Oncoimmunology最新文献

Nivolumab plus ipilimumab (aCTLA-4/aPD-1) combination therapy has significantly improved clinical outcomes in patients with metastatic melanoma, with 50%-60% of patients responding to treatment, but predictors of response are poorly characterized. We hypothesized that circulating cytokines and peripheral white blood cells may predict response to therapy and evaluated 15 cytokines and complete blood counts (CBC with differentials) from 89 patients with advanced melanoma treated with combination therapy from three points in time: pre-treatment, one month and approximately three months after starting therapy. Clinical endpoints evaluated included durable clinical benefit (DCB), progression-free survival (PFS), and overall survival (OS). A parsimonious predictive model was developed to identify cytokines predictors of response to combination therapy. In this study, we found that pre-treatment, patients with DCB had higher IL-23, lower CXCL6, and lower IL-10 levels. Lower NLR one month after starting therapy predicted better PFS and OS, primarily driven by an increase in absolute lymphocytes. A multivariate model demonstrated that baseline CXCL6, IL-10, IL-23 were independent predictors of therapy response, and the combined model has reached an area under the curve (AUC) of 0.79 in prediction of response to combination therapy. Our study identified baseline CXCL6, IL-23, and IL-10 as predictors of response to aCTLA4/aPD1 combination therapy among patients with metastatic melanoma. This study also provides a framework for identifying patients who are likely to respond to combination ICB, as well as a subset of patients with high risk of developing resistance and are thus in need of alternative therapeutic options, such as clinical trials.

Nonmutated mitochondrial DNA (mtDNA) from T lymphocytes can be incorporated into cancer cells bearing mutated mtDNA to repair their bioenergetic deficiency. However, a recent paper by Ikeda et al. indicates that mutated mtDNA from malignant cells can also be transferred into tumor-infiltrating T lymphocytes to subvert their function in cancer immunosurveillance.

Glioblastoma (GB) remains refractory to chimeric antigen receptor (CAR)-T cell therapy, mainly attributed to tumor heterogeneity and antigen escape. CAR-T cells utilizing monomeric streptavidin-2 (mSA2) instead of a traditional target binding domain, bind biotinylated antibodies and can be directed to variable targets to mediate anti-tumor effects. Although such an approach might circumvent the aforementioned challenges, the potential of mSA2 CAR-T cells for brain tumor treatment remains unexplored. In this study, we generated mSA2 CAR-T cells and tested their efficacy against GB by tailoring their specificity toward GB-associated markers CD276, EPHA2, CD70 and IL13Ra2. In vitro, mSA2 CAR-T cells specifically recognized multiple primary GB cell lines in a target- and biotinylated antibody-dependent manner. Moreover, in heterogenous tumor environments, mSA2 CAR-T cells simultaneously targeted multiple subpopulations, guided by combinations of biotinylated antibodies, indicating their potential to address tumor heterogeneity. Finally, the mSA2 CAR-T cell-mediated anti-tumor functions were demonstrated in vivo. Immunocompromised mice orthotopically implanted with CD70⁺ or CD276⁺ GB cells and treated with mSA2 CAR-T cells pre-armed with antibodies against these two antigens exhibited control of tumor growth and induction of GB cell apoptosis after therapy. Taken together, our study suggests that antibody-guided mSA2 CAR-T cells can target potentially any surface GB-related antigen both in vitro and in vivo, either univalently or multivalently, with underlined clinical implications.

In most cancers, T lymphocytes comprise an essential cellular component of the non-neoplastic microenvironment, where they have the capacity to both suppress and support tumor growth. One specialized T lymphocyte population is the CD8⁺ exhausted T cell, which has been intensely studied as an actionable therapeutic target. Unfortunately, there is currently no uniformly accepted classification scheme for these specialized T cells. To provide a potential model for classifying CD8⁺ exhausted T cells, we leveraged single cell transcriptomic analysis of a diverse collection of both human (n = 8) and mouse (n = 4) cancers to identify unique subpopulations shared across tumor types and species. By integrating data from both human and mouse cancer studies, as well as previously described CD8⁺ exhausted T cell subsets, we provide an integrated framework to characterize the heterogeneity of exhausted CD8⁺ T cells. As such, one of these subpopulations (cluster C1) increases following immune checkpoint inhibitor treatment in the setting of cancer in mice and patients. Taken together, this proposed classification scheme may be useful for the design and interpretation of current and future immune-based therapy studies.

The efficacy of systemic immunotherapies is limited for poorly immunogenic tumors which suppress T cell priming and tumor infiltration. Modern antigen carriers including viral vectors and messenger RNA/lipid nanoparticle (LNP) combinations have renewed the interest in local immunotherapy due to their ability to express multiple transgene constructs simultaneously. The identification of therapeutically active combinations, however, is hampered by the lack of preclinical models to rapidly express and evaluate transgenes combinations in vivo. To enable empirical testing of immunogenic transgenes, we have combined a doxycycline-inducible expression system with flow cytometry and multiplex immunohistochemistry imaging. In animal models of liver and colon cancer, we demonstrate that the impact of a single transgene on the immune milieu is limited and heavily dependent on the studied tumor entity. Compared to single transgenes, transgene combinations induced more complex and only partially predictable alterations in the tumor micromilieu but strongly enhanced therapeutic efficacy. By combining expression of transgenes with impact on antigen-presenting cells and T cells, we identified a combination of IL-12, CXCL9 and FLT3L as the most promising combinatorial approach, resulting in complete tumor remissions in mice. Taken together, we demonstrate the ability of our preclinical model to identify therapeutic transgene combinations for more efficacious locoregional immunotherapy of solid tumors.

CDK4/6 inhibitors are central to the clinical management of HR⁺HER2^- breast cancer. We have recently demonstrated that immunosuppressive, IL17-secreting γδ T cells recruited to the tumor microenvironment by a CCL2-dependent mechanism upon CDK4/6 inhibition can repolarize tumor-associated macrophages toward a CX3CR1⁺ phenotype associated with resistance to therapy.

Recent findings reveal that macrophages actively control clearance by desialylating target cells via NEU1 and releasing cathepsin-cleaved calreticulin (CALR) to mark them for phagocytosis. This uncovers a dual role for CALR as immune activator or repressor, depending on its form and context, with distinct implications for cancer immunity.

Pancreatic ductal adenocarcinoma (PDAC) is characterized by dense stroma and myeloid-rich microenvironment that confer resistance to immunotherapies. Previous studies demonstrated that disrupting the immune-stroma CXCR4-CXCL12 axis facilitates T cell recruitment and mobility to collaborate with anti-PD1/PD-L1 therapy. We sought to test the clinical viability of this immunotherapeutic strategy. 21 patients with metastatic PDAC were enrolled and treated in a phase 2 trial evaluating the effects of the plerixafor/AMD3100 and cemiplimab. Primary endpoint was objective response rate. Blood and tissue biospecimens were collected for correlative analyses. Parallel mouse studies were used to determine potential mechanisms of resistance. Treatments were well-tolerated, but only two patients demonstrated a best response of stable disease. Correlative analyses confirmed significant mobilization of immune cells into circulation as well as increased immune infiltration into the tumor. High-parameter imaging revealed higher levels of CD8⁺ T cells but also granulocytes and macrophages upon treatment. Spatial analysis showed that treatment resulted in closer proximity between macrophages and T cells but not between granulocytes and T cells. Mouse studies revealed that whereas total granulocyte depletion had no effect on immunotherapeutic efficacy, macrophage-targeting yielded significant benefit. Tumor growth measurements and immune profiling of immunotherapeutic combinations incorporating macrophage-targeting showed that despite the increased T cell infiltration, CXCR4 antagonism was in fact associated with enrichment of CD206^hiIA/IE^lo macrophage subtypes and modestly dampened efficacy. Our findings validate the utility of CXCR4 antagonism as an effective immune-recruiting platform but also underscores the need for strategies that better leverage its effects.

T cell bispecific antibodies (TCBs) have demonstrated promising results in patients with solid tumors, yet the immunological mechanisms influencing their efficacy require further investigation. T cell exhaustion, induced by prolonged antigen exposure, is known to compromise T cell-based immunotherapies, but its effect on TCB efficacy remains unclear. Herein, we assessed the TCB efficacy on tumor-specific T cells, emphasizing their functional status. Utilizing an immunocompetent mouse model with melanoma expressing an immunogenic antigen, we showed that tumor-specific T cells acquire an exhausted phenotype and fail to expand under TCB treatment. Both mouse and human tumor-specific T cells in vitro demonstrated that chronically stimulated T cells exhibit a reduced response to TCBs. The comparison of TCB efficacy in T cell-inflamed versus non-inflamed tumors in mice revealed TCB success depends more on T cell functional fitness than their initial abundance. These data underscore the importance of T cell exhaustion, suggesting that exhausted tumor-specific T cells are unlikely to be the primary effectors redirected by TCBs for tumor eradication. Our study highlights the need to maintain T cell fitness and prevent exhaustion to enhance TCB therapy outcomes, which may help identify patients who could benefit most from TCB treatments in clinics.

Immune checkpoint blockers have substantially improved prognosis of melanoma patients, nevertheless, resistance remains a significant problem. Here, intrinsic and extrinsic factors in the tumor microenvironment are discussed, including the expression of alternative immune checkpoints such as lymphocyte activation gene 3 (LAG-3) and T-cell immunoglobulin and mucin domain-containing protein 3 (TIM-3). While most studies focus on immune cell expression of these proteins, we investigated their melanoma cell intrinsic expression by immunohistochemistry in melanoma metastases of 60 patients treated with anti-programmed cell death protein 1 (PD-1) and/or anti-cytotoxic T-lymphocyte-associated protein 4 (CTLA-4) therapy, and correlated it with the expression of potential ligands, RNA sequencing data and clinical outcome. LAG-3 and TIM-3 were commonly expressed in melanoma cells. In the stage IV cohort, expression of LAG-3 was associated with M1 stage (p < 0.001) and previous exposure to immune checkpoint inhibitors (p = 0.029). Moreover, in the anti-PD-1 monotherapy treatment group patients with high LAG-3 expression by tumor cells tended to have a shorter progression-free survival (p = 0.088), whereas high expression of TIM-3 was associated with a significantly longer overall survival (p = 0.007). In conclusion, we provide a systematic analysis of melanoma cell intrinsic LAG-3 and TIM-3 expression, highlighting potential implications of their expression on patient survival.