Cancer immunology research最新文献

Immune checkpoint inhibitors have revolutionized the treatment of unresectable hepatocellular carcinoma (HCC), but their impressive efficacy is seen in just a fraction of patients. One key mechanism of immunotherapy resistance is the paucity of dendritic cells (DC) in liver malignancies. In this study, we tested combination blockade of PD-1 and CXCR4, a receptor for CXCL12, a pleiotropic factor that mediates immunosuppression in tumors. Using orthotopic grafted and autochthonous HCC models with underlying liver damage, we evaluated treatment feasibility and efficacy. In addition, we examined the effects of treatment using immunofluorescence, flow cytometric analysis of DCs in vivo and in vitro, and RNA sequencing. The combination anti-CXCR4 and anti-PD-1 therapy was safe and significantly inhibited tumor growth and prolonged survival in all murine preclinical models of HCC tested. The combination treatment successfully reprogrammed antigen-presenting cells, revealing the potential role of conventional type 1 DCs (cDC1) in the HCC microenvironment. Moreover, DC reprogramming enhanced anticancer immunity by facilitating CD8+ T-cell accumulation and activation in the HCC tissue. The effectiveness of anti-CXCR4/PD-1 therapy was compromised entirely in Batf3 knockout mice deficient in cDC1s. Thus, combined CXCR4/PD-1 blockade can reprogram intratumoral cDC1s and holds the potential to potentiate antitumor immune response against HCC.

Resistance to immune checkpoint inhibitors (ICI) is common, even in tumors with T-cell infiltration. We thus investigated consequences of ICI-induced T-cell infiltration in the microenvironment of resistant tumors. T cells and neutrophil numbers increased in ICI-resistant tumors following treatment, in contrast to ICI-responsive tumors. Resistant tumors were distinguished by high expression of IL1 receptor 1, enabling a synergistic response to IL1 and TNFα to induce G-CSF, CXCL1, and CXCL2 via NF-κB signaling, supporting immunosuppressive neutrophil accumulation in tumor. Perturbation of this inflammatory resistance circuit sensitized tumors to ICIs. Paradoxically, T cells drove this resistance circuit via TNFα both in vitro and in vivo. Evidence of this inflammatory resistance circuit and its impact also translated to human cancers. These data support a mechanism of ICI resistance, wherein treatment-induced T-cell activity can drive resistance in tumors responsive to IL1 and TNFα, with important therapeutic implications.

NK cell tumor infiltration is associated with good prognosis in patients with metastatic castration-resistant prostate cancer (mCRPC). NK cells recognize and kill targets by a process called natural cytotoxicity. We hypothesized that promoting an antigen-specific synapse with coactivation may enhance NK cell function in mCRPC. We describe a tri-specific killer engager (TriKE) construct that engages with the activating receptor CD16 on NK cells and prostate-specific membrane antigen (PSMA) on mCRPC cells and has an IL15 moiety that is essential for NK cell survival, proliferation, and priming. We show that the PSMA TriKE specifically binds to PSMA-expressing cells and significantly enhances expansion, degranulation, and cytokine production of NK cells derived from healthy donors or patients with prostate cancer. Bystander killing of PSMA-negative tumor cells was also achieved with PSMA TriKE treatment when cocultured with PSMA-positive cells, suggesting potential PSMA TriKE benefit in controlling tumor antigen escape. When tested under physiologic conditions recapitulating the mCRPC tumor microenvironment, NK cells treated with PSMA TriKE and prolonged exposure to hypoxia or myeloid-derived suppressor cells maintained their potent function whereas IL15-treated NK cells showed greatly impaired cytotoxicity. Finally, in vivo testing of PSMA TriKE showed improved tumor control and survival of mice as compared with IL15-treated and untreated control groups. In conclusion, PSMA TriKE demonstrates potential as a new therapy for advanced prostate cancer by providing additional signals to NK cells to maximize their antitumor potential in prostate cancer, especially in the setting of a hostile tumor microenvironment.

Cervical tumors are usually treated using surgery, chemotherapy, and radiotherapy, and would benefit from immunotherapies. However, the immune microenvironment in cervical cancer remains poorly described. Tertiary lymphoid structures (TLS) were recently described as markers for better immunotherapy response and overall better prognosis in cancer patients. We evaluated the cervical tumor immune microenvironment, specifically focusing on TLS, using combined high-throughput phenotyping, soluble factor concentration dosage in the TME and spatial interaction analyses. We found that TLS presence was associated with a more inflammatory soluble microenvironment, with the presence of B cells as well as more activated macrophages and dendritic cells (DCs). Furthermore, this myeloid cell activation was associated with expression of immune checkpoints, such as PD-L1 and CD40, and proximity of activated conventional type 2 DCs (DC2) to CD8+ T cells, indicating better immune interactions and tumor control. Finally, we associated TLS presence, greater B cell density, and activated DC density with improved progression-free survival, substantiating TLS presence as a potential prognostic marker. Our results provide evidence that TLS presence denotes cell activation and immunotherapy target expression.

Radio-immunotherapy has antitumor activity but also causes toxicity, which limits its clinical application. JS-201 is a dual antibody targeting PD-1 and TGF-β signaling. We investigated the antitumour effect of JS-201 combined with radiotherapy and the effect on radiation-induced lung injury (RILI). Different tumor models were established to detect the antitumor effects of the combination of JS-201 and RT, and RILI models were established to observe the effects of JS-201. Transcriptome sequencing showed that JS-201 optimized the TME by inhibiting extracellular matrix formation and angiogenesis. Combining JS-201 with radiotherapy further increased the inflammatory response and immune infiltration and showed great abscopal effects in LLC-luc models. Single-cell sequencing demonstrated that JS-201 reduced fibroblast proliferation by inhibiting the TGF-β/Smad pathway and the release of neutrophil extracellular traps mediated by ROS, thereby relieving radiation-induced pulmonary fibrosis. In conclusion, the JS-201 and radiotherapy combination enhances antitumor effects while mitigating acute and chronic RILI, and it may have potential for translational investigation as a cancer treatment strategy.

Testing for PD-L1 expression by immunohistochemistry (IHC) is used to predict immune checkpoint blockade (ICB) benefit but has performed inconsistently in urothelial cancer (UC) clinical trials. Different approaches are used for PD-L1 IHC. We analyzed paired PD-L1 IHC data on UC samples using the SP142 and 22C3 assays from the phase 3 IMvigor130 trial and found discordant findings summarized by four phenotypes: PD-L1 positive by both assays (PD-L1 double positive; PD-L1DP), PD-L1 positive by the SP142 assay only (SP142 single positive; SP142SP), PD-L1 positive by the 22C3 assay only (22C3 single positive; 22C3SP), and PD-L1 negative by both assays double negative (PD-L1 double negative; PD-L1DN). PD-L1DP and SP142SP UCs were associated with more favorable ICB outcomes and increased dendritic-cell (DC) infiltration. SP142 PD-L1 staining co-localized with DC-LAMP, a DC marker, while 22C3 staining was more diffuse. 22C3SP UCs, associated with worse outcomes, were enriched in tumor cell-dominant PD-L1 expression. Multiplex IHC in an independent ICB-treated cohort confirmed that tumor cell-dominant PD-L1 expression was associated with shorter survival. Using different PD-L1 assays, we uncovered that SP142 may preferentially stain PD-L1-expressing DCs, key to orchestrating antitumor immunity, while tumor cell-dominant PD-L1 expression, which underlies a subset of "PD-L1 positive" specimens, is associated with poor ICB outcomes.

Natural killer T cells (NKTs) are a promising platform for cancer immunotherapy, but few genes involved in regulation of NKT therapeutic activity have been identified. To find regulators of NKT functional fitness, we developed a CRISPR/Cas9-based mutagenesis screen that employs a guide RNA (gRNA) library targeting 1,118 immune-related genes. Unmodified NKTs and NKTs expressing a GD2-specific chimeric antigen receptor (GD2.CAR) were transduced with the gRNA library and exposed to CD1d+ leukemia or CD1d-GD2+ neuroblastoma cells, respectively, over six challenge cycles in vitro. Quantification of gRNA abundance revealed enrichment of PRDM1-specific gRNAs in both NKTs and GD2.CAR NKTs, a result that was validated through targeted PRDM1 knockout. Transcriptional, phenotypic, and functional analyses demonstrated that CAR NKTs with PRDM1 knockout underwent central memory-like differentiation and resisted exhaustion. However, these cells downregulated the cytotoxic mediator granzyme B and showed reduced in vitro cytotoxicity and only moderate in vivo antitumor activity in a xenogeneic neuroblastoma model. In contrast, shRNA-mediated PRDM1 knockdown preserved effector function while promoting central memory differentiation, resulting in GD2.CAR NKTs with potent in vivo antitumor activity. Thus, we have identified PRDM1 as a regulator of NKT memory differentiation and effector function that can be exploited to improve the efficacy of NKT-based cancer immunotherapies.

Based on the notion that hypomorphic germline genetic variants are linked to autoimmune diseases, we reasoned that novel targets for cancer immunotherapy might be identified through germline variants associated with greater T-cell infiltration into tumors. Here, we report that while investigating germline polymorphisms associated with a tumor immune gene signature, we identified PKCδ as a candidate. Genetic deletion of PKCδ in mice resulted in improved endogenous antitumor immunity and increased efficacy of anti-PD-L1. Single-cell RNA sequencing revealed myeloid cell expression of Prkcd, and PKCδ deletion caused a shift in macrophage gene expression from an M2-like to an M1-like phenotype. Conditional deletion of PKCδ in myeloid cells recapitulated improved tumor control that was augmented further with anti-PD-L1. Analysis of clinical samples confirmed an association between PRKCD variants and M1/M2 phenotype, as well as between a PKCδ KO-like gene signature and clinical benefit from anti-PD-1. Our results identify PKCδ as a candidate therapeutic target that modulates myeloid cell states.

Tumor-specific HLA class I expression is required for cytotoxic T-cell elimination of cancer cells expressing tumor-associated or neo-antigens. Cancers downregulate antigen presentation to avoid adaptive immunity. The highly polymorphic nature of the genes encoding these proteins, coupled with quaternary-structure changes after formalin fixation, complicate detection by immunohistochemistry. In this study we determined recognition of 16 specific HLA-A, B and C alleles by 15 antibodies commercially available for immunohistochemical use, identifying and validating pan and specific HLA-A, B, and C antibodies, providing a validated method that can be applied to investigate HLA-A, B and C molecule-specific loss in cancer. We applied this approach to a series of breast cancers as a proof of utility, identifying differential HLA-A, B and C loss, with a higher incidence of HLA-A and B loss in hormone-driven breast cancers, HLA-B loss in HER2+ cancers, and an equal loss of all three molecules in triple-negative disease. Additionally, we found that at the protein level, HLA-A and B loss were early events prevalent in premalignant lesions, while HLA-C loss was less common throughout tumor evolution. Effective response to immunotherapies such as checkpoint inhibitors and MHC-I-targeted cancer vaccines, which hinge on the carriage of specific allele groups, require MHC-I expression on tumor cells. These findings have implications for the success of checkpoint inhibitors and vaccine strategies.

The T-cell antigen coupler (TAC) is a chimeric receptor that facilitates tumor antigen-specific activation of T cells by co-opting the endogenous T-cell receptor complex in the absence of tonic signaling. Previous data demonstrate that the TAC affords T cells with the ability to induce durable and safe antitumor responses in preclinical models of hematologic and solid tumors. In this study, we describe the preclinical pharmacology and safety of an autologous Claudin 18.2 (CLDN18.2)-directed TAC T-cell therapy, TAC01-CLDN18.2, in preparation for a phase I/II clinical study in subjects with CLDN18.2-positive solid tumors. Following a screen of putative TAC constructs, the specificity, activity, and cytotoxicity of TAC T cells expressing the final CLDN18.2-TAC receptor were evaluated in vitro and in vivo using gastric, gastroesophageal, and pancreatic tumor models as well as human cells derived from normal tissues. CLDN18.2-specific activity and cytotoxicity of CLDN18.2-TAC T cells were observed in coculture with various 2D tumor cultures naturally expressing CLDN18.2 as well as tumor spheroids. These effects occurred in models with low antigen levels and were positively associated with increasing CLDN18.2 expression. CLDN18.2-TAC T cells effectively eradicated established tumor xenografts in mice in the absence of observed off-target or on-target/off-tumor effects, elicited durable efficacy in recursive killing and tumor rechallenge experiments, and remained unreactive in coculture with human cells representing vital organs. Thus, the data demonstrate that CLDN18.2-TAC T cells can induce a specific and long-lasting antitumor response in various CLDN18.2-positive solid tumor models without notable TAC-dependent toxicities, supporting the clinical development of TAC01-CLDN18.2.