Journal for Immunotherapy of Cancer最新文献

Background: Mitochondrial antiviral signaling protein (MAVS), a central adaptor in cytosolic RNA sensing, is critical for antitumor innate immunity and maintains mitochondrial homeostasis via its mitochondrial localization. Mitochondrial dysfunction acts as a key driver and amplifier of the senescence-associated secretory phenotype (SASP), a double-edged sword in tumor progression. However, whether tumor-intrinsic MAVS can regulate antitumor immunity via cellular senescence independently of its well-established interferon signaling remains unclear.

Methods: Our study employed an integrated strategy. Clinically, we profiled MAVS expression and its association with prognosis and immune infiltration in renal tumor specimens. Mechanistic insights into tumor-intrinsic MAVS were gained through a battery of techniques spanning quantitative PCR, immunoblotting, RNA sequencing, senescence and mitochondrial function assays, confocal imaging, immunohistochemical, mass spectrometry, and co-immunoprecipitation. In vivo, we used MAVS-deficient models combined with CD8⁺ T-cell depletion, programmed cell death protein-1 (PD-1) blockade, or reactive oxygen species (ROS) scavenging by N-acetylcysteine (NAC), with immune infiltration characterized by flow cytometry.

Results: Clinical evidence links elevated MAVS expression in renal tumors to poor prognosis and diminished CD8⁺ T-cell infiltration. Strikingly, tumor-intrinsic MAVS deficiency curbed malignant progression by triggering cellular senescence and fostering a permissive niche for CD8⁺ T-cell activation and recruitment. Mechanistically, MAVS orchestrates mitochondrial integrity by co-localizing with and stabilizing chemokine-like factor-like MARVEL transmembrane domain-containing 6 (CMTM6), thereby shielding it from lysosomal degradation. Disruption of this axis provoked mitochondrial dysfunction and ROS accumulation, culminating in senescence and an SASP marked by chemokine C-C motif ligand 3 (CCL3). Thus, despite dampening canonical innate immune signaling, MAVS deletion unleashed potent antitumor immunity via CCL3-mediated CD8⁺ T-cell recruitment, an effect abolished by CD8⁺ T-cell depletion or ROS scavenging with NAC. Leveraging this paradigm, we demonstrated that tumor-specific MAVS deficiency acts synergistically with PD-1 blockade to achieve robust therapeutic efficacy.

Conclusions: Our findings establish the tumor-intrinsic MAVS/CMTM6/CCL3 axis as a previously unrecognized critical regulator of senescence-driven antitumor immunity in renal carcinoma. Therapeutic targeting of this axis presents a promising strategy to curtail tumor progression and potentiate immunotherapy.

Background: Immunotherapies have revolutionized cancer care in recent decades, but approved therapies often fail and currently only target specific steps in the generation of anti-cancer immune responses. Notably, the majority of approved immunotherapies do not target antigen processing and presentation, which are key steps in the development of immune responses and harbor potential as targets to improve immunotherapy. Here, we hypothesize that tumor-mediated alterations in cytokine concentrations alter antigen presentation, which can be normalized by locoregional cytokine delivery or targeted immunological adjuvant delivery.

Methods: We used mouse models of breast cancer, with analysis by flow cytometry, immunofluorescence, confocal imaging, and single-cell RNA sequencing to address the impacts of tumors on locoregional antigen presentation, along with mechanisms to remedy these impacts.

Results: Here, we demonstrate that breast tumors induce locoregional impairments in dendritic cell antigen presentation that limits anti-cancer antigen-specific T cell responses. Antigen processing was not impaired in dendritic cells within the tumor-draining lymph node. A reduction of the cytokine IL-1β in tumor-draining lymph nodes was responsible for impairments in antigen presentation by dendritic cells. As such, we tested the ability of dendritic cells in lymph nodes at various distances from the primary tumor to be activated utilizing an antigen-agnostic immunological adjuvant delivery strategy. We observed improved antitumor T cell responses when immunological adjuvant was delivered to cancer antigen-positive lymph nodes distant from the tumor, suggesting that these lymph nodes can be targeted to improve anti-cancer immune responses. When combined with immune checkpoint blockade, delivery of immunological adjuvant to distant lymph nodes led to long-term survival and protection from recurrence. Antigen presentation by dendritic cells and T cell responses could also be recovered by exogenous delivery of IL-1β via intratumoral injection, with improved survival when combined with immune checkpoint blockade.

Conclusions: This study demonstrates that tumor-induced impairments in antigen presentation in tumor-draining lymph nodes can be overcome by the appropriate introduction of immunological adjuvant to tumor-distant lymph nodes or by restoring IL-1β to the tumor-draining lymph node. These strategies can induce high-quality, durable immune responses and have clinical implications for expanding the efficacy of immunotherapies.

Background: Chimeric antigen receptor (CAR) T-cell therapies are highly efficacious for several different hematologic cancers. However, for most CAR T targets it is observed that low surface antigen density on tumors can significantly reduce therapeutic efficacy. In this study, we explore this dynamic in the context of CD72, a surface antigen we recently found as a promising target for refractory B-cell cancers, but for which CD72 low antigen density can lead to therapeutic resistance in preclinical models.

Methods: Primary samples were accessed via institutional review board-approved protocols. Affinity-matured and humanized nanobody clones were previously described in Temple et al. (2023). CAR T cells were generated via lentiviral transduction. In vitro cytotoxicity assays were performed using luciferase-labeled cell lines. In vivo studies were performed using cell line-derived or patient-derived xenografts implanted in NOD scid gamma mice.

Results: We first confirmed ubiquitous CD72 expression across a range of primary B-cell non-Hodgkin lymphomas. We further found that after resistance to CD19-directed therapies, across both B-cell acute lymphoblastic leukemia (B-ALL) models and primary tumor samples, surface CD72 expression was largely preserved while CD22 expression was significantly diminished. Affinity maturation of a nanobody targeting CD72, when incorporated into CAR T cells, led to more effective elimination in vitro of isogenic models of CD72 low-expressing tumors. These results suggested that nanobody-based CAR T cells (nanoCARs) may exhibit a similar relationship between binder affinity, antigen expression, and efficacy as previously demonstrated only for single chain variable fragment-based CAR T cells. Surprisingly, however, this significantly improved in vitro efficacy only translated to modest in vivo survival benefit. As a parallel strategy to enhance CAR T function, we found that the small molecule bryostatin could also significantly increase CD72 surface antigen density on B-cell malignancy models. Structural modeling and biochemical analysis identified critical residues improving CD72 antigen recognition of our lead affinity-matured nanobody.

Conclusions: Together, these findings support affinity-matured CD72 nanoCARs as a potential immunotherapy product for CD19-refractory B-cell cancers. Our results also suggest that for B-ALL in particular, CD72 may be a preferable second-line immunotherapy target over CD22.

Genetic engineering has fundamentally transformed T cell-based therapies by enabling tumor targeting capability, improving their functionality, and facilitating allogeneic use. These strategies-originally developed in αβ chimeric antigen receptor (CAR)-T cells-have become increasingly established as blueprints for enhancing the function of other immune effector cells, including gamma delta (γδ) T cells. A recent study by Nishimoto et al showcased the adaptation of these engineering approaches to Vδ1 γδ T cells (ADI-270) by coexpressing a CD70-targeted CAR and a dominant-negative TGFβRII receptor (dnTGFβRII) to target CD70⁺ malignancies, addressing immunosuppression and host-versus-graft rejection. This commentary explores αβ T cell-derived engineering strategies applicable to γδ T cells, while also highlighting genome-editing innovations poised to advance next-generation γδ CAR-T development.

The biological clock plays a central role in hematopoiesis and immune regulation, making circadian rhythms an increasingly important factor in immunotherapies and cellular therapies such as allogeneic hematopoietic stem cell transplantation (allo-HSCT). Previous work by Hou et al suggested that afternoon graft infusions were associated with a higher risk of acute graft-versus-host disease and worse survival, highlighting a potential role for infusion timing in shaping transplant outcomes.To further investigate this, we performed a retrospective analysis of 368 patients who underwent allo-HSCT at Geneva University Hospitals between 2015 and 2024. Observing that infusion timing patterns at our center differed from those reported by Hou et al, we applied a data-driven approach using receiver operating characteristic analysis, which identified 11:17 as the optimal cut-off for overall survival.Stratification using this threshold revealed that patients receiving grafts before 11:00 had significantly improved 2-year overall survival and lower non-relapse mortality compared with those infused later in the day, with no differences in relapse or engraftment rates.These findings suggest that infusion timing may be an important, under-recognized factor influencing allo-HSCT outcomes. Prospective clinical trials are needed to confirm these observations and explore their applicability across different clinical contexts.

Background: The CpG/α-OX40 in situ vaccine strategy has shown efficacy in immune-hot tumors but remains ineffective in immune-cold tumors possibly due to immunosuppressive microenvironments characterized by myeloid-derived suppressor cells (MDSCs) infiltration and T cell exclusion. This study aims to investigate the antitumor effect of non-α-biased IL-2 combined with CpG/α-OX40 in mice.

Methods: Using 4T1 breast cancer and CT26 colon cancer models, we evaluated the antitumor effects of combining CpG/α-OX40 with a non-α-biased IL-2 variant via both intratumoral and subcutaneous routes. Tumor growth, lung metastasis, immune profile, and in vitro function analysis were assessed through flow cytometry, transcriptomic analysis, and T cell suppression assays.

Results: The combination therapy significantly inhibited primary and distant tumor growth and reduced lung metastasis in 4T1 models. Subcutaneous administration induced complete tumor regression in 55% (5/9) of CT26-tumor-bearing mice and conferred durable tumor-specific memory. Mechanistically, the treatment enhanced CD8⁺ T cell activation, metabolic reprogramming, and IFN-γ production, while suppressing MDSC expansion and immunosuppressive function.

Conclusions: These findings demonstrate that non-α-biased IL-2 synergizes with CpG/α-OX40 to overcome microenvironmental immunosuppression and achieve systemic antitumor immunity via a subcutaneous route, offering a translatable combinatorial strategy for immune-cold tumors.

Casitas B lymphoma-b (Cbl-b) is an E3 ubiquitin ligase that serves as a critical brake on immune cell activations. It negatively fine-tunes immune responses through ubiquitination of signaling proteins. Cbl-b deficiency in mice leads to spontaneous tumor rejection and induces only mild, non-lethal autoimmunity, highlighting its potential as a promising immunotherapy target. NX-1607 is the first oral small molecule inhibitor of Cbl-b and it is currently in phase I clinical trial. A recent publication employed high-throughput drug combination screening to systematically elucidate the molecular pathways by which NX-1607 enhances T cell activation. The authors administered 81 well-characterized inhibitors to Jurkat T cells under CD3-stimulated and unstimulated conditions in the presence of NX-1607. Inhibitors of the MAPK/ERK pathway significantly attenuated NX-1607-enhanced T cell activation as indicated by CD69 markers. Proto-oncogene tyrosine-protein kinase Src (SRC) family kinase inhibitors also reduced both CD69 activation markers and the phosphorylation of PLCγ1 and HCLS1 which are upstream of MAPK/ERK pathways. These findings were validated in an immunocompetent B-cell lymphoma mouse model, where NX-1607 consistently upregulated PLCγ1 and ERK phosphorylation. Together, this work delineates a PLCγ1-MAPK/ERK axis through which Cbl-b inhibition unleashes T cell activation, providing critical insight for the development of NX-1607 based immunotherapy.

Background: Talimogene laherparepvec (T-VEC) is an oncolytic herpes simplex virus therapy approved for treatment of unresectable and metastatic melanoma. However, real-world use often occurs in heavily pretreated patients, where evidence of effectiveness remains limited. This study evaluates treatment responses and clinical factors influencing T-VEC outcomes in patients with diverse treatment histories.

Methods: We analyzed patients with metastatic melanoma treated with T-VEC between 2015 and 2024. Objective responses (OR), complete response (CR) and partial response were assessed using univariate and multivariate Cox regression models. Durability of responses, progression-free survival (PFS), and overall survival (OS) were evaluated using Kaplan-Meier estimates.

Results: Among 121 patients, 105 (87%) patients received ≥1 prior lines of systemic therapy; 48 (40%) had a current or prior history of distant metastatic disease, and 42 (35%) had both injectable and non-injectable disease at the T-VEC initiation. Median PFS was 12.2 months (95% CI 6.2 to 20.9), and median OS was 35.5 months (95% CI 25.8 to 63.9). Of 113 evaluable patients, 76 (67%, 95% CI 58% to 76%) achieved an OR, including 39 (35%, 95% CI 26% to 44%) CR. The probability OR by 6 months was 56% (95% CI 46% to 65%). Of the 39 patients achieving CR, 37 (95%) remained alive and progression-free at last follow-up (median 19.1 months). In multivariate analysis, the adjusted HR (aHR) for OR in patients with non-injectable distant metastases at T-VEC initiation relative to those without was 0.43 (95% CI 0.23 to 0.78; p=0.006). The aHR for OR among those immunosuppressed compared with those not immunosuppressed was 0.18 (95% CI 0.04 to 0.69; p=0.013), indicating a reduced likelihood of response for patients who were immunosuppressed. Unadjusted HRs for achieving an OR after 1, 2, and ≥3 prior therapies (vs none) were 1.20 (95% CI 0.57 to 2.52; p=0.627), 1.21 (95% CI 0.52 to 2.80; p=0.653), and 0.77 (95% CI 0.35 to 1.68; p=0.507), respectively.

Conclusions: This study demonstrates T-VEC's potential efficacy in achieving meaningful disease control and response durability in patients with unresectable and/or metastatic melanoma, including those with diverse prior-treatment histories and comorbidities.

Background: The biological sciences are producing increasingly larger datasets for biomarker discovery. While common data models have been developed for medical terms as they relate to patient health outcomes, a data model that supports longitudinal tracking of biospecimens and relating them against an individual patient experience is a large, unmet need.

Method: A structure and associated taxonomy were achieved through a six-tier build in Research Electronic Data CAPture (REDCap), which organizes the complexity of the therapeutic decisions, biospecimens, and outcomes that characterize a longitudinal patient experience. Modules were developed to support export of REDCap data into a Structured Query Language (SQL) format for merging with extended biomarker data, also housed in SQL.

Results: The resultant AstroID resource is a relational structure for clinical and biospecimen data that meets several desired goals: searchable, flexible, generic, Health Insurance Portability and Accountability Act-compliant, auditable, and easy-to-use. The essential elements forming the core of the six-tiered build are provided, so others can readily adopt this schema, as well as an example of an extended, customized build to support biomarker discovery for patients with melanoma. Two examples where this data structure was used to support biomarker discovery and development are described, and example queries of the database are also presented. To the extent possible, the data dictionary was aligned with large data models, such as those for the National Institutes of Health's Human Tumor Atlas Network. The structure can readily scale to accommodate thousands of patients, multimodality data, and spatial characterization of billions of cells. Radiologic imagery can also be included along with pathology imagery to support spatial studies, including artificial intelligence-driven analyses.

Conclusions: This effort provides a database model for investigators conducting research on large volumes of biospecimens with clinical annotation. We have now deployed this structure in our laboratories and have over 1B cells spatially mapped, each effectively tagged with the clinical information from longitudinal patient experiences. While the description uses the example of cancer biomarkers, this data structure could be used to characterize longitudinal biospecimens from any disease process. In the near future, automatic synchronization between the electronic medical record and one or more AstroID databases is anticipated.

Over the last decades, a growing number of distinct CD4+T helper cells has been identified and our understanding of CD4+T cell differentiation and function in various disease contexts has increased immensely. It has long been thought that the role of CD4+T cells in the tumor microenvironment (TME) was limited to coordinating the immune response by stimulating other immune cells and by secretion of cytokines with antitumor activity, while direct killing of tumor cells has been largely attributed to cytotoxic CD8+T cells. Notably, CD4+T cells with direct cytotoxic activity (CD4+CTLs) have been reported in the context of viral infections, autoimmune disorders, and more recently in patients with various cancer types. These cells have the ability to secrete cytotoxic molecules and kill target cells in a major histocompatibility complex (MHC) class II-dependent manner. In this review, we give an overview of phenotypical characteristics of CD4+CTLs in human cancers and the antitumor mechanisms employed by these cells. Further, we explore their role and clinical relevance in the context of cancer and describe how these cells may be used for the development of novel immunotherapeutic options to benefit patients with cancer with MHC class II-positive tumors.