Oncoimmunology最新文献

Antibody-drug conjugates (ADCs) enable targeted delivery of cytotoxic payload to cancer cells. Here, we characterized the mode of action of the ADC patritumab deruxtecan, which is a monoclonal antibody specific for Erb-B2 Receptor Tyrosine Kinase 3 (ERBB3, best known as HER3) coupled to the topoisomerase-I inhibitor DXd. Patritumab deruxtecan decreased viability and induced the relocation of calreticulin fused to green fluorescent protein (CALR-GFP) to the periphery of human osteosarcoma U2OS cells engineered to express HER3 but not in their parental counterparts only expressing the CALR-GFP biosensor. Patritumab deruxtecan as well as its payload DXd induced various traits of immunogenic cell death (ICD) including antibody detectable calreticulin membrane exposure, exodus of high mobility group protein B1 (HMGB1), as well as the release of ATP into cell culture supernatants. Moreover, DXd causes rapid inhibition of DNA-to-RNA transcription, which is a key predictor for ICD. Mouse cancer cells treated with DXd were able to vaccinate syngeneic immunocompetent mice against tumor challenge. Tumor-free mice developed immune memory that led to the rejection of syngeneic tumors after rechallenge. In conclusion, patritumab deruxtecan is equipped with a cytotoxic payload that induces hallmarks of ICD in vitro and elicits antitumor immunity in vivo.

Adoptive cell therapy and the use of monoclonal antibodies are two therapeutic modalities implemented in the treatment of multiple myeloma (MM). In this study, we combined the anti-CD38 therapeutic mAb daratumumab with different types of NK cells, leveraging the antibody-dependent cell-mediated cytotoxicity (ADCC) performed by these immune cells. Daratumumab was initially combined with activated and expanded NK cells (eNK), resulting in significant cytotoxic activity against human MM cell lines. As an alternative model to minimize the variability among donors of NK cells, the NK92 cell line was used, which showed greater cytotoxic activity than eNK cells against MM cell lines. However, since NK92 cells lacked CD16 receptor expression, they could not be used in combination with mAbs. To circumvent this, we performed a CD16 transfection on NK92 cells, generating the stable NK92-CD16 cell line. These cells were tested in combination with daratumumab against human MM cell lines with excellent results under various conditions, such as 2D and 3D cultures, even at very low effector-to-target ratios. NK92-CD16 cells were then tested in the presence of daratumumab against plasma cells from MM patients, with anti-myeloma activity even against cells from relapsed patients. In vivo experiments using MM xenografts or intravenous injection of MM cells in NGS mice, followed by treatment with NK92-CD16 cells in the presence or absence of daratumumab showed tumor regressions, especially in the second model, with nearly complete elimination of the MM cells when NK92-CD16 cells were combined with daratumumab.

Adoptive cell therapy with tumor-infiltrating lymphocytes (TILs) has demonstrated consistent clinical efficacy in treating advanced melanoma and other "hot" tumors. However, it has shown limited success in "cold" tumors like glioblastoma. We present the successful treatment of a rapidly progressing glioblastoma patient with TILs expanded using a defined cytokine combination of IL-2, IL-15, and IL-21. The patient received lymphodepletion with cyclophosphamide one day pre-TIL infusion, followed by a single dose of IL-2 post-transfer. Complete tumor regression was observed after two TIL infusions administered two weeks apart. The TIL products were enriched for CD8⁺ T-cells and demonstrated specific lysis of the autologous tumor cell line. Transcriptomic analysis of tumor biopsies post-TIL infusion revealed increased expression of genes associated with immunological synapse formation and T-cell effector function, correlating with the patient's clinical outcome. T-cell receptor (TCR) next-generation sequencing of the infused TILs and post-treatment tumor biopsies confirmed the infiltration and expansion of TIL-derived clonotypes within the tumor microenvironment. CD8⁺ T-cell clonotypes exhibited robust tumor migration and expansion, while CD4⁺ T-cells showed limited tumor infiltration. In conclusion, TILs expanded with IL-2/IL-15/IL-21 represent a promising therapeutic approach for glioblastoma, overcoming traditional challenges posed by the tumor microenvironment and achieving significant clinical outcomes.

PT-112 is a novel small molecule exhibiting promising clinical activity in patients with solid tumors. PT-112 kills malignant cells by inhibiting ribosome biogenesis while promoting the emission of immunostimulatory signals. Accordingly, PT-112 is an authentic immunogenic cell death (ICD) inducer and synergizes with immune checkpoint inhibitors in preclinical models of mammary and colorectal carcinoma. Moreover, PT-112 monotherapy has led to durable clinical responses, some of which persisting after treatment discontinuation. Mitochondrial outer membrane permeabilization (MOMP) regulates the cytotoxicity and immunogenicity of various anticancer agents. Here, we harnessed mouse mammary carcinoma TS/A cells to test whether genetic alterations affecting MOMP influence PT-112 activity. As previously demonstrated, PT-112 elicited robust antiproliferative and cytotoxic effects against TS/A cells, which were preceded by the ICD-associated exposure of calreticulin (CALR) on the cell surface, and accompanied by the release of HMGB1 in the culture supernatant. TS/A cells responding to PT-112 also exhibited eIF2α phosphorylation and cytosolic mtDNA accumulation, secreted type I IFN, and exposed MHC Class I molecules as well as the co-inhibitory ligand PD-L1 on their surface. Acute cytotoxicity and HMGB1 release caused by PT-112 in TS/A cells were influenced by MOMP competence. Conversely, PT-112 retained antiproliferative effects and its capacity to drive type I IFN secretion as well as CALR, MHC Class I and PD-L1 exposure on the cell surface irrespective of MOMP defects. These data indicate a partial involvement of MOMP in the mechanisms of action of PT-112, suggesting that PT-112 is active across various tumor types, including malignancies with MOMP defects.

Aclarubicin (also called aclacinomycin A) is an antineoplastic from the anthracycline class that is used in China and Japan but not in Europe nor in the USA. Aclarubicin induces much less DNA damage than the classical anthracyclines doxorubicin, daunorubicin, epirubicin, idarubicin, and the anthracene mitoxantrone, but is equally effective in inhibiting DNA-to-RNA transcription and in eliciting immunogenic stress in malignant cells. Accordingly, aclarubicin lacks the DNA damage-associated cardiotoxicity that is dose-limiting for classical anthracyclines. Conversely, aclarubicin is at least as potent as other anthracyclines in inducing immunogenic cell death (ICD), which is key for the mode of action of efficient chemotherapeutics. This combination of reduced toxicity and equivalent ICD-stimulatory activity may explain why, as compared to other anthracyclines, aclarubicin is particularly efficient against acute myeloid leukemia. As a result, we advocate for clinical studies seeking to replace the anthracyclines used in Western medicine by aclarubicin-like compounds. Such clinical studies should not only embrace hematological malignancies but should also concern solid cancers, including those in which ICD-inducing chemotherapies are followed by immunotherapies targeting the PD-1/PD-L1 interaction.

Mature tertiary lymphoid structures (TLSs) are immune aggregates associated with immune checkpoint blockade (ICB) responses in various cancers, yet their role in chemoimmunotherapy response in head and neck squamous cell carcinoma (HNSCC) remains unclear. By analyzing TCGA-HNSC transcriptomic data and pathology slides, we identified an immune subtype enriched in TLSs, predominantly in HPV-positive tumors, which correlated with favorable immunotherapy response. Single-cell and spatial transcriptomics further revealed distinct TLS compositions, with mature TLSs enriched in germinal center B cells, follicular helper T cells, and resident memory CD8 T cells, while immature TLSs contained FCRL4+ B cells and peripheral helper T cells. Multispectral immunohistochemistry, flow cytometry, and ELISA validated these findings. Notably, neoadjuvant chemoimmunotherapy promoted mature TLS formation. These results suggest that TLS maturity correlates with HPV status and response to anti-PD-1-based chemoimmunotherapy, providing insights for potential therapeutic strategies in HNSCC.

Human polymorphonuclear-myeloid-derived suppressor cells (PMN-MDSCs) consist of circulating low-density neutrophils (LDNs) characterized by the ability to inhibit T-cell responses. In previous studies, we demonstrated that the mature fraction of PMN-MDSCs (i.e. mPMN-MDSCs) exerts more potent immunosuppressive functions than its immature counterpart. More recently, we defined a specific gene signature of mPMN-MDSCs from cancer patients and G-CSF-treated donors (GDs) by bulk RNA sequencing (RNA-seq) experiments. In this study, by performing single-cell RNA-seq (scRNA-seq) experiments of circulating mPMN-MDSCs from non-small cell lung cancer (NSCLC) patients, we identified a major scRNA-seq cell cluster (arbitrarily named NSCLC c6) specifically displaying immunosuppressive and protumor transcriptomic features. Then, by analyzing publicly available scRNA-seq datasets from human tumor-associated neutrophils (TANs), we uncovered three TAN clusters (arbitrarily named TAN c6-c8) that were found to share with NSCLC c6 several common genes and transcription factor (TF) regulons associated with response to hypoxia, positive regulation of angiogenesis, and metabolic reprogramming. Furthermore, by performing scRNA-seq experiments of GD mPMN-MDSCs, we uncovered four scRNA-seq cell clusters (arbitrarily named GD c4-c7) that were enriched for the same genes and pathways characterizing NSCLC c6 and TAN c6-c8 cells. Altogether, these data uncover that human circulating mPMN-MDSCs and TANs from different cancer types share scRNA-seq cell clusters with transcriptomic similarities, supporting the notion that they might be strictly related.

Multiple myeloma (MM) orchestrates a profound disruption of immune balance within the bone marrow (BM) microenvironment, driving disease progression and therapeutic resistance. To better understand these complex immune dynamics, we used high-dimensional mass cytometry (CyTOF) profiling to comprehensively characterize the immune landscape of the BM across different stages of myeloma progression, including MGUS (n = 16), smoldering MM (SMM; n = 25), and active MM, both newly diagnosed (n = 43) and relapsed/refractory (n = 104). Our analysis revealed substantial immune remodeling during disease progression, characterized by adaptive immune suppression and extensive infiltration of innate immune populations. Transformation from MGUS to SMM was marked by significant alterations in central and effector memory T helper cells, effector cytotoxic T cells, and an enrichment of monocytic and neutrophil subsets. Active MM stages were further distinguished by increased expansion of myeloid and monocytic lineages, alongside a pronounced reduction in progenitor and transitional B cells. Correspondence analysis demonstrated that specific immune profiles were significantly associated with clinical outcomes, including progression-free survival and overall survival. This study highlights the potential of CyTOF-based molecular profiling to unravel the intricate immune dynamics of the BM microenvironment across MM disease stages, enhancing our understanding of MM pathogenesis and providing a foundation for identifying prognostic biomarkers and tailoring precision immunotherapeutic strategies.

CAR-based cell therapies have shown clinical success in treating various cancers, with CAR T cell therapies entering the clinical route and CAR NK cell therapies being evaluated in early-stage clinical trials. A key challenge is the presence of tumor-associated antigens on healthy cells, risking on-target off-tumor toxicities. Our comparative analysis of CAR T and CAR NK cells targeting the multiple myeloma-associated antigens BCMA, SLAMF7, and CD38 revealed that antigen density on target cells significantly modulates CAR NK cell activation and cytotoxicity. The cytotoxic potential of CAR NK cells was comparable to that of CAR T cells when targeting BCMA and CD38, but notable differences were observed in SLAMF7-directed CAR cells. While CAR sensitivity was similar in both cell types, CAR NK cell activity was balanced by inhibitory receptors like KIRs and NKG2A. This balance allows effective tumor control while potentially reducing on-target off-tumor effects on healthy cells with low antigen expression. Consequently, CAR NK cells offer greater flexibility in target antigen selection, potentially expanding the range of targetable antigens for cancer immunotherapy.