The tumor microenvironment (TME) represents a heterogeneous, complicated ecosystem characterized by intricate interactions between tumor cells and immune cells. During the past decade, immune cells especially T cells were found to play an important role in the progression of tumor and many related immune checkpoints drugs were created. In recent years, more and more scientists revealed the critical role of B-cells within the TME, particularly various populations of non-malignant B cells. Some studies indicated that non-malignant B cells may exert a 'double-edged sword' role in solid tumors. However, there has been comparatively less focus on the role of non-malignant B cells in hematologic malignancies. In this review, we characterized the development of B cells and summarized its functions of antitumor immunity within TME, with an emphasis on elucidating the roles and potential mechanisms of non-malignant B cells in the progression of hematologic diseases including classical Hodgkin's lymphoma, non-Hodgkin's B-cell lymphoma, non-Hodgkin's T-cell lymphoma, leukemia and multiple myeloma.

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 7th Immunorad Conference held in Paris-Les Cordeliers (France) from September 27th to 29th 2023, and set the stage for the 8th edition of Immunorad which will be held at Weill Cornell Medical College (New-York, USA) in October 2024.

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.

Sarcomas are highly malignant tumors characterized by their heterogeneity and resistance to conventional therapies, which significantly limit treatment options. EZH2 is highly expressed in sarcomas, but targeting it is difficult. In this study, we uncovered the non-canonical transcriptional mechanisms of EZH2 in sarcoma and highlighted the essential role of EZH2 in regulating YAP1 through non-canonical transcriptional pathways in the progression of sarcoma. Building on this, we developed YM@VBM, a novel and versatile nano-PROTAC (proteolysis-targeting chimera), by integrating a polyphenol-vanadium oxide system with the EZH2 degrader YM281 PROTAC, encapsulated in methoxy polyethylene glycol-NH2 to enhance biocompatibility. To further facilitate targeted drug delivery to tumors, YM@VBM nano-PROTACs were incorporated into microneedle patches. Our engineered YM@VBM exhibited multiple functionalities, including the peroxidase-like activity to generate reactive oxygen species, depletion of glutathione, and photothermal effects, specifically targeting sarcoma characteristics. YM@VBM significantly enhanced targeting efficacy via inducing potent EZH2 degradation. Most importantly, it can also activate anti-tumor immunity via excluding myeloid-derived suppressor cells, maturing dendritic cells, and forming tertiary lymphoid structures. Hence, we reveal that YM@VBM presents a promising treatment strategy for sarcoma, offering a multifaceted approach to combat this challenging malignancy.

Immune checkpoint blockade (ICB) therapies have demonstrated significant clinical efficacy in immune-infiltrated tumors such as melanoma and non-small cell lung cancer. However, "cold tumors"-including ovarian cancer, pancreatic cancer, and gliomas-exhibit insufficient immune infiltration, leading to poor therapeutic responses to ICBs and limited improvement in patient prognosis. Recent studies have shown that tumor-associated tertiary lymphoid structures (TLSs) can induce strong local immune responses within the tumor microenvironment (TME), serving as important biological markers for predicting ICB therapy efficacy. Notably, preclinical and clinical studies on cold tumors have confirmed that TLSs can potently enhance ICB efficacy through TME remodeling-a breakthrough that has attracted considerable attention. Here, we systematically examine the immunological profile of cold tumors and decipher the mechanistic basis for their impaired immune cell infiltration. We further delineate the distinctive features of tumor-associated TLSs in generating antitumor immunity and establish criteria for their identification. Significantly, we emphasize the unique capability of TLSs to reprogram the immunosuppressive tumor microenvironment characteristic of cold tumors. Based on these insights, we evaluate clinical evidence supporting TLS-mediated enhancement of ICB efficacy and discuss emerging strategies for exogenous TLSs induction.

Lung adenocarcinoma (LUAD) remains associated with limited effective pharmacological treatment options. This study aimed to identify potential therapeutic targets for LUAD through the integration and analysis of multi-omics datasets.

A meta-analysis was conducted using two extensive proteomics datasets, the UK Biobank Proteomics Project (UKB-PPP) and the Fenland study, to identify disease-associated targets for LUAD through the Summary-Data-Based Mendelian Randomization method. Sensitivity analysis, including heterogeneity tests for dependent instruments, were conducted to validate the findings. The prognostic relevance of the identified candidate targets was assessed using transcriptomic data. Functional interactions were explored via protein-protein interaction network analysis, while single-cell analyses were employed to determine cell-specific expression patterns and differentiation trajectories. Potential side effects and therapeutic indications of these targets were evaluated using phenome-wide association studies and pharmacological data mining.

Following meta-analysis, a primary significant target, intercellular adhesion molecule 5 (ICAM5), along with potential targets FUT8 and KLK13, were identified as therapeutic candidates for LUAD. FUT8 demonstrated a positive association with LUAD risk (OR = 1.02, p = 0.049), while ICAM5 (OR = 0.88, p = 0.002) and KLK13 (OR = 0.85, p = 0.021) exhibited negative associations. ICAM5 was further identified as an independent prognostic factor for patient survival (HR: 0.788, 95% CI: 0.663-0.936, p = 0.007) and revealed significant diagnostic and prognostic utility in LUAD. ICAM5 expression correlated with various immune infiltration patterns, suggesting potential modulation of the tumor immune microenvironment. Single-cell analysis revealed that ICAM5 did not directly impact LUAD cell differentiation, though its downstream target, MUC1, may contribute to differentiation processes, particularly in KRAS-mutated LUAD. Furthermore, phenome-wide association studies did not reveal substantial evidence of adverse phenotypes linked to ICAM5, supporting its safety profile for drug development.

ICAM5 emerges as a promising biological marker with significant prognostic and therapeutic potential in LUAD.

RORc-expressing immune cells play important roles in inflammation, autoimmune disease and cancer. They are required for lymphoid organogenesis and have been implicated in tertiary lymphoid structure (TLS) formation. TLSs are formed in many cancer types and have been correlated with better prognosis and response to immunotherapy. In liver cancer, some TLSs are pro-tumorigenic as they harbor tumor progenitor cells and support their growth. The processes involved in TLS development and acquisition of pro- or anti-tumorigenic roles are largely unknown. This study aims to explore the role of RORc-expressing cells in TLS development in the context of inflammation-associated liver cancer.

IKKβ(EE)Hep mice, exhibiting chronic liver inflammation, TLS formation and liver cancer, were crossed with RORc knockout mice to explore RORc's effect on TLS and tumor formation. TLS phenotypes were analyzed using transcriptional, proteomic, and immunohistochemical techniques. CD4, CD8, and B-cell depletions were used to assess their contribution to liver TLS and tumor formation.

RORc-expressing cells are detected within TLSs of both human patients and mice developing intrahepatic cholangiocarcinoma. In mice, these cells negatively regulate TLS formation, as excess TLSs form in their absence. CD4 cells are essential for liver TLS formation, while B cells are required for TLS formation specifically in the absence of RORc-expressing cells. Importantly, in chronically inflamed livers lacking RORc-expressing cells, TLSs become anti-tumorigenic, reducing tumor load. Anti-tumorigenic TLSs revealed enrichment of exhausted CD8 cells with effector functions, germinal center B cells and plasma cells. B cells are key in limiting tumor development, possibly via tumor-directed antibodies.

RORc-expressing cells negatively regulate B-cell responses and facilitate the pro-tumorigenic functions of hepatic TLSs.

RORc-expressing immune cells play critical roles in immune regulation, yet their specific influence on tertiary lymphoid structures (TLSs) in liver pathology and cancer has not been elucidated. Our study reveals that RORc-expressing cells act as negative regulators of TLS formation and shape the immune microenvironment in a manner that promotes tumor development. In the absence of RORc-expressing cells, TLSs not only increase in number but also acquire anti-tumorigenic properties. These findings suggest that RORc-expressing cells serve as key modulators of liver immune dynamics, with potential implications for the use of RORc as a biomarker to differentiate between pro- and anti-tumorigenic immune environments and as a target for manipulating TLS abundance and phenotype in liver cancer.

Gastrointestinal stromal tumors (GISTs) are a type of tumor that originates from gastrointestinal mesenchymal tissue. Although several somatic or germline mutation GIST mice were established, however, there is still a lack of an authentic mice GIST cell lines for further experimental study.

We developed a chemically induced C57BL/6 J GIST model using 3- methylcholanthrene. Tumor characteristics were confirmed through histology and IHC. Primary cells were isolated to establish the mGSTc01 cell line, and molecular profiling was conducted. Additionally, we established GIST model in immunocompetent mice to evaluate their sensitivity to imatinib.

Our study successfully developed a chemically induced murine GIST model, characterized by positive staining of c-kit and DOG-1. The mGSTc01 monoclonal cell line exhibited slender morphology and expressed the c-kit marker, Whole exome sequencing uncovered mutations of Lamb1, MMP9, and c-kit in GIST cells and provided a detailed picture of the entire genome's copy number variations. RNA sequencing indicated genes associated with cell adhesion and focal adhesion were enriched in mGSTc01 cells. The mGSTc01 cells demonstrated obvious malignant behaviors, notably elevated migration, adhesion, and proliferation. In immunocompetent mice, subcutaneous xenografts not only reserved the aggressive phenotype but also displayed a response to imatinib, underscoring the model's applicability for advancing therapeutic research.

We firstly established a mGSTc01 cell line derived from C57BL/6 J mice GIST tumor offers, which closely mimicking human disease characteristics. It is a potent platform for investigating tumor microenvironment of GIST in mice model, and provides a novel way for new therapeutic discoveries in GIST.

Soft tissue sarcoma (STS) is a rare, heterogeneous malignancy with limited treatment options for metastatic disease. Despite advances in immunotherapy, including PD-1 inhibitors, clinical outcomes remain suboptimal, highlighting the need for novel biomarkers and therapeutic strategies. This study investigated the role of TACC2 in STS, focusing on its impact on the immune microenvironment and immunotherapy response.

Whole-exome sequencing was performed to characterize TACC2-related genomic alterations in STS cohorts, complemented by immunohistochemistry for protein-level validation. Mechanistic insights were obtained through chromatin immunoprecipitation (ChIP) and co-immunoprecipitation assays, focusing on TACC2's interaction with the NuRD/CoREST complex. The efficacy of anti-PD-1 therapy was evaluated in TACC2-overexpressing mouse models, and clinical relevance was analyzed using patient survival and treatment response data.

TACC2 acted as a tumor suppressor in STS, with low expression associated with poor overall survival. Mechanistically, TACC2 enhanced CCL3 and CCL4 transcription, promoting CD8 + T cell infiltration by inhibiting NuRD/CoREST nuclear translocation. In vivo, TACC2 overexpression synergized with PD-1 blockade therapy, leading to a significant reduction in tumor volume and prolonged survival. Clinically, high TACC2 expression was associated with improved responses to immunotherapy.

In conclusion, TACC2 is an important regulator of the immune response in STS, functioning as a tumor suppressor and a modulator of response to PD-1 blockade. Its role in modulating chemokine expression and CD8 + T cell infiltration highlights its potential as a therapeutic target and predictive biomarker for STS immunotherapy.

Recent advances in immuno-oncology research have revolutionised our understanding of the interplay between immune cells and the tumour microenvironment (TME), profoundly impacting patient responses to therapy. The TME, comprising tumour cells, immune cells, extracellular matrix, stromal cells, and co-existing microbes, orchestrates the immune phenotype of cancers, shaping disease progression and treatment outcomes. Immune-cell infiltration serves as a significant prognostic marker in various cancers, with higher rates correlating with improved prognosis. Recent discoveries have paved the way for immune checkpoint blockade therapies, which exhibit remarkable efficacy across multiple cancer types. However, understanding the nuanced contributions of different immune-cell populations to therapeutic responses remains a challenge. The majority of research has focussed on the role of T cells in the immune response to cancer therapies, with the potential importance of B cells only recently being recognised. Here, we review the diverse phenotypes of B cells within the TME, their structural organisation within tertiary lymphoid structures (TLS), and the role of both B cells and TLS in cancer prognosis and response to different therapies for cancer treatment.

The objective of this work was to establish prognostic models in stage III colon cancer (CC) on the basis of transcriptomic signatures of the tumor microenvironment (TME) and cell cycle from the PETACC-8 (training set) and IDEA-France (validation set) trials.

3'RNA sequencing was performed in 1,733 patients from the PETACC-8 trial and 1,248 patients from the IDEA-France trial. Four transcriptomic signatures were analyzed: T-cell and macrophage M2 signatures, the expression of CXCL13, and a score on the basis of the Oncotype DX CC Recurrence Score using the same formula from the stromal score and the cell cycle score. The Immune Proliferative Stromal (IPS) score was defined as the number of dichotomized signatures that fall under the category of a dismal prognosis (from 0 to 4). Time to recurrence (TTR) was defined as the time from the date of random assignment to local and/or metastatic relapse and/or death because of CC, whichever occurs first.

High Oncotype-like and M2 scores and low CXCL13 expression and T-cell score were associated with a shorter TTR. A multivariable model including these signatures and all known prognostic factors applied to the IDEA-France cohort by obtaining a value of this model for each patient showed TTR significantly different depending on the quartile of this value and a 3-year rate of patients without recurrence ranging from 56% for the lowest quartile to 89% for the highest quartile (P < .0001). The IPS score was significantly associated with TTR in multivariable analysis.

Using transcriptomic data of patients with stage III CC from two large-scale adjuvant trials, a prognostic model on the basis of signatures of the TME and the cell cycle provides important information in addition to known prognostic factors for patient stratification on risk of recurrence.

The success of cancer prevention vaccines targeting cancer-causing viruses has drastically reduced cancer mortality worldwide. However, the development of therapeutic cancer vaccines, which aim to elicit an immune response directly against cancer cells, has faced notable clinical setbacks. In this Review, we explore lessons learned from past cancer vaccine trials and how the field has progressed into an era of renewed promise. Previous vaccines primarily targeted tumour-associated antigens and were mainly tested as monotherapies in late-stage cancers. In contrast, contemporary vaccines focus on targeting tumour-specific antigens (neoantigens) and are showing initial evidence of clinical efficacy, particularly in early-stage cancers and precancers when combined with immune checkpoint inhibitors. Advances in tumour profiling and novel vaccine platforms have enhanced vaccine specificity and potency. We discuss recent clinical trials of therapeutic cancer vaccines and outline future directions for the field.

The treatment landscape of non-small-cell lung cancer (NSCLC) is evolving rapidly, driven by advances in the development of targeted agents and immunotherapies. Despite this progress, some patients have suboptimal responses to treatment, highlighting the need for new therapeutic strategies. In the past decade, the important role of the tumour microenvironment (TME) in NSCLC progression, metastatic dissemination and response to treatment has become increasingly evident. Understanding the complexity of the TME and its interactions with NSCLC can propel efforts to improve current treatment modalities, overcome resistance and develop new treatments, which will ultimately improve the outcomes of patients. In this Review, we provide a comprehensive view of the NSCLC TME, examining its components and highlighting distinct archetypes characterized by spatial niches within and surrounding tumour nests, which form complex neighbourhoods. Next, we explore the interactions within these components, focusing on how inflammation and immunosuppression shape the dynamics of the NSCLC TME. We also address the emerging influences of patient-related factors, such as ageing, sex and health disparities, on the NSCLC-TME crosstalk. Finally, we discuss how various therapeutic strategies interact with and are influenced by the TME in NSCLC. Overall, we emphasize the interconnectedness of these elements and how they influence therapeutic outcomes and tumour progression.

B cells engage in anti-tumor immunity but how they contribute to cancer suppression remains unclear. We report that inhibiting plasma cell differentiation either in IgMi mice lacking Igh elements needed for antibody secretion or in mice with B cell-specific knockout of Blimp-1 (Blimp-1 BcKO) promotes rather than inhibits antitumor immunity and increases numbers of activated B cells. Deficiency of Blimp-1 in tumor-infiltrating B cells generates a unique transcription profile associated with expansion of mutated clones targeting cognate tumor cells. Major histocompatibility complex class II (MHC II) is required for anti-tumor efficacy. Blimp-1-deficient B cells have increased expression of CD80 and CD86 costimulatory molecules that enhance effector T cell function. The Blimp-1 inhibitor valproic acid suppresses tumor growth in a B cell-dependent manner. Thus, inhibition of plasma cell differentiation results in enhanced tumor-specific antigen presentation by B cells and thereby tumor repression, suggesting a potential avenue of immunotherapy against cancer.

Lung cancer is the deadliest cancer globally. Non-small cell lung cancer (NSCLC), including adenocarcinoma, squamous cell carcinoma, and large cell carcinoma, constitutes a significant portion of cases. Adenocarcinoma, the most prevalent type, has seen a rising incidence. Immune checkpoint inhibitors (ICIs) have improved outcomes in lung adenocarcinoma (LUAD), yet response rates remain unsatisfactory. PD-1/PD-L1 inhibitors are primary ICIs for LUAD, targeting the PD-1/PD-L1 pathway between CD8+ T cells and tumor cells. However, LUAD presents a "cold tumor" phenotype with fewer CD8+ T cells and lower PD-1 expression, leading to resistance to ICIs. Thus, understanding the function of other immune cell in tumor microenvironment is crucial for developing novel immunotherapies for LUAD. B cells, which is part of the adaptive immune system, have gained attention for its role in cancer immunology. While research on B cells lags behind T cells, recent studies reveal their close correlation with prognosis and immunotherapy effectiveness in various solid tumors, including lung cancer. B cells show higher abundance, activity, and prognostic significance in LUAD than that in LUSC. This review summarizes the difference of B cell immunity between LUAD and other lung cancers, outlines the role of B cell immunity in LUAD.

Tumor tertiary lymphoid structures (TLS), especially mature TLS (mTLS), have been associated with better prognosis and improved responses to immune checkpoint blockade (ICB), but the underlying mechanisms remain incompletely understood. Here, by performing single-cell RNA, antigen receptor sequencing and spatial transcriptomics on tumor tissue from head and neck squamous cell carcinoma (HNSCC) patients with different statuses of TLS, we observe that mTLS are enriched with stem-like T cells, and B cells at various maturation stages. Notably, progenitor exhausted CD4+ T cells, with features resembling follicular helper T cells, support these responses, by activating B cells to produce plasma cells in the germinal center, and interacting with DC-LAMP+ dendritic cells to support CD8+ T cell activation. Conversely, non-mTLS tumors do not promote local anti-tumor immunity which is abundant of immunosuppressive cells or a lack of stem-like B and T cells. Furthermore, patients with mTLS manifest improved overall survival and response to ICB compared to those with non-mTLS. Overall, our study provides insights into mechanisms underlying mTLS-mediated intra-tumoral immunity events against cancer.

C-X-C motif chemokine ligand 13 (CXCL13) is a crucial chemokine for the recruitment of immune cells and the formation of tertiary lymphoid structure (TLS) in the tumor microenvironment. However, the relationship between CXCL13 and immune infiltration in cutaneous squamous cell carcinoma (cSCC) remains unclear.

We aimed to investigate the expression of CXCL13 and explore its association with immune activation and TLS in cSCC.

A total of 63 cSCC patients were involved in the present study. Hematoxylin and eosin staining was used for pathological examination of cSCC. Bioinformatics analyses and immunohistochemical staining were employed to access the expression of CXCL13 and TLS states. Public single cell RNA-sequencing atlas of skin disorders and multiplex immunofluorescence were used to explore CXCL13-producing cells.

Utilizing the public database and our clinical cohort, we observed robust CXCL13 expression in cSCC tissues and a significant correlation with immune activation. Higher expression levels of CXCL13 were associated with lower histopathological grades and increased TLS formation. Furthermore, we confirmed that T cells and fibroblasts were the predominant cell types of CXCL13 secretion in cSCC.

CXCL13 is up-regulated in cSCC, which shows a significant positive correlation with immune infiltration and TLS formation. Our results underscore the role of CXCL13 in shaping the cSCC microenvironment, highlighting its potential as a therapeutic target.

Given their rarity and diversity, a fundamental understanding of the genomic underpinnings for many sarcoma subtypes is still lacking. To better define the molecular landscape of this group of diseases, we perform matched whole exome sequencing and RNA sequencing on a cohort of 1340 sarcoma tumor specimens. We identify recurrent somatic mutations and observe an increased mutational burden in metastatic vs. primary samples (p < 0.001). We observe frequent copy number alterations including whole genome doubling, with this feature being more common in metastatic tumors (p = 0.026). Estimation of immune cell abundances followed by hierarchical clustering identifies five immune subtypes ranging from low to high and we observe inferior overall survival in immune deplete clusters compared to immune enriched (p < 0.01). Interestingly, GIST predominantly form a distinct "immune intermediate" cluster that is marked by a specific enrichment for NK cells (FDR < 0.01).

Immune checkpoint inhibitors such as anti-Programmed Death-1 antibodies (aPD-1) can be effective in treating advanced cancers. However, many patients do not respond, and the mechanisms underlying these differences remain incompletely understood. In this study, we profile a cohort of patients with locally advanced or metastatic basal cell carcinoma undergoing aPD-1 therapy using single-cell RNA sequencing, high-definition spatial transcriptomics in tumors and draining lymph nodes, and spatial immunoreceptor profiling, with long-term clinical follow-up. We find that successful responses to PD-1 inhibition are characterized by an induction of B cell receptor (BCR) clonal diversity after treatment initiation. These induced BCR clones spatially colocalize with T cell clones, facilitate their activation, and traffic alongside them between tumor and draining lymph nodes to enhance tumor clearance. Furthermore, we validated aPD-1-induced BCR diversity as a predictor of clinical response in a larger cohort of glioblastoma, melanoma, and head and neck squamous cell carcinoma patients, suggesting that this is a generalizable predictor of treatment response across many types of cancers. We find that pretreatment tumors harbor a characteristic gene expression signature that portends a higher probability of inducing BCR clonal diversity after aPD-1 therapy, and we develop a machine learning model that predicts PD-1-induced BCR clonal diversity from baseline tumor RNA sequencing. These findings underscore a dynamic role of B cell diversity during immunotherapy, highlighting its importance as a prognostic marker and a potential target for intervention in non-responders.

Brain metastases (BrM) are the most common cancers in the brain and linked to poor prognosis. Given the high incidence and often limited treatment options, understanding the complexity of the BrM tumor microenvironment is crucial for the development of novel therapeutic strategies. We performed transcriptome-wide gene expression profiling combined with spatial immune cell profiling to characterize the tumor immune microenvironment in 95 patients with BrM from different primary tumors. We found that BrM from lung carcinoma and malignant melanoma showed overall higher immune cell infiltration as compared to BrM from breast carcinoma. RNA sequencing-based immune cell deconvolution revealed gene expression signatures indicative of tertiary lymphoid structures (TLS) in subsets of BrM, mostly from lung cancer and melanoma. This finding was corroborated by multiplex immunofluorescence staining of immune cells in BrM tissue sections. Detection of TLS signatures was more common in treatment-naïve BrM and associated with prolonged survival after BrM diagnosis in lung cancer patients. Our findings highlight the cellular diversity of the tumor immune microenvironment in BrM of different cancer types and suggest a role of TLS formation for BrM patient outcome.

Cervical tumors are usually treated using surgery, chemotherapy, and radiotherapy and would benefit from immunotherapies. However, the immune microenvironment in cervical cancer remains poorly described. Tertiary lymphoid structures (TLS) were recently described as markers for better immunotherapy response and overall better prognosis in patients with cancer. We evaluated the cervical tumor immune microenvironment, specifically focusing on TLS, using combined high-throughput phenotyping, soluble factor concentration dosage in the tumor microenvironment, and spatial interaction analyses. We found that TLS presence was associated with a more inflammatory soluble microenvironment, with the presence of B cells as well as more activated macrophages and dendritic cells (DC). Furthermore, this myeloid cell activation was associated with the expression of immune checkpoints, such as PD-L1 and CD40, and the proximity of activated conventional type 2 DCs to CD8+ T cells, indicating better immune interactions and tumor control. Finally, we associated TLS presence, greater B-cell density, and activated DC density with improved progression-free survival, substantiating TLS presence as a potential prognostic marker. Our results provide evidence that TLS presence denotes cell activation and immunotherapy target expression.

Soft-tissue sarcomas represent a diverse group of rare malignancies originating from mesenchymal tissue, accounting for less than 1% of adult cancers in the USA. With over 13,000 new cases and around 5350 deaths annually, patients with metastatic soft-tissue sarcomas face limited therapeutic options and an estimated median overall survival of 18 months. While immunotherapy has demonstrated effectiveness in several cancers, its application in soft-tissue sarcomas remains challenging owing to the tumors' largely "cold" immunological environment, characterized by low levels of tumor-infiltrating lymphocytes and a lack of soft-tissue sarcoma-specific biomarkers. This review examines potential mechanisms underlying immunotherapy resistance in soft-tissue sarcomas, including the complex interplay between innate and adaptive immunity, the tumor microenvironment, and the role of immune-related genes. Despite preliminary findings suggesting correlations between immune profiles and histological subtypes, consistent biomarkers for predicting immunotherapeutic responses across soft-tissue sarcoma types are absent. Emerging strategies focus on converting "cold" tumors to "hot" tumors, enhancing their susceptibility to immunologic activation. While research is ongoing, personalized treatment approaches may offer hope for overcoming the inherent heterogeneity and resistance seen in soft-tissue sarcomas, ultimately aiming to improve outcomes for affected patients.

Gastroesophageal junction (GEJ) cancer exhibits unique biological characteristics and currently lacks specific targeted therapies. Given the clinical efficacy of antibody-drug conjugates (ADCs) in solid tumor treatment, we aimed to identify a novel ADC target and suitable payload for GEJ-targeted therapy.

In this study, we conducted bioinformatic analyses of multi-omics data, including transcriptomics, proteomics, and phosphoproteomics, to identify CD66c as a promising ADC target for GEJ cancer. We then engineered a CD66c-directed antibody-drug conjugate (CD66c-DXd) incorporating a GGFG linker. The preclinical efficacy of CD66c-DXd was determined in multi GEJ xenograft models.

Proteomic analyses of 103 cases of GEJ cancer revealed that CD66c expression was significantly higher in tumoral tissues compared to normal tissues. Proteomic and phosphoproteomic analyses identified deruxtecan (DXd) as a potentially potent payload for ADCs targeting GEJ cancer. Furthermore, high CD66c expression in GEJ was associated with a significantly lower proportion of plasma cells. The drug-to-antibody ratio (DAR) of CD66c-DXd was determined to be 3.6. CD66c-DXd effectively and selectively ablated multiple human GEJ cell lines (OE-19, OE33 and SK-GT-4) without affecting non-malignant cells (GES-1) in vitro. Eventually, CD66c-DXd mediated potent and durable tumor regression in vivo with excellent safety profiles.

This preclinical study provides a strong rationale for the further development of CD66c-DXd as promising therapeutic candidates to treat advanced GEJ cancer. Additionally, the study demonstrates the robustness of the multi-omics data in identifying novel potential ADC targets and payloads.

B cells play diverse roles in different pathological circumstances, such as neoplastic diseases, autoimmune disorders, and neurological maladies. B cells, which are essential elements of the adaptive immune system, demonstrate exceptional functional variety, including the generation of antibodies, the presentation of antigens, and the secretion of cytokines. Within the field of oncology, B cells display a multifaceted nature in the tumor microenvironment, simultaneously manifesting both tumor-promoting and tumor-suppressing characteristics. Studies have found that the existence of tertiary lymphoid structures, which consist of B cells, is linked to better survival rates in different types of cancers. This article examines the involvement of B cells in different types of malignancies, emphasizing their importance in the development of the diseases and their potential as biomarkers. Additionally, the review also examines the crucial role of B cells in autoimmune illnesses and their potential as targets for therapy. The article also analyses the role of B cells in immunization and exploring their potential uses in cancer immunotherapy. This analysis highlights the intricate and occasionally contradictory roles of B cells, underlining the necessity for additional research to clarify their varied actions in various illness scenarios.

Immune checkpoint inhibitor (ICI) therapy has been successfully applied to various cancers; however, not all patients respond to ICI therapy. Tumors with an immune-activated environment are highly responsive to ICIs. To identify the cells and molecules essential to the formation of an immune-activated cancer microenvironment, we focused on the tertiary lymphoid structure (TLS) and performed histological and genomic analyses using endometrial cancer material. In the high immunogenic group, numerous TLSs were observed, and CXCL9 and CXCL13 expression was markedly increased. CXCL9-positive antigen-presenting and CXCL13-positive follicular dendritic cells were distributed in the T- and B-cell zones of TLSs, respectively. A group of molecules whose expression was upregulated along with CXCL9 and CXCL13 expression was strongly associated with cellular immunity. These results suggest that CXCL9-expressing antigen-presenting cells and CXCL13-expressing follicular dendritic cells coordinately shape the immune-activated microenvironment through TLS formation. The current findings will contribute to a better understanding of the mechanisms underlying the activated cancer immune microenvironment, thereby advancing the field of precision cancer medicine.

The intratumoral immune milieu is crucial for the success of anti-cancer immunotherapy. We show here that stromal modulation by the tubulin-binding anti-cancer drugs combretastatin A4 (CA-4) and eribulin improved tumor perfusion and anti-tumor immunity. This was achieved by reverting highly proliferative, angiogenic pericytes into a quiescent, contractile state which durably normalized the vascular bed and reduced hypoxia in mouse models of pancreatic neuroendocrine cancer, breast cancer and melanoma. The crucial event in pericyte phenotype switching was RhoA kinase activation, which distinguished CA-4 and eribulin effects from other anti-mitotic drugs such as paclitaxel and vinorelbine. Importantly, eribulin pre-treatment sensitized tumors for adoptive T cell therapy or checkpoint inhibition resulting in effector cell infiltration and better survival outcomes in mice. In breast cancer patients, eribulin neoadjuvant treatment induced pericyte maturity and RhoA kinase activity indicating similar vessel remodeling effects as seen in mice. Moreover, a contractile pericyte signature was associated with overall better survival outcome in two independent breast cancer cohorts. This underscores the potential of re-purposing specific anti-cancer drugs to enable synergistic complementation with emerging immunotherapies.

Soft tissue sarcomas (STSs) are conventionally viewed as poorly immunogenic tumors; however, some human STSs have recently been reported to elicit an immune response, thus representing potential candidates for immunotherapy. Data regarding immune cell infiltrates in canine STSs are limited and reported without tumor-type stratification. The aim of this study was to retrospectively assess tumor-infiltrating lymphocytes (TILs) in canine STSs of 5 different histotypes. Eighty-seven canine STSs were collected: 22 perivascular wall tumors (PWTs), 19 liposarcomas, 17 fibrosarcomas, 16 myxosarcomas, and 13 leiomyosarcomas. The tumors were graded and immunolabeled for CD3, CD20, and FoxP3, and slides were scanned. T-cell, B-cell, Treg, and total TIL densities were quantified with QuPath software and expressed as cells/mm2. The B/T-cells ratio and Treg/T-cell proportions were calculated. Total TIL densities were higher in PWTs and myxosarcomas (median = 225 and 303, respectively). PWTs had higher T-cell density but lower Treg proportion (median = 152 and 7.6% respectively). Myxosarcomas had higher Treg densities and B/T-cell ratios (median = 24.4 and 1.57, respectively). No association with grade was found among STSs as a group. In myxosarcomas, higher grade was significantly associated with higher total TILs, and CD20+ and FoxP3+ cell densities (p < .05). The results suggest that PWTs and myxosarcomas may represent the most immunogenic STS types. Myxosarcomas elicit a B-cell and Treg-rich immune response; PWTs stimulate a T-cell-rich and Treg-poor reaction. The immune system response may contribute to the more aggressive behavior of myxosarcomas and the more indolent course of PWTs.

Dedifferentiated liposarcoma (DDLPS) is one of the most common types of soft tissue sarcoma (STS) characterized by liposarcomatous differentiation and a predilection for the retroperitoneum. Despite the growing number of histology-specific immune checkpoint blockade (ICB) trials in STS, it is still difficult to identify the radiographic objective response rate (ORR) for DDLPS in the real world setting. This study aimed to evaluate the ORR and survival of patients with DDLPS treated with ICB at a single center.

We conducted a retrospective study of 31 patients with pathologically confirmed DDLPS treated with ICB at MD Anderson Cancer Center between 2018 and 2023. Patient demographics, disease characteristics, treatment history, and response to ICB were analyzed. Immunohistochemical analysis was performed on tumor samples to assess immune-related markers.

ORR by RECIST 1.1 was 3.2% (n=1/31). Among all patients (n=31), 6% achieved partial radiographic response, while 39% had stable disease, and 55% showed progressive disease. Median progression-free survival (PFS) was 3.5 (95%CI:1.9, 4.7) months, and overall survival (OS) after ICB initiation was 19.7 (95%CI: 8.8, not reached) months. Patients without prior systemic therapy demonstrated better OS (p=0.004). Immunohistochemistry revealed no relationship between pre- or post-ICB expression of CD8, CD20, CD21 and PDL-1 and response.

While the response to ICB in DDLPS remains limited, specific immune markers may influence treatment outcomes. CD20/21 post-ICB appear more important for prognosis. Further research is warranted to identify predictive factors for ICB efficacy in DDLPS.

Cancer antigen discovery has mostly focused on T cell antigens, while antigens driving B cell responses have been largely overlooked despite representing another important branch of adaptive immune responses in cancer. Traditional B cell antigens in cancer have been studied using serological approaches analyzing polyclonal antibodies in serum. With recent technological advances in single-cell sequencing, a few studies have begun to investigate single B cell antigen specificity in the tumor microenvironment using immunoglobulin single-cell sequencing, recombinant monoclonal antibody production, cancer binding screening, and antigen identification. In this review, we highlight the initial insights into B cell directed cancer antigens and categorize them into cancer-associated viral antigens and non-viral antigens, with the latter featuring autoantigens. We will further discuss the functions of B cells in cancer in the context of their antigen specificity, and categorize their functions into antibody effector function, T cell activation, and B cell secretion. Lastly, we will provide perspectives on the challenges and opportunities in the identification of new B cell cancer antigens and highlight their translational potential.