Oncoimmunology最新文献

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.

Over the last decade, the annual Immunorad Conference, held under the joint auspicies of Gustave Roussy (Villejuif, France) and the Weill Cornell Medical College (New-York, USA) has aimed at exploring the latest advancements in the fields of tumor immunology and radiotherapy-immunotherapy combinations for the treatment of cancer. Gathering medical oncologists, radiation oncologists, physicians and researchers with esteemed expertise in these fields, the Immunorad Conference bridges the gap between preclinical outcomes and clinical opportunities. Thus, it paves a promising way toward optimizing radiotherapy-immunotherapy combinations and, from a broader perspective, improving therapeutic strategies for patients with cancer. Herein, we report on the topics developed by key-opinion leaders during the 7^th Immunorad Conference held in Paris-Les Cordeliers (France) from September 27th to 29th 2023, and set the stage for the 8^th edition of Immunorad which will be held at Weill Cornell Medical College (New-York, USA) in October 2024.

Tumor-resident immune cells play a crucial role in eliciting anti-tumor immunity and immunomodulatory drug responses, yet these functions have been difficult to study without tractable models of the tumor immune microenvironment (TIME). Patient-derived ex vivo models contain authentic resident immune cells and therefore, could provide new mechanistic insights into how the TIME responds to tumor or immune cell-directed therapies. Here, we assessed the reproducibility and robustness of immunomodulatory drug responses across two different ex vivo models of breast cancer TIME and one of renal cell carcinoma. These independently developed TIME models were treated with a panel of clinically relevant immunomodulators, revealing remarkably similar changes in gene expression and cytokine profiles among the three models in response to T cell activation and STING-agonism, while still preserving individual patient-specific response patterns. Moreover, we found two common core signatures of adaptive or innate immune responses present across all three models and both types of cancer, potentially serving as benchmarks for drug-induced immune activation in ex vivo models of the TIME. The robust reproducibility of immunomodulatory drug responses observed across diverse ex vivo models of the TIME underscores the significance of human patient-derived models in elucidating the complexities of anti-tumor immunity and therapeutic interventions.

T cells that recognize tumor-specific mutations are crucial for cancer immunosurveillance and in adoptive transfer of TILs or transgenic-TCR T cell products. However, their challenging identification and isolation limits their use in clinical practice. Therefore, novel approaches to isolate tumor-specific T cells are needed. Here, we report the isolation of neoantigen-specific CD8⁺ T cells from a vaccination site of a metastatic breast cancer patient who received a personalized vaccine. Based on the somatic mutations, potential MHC binding epitopes were predicted, of which 17 were selected to generate a peptide vaccine. Cutaneous biopsies were processed after the fifth vaccination cycle to obtain infiltrating lymphocytes from the vaccination site (VILs). IFNγ ELISpot revealed reactivity to four peptides used in the vaccine. Reactive T cells from VILs were non-overlapping with those detected in the blood and the tumor-microenvironment. ScTCR Seq analysis revealed the presence of a clonotype in VILs that further expanded after a round of in vitro stimulation and validated to be specific against a private mutation, namely NCOR1^L1475R, presented in the context of HLA-B * 07:02, with no reactivity to the wild-type peptide. Our study shows, for the first time, that tumor mutation - specific T cells are generated at high frequencies in the vaccination site and can be isolated with standard methods for TCR screening. The easy and safe accessibility of skin biopsies overcomes the major hurdles of current TCR screening approaches and present exciting opportunities for the development of innovative immunotherapeutic strategies.

Adoptive cell therapy including chimeric antigen receptor (CAR) T cells targeting CD19 has been approved by FDA to treat B cell-derived malignancies with remarkable success. The success has not yet been expanded to treating Acute Myeloid Leukemia (AML). We previously showed that a nanobody and single-chain fragment variable (scFv) CD13 (Nanobody)/TIM-3 (scFv) directed bispecific split CAR (bissCAR) T cells, while effective in eliminating AML in preclinical models, also caused substantial toxicity to human hematopoietic stem cells (HSCs) and other lineages. To maintain the bissCART specificity and efficacy, yet reduce toxicity to normal cells including HSCs, we generated new anti-TIM-3 nanobodies and constructed new cognate nanobodies-directed CD13/41BB and TIM3/CD3zeta nbiCARTs. The resultant nbiCARTs showed strong antitumor activity to CD13/TIM3 positive leukemic cells in vitro and in preclinical models. Importantly, the 3^rd generation of nbiCARTs had little toxicity to human bone marrow-derived colony forming progenitors ex vivo and the human HSCs in mice with a humanized immune system. Together, the current studies generated novel and 3^rd G CD13/TIM-3 nbiCARTs that displayed stronger antitumor activity yet minimal toxicity to normal tissues like HSCs that express a moderate level of CD13, paving the way to further evaluate the novel CD13/TIM-3CARTs in treating aggressive and refractory AML in clinical studies.

The 4662 KPC model is one of the most widely used mouse models of pancreatic cancer. It represents an excluded immune phenotype and closely recapitulates the pathophysiology of pancreatic cancer in humans. We set out to identify the endogenous neoepitopes present in 4662 cells. By combining whole-exome and RNA-sequencing and a bioinformatic neoantigen prediction pipeline, we have identified 15 potential candidate neoantigen epitopes. Ten more highly expressed were selected for validation in an in vivo vaccination study with 4662-tumor bearing mice. The Mrps35-derived neoantigen was found to be immunogenic as we have identified endogenous T-cells responding to this neoepitope, and the response was significantly increased upon vaccination with a synthetic peptide and upon PD1-IL2v therapy. Dextramers based on this peptide were validated and can be used to monitor endogenous tumor-specific CD8+ T-cells in response to immunotherapy. This will support the development of novel therapies for this highly unmet medical need indication.

Metabolic processes are crucial in immune regulation, yet the impact of metabolic heterogeneity on immunological functions remains unclear. Integrating metabolomics into immunology allows the exploration of the interactions of multilayered features in the biological system and the molecular regulatory mechanism of these features. To elucidate such insight in lung squamous cell carcinoma (LUSC), we analyzed 106 LUSC tumor tissues. We performed high-resolution matrix-assisted laser desorption/ionization (MALDI) mass spectrometry imaging (MSI) to obtain spatial metabolic profiles, and immunohistochemistry to detect tumor-infiltrating T lymphocytes (TILs). Unsupervised k-means clustering and Simpson's diversity index were employed to assess metabolic heterogeneity, identifying five distinct metabolic tumor subpopulations. Our findings revealed that TILs are specifically associated with metabolite distributions, not randomly distributed. Integrating a validation cohort, we found that heterogeneity-correlated metabolites interact with CD8+ TIL-associated genes, affecting survival. High metabolic heterogeneity was linked to worse survival and lower TIL levels. Pathway enrichment analyses highlighted distinct metabolic pathways in each subpopulation and their potential responses to chemotherapy. This study uncovers the significant impact of metabolic heterogeneity on immune functions in LUSC, providing a foundation for tailoring therapeutic strategies.

Induction of endoplasmic reticulum (ER) stress is followed by exposure of calreticulin (CRT) on the cancer cell plasma membrane and elicits an anticancer immune response, referred to as immunogenic cell death (ICD). Smad7 is highly expressed by colorectal cancer (CRC) cells, and its knockdown with a specific antisense oligonucleotide (AS) induces ER stress. We hypothesized that, by preventing ER stress, high Smad7 in CRC cells can contribute to limiting ICD. This study aimed to investigate whether targeted inhibition of Smad7 in CRC cells promotes an anti-cancer immune response. Downregulation of Smad7 in the human HCT116 and DLD1 cells and murine CT26 cells promoted calreticulin translocation to the plasma membrane and this phenomenon was prevented by Tauro-urso-deoxycholic acid, an inhibitor of ER stress. Smad7-deficient cells secreted high levels of ATP and HMGB1, thereby promoting the activation of co-cultured dendritic cells. Mice engrafted with Smad7-deficient CT26 cells developed fewer and smaller tumors than wild-type CT26 cell-engrafted mice and exhibited a marked tumor infiltration with CD8⁺ cells and to a lesser extent CD4⁺ cells. Depletion of CD8⁺ T cells abrogated the inhibitory effect of Smad7 knockdown on the tumor volume. Finally, we showed that, in a vaccination model, implanted Smad7-deficient CT26 cells protected mice from the development of tumors induced by wild-type CT26 cells. These data show that Smad7 deficiency triggers ICD in CRC cells, thus reducing tumor development and growth, and suggest that Smad7 inhibitors could be developed as novel ICD inducers, providing a new concept for antitumor immunotherapy.