Oncoimmunology最新文献

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.

T cells recognize peptides presented by human leukocyte antigen molecules on the cell surface, enabling the immune surveillance of pathological conditions such as cancer. Cancer-testis (CT) antigens are promising targets for cancer immunotherapy because of their restricted expression in normal tissues. In this study, we performed antigen screening of T cell receptors isolated from tumor-infiltrating lymphocytes (TILs) in acral melanoma, using cDNA expression cloning and identified a novel CT antigenic epitope encoded by MAGE-A6 with a single nucleotide polymorphism (SNP). This SNP conferred immunogenicity to the epitope, eliciting a robust immune response against tumor cells. While antigen identification has increasingly relied on reverse immunology approaches using reference sequences that do not contain SNPs, forward immunology approaches, such as cDNA expression cloning, directly identify antigens recognized by T cells exhibiting immune responses, enabling the detection of SNP-derived epitopes. Furthermore, in hot tumors such as acral melanoma that are characterized by a low tumor mutational burden, but high TIL infiltration, TILs predominantly respond to shared antigens with high immunogenicity. These findings underscore the utility of forward immunology in antigen discovery and highlight the potential of SNP-dependent tumor antigens in cancer immunotherapy.

Pancreatic ductal adenocarcinoma (PDAC) is an aggressive disease with poor survival. The immunosuppressive tumor microenvironment (TME) drives resistance to therapy, including immunotherapy. This may be, in part, mediated by the formation of neutrophil extracellular traps (NETs), formed when neutrophils release their intracellular contents. NETs are elevated in PDAC and are associated with nearly every stage of tumor progression. We investigated the influence of NETs on the PDAC TME and immunotherapy response. An orthotopic PDAC model was utilized in C57BJ6 or PAD4^-/- mice receiving one of the following: control, DNase, anti-PD-1 therapy, or DNase and anti-PD-1. NET markers, fibrosis, and the TME immune profile were evaluated. Human PDAC patients were also evaluated for levels of NETs and tumor-infiltrating T cells. Circulating NET markers correlated with intra-tumoral CD8⁺ cells in PDAC patients. Patients with high NET levels also experienced more post-operative complications. NET inhibition in mice reduced tumor growth and enhanced survival. Decreased expression of collagen and matrix metalloproteinase (MMP) genes, as well as reduced intra-tumoral collagen deposition were found in NET deficient mice. Additionally, an increase in TCF1⁺PD-1⁺CD44⁺CD8⁺ progenitor T cells, a subpopulation of T cells responsive to immunotherapy, were identified. These changes resulted in further tumor burden reduction and prolonged survival when anti-PD-1 therapy was given in conjunction with NET inhibition. NETs influence extracellular matrix remodeling and the T cell response to PDAC, allowing for a significant response to anti-PD-1 therapy. These findings support the combination therapy of immunotherapy and NET inhibition in patients with PDAC.

The tumor microenvironment (TME) has a central role in many cancers, particularly by fostering an immunosuppressive milieu. Chimeric antigen receptor (CAR)-based immunotherapy displays a promising strategy to re-direct immune cells toward specific antigens, thereby inducing targeted cytotoxicity. The fibroblast activation protein (FAP) is overexpressed in various cancer types and has shown promise in CAR-based therapies. However, its application in gynecological cancers remains unexplored. This study evaluates the efficacy of anti-FAP CAR-NK cells as a targeted immunotherapy for cervical cancer and cancer-associated fibroblasts (CAFs). FAP expression was quantified on cervical cancer cell lines, primary cervical cancer tissues, and cells isolated from these tissues. Alpharetroviral SIN vectors were used to transduce NK-92 cells and primary cord blood-derived NK cells with 3^rd-generation anti-FAP CARs. Immunohistochemistry and flow cytometry revealed high FAP expression on CaSki cells, cervical cancer tissues, and primary cervical CAFs. In 2D co-cultures with FAP-positive target cells, anti-FAP CAR-NK cells exhibited significantly enhanced cytotoxicity and elevated degranulation compared to control NK cells, with no observed effects against FAP-negative target cells. Primary NK cells revealed high cytotoxicity against cervical cancer cells with a high release of cytolytic enzymes. Anti-FAP CAR-NK cells also showed efficient elimination of cervical cancer cells and CAFs in 3D tumor spheroid models. These findings underscore the potential of anti-FAP CAR-NK cells as a potent therapeutic approach for cervical cancer and suggest broader applicability in diseases characterized by high FAP expression.

Soft tissue sarcomas (STS) are aggressive high-fatality cancers that affect children and adults. Most STS subtypes harbor an immunosuppressive tumor microenvironment (TME) and respond poorly to immunotherapy. Therapies capable of dismantling the immunosuppressive TME are needed to improve sensitivity to emerging immunotherapies. Activation of the Stimulator of INterferon Genes (STING) pathway has shown promising anti-tumor effects in preclinical models of carcinoma, but evaluations in sarcoma are lacking. Herein, we sought to examine the immune modulation and therapeutic efficacy of three translational small molecule STING agonists in an immunologically cold model of STS. Three classes of STING agonists, ML RR-S2 CDA, MSA-2, and E7766 were evaluated in an orthotopic KrasG12D/+ Trp53-/- model of STS. Dose titration survival studies, cytokine serology, and tumor immune phenotyping were used to examine STING agonist efficacy following intra-tumoral treatment. All STING agonists significantly increased survival time, however, only E7766 resulted in durable tumor clearance, inducing CD8+ T-cell infiltration and activated lymphocyte transcriptomic signatures in the TME. Antibody depletion was used to assess the dependency of treatment responses on CD8+ T-cells, showing that in their absence, tumor clearance did not occur following E7766 therapy. Using STING deficient mice, and CRISPR/Cas9 gene editing, we demonstrated that STS clearance following STING therapy was dependent on host STING and not tumor-intrinsic STING pathway functionality. E7766 represents a promising candidate able to remodel the TME of murine STS tumors toward an inflamed phenotype independent of tumor-intrinsic STING functionality, and should be considered for potential translation in STS treatment.

Therapeutic vaccines represent a promising treatment option for (pre)cancerous lesions, such as human papillomavirus-induced malignancies. They act via administration of tumor-specific antigens, leading to induction of antigen-specific cytotoxic T cell responses. However, vaccination efficiency is often limited when the antigen is administered alone, due to antigen instability and inefficient uptake by antigen-presenting cells (APCs). To address these limitations, nanoparticle-based vaccine delivery systems are currently under investigation. Here, we present a novel silica nanoparticle (SiNP)-based vaccine delivery platform that can be applied for the treatment of various diseases and cancer types. We show that surface-functionalized SiNPs are non-cytotoxic and quickly taken up by APCs. Incorporation of a linker/solubilizer sequence N-terminal of the epitope allows attachment of peptides regardless of their solubility as well as efficient processing and surface presentation by APCs. Whole-body distribution studies confirmed retention of the antigen at the injection site and decelerated excretion when connected to SiNPs. Furthermore, treatment with SiNPs, especially when combined with the adjuvant poly(I:C), resulted in activation of dendritic cells capable of priming CD8⁺ T cells. In C57BL/6 and MHC-humanized A2.DR1 mice, the SiNP-based vaccinations induced epitope-specific CD8⁺ T cells. Moreover, they exhibited anti-tumor activity and provided a survival benefit in a tumor model using HPV16 E6/E7-expressing PAP-A2 cells. Thus, the novel SiNP platform represents a promising new vehicle for therapeutic vaccine delivery.

Pancreatic ductal adenocarcinoma (PDAC) presents a unique challenge for researchers due to its late diagnosis caused by vague symptoms and lack of early detection markers. Additionally, PDAC is characterized by an immunosuppressive microenvironment (TME), making it a difficult tumor to treat. While γδ T cells have shown potential for anti-tumor activity, conflicting studies exist regarding their effectiveness in pancreatic cancer. This study aims to explore the hypothesis that the PDAC TME hinders the anti-tumor capabilities of γδ T cells through blockade of cytotoxic functions. For this reason, we chose to enroll PDAC treatment-naive patients to avoid the possibility of therapy modifying the TME. By flow cytometry, our research findings indicate that the presence of γδ T cells among CD45+ cells in tumor tissue is lower compared to CD66+ cells, but higher than in blood. Circulating Vδ1 T cells exhibit a terminal effector memory phenotype (TEMRA) more than Vδ2 T cells. Interestingly, Vδ1 and Vδ2 T cells appear to be more prevalent at different stages of tumor development. In our in vitro culture using conditioned medium derived from Patient-derived organoids ;(PDOs), we observed a shift in expression markers in γδ T cells of healthy individuals toward an activation and exhaustion phenotype, as confirmed by scRNA-seq analysis extracted from a public database. A deeper understanding of γδ T cells in PDAC could be valuable for developing novel therapies aimed at mitigating the impact of the pancreatic tumor microenvironment on this cell population.

Accumulating evidence suggests that phenotype switching of cancer cells is essential for therapeutic resistance. However, the immunological characteristics of drug-induced phenotype-switching melanoma cells (PSMCs) are unknown. We investigated PSMC elimination by host immunity using hyperdifferentiated melanoma model cells derived from murine B16F10 melanoma cells. Exposure of B16F10 cells to staurosporine induced a hyperdifferentiated phenotype associated with transient drug tolerance. Staurosporine-induced hyperdifferentiated B16F10 (sB16F10) cells expressed calreticulin on their surface and were phagocytosed efficiently. Furthermore, the inoculation of mice with sB16F10 cells induced immune responses against tumor-derived antigens. Despite the immunogenicity of sB16F10 cells, they activated the PD-1/PD-L1 immune checkpoint system and strongly resisted T cell-mediated tumor destruction. However, in vivo treatment with immune checkpoint inhibitors successfully eliminated the tumor. Thus, hyperdifferentiated melanoma cells have conflicting immunological properties - enhanced immunogenicity and immune evasion. Inhibiting the ability of PSMCs to evade T cell-mediated elimination might lead to complete melanoma eradication.