistence and cytotoxic activity. This combined approach improves anti-tumor efficacy in vitro and in vivo by limiting immune escape and enhancing anti-tumor immunity. Together, these findings establish a promising platform for multimodal immunotherapy targeting glioblastoma and other solid tumors.

Author Info: (1) Department of Neurodegenerative Diseases, Beckman Research Institute of City of Hope, 1500 E. Duarte Rd., Duarte, CA, USA. (2) Department of Surgery, City of Hope, 1500 E. Duar

Author Info: (1) Department of Neurodegenerative Diseases, Beckman Research Institute of City of Hope, 1500 E. Duarte Rd., Duarte, CA, USA. (2) Department of Surgery, City of Hope, 1500 E. Duarte Rd., Duarte, CA, USA. (3) Department of Neurodegenerative Diseases, Beckman Research Institute of City of Hope, 1500 E. Duarte Rd., Duarte, CA, USA. (4) Department of Neurodegenerative Diseases, Beckman Research Institute of City of Hope, 1500 E. Duarte Rd., Duarte, CA, USA. (5) Department of Neurodegenerative Diseases, Beckman Research Institute of City of Hope, 1500 E. Duarte Rd., Duarte, CA, USA. (6) Department of Neurodegenerative Diseases, Beckman Research Institute of City of Hope, 1500 E. Duarte Rd., Duarte, CA, USA. (7) Department of Neurodegenerative Diseases, Beckman Research Institute of City of Hope, 1500 E. Duarte Rd., Duarte, CA, USA. (8) Department of Hematology & Hematopoietic Cell Transplantation, City of Hope, 1500 E. Duarte Rd., Duarte, CA, USA. (9) Department of Surgery, City of Hope, 1500 E. Duarte Rd., Duarte, CA, USA. (10) Cellular Immunotherapy Program Cancer Center, Massachusetts General Hospital, Boston, MA, USA. Harvard Medical School, Boston, MA, USA. (11) Department of Neurodegenerative Diseases, Beckman Research Institute of City of Hope, 1500 E. Duarte Rd., Duarte, CA, USA. yshi@coh.org.

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