Oncoimmunology最新文献

CD8⁺ T cells shape the antitumor immune response. Here, we evaluated CD8⁺ T cells expressing different levels of PD-1, their functional status, and distribution in different tissues of luminal breast cancer (BC) patients. We characterized the exhaustion stages of CD8⁺ T cells in tumors, juxtatumoral tissues (JTs), and tumor-draining lymph nodes (TDLNs). Terminal exhausted CD8⁺ T cells (PD-1^High CD8⁺) were predominant in tumors and nearly absent in other tissues. However, in all tissues evaluated, most CD8⁺ T cells exhibited a pre-exhausted phenotype (PD-1^Int CD8⁺) or did not express PD-1. PD-1^High and PD-1^Int CD8⁺ T cells from tumors and JTs presented central and effector memory phenotypes, while in TDLNs were primarily central memory. TCR-β sequencing revealed higher clonality among CD8⁺ T cells from tumor than TDLNs, with tumor-enriched clones also detected in TDLNs. Analysis of scRNA-seq datasets from tumors and JTs of colorectal and non-small cell lung cancer patients, identified a CD8⁺ terminal exhaustion and a CD8⁺ pre-exhausted signatures. High expression of exhaustion-associated genes in BC tumors correlated with improved overall survival. Overall, PD-1 expression effectively distinguishes exhaustion stages in CD8⁺ T cells. PD-1^Int cells found in tumors, JTs, and TDLNs represent a promising therapeutic target for cancer immunotherapy.

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.

Targeted therapies leveraging the innate immune system are emerging as promising cancer treatments. The mitochondrial antiviral signaling protein (MAVS) plays a crucial role in initiating innate immune responses, but its clinical use is limited by the risk of uncontrolled activation and systemic toxicity. To address this, we developed a novel therapeutic agent, the truncated interferon activation switch (TRIAS), combining MAVS truncates with a tumor antigen-targeting single-chain variable fragment (scFv). This design ensures antigen-dependent, controlled activation. Lentiviral delivery of TRIAS induced significant antitumor responses, including complete tumor regression in some cases. Flow cytometry (FCM) analysis further confirmed that tumor cells were the predominant population expressing the transgene. TRIAS-expressing tumor cells exhibited enhanced antitumor activity, likely due to increased cytokine release and upregulated major histocompatibility complex (MHC) expression, enabling tumor cells to function as antigen-presenting cells. This activated other immune cells, driving adaptive immune responses. Additionally, TRIAS promoted a proinflammatory shift in the tumor microenvironment (TME). In conclusion, TRIAS was validated as an innovative immunotherapeutic agent with MAVS-like immune-activating properties and tightly controlled mechanisms, offering a safer and more effective approach for clinical cancer immunotherapy.

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.

Peritoneal metastases remain a significant clinical challenge owing to the immunosuppressive nature of the omentum, which serves as a protective niche for disseminated tumor cells. Our recent study explored the targeted delivery of immunomodulatory cytokine-encoded mRNAs to the omentum, aiming to shift its role from a tumor-supportive site to an immune-activating ally. Our findings highlight the potential of cytokine mRNA delivery as a novel and safe immunotherapeutic strategy for peritoneal metastases.

The crossing of the endothelial basement membranes (BMs) is a limiting step for leukocyte diapedesis. Heterotrimeric laminins (LMs) containing α4- and α5-chains are major BM components with opposite effects on transendothelial migration. Here, we examined whether LMα4 levels influence intratumor accumulation of specific immune cells and their impact on prognosis of early-stage colorectal cancer (CRC). Using two independent patient cohorts, we found that LMα4 expression positively correlated with intratumor infiltration of CD8⁺ T cells and macrophages, but not with regulatory T (Treg) cells. Kaplan-Meier and multivariate Cox regression analyses identified CD8⁺ T cell density as the strongest independent prognostic factor associated with reduced tumor relapse in both cohorts. While intratumor macrophage and Treg cell densities alone were not independently associated with prognosis, their abundance modulated outcomes specifically in tumors with high CD8⁺ T cell infiltration, with macrophage-rich tumors showing improved outcomes and Treg cell-enriched tumors exhibiting worse prognosis. Analysis of The Cancer Genome Atlas (TCGA) COAD cohort confirmed the positive correlation of LMα4 expression with both CD8⁺ T cell and macrophage infiltration, an association that was independent of the CRC clinical stage. Our findings suggest a subtype-specific effect for LMα4 in intratumor leukocyte infiltration, and underscore the prognostic interactions among CD8⁺ T cells, Treg cells and macrophages in early-stage colorectal cancer.

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.