Oncoimmunology最新文献

Most exhaustion studies have focused on CD8⁺ T cells. Here, we demonstrated reciprocal growth inhibition of CD4⁺ T cells and colorectal cancer cells, which induced the expression of PD-1, PD-L1, and PD-L2 in CD4⁺ T cells. The accelerated exhaustion of CD4⁺ T cells was evidenced by the reduced secretion of several cytokines, including IL-2, IFN-γ, or TNFα, and elevated secretion of CXCL family chemokines. Progressive expression of PD-L1, CTLA4, and IDO1 exhaustion markers occurred concomitantly with tumor growth in vivo in a mouse model. The pattern of CD4⁺ T cell exhaustion was analogous to that observed in CD8⁺ T cells, although with altered dynamics. The PD-L1-high phenotype can be induced by co-culture with tumor cells and is mediated by secreted factors in addition to cell contact. Our findings revealed that IFN-γ receptor knockout T cells exhibited PD-L1 protein expression when cultured with tumor cells, suggesting that PD-L1 expression is not fully dependent on IFN-γ. The TIL population undergoing exhaustion due to persistent antigen stimulation in the presence of cancer cells gradually acquires an immunosuppressive phenotype. The accumulation of inhibitory signals exerted by both cancer cells and T cells, which had converted to a suppressive phenotype, accelerated T cell exhaustion.

Gamma-delta T cells are a subset of T cells that have features of both innate and adaptive immunity. Their role in cancer remains controversial, since both anti- and protumor functions have been reported. We aimed to shed light on the distinct characteristics of γδ T cells in colorectal cancer (CRC). In two independent cohorts, including 1 687 CRC patients, we identified γδ and αβ T cells with multiplex immunohistochemistry to evaluate their prognostic significance. To further analyze the characteristics of γδ T cells, we utilized single-cell RNA sequencing data of 62 CRC patients. High γδ T cell densities were associated with prolonged survival in both cohorts, and this association was independent of other tumor and patient characteristics in Cohort 1, where the multivariable HR for high (vs. low) γδ T cell density was 0.65 (95% CI 0.47-0.90), while the corresponding HR in Cohort 2 was 0.82 (0.50-1.33). αβ T cells demonstrated a stronger association with longer survival that was independent of other prognostic factors in both cohorts. γδ T cells were enriched in mismatch repair (MMR) deficient and BRAF mutated tumors. Single-cell RNA sequencing analysis revealed that γδ T cells were abundant in tumors with weak antigen presentation signaling in tumor cells. Immunohistochemically, high γδ T cell densities were associated with beta-2 microglobulin loss independent of MMR status. These findings indicate that γδ T cells are associated with prolonged survival in CRC and are concentrated in tumors with impaired antigen presentation and MMR deficiency.

Immune checkpoint blockade (ICB) is the standard of care for recurrent/metastatic head and neck squamous cell carcinoma (HNSCC), yet efficacy remains low. The combined positive score (CPS) for PD-L1 is the only biomarker approved to predict response to ICB and has limited performance. Tertiary Lymphoid Structures (TLS) have shown promising potential for predicting response to ICB. However, their exact composition, size, and spatial biology in HNSCC remain understudied. To elucidate the impact of TLS spatial biology in response to ICB, we utilized pre-ICB tumor tissue sections from 9 responders (complete response, partial response, or stable disease) and 11 non-responders (progressive disease) classified via RECISTv1.1. A custom multi-immunofluorescence (mIF) staining assay was applied to characterize tumor cells (pan-cytokeratin), T cells (CD4, CD8), B cells (CD19, CD20), myeloid cells (CD16, CD56, CD163), dendritic cells (LAMP3), fibroblasts (α Smooth Muscle Actin), proliferative status (Ki67) and immunoregulatory molecules (PD1). A machine learning model was employed to measure the effect of spatial metrics on achieving a response to ICB. A higher density of B cells (CD20+) was found in responders compared to non-responders to ICB (p = 0.022). The presence of TLS within 100 µm of the tumor was associated with improved overall (p = 0.04) and progression-free survival (p = 0.03). A multivariate machine learning model identified TLS density as a leading predictor of response to ICB with 80% accuracy. Immune cell densities and TLS spatial location play a critical role in the response to ICB in HNSCC and may potentially outperform CPS as a predictor of response.

α- and β^--emitting radionuclides targeting human fibroblast activation protein-α (hFAP) are under investigation for cancer therapy. In prior work, analysis of the tumor microenvironment 24 h after therapy completion indicated therapy-induced immune activation. Here, we analyzed systemic immune responses at varying timepoints during treatment to further elucidate the immune-stimulating effects of the therapy. Moreover, we analyzed end-stage tumors to gain insight in potential mechanisms of therapy resistance. Single domain antibody 4AH29 that binds hFAP was labeled with ¹³¹I or ²²⁵Ac, generating [¹³¹I]I-GMIB-4AH29 and [²²⁵Ac]Ac-DOTA-4AH29, respectively. These were used to treat C57BL/6 mice bearing subcutaneous TC-1-hFAP tumors. Blood analysis was conducted using flow cytometry, while tumor characterization was performed using flow cytometry and RNA sequencing. Given the distinct properties and doses of both radiopharmaceuticals, no head-to-head comparison was performed. Both treatments activated inflammatory responses in the tumor. Increased PD-1 expression on CD8⁺ T-cells was observed following both treatments in the tumor and periphery. In the tumor, [¹³¹I]I-GMIB-4AH29 therapy uniquely induced the expression of genes involved in tumor cell replication, TNF-α, IL-6/STAT3, IL-2/STAT5 and complement pathways, while in the blood [¹³¹I]I-GMIB-4AH29 therapy upregulated SIRPα on monocytes and TIGIT on NK cells, and downregulated CD86 expression on monocytes. Longitudinal blood immune cell analysis showed changes in composition and phenotype early in therapy, e.g. in effector and regulatory T-cells. Overall, this study corroborates the immune sensitizing capacity of α- and β^--emitting radionuclides, triggering a variety of inflammatory effector responses.

While most ovarian cancer (OC) patients respond to front-line platinum/taxane chemotherapy and surgical debulking, the majority will develop platinum-resistance and recur. Our study investigated how tumor-associated macrophages (TAMs) within the tumor microenvironment (TME) affect chemotherapy outcomes using OC patient-derived organoids and humanized patient-derived xenografts (huPDX). In vitro macrophage migration assays demonstrated the selective recruitment of M2 macrophages to organoids. M2 macrophages, but not M1, increase organoid viability and reduce their sensitivity to paclitaxel in co-culture assays. Furthermore, BMS777607, a receptor tyrosine kinase inhibitor capable of repolarizing M2 macrophages in vitro, reduced organoid viability via a macrophage-dependent mechanism. In a platinum-sensitive huPDX model, the presence of human immune cells increased between-mouse variability in response to paclitaxel with two of four mice demonstrating tumor regrowth after two weeks. A TAM-targeted CSF-1 R inhibitor, BLZ945, combined with paclitaxel reduced tumor burden with no regrowth, suggesting that TAMs promote paclitaxel resistance in this model. Our study demonstrates that TAMs influence response to paclitaxel in both patient-derived OC organoids and huPDX. These models are useful for evaluating immunomodulatory therapy effects and could serve as a robust platform for preclinical testing of novel anti-cancer treatments, providing insights into the complex interplay between immune cells and cancer therapeutics.

Despite recent advances in immunotherapy against B cell malignancies such as BCMA (B cell maturation antigen) and CD19-targeted treatments using soluble T cell-engaging (TCE) antibodies or chimeric antigen receptor T cells (CAR-T), there is still an important number of patients experiencing refractory/relapsed (R/R) disease. Approaches to avoid tumor-intrinsic mechanisms of resistance such as immune pressure-mediated antigen downmodulation, are being broadly investigated. These strategies include BCMA/CD19 dual-targeting therapies, which may be of particular interest to patients with B cell lymphoma and multiple myeloma, where a specific double-positive immature subpopulation is commonly associated with poor prognosis and poor response to current treatments. In fact, several clinical trials targeting both antigens through different strategies are currently underway. Here, based on the previously validated STAb (in situ secretion of T cell-redirecting bispecific antibodies) concept, we used two different engineering strategies (pool and co-transduction) to generate dual-targeted STAb-T cells simultaneously secreting BCMA TCE and CD19 TCE that outperformed single-targeted STAb-T cells in different in vitro models. These promising results encourage further preclinical clinical testing of dual STAb-T cells in R/R B-cell malignancies.

Head and neck squamous cell carcinoma (HNSCC) continues to be among the most common malignancies worldwide with limited treatment options for patients. Targeting the PD-1/PDL-1 axis is currently the only FDA approved immune checkpoint inhibitor treatment for HNSCC. Novel therapies targeting other pathways are needed along with testing a combinational approach to find new and more efficient ways to treat this disease. We utilized a tamoxifen inducible TgfβR1/Pten deletion mouse model to explore the efficacy of combined anti-LAG-3 and anti-PD-1 therapy against tongue HNSCC and determine underlying immunological mechanisms. Combined anti-LAG-3/anti-PD-1 therapy was effective at decreasing the tumor burden and lymphatic metastasis compared to anti-LAG-3 treatment but not when compared to the anti-PD-1 treatment alone. Anti-tumoral effects of anti-PD1 and anti-LAG-3/anti-PD-1 combined therapy were associated with increased CD4+ and CD8+ T-cell proliferative responses in secondary lymphoid organs along with increased CD8+ T-cell tumor infiltration. Anti-LAG-3 treatment potentiated the anti-tumoral properties of CD4+ T-cells treated with anti-PD-1, including enhanced systemic IFN-γ production and TNF-α production in the tumor microenvironment. Further, anti-tumoral cytotoxic CD8+ T-cell effector function and granzyme B production were enhanced by anti-PD-1 and combinatorial anti-LAG-3/anti-PD-1 immunotherapy, resulting in greater tumor cell death. Our results demonstrate that anti-LAG-3 has the potential to enhance the efficacy of anti-PD-1 therapy; however, humanized mouse models that better recapitulate the human disease with FDA approved antibodies are needed to further characterize the efficacy of this treatment as a viable treatment option for HNSCC patients.

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.

Medulloblastoma (MB) is a pediatric brain tumor that develops in the cerebellum, representing one of the most common malignant brain cancers in children. Standard treatments include surgery, chemotherapy, and radiation, but despite a 5-y survival rate of approximately 70%, these therapies often lead to significant neurological damage in the developing brain. This underscores the urgent need for less toxic, more effective therapeutic alternatives. Recent advancements in cancer immunotherapy, including immune checkpoint inhibitors and CAR-T cell therapy, have revolutionized cancer treatment. One promising avenue is the use of Gamma Delta (γδ)T cells, a unique T cell population with potential advantages, such as non-alloreactivity, potent tumor cell lysis, and broad antigen recognition. However, their capacity to recognize and target MB cells remains underexplored. To investigate the therapeutic potential of γδT cells against MB, we analyzed the proportion and status of MB-infiltrated γδT cells within patient datasets. We next investigated the expression of γδT cell ligands on MB cells and identified the EphA2 receptor and the phosphoantigen/Butyrophilin complex as key ligands, activating Vγ9 Vδ1 and Vγ9 Vδ2 T cells, respectively, leading to significant MB cell lysis in both monolayer and spheroid models. Importantly, preliminary safety data showed that γδT cells did not target differentiated neurons or neuroepithelial stem cells derived from induced pluripotent stem cells, underscoring the selectivity and safety of this approach. In conclusion, γδT cells trigger an efficient and specific killing of MB and would offer a promising novel therapeutic strategy.

Renal cell carcinoma (RCC) is recognized as an immunogenic tumor, yet tumor-infiltrating lymphocytes often exhibit diminished effector function. However, the mechanisms underlying reduced T and NK cell activity in RCC remain unclear. Here, we examined the immune contexture in RCC patients undergoing nephrectomy to identify immune-related biomarkers associated with disease progression. Immune cell phenotypes and secretion profiles were assessed using flow cytometry and Luminex multiplex analysis. Supervised multivariate analysis revealed several changes of which frequencies of T and NK cells expressing CCR5, CXCR3, and PD-1 were elevated within tumors compared with peripheral blood. In addition, higher levels of regulatory T cells, PD-1+, and CXCR3+ T and NK cells were observed in patients with relapse following nephrectomy. With regards to soluble factors, tumor-derived CXCL8 was associated with higher Fuhrman grade and increased frequency of polymorphonuclear myeloid-derived suppressor cells (PMN-MDSCs). These biomarkers demonstrate potential relevance in the progression of RCC and merit further investigation in prospective studies.