Tumor-Infiltrating Plasma Cells Are Associated with Tertiary Lymphoid Structures, Cytolytic T-Cell Responses, and Superior Prognosis in Ovarian Cancer

Artificial intelligence-based spatial analysis of tertiary lymphoid structures and clinical significance for endometrial cancer

With the incorporation of immune checkpoint inhibitors into the treatment of endometrial cancer (EC), a deeper understanding of the tumor immune microenvironment is critical. Tertiary lymphoid structures (TLSs) are considered favorable prognostic factors for EC, but the significance of their spatial distribution remains unclear. B cell receptor repertoire analysis performed using six TLS samples located at various distances from the tumor showed that TLSs in distal areas had more shared B cell clones with tumor-infiltrating lymphocytes. To comprehensively investigate the distribution of TLSs, we developed an artificial intelligence model to detect TLSs and determine their spatial locations in whole-slide images. Our model effectively quantified TLSs, and TLSs were detected in 69% of the patients with EC. We identified them as proximal or distal to the tumor margin and demonstrated that patients with distal TLSs (dTLSs) had significantly prolonged overall survival and progression-free survival (PFS) across multiple cohorts [hazard ratio (HR), 0.56; 95% confidence interval (CI), 0.36-0.88; p = 0.01 for overall survival; HR, 0.58; 95% CI, 0.40-0.84; p = 0.004 for PFS]. When analyzed by molecular subtype, patients with dTLSs in the copy-number-high EC subtype had significantly longer PFS (HR, 0.51; 95% CI, 0.29-0.91; p = 0.02). Moreover, patients with dTLSs had a higher response rate to immune checkpoint inhibitors (87.5 vs. 41.7%) and a trend toward improved PFS. Our findings indicate that the functions and prognostic implications of TLSs may vary with their locations, and dTLSs may serve as prognostic factors and predictors of treatment efficacy. This may facilitate personalized therapy for patients with EC.

Dynamic roles of tumor-infiltrating B lymphocytes in cancer immunotherapy

The amazing diversity of B cells within the tumor microenvironment is the basis for the diverse development of B cell-based immunotherapies. Here, we focus on elucidating the mechanisms of tumor intervention mediated by four tumor-infiltrating B lymphocytes. Naive B cells present the initial antigen, germinal center B cell subsets enhance antibody affinity, and immunoglobulin subtypes exert multiple immune effects, while regulatory B cells establish immune tolerance. Together they reflect the complexity of the changing dynamics of cancer immunity. Additionally, we have investigated the dynamic effects of tumor-infiltrating B lymphocytes in immunotherapy and their relationship to prognosis, providing new insights into potential treatment strategies for patients.

Immune evasion in ovarian cancer: implications for immunotherapy and emerging treatments

Ovarian cancer (OC) is the most lethal gynecologic malignancy, characterized by multiple histological subtypes, each with distinct pathological and clinical features. Current treatment approaches include cytotoxic chemotherapies, poly(ADP-ribose) polymerase (PARP) inhibitors, bevacizumab, hormonal therapy, immunotherapy, and antibody-drug conjugates (ADCs). In this review we discuss immune evasion mechanisms in OC and the role of genetics, the tumor microenvironment, and tumor heterogeneity in influencing these processes. We also discuss the use of immunotherapies for OC treatment, either alone or in combination with other anticancer agents, with a focus on their clinical outcomes. Finally, we highlight emerging immunotherapies that have either succeeded or are on the verge of significantly impacting cancer treatment, and we discuss their potential utility in the effective treatment of OC.

Neutrophil extracellular traps promote pre-metastatic niche formation in the omentum by expanding innate-like B cells that express IL-10

Disseminated cancer cells in the peritoneal fluid often colonize omental fat-associated lymphoid clusters but the mechanisms are unclear. Here, we identify that innate-like B cells accumulate in the omentum of mice and women with early-stage ovarian cancer concomitantly with the extrusion of chromatin fibers by neutrophils called neutrophil extracellular traps (NETs). Studies using genetically modified NET-deficient mice, pharmacologic inhibition of NETs, and adoptive B cell transfer show that NETs induce expression of the chemoattractant CXCL13 in the pre-metastatic omentum, stimulating recruitment of peritoneal innate-like B cells that in turn promote expansion of regulatory T cells and omental metastasis through producing interleukin (IL)-10. Ex vivo studies show that NETs elicit IL-10 production in innate-like B cells by inactivating SHP-1, a phosphatase that inhibits B cell activation pathways, and by generating reactive oxygen species. These findings reveal that NETs alter immune cell dynamics in the pre-metastatic omentum, rendering this niche conducive for colonization.

Toll-like receptor agonists promote the formation of tertiary lymphoid structure and improve anti-glioma immunity

BACKGROUND

Glioma, characterized by limited lymphocytic infiltration, constitutes an "immune-desert" tumor displaying insensitivity to various immunotherapies. This study aims to explore therapeutic strategies for inducing tertiary lymphoid structure (TLS) formation within the glioma microenvironment (GME) to transition it from an immune resistant to an activated state.

METHODS

TLS formation in GME was successfully induced by intracranial administration of Toll-like receptor (TLR) agonists (OK-432, TLR2/4/9 agonist) and glioma antigens (i.c. αTLR-mix). We employed staining analysis, antibody neutralization, single-cell RNA sequencing (scRNA-Seq), and BCR/TCR sequencing to investigate the underlying mechanisms of TLS formation and its role in anti-glioma immunity. Additionally, a preliminary translational clinical study was conducted.

RESULTS

TLS formation correlated with increased lymphocyte infiltration in GME and led to improved prognosis in glioma-bearing mice. In the study of TLS induction mechanisms, certain macrophages/microglia and Th17 displayed markers of "LTo" and "LTi" cells, respectively, interaction through LTα/β-LTβR promoted TLS induction. Post-TLS formation, CD4 + and CD8 + T cells but not CD19 + B cells contributed to anti-glioma immunity. Comparative analysis of B/T cells between brain and lymph node showed that brain B/T cells unveiled the switch from naïve to mature, some B cells highlighted an enrichment of class switch recombination (CSR)-associated genes, V gene usage, and clonotype bias were observed. In related clinical studies, i.c. αTLR-mix treatment exhibited tolerability, and chemokines/cytokines assay provided preliminary evidence supporting TLS formation in GME.

CONCLUSIONS

TLS induction in GME enhanced anti-glioma immunity, improved the immune microenvironment, and controlled glioma growth, suggesting potential therapeutic avenues for treating glioma in the future.

Tertiary lymphoid structures and cancer immunotherapy: From bench to bedside

Tertiary lymphoid structures (TLSs) are organized ectopic lymphoid aggregates within the tumor microenvironment that serve as crucial sites for the development of adaptive antitumor cellular and humoral immunity. TLSs have been consistently documented in numerous cancer types, correlating with improved prognosis and enhanced responses to immunotherapy, especially immune-checkpoint blockade (ICB). Given the potential role of TLSs as predictive biomarkers for the efficacy of ICB in cancer patients, the therapeutic manipulation of TLSs is gaining significant attention as a promising avenue for cancer treatment. Herein, we comprehensively review the composition, definition, and detection methods of TLSs in humans. We also discuss the contributions of TLSs to antitumor immunity, their prognostic value in cancer patients, and their association with therapeutic response to ICB-based immunotherapy. Finally, we present preclinical data supporting the potential of therapeutically manipulating TLSs as a promising approach for innovative cancer immunotherapy.

Immune Biomarkers on Tissue Microarray Cores Support the Presence of Adjacent Tertiary Lymphoid Structures in Soft Tissue Sarcoma

Immunotherapy has emerged as a new treatment modality in some soft tissue sarcomas, particularly for tumors associated with tertiary lymphoid structures (TLS). These structures are functional lymphoid aggregates, and their presence is indicative of an active anticancer immune response in the tumor microenvironment. The assessment of TLS as a predictive biomarker at scale on patient specimens remains challenging. While tissue microarrays could facilitate this assessment, it is unclear whether small microarray cores can represent and identify associated TLS responses. We sought to use multiplex immunohistochemistry to identify key components of TLS: T cells, B cells, and dendritic cells. The multiplex panels (CD3, CD20, CD208 and PNAd) were applied onto 80 cases both on tissue microarrays and on their cognate available full-faced sections from epithelioid sarcoma and dedifferentiated/well-differentiated liposarcoma case series. Tissue microarrays were digitally scored for the number of immune cells using the HALO image analysis platform, and cognate full-faced sections were visually evaluated for the presence of TLS. An independent validation set of soft tissue sarcomas (N=49) was stained with the CD3, CD20, and CD208, and scored by QuPath. A Combined Immune Marker (defined as the presence of more than more than 24% CD3+T cell, or 0.51% CD20+B cell, or more than 0.14% CD208+mature dendritic cell on tissue microarray core) is highly specific (100%) and moderately sensitive (61%) to predict the existence of TLS on full-faced sections. The Combined Immune Marker showed a sensitivity of 25% and specificity of 91% on the validation set. The Combined Immune Marker assessed on tissue microarrays is highly specific to infer the presence of TLS present on cognate full-faced sections. Therefore, despite the small area sampled, tissue microarrays may be utilized to assess the clinical value of TLS on datasets where specificity is critical and large sample size can mitigate low to moderate sensitivity.

Chemotherapy Drives Tertiary Lymphoid Structures That Correlate with ICI-Responsive TCF1+CD8+ T Cells in Metastatic Ovarian Cancer

PURPOSE

Patients with high-grade serous ovarian carcinoma (HGSOC) are virtually insensitive to immune checkpoint inhibitors (ICI) employed as standalone therapeutics, at least in part reflecting microenvironmental immunosuppression. Thus, conventional chemotherapeutics and targeted anticancer agents that not only mediate cytotoxic effects but also promote the recruitment of immune effector cells to the HGSOC microenvironment stand out as promising combinatorial partners for ICIs in this oncological indication.

EXPERIMENTAL DESIGN

We harnessed a variety of transcriptomic, spatial, and functional assays to characterize the differential impact of neoadjuvant paclitaxel-carboplatin on the immunological configuration of paired primary and metastatic HGSOC biopsies as compared to neoadjuvant chemotherapy (NACT)-naïve HGSOC samples from five independent patient cohorts.

RESULTS

We found NACT-driven endoplasmic reticulum stress and calreticulin exposure in metastatic HGSOC lesions culminates with the establishment of a dense immune infiltrate including follicular T cells (TFH cells), a prerequisite for mature tertiary lymphoid structure (TLS) formation. In this context, TLS maturation was associated with an increased intratumoral density of ICI-sensitive TCF1+PD1+ CD8+ T cells over their ICI-insensitive TIM-3+PD1+ counterparts. Consistent with this notion, chemotherapy coupled with a PD1-targeting ICI provided a significant survival benefit over either therapeutic approach in syngeneic models of HGSOC bearing high (but not low) tumor mutational burden.

CONCLUSIONS

Altogether, our findings suggest that NACT promotes TLS formation and maturation in HGSOC lesions, de facto preserving an intratumoral ICI-sensitive T-cell phenotype. These observations emphasize the role of rational design, especially relative to the administration schedule, for clinical trials testing chemotherapy plus ICIs in patients with HGSOC. See related commentary by Bravo Melgar and Laoui, p. 10.

Tertiary lymphoid structures in high-grade serous tubo-ovarian carcinoma: anatomical site matters

Tertiary lymphoid structures (TLS) in the tumor microenvironment are prognostically beneficial in many solid cancer types. Reports on TLS in high-grade serous tubo-ovarian carcinoma (HGSC) are few, and the prognostic impact is unclear. We investigated mature TLS (mTLS), immature TLS (iTLS) and lymphoid aggregates (LA) in primary adnexal tumors (PTs) and synchronous omental/peritoneal metastases (pMets) of HGSC. Whole H&E slides were scrutinized for mTLS and LA in a population-based cohort of 130 cases with stage III-IV HGSC. The immune cell tumor infiltration was evaluated with single chromogenic immunohistochemistry (IHC) on a tissue microarray (TMA) from the same cases. Selected whole slides (PT n = 11, pMet n = 10) of the cases most abundant in mTLS and LA were further investigated with multiplex IHC and immunofluorescence using digital image analysis (QuPath), to confirm TLS status and map the T and B lymphocyte subtypes. The results showed that mTLS were more common in pMets than in PTs but did not have an independent prognostic impact on overall or progression-free survival. The presence of mTLS correlated with intratumoral infiltration of CD8+ cytotoxic T cells, FOXP3+ regulatory T cells and PD-1+ lymphocytes in pMets only. Although overall mTLS cell composition was similar between PTs and pMets, the outer zones of mTLS in PTs were more immune cell-rich. In conclusion, our results indicate differences in TLS presence and cellular elements between primary adnexal tumors and synchronous peritoneal metastases, which are important to consider when conducting studies of the immune environment in HGSC.

Lympho-myeloid aggregate-infiltrating CD20+ B cells display a double-negative phenotype and correlate with poor prognosis in esophageal squamous cell carcinoma

According to morphological features, tumor-infiltrating B cells (TIL-Bs) can be classified as lympho-myeloid aggregates (LMAs) and tertiary lymphoid structures (TLSs). As a disease with high incidence and mortality, research on esophageal squamous cell carcinoma (ESCC) TIL-Bs is still unclear. Thus, we aimed to investigate the prognostic value and functional involvement of TIL-Bs in ESCC. Based on CD20 immunohistochemical staining of 147 ESCC samples, the TIL-Bs at different anatomic subregions (intra-tumor (T), invasive margin (IM) and peri-tumor (P)) were quantified and correlated with survival by Kaplan-Meier analyses. We found that LMAs were widely distributed throughout the whole section and were associated with poor prognosis, especially those located in the T subregion, which was contrary to the positive clinical significance of TLSs. Based on the number of LMAs and TLSs, a four-level immune type was constructed as an independent predictor for survival. Using multiplexed immunofluorescence (mIF) staining, we found that the main phenotype of infiltrating B cells in LMAs was CD20+IgD-CD27- double-negative (DN) B cells. DN B cells were abundant in ESCC tumor tissue, and their high expression was related to shortened overall survival time. Subsequently, we demonstrate a close relationship between DN B cells and regulatory T cells (Tregs) using single cell RNA-seq data, bulk RNA-seq data and flow cytometry, and verified the spatial proximity of DN B cells and Tregs by mIF staining. Trajectory analysis and flow cytometry revealed that DN B cells highly expressed genes involved in the antigen processing and presentation pathway, such as HLA-DR. The abundance of DN B cells and LMAs in ESCC provides novel potential targets for optimal immunotherapy against ESCC.

Method Development for Sorting Immune Cell Populations Within Tertiary Lymphoid Structures

The tumor microenvironment is a complex network of interacting cells composed of immune and nonimmune cells. It has been reported that the composition of the immune contexture has a significant impact on tumor growth and patient survival in different solid tumors. For instance, we and other groups have previously demonstrated that a strong infiltration of T-helper type 1 (Th1), memory CD8+ T cells, and immune cells organized into tertiary lymphoid structures is associated with the long-term survival of cancer patients. Nevertheless, the prognostic value of the other immune populations, namely regulatory T cells (Treg), B cells, and gamma-delta (γδ) T cells remains a matter of debate. Herein, we describe novel flow cytometry-based strategies to sort out these different immune populations to evaluate their role in non-small-cell lung cancer (NSCLC).

Laser Capture Microdissection of Tertiary Lymphoid Structures from Formalin-Fixed Paraffin-Embedded Sections of Canine Cutaneous and Subcutaneous Sarcomas for NanoString Direct RNA Counting

Laser capture microdissection (LCM) of formalin-fixed, paraffin-embedded sections is a way to analyze gene expression of morphologically distinct areas of tissue, as microscopically visualized with stained tissue sections. Herein, I describe a method for laser dissecting lymphoid aggregates in canine cutaneous and subcutaneous sarcomas and their adjacent sarcoma tissue to determine the differential expression of RNA as determined by NanoString® nCounter technology. Canine soft tissue sarcomas (STS) are diversely derived mesenchymal neoplasms that, regardless of exact histogenesis, behave similarly and thus have been grouped together as a diagnostic entity. The risk of recurrence and/or metastasis depends on the extent of surgical excision and histologic grade. Lymphoid aggregates are described in these tumors but have not been characterized. In humans, lymphoid aggregates characterized as tertiary lymphoid structures (TLS) improve the prognosis of several tumors, including sarcomas. We sought to determine if RNA expressed by lymphoid aggregates in canine sarcomas was compatible with TLS RNA expression. This chapter describes tissue preparation, staining, laser capture microdissection, and RNA isolation in preparation for digital RNA counting.

Automated Quantification of Tertiary Lymphoid Structures in Human Tumor Samples Using Immunofluorescence and AI-Powered Analysis Pipeline

The tumor microenvironment (TME) is a complex entity comprising not only tumor cells but also immune, stromal, and endothelial cells. Preclinical and clinical studies indicate that the density, localization, function, and organization of immune infiltration can influence survival probability and treatment response in many cancers. Among these cell organizations, the clustering of T and B cells into tertiary lymphoid structures (TLS) has been associated with favorable clinical outcomes. In this protocol, we propose a protocol for 7-plex immunofluorescence staining for identifying six cell types enriched in TLS in formalin-fixed paraffin-embedded (FFPE) human tumor sections. Additionally, we provide a detailed methodology for quantifying these cell subtypes using the Halo-AI analysis software. This approach will enable a more precise and detailed characterization of TLS in the TME, opening new avenues for understanding their role in anticancer treatment response.

An Introduction to Tertiary Lymphoid Structures in Cancer

Immunotherapy has revolutionized therapeutics for cancer patients, which signifies the importance of effective antitumor immunity in combatting cancer. However, the benefit of immunotherapies is limited to specific patient populations and tumor types, suggesting the overt need for new immunotherapeutic targets. Tertiary lymphoid structures (TLS) are ectopic lymph node-like structures that develop at the sites of chronic inflammation such as cancer. TLS are correlated with favorable clinical outcomes across multiple solid tumors and are associated with increased tumor-infiltrating lymphocytes (TILs), particularly effector memory CD8+ T cells. Despite strong clinical data in humans, there are still major knowledge gaps on the function of TLS in cancer. Herein, we highlight the known biology and clinical impact of TLS, which offer further evidence to harness TLS for improved immunotherapeutics.

Maturation of Tertiary Lymphoid Structures

Tertiary lymphoid structures (TLS) are organized collections of B and T lymphocytes that arise in nonlymphoid tissue in response to chronic, unresolved inflammation. TLS have structural and functional similarities to germinal centers found in lymph nodes and are believed to support the establishment of lymph node-like adaptive immune responses at local sites of inflammation. However, understanding of the underlying biology of these structures remains limited, particularly the different stages of TLS life cycle and the signals governing the initiation, maturation, and termination of TLS. Here, we review current understanding of the maturation of TLS and the signals and cell types involved in various stages of development with particular emphasis on recent studies of TLS in cancer, where evidence suggests that TLS may play an important role in supporting antitumor immune responses in solid tumors.

Tertiary Lymphoid Structures are Linked to Enhanced Antitumor Immunity and Better Prognosis in Muscle-Invasive Bladder Cancer

The prognosis for muscle-invasive bladder cancer (MIBC) remains poor, and reliable prognostic markers have yet to be identified. Tertiary lymphoid structures (TLS) have been associated with favorable outcomes in certain cancers. However, the relationship between TLS and MIBC remains unclear. A multi-omics approach is utilized, leveraging single-cell RNA sequencing, spatial transcriptomics, bulk RNA sequencing, and immunohistochemistry, to investigate the roles of B cells and TLS in MIBC. These findings indicate that elevated levels of B cells and TLS correlate with improved prognoses in patients with MIBC, aligning with the robust antitumor immune responses observed in the TLS region. From a mechanistic perspective, CXCL13 serves as a critical cytokine for TLS formation in MIBC, primarily secreted by clonally expanded CXCL13+ T cells. This cytokine interacts with the CXCR5 receptor on NR4A2+ B cells, promoting TLS development. Plasma cells arising within the TLS microenvironment predominantly produce the IGHG antibody, potentially enhancing the phagocytic capabilities of C1QC+ macrophages. From an application standpoint, a TLS-specific gene signature is developed that effectively predicts outcomes in MIBC and other cancers. This study highlights the prognostic potential of TLS in MIBC and reveals immune mechanisms, offering insights for personalized treatment strategies.

Identification of B Cell Subpopulations with Pro- and Anti-Tumorigenic Properties in an Immunocompetent Mouse Model of Head and Neck Squamous Cell Carcinoma

Due to their high developmental diversity and different regulatory and functional roles, B cell subpopulations can promote or inhibit tumor growth. An orthotopic murine HNSCC model was applied to investigate the B cell composition and function in HNSCCs. Using flow cytometry approaches, cells from the spleen, lymph nodes and tumors were analyzed. Additionally, immunoglobulin (Ig) levels post-tumor induction were tracked via enzyme-linked immunosorbent assays (ELISA). Following tumor induction, GCs, as well as increasing numbers of GL7+CD95+ GC B cells in the spleen and tumor tissues, were detected. In parallel, we observed CD39+CD73+ B cells in tumors and spleens of tumor-bearing mice. Notably, CD39+CD73+ expression was primarily detected on MZ B cells and to a lesser extent on follicular (FO) and non-follicular, newly formed (NF) B cells, supposing an immunosuppressive function of MZ B cells in the TME. Parallel to increased MZ B cell numbers in secondary lymphoid organs (SLOs) as well as in the tumor tissue, IgM antibody (Ab) levels rose continuously. In contrast, IgG1, IgG2, and IgG3 levels increased at later time points. Understanding the complex interactions between B cell subsets and the TME could lead to new strategies for enhancing the treatment and prognosis of HNSCC patients.

Ovarian cancer-derived IL-4 promotes immunotherapy resistance

Ovarian cancer is resistant to immunotherapy, and this is influenced by the immunosuppressed tumor microenvironment (TME) dominated by macrophages. Resistance is also affected by intratumoral heterogeneity, whose development is poorly understood. To identify regulators of ovarian cancer immunity, we employed a spatial functional genomics screen (Perturb-map), focused on receptor/ligands hypothesized to be involved in tumor-macrophage communication. Perturb-map recapitulated tumor heterogeneity and revealed that interleukin-4 (IL-4) promotes resistance to anti-PD-1. We find ovarian cancer cells are the key source of IL-4, which directs the formation of an immunosuppressive TME via macrophage control. IL-4 loss was not compensated by nearby IL-4-expressing clones, revealing short-range regulation of TME composition dictating tumor evolution. Our studies show heterogeneous TMEs can emerge from localized altered expression of cancer-derived cytokines/chemokines that establish immune-rich and immune-excluded neighborhoods, which drive clone selection and immunotherapy resistance. They also demonstrate the potential of targeting IL-4 signaling to enhance ovarian cancer response to immunotherapy.

Development of a prognostic model based on lysosome-related genes for ovarian cancer: insights into tumor microenvironment, mutation patterns, and personalized treatment strategies

BACKGROUND

Ovarian cancer (OC) is often associated with an unfavorable prognosis. Given the crucial involvement of lysosomes in tumor advancement, lysosome-related genes (LRGs) hold promise as potential therapeutic targets.

METHODS

To identify differentially expressed lysosome-related genes (DE-LRGs), we performed a matching analysis between differentially expressed genes (DEGs) in OC and the pool of LRGs. Genes with prognostic significance were analyzed using multiple regression analyses to construct a prognostic risk signature. The model's efficacy was validated through survival analysis in various cohorts. We further explored the model's correlation with clinical attributes, tumor microenvironment (TME), mutational patterns, and drug sensitivity. The quantitative real-time polymerase chain reaction (qRT-PCR) validated gene expression in OC cells.

RESULTS

A 10-gene prognostic risk signature was established. Survival analysis confirmed its predictive accuracy across cohorts. The signature served as an independent prognostic element for OC. The high-risk and low-risk groups demonstrated notable disparities in terms of immune infiltration patterns, mutational characteristics, and sensitivity to therapeutic agents. The qRT-PCR results corroborated and validated the findings obtained from the bioinformatic analyses.

CONCLUSIONS

We devised a 10-LRG prognostic model linked to TME, offering insights for tailored OC treatments.

Immune-molecular interactions in high-grade serous ovarian cancer distinguish long-term survivors

The approach and efficacy of treatments for high-grade serous carcinoma (HGSC) of the ovary have changed little in decades. Although numerous studies demonstrated immune infiltration as frequent and prognostically beneficial, clinical trials of immunotherapies have generated benefit in fewer than 15% of patients. In this issue of the JCI, Nelson and colleagues compiled 1,233 HGSC samples from patients across four continents and compared the molecular and immunologic features that associate with long-term survival (greater than 10 years). Diversity among HGSC tumors is well defined, but this study explored the combined influence of immunologic and molecular features. Long-term survivors harbored tumors with high epithelial content and overrepresentation of the C4/differentiated molecular signature, with cytotoxic T and B cells infiltrating to the tumor epithelium and stroma, respectively. These findings highlight features that might underly poor responsiveness to existing immunotherapies of most HGSC tumors and considerations for the design of future, more precise treatments for HGSC.

Spatial Dynamics of T- and B-Cell Responses Predicts Clinical Outcome of Resectable and Unresectable Hepatocellular Carcinoma

PURPOSE

Immunotherapies have led to a paradigm shift in the treatment of hepatocellular carcinoma (HCC). Studies have revealed the single-cell catalogs of tumor-infiltrating immune cells and the trajectories of their differentiation. Nevertheless, the spatial distribution of these immune cells with distinct phenotypes in the tumor microenvironment and their clinicopathologic significance in resectable and unresectable HCCs are still largely unclear.

EXPERIMENTAL DESIGN

We analyzed the spatial dynamics of intratumoral CD4 and CD8 T cells and their association with B and plasma cells using 283 surgically resected HCC samples, 58 unresectable HCC samples before combined immunotherapy [atezolizumab plus bevacizumab (Atezo + Bev)], and autopsy specimens from 50 cases of advanced-stage HCC through multiplex IHC combined with transcriptomic and driver gene mutation analyses. Classification based on the spatial dynamics of T- and B-cell responses (refined immunosubtype) was developed, and its clinicopathologic significance was analyzed.

RESULTS

We found that stem-like CD4 and CD8 T cells were mainly observed in T-cell aggregates and T-cell zone of tertiary lymphoid structure (TLS). The differentiation of T follicular helper cells was associated with the development of TLS, whereas the differentiation of CXCL13-expressing CD4 TCXCL13 cells with a phenotype resembling T peripheral helper cells was associated with the development of the lymphoplasmacytic microenvironment. The refined immunosubtype could predict clinical outcomes of resectable HCC after surgery and unresectable HCC after Atezo + Bev therapy. The immune microenvironment of metastatic lesions tended to reflect those of primary lesions.

CONCLUSIONS

We revealed the spatial dynamics of T- and B-cell responses in HCC, which is closely associated with the clinical outcome after surgical resection or Atezo + Bev therapy.

Single-Nucleus and Spatial Transcriptome Profiling Delineates the Multicellular Ecosystem in Hepatocellular Carcinoma After Hepatic Arterial Infusion Chemotherapy

Hepatic arterial infusion chemotherapy (HAIC) has emerged as a promising treatment strategy for hepatocellular carcinoma (HCC), but a detailed understanding of the multicellular ecosystem after HAIC treatment is lacking. Here, we collected tumor samples from treatment-naïve primary and post-HAIC HCC, and integrated single-nucleus RNA sequencing with spatial transcriptomics to characterize the tumor ecosystem in the post-HAIC HCC. Increased fractions and enhanced cellular communication of CD4+ T, CD20+ B, and dendritic cell subtypes were identified in post-HAIC tumors. Moreover, it is substantiated that HAIC promoted tertiary lymphoid structures (TLS) formation, and addressed the roles of TLSs as spatial niches of cellular communication. Specifically, intermediate exhausted CD8+ T cells expressing Granzyme-K and PD-1 (PD-1+CD8+ Tex-int) expanded following HAIC and exhibited a functionally antitumor phenotype. PD-1+CD8+ Tex-int accumulated in the TLS vicinity and disseminated throughout the tumor microenvironment, demonstrating potential as an effective biomarker for HAIC-based treatment in HCC. This study provides valuable resources and biological insights in the cellular underpinnings of HAIC treatment.

TLS and immune cell profiling: immunomodulatory effects of immunochemotherapy on tumor microenvironment in resectable stage III NSCLC

Background

The use of programmed death-1 (PD-1) inhibitors in the neoadjuvant setting for patients with resectable stage III NSCLC has revolutionized this field in recent years. However, there is still 40%-60% of patients do not benefit from this approach. The complex interactions between immune cell subtypes and tertiary lymphoid structures (TLSs) within the tumor microenvironment (TME) may influence prognosis and the response to immunochemotherapy. This study aims to assess the relationship between immune cells subtypes and TLSs to better understand their impact on immunotherapy response.

Methods

This study initially compared the tertiary lymphoid structures (TLSs) density among patients who underwent immunochemotherapy, chemotherapy and upfront surgery using 123 tumor samples from stage-matched patients. Multiplex immunohistochemistry (mIHC) was employed to analyze the spatial distribution of PD-L1+CD11c+ cells and PD1+CD8+ T cells within TLSs. Cytometry by time-of-flight (CyTOF) was used to assess immune cell dynamics in paired biopsy and resection specimens from six patients who underwent immunochemotherapy. Key immune cells were validated in newly collected samples using flow cytometry, mIHC, and in vitro CAR-T cells model.

Results

Patients who underwent neoadjuvant chemotherapy or immunochemotherapy exhibited increased TLSs compared to those who opted for upfront surgery. The TLS area-to-tumor area ratio distinguished pCR+MPR and NR patients in the immunochemotherapy group. Spatial analysis revealed variations in the distance between PD-L1+CD11c+ cells and PD1+CD8+ T cells within TLSs in the immunochemotherapy group. CyTOF analysis revealed an increase in the frequency of key immune cells (CCR7+CD127+CD69+CD4+ and CD38+CD8+ cells) following combined therapy. Treatment responders exhibited an increase in CCR7+CD4+ T cells, whereas CD38+CD8+ T cells were associated with compromised treatment effectiveness.

Conclusions

Immunochemotherapy and chemotherapy increase TLSs and granzyme B+ CD8+ T cells in tumors. The TLS area-to-tumor ratio distinguishes responders from non-responders, with PD-L1+ dendritic cells near CD8+PD-1+ T cells linked to efficacy, suggesting that PD-1 inhibitors disrupt harmful interactions. Post-immunochemotherapy, CD8+ T cells increase, but CD38+CD8+ T cells show reduced functionality. These findings highlight the complex immune dynamics and their implications for NSCLC treatment.

Plasticity and Tumor Microenvironment in Pancreatic Cancer: Genetic, Metabolic, and Immune Perspectives

Cancer has long been believed to be a genetic disease caused by the accumulation of mutations in key genes involved in cellular processes. However, recent advances in sequencing technology have demonstrated that cells with cancer driver mutations are also present in normal tissues in response to aging, environmental damage, and chronic inflammation, suggesting that not only intrinsic factors within cancer cells, but also environmental alterations are important key factors in cancer development and progression. Pancreatic cancer tissue is mostly comprised of stromal cells and immune cells. The desmoplasmic microenvironment characteristic of pancreatic cancer is hypoxic and hypotrophic. Pancreatic cancer cells may adapt to this environment by rewiring their metabolism through epigenomic changes, enhancing intrinsic plasticity, creating an acidic and immunosuppressive tumor microenvironment, and inducing noncancerous cells to become tumor-promoting. In addition, pancreatic cancer has often metastasized to local and distant sites by the time of diagnosis, suggesting that a similar mechanism is operating from the precancerous stage. Here, we review key recent findings on how pancreatic cancers acquire plasticity, undergo metabolic reprogramming, and promote immunosuppressive microenvironment formation during their evolution. Furthermore, we present the following two signaling pathways that we have identified: one based on the small G-protein ARF6 driven by KRAS/TP53 mutations, and the other based on the RNA-binding protein Arid5a mediated by inflammatory cytokines, which promote both metabolic reprogramming and immune evasion in pancreatic cancer. Finally, the striking diversity among pancreatic cancers in the relative importance of mutational burden and the tumor microenvironment, their clinical relevance, and the potential for novel therapeutic strategies will be discussed.

B cells spatial organization defines their phenotype and function in cancer "Tell me with whom you consort, and I will tell you who you are" - Goethe

The presence of B cells and their subtypes in the tumor environment has been recognized a for very long time. Immunoglobulins specific for more than thousands of tumor-associated antigens were detected in the sera of patients with cancer; however, antibody-mediated cancer cell killing is usually impaired. The role of humoral immune response remained elusive until recently, with new discoveries regarding their contribution in regulating antitumor immunity, particularly during immunotherapy. Humoral immunity has been described to promote or attenuate tumorigenesis and can have opposing effects on therapeutic outcome in different tumor entities. The antagonism effect of B cells depends on their subtypes and immunoglobulin isotypes and is regulated by their spatial distribution and localization. In this short review, we will focus on how the spatial organization of B cells within the tumor microenvironment, tumor-associated lymph nodes, and tertiary lymphoid structures define their fate and function and contribute to the regulation of antitumor immunity.

Single-cell sequencing reveals PTX3 involvement in ovarian cancer metastasis

BACKGROUND

Pentraxin 3 (PTX3) has been associated with the development and progression of various malignant tumors. However, its roles and the mechanisms underlying its involvement in ovarian cancer (OC) peritoneal metastasis remain unclear.

METHODS

Single-cell RNA sequencing (scRNA-seq) and immunohistochemistry (IHC) were conducted to determine the expression profiles, potential functionalities, and underlying mechanisms of PTX3 within the context of OC. To assess the proliferative response of OC cells, we utilized both EdU (5-ethynyl-2' -deoxyuridine) and CCK8 assays. The role of PTX3 in facilitating cell migration and invasion was quantified through the use of Transwell assays. The protein expression levels were meticulously analyzed via Western blotting. Furthermore, to explore the interactions between proteins, we conducted immunofluorescence (IF) staining and co-immunoprecipitation (Co-IP) experiments. To determine the factors responsible for the upregulation of PTX3, we performed both coculture and suspension assays, providing a comprehensive approach to understanding the regulatory mechanisms involved.

RESULTS

This study confirmed, for the first time, that the expression of PTX3 in OC metastatic lesions is greater than that in primary lesions and that tumor cells with high PTX3 expression have greater metastatic ability. PTX3 can activate the EMT and NF-κB signaling pathways in OC cells and can interact with the TLR4 and CD44 receptors in OC cells. Additionally, PTX3's modulation of the EMT and NF-κB pathways is partially dependent on its interaction with TLR4. Furthermore, this study revealed the intercellular regulatory network related to PTX3 in OC cells via bioinformatic analysis. High levels of PTX3 in OC cells potentially enhance the attraction of dendritic cells (DCs) and CD4 + T cells while diminishing the recruitment of B cells and CD8 + T cells. Finally, this study indicated that PTX3 upregulation was driven by multiple factors, including specific transcription factors (TFs) and modifications within the tumor microenvironment (TME).

CONCLUSIONS

Our research revealed the contribution of PTX3 to the peritoneal dissemination process in OC patients, identifying a novel potential biomarker and therapeutic target for this disease.

Research trends, hotspots and future directions of tertiary lymphoid structures in cancer: a comprehensive informatics analysis and visualization study

Many studies have reported the presence of tertiary lymphoid structures (TLSs) in cancer, but the research progress of TLSs in cancer has not been systematically analyzed. Therefore, we analyzed the global scientific knowledge in the field using informatics methods. The results showed that TLSs in cancer have received increasing attention since the 21st century, with an annual publication growth rate of 27.86%. Unsupervised hierarchical clustering based on machine learning further categorized the research features into four clusters, with the cluster related to immunotherapy being considered an emerging cluster. TLSs and immunotherapy were identified as the top two hotspots with the highest occurrence frequency and total link strength. The Walktrap algorithm indicated that "TLSs, carcinoma, prognostic value" and "high endothelial venules, germinal-centers, node-like structures" are important to TLSs but remain underexplored, representing promising research directions. These findings suggest that cancer-related TLSs have brought new insights into antitumor immunity, and targeting TLSs has the potential to transform the landscape of antitumor immunotherapy.

The activity of tertiary lymphoid structures in high grade serous ovarian cancer is governed by site, stroma, and cellular interactions

Most high grade serous ovarian cancers (HGSOC) originate in the fallopian tube but spread to the ovary and peritoneal cavity, highlighting the need to understand antitumor immunity across HGSOC sites. Using spatial analyses, we discover that tertiary lymphoid structures (TLSs) within ovarian tumors are less developed compared with TLSs in fallopian tube or omental tumors. We reveal transcriptional differences across a spectrum of lymphoid structures, demonstrating that immune cell activity increases when residing in more developed TLSs and produce a prognostic, spatially derived TLS signature from HGSOC tumors. We interrogate TLS-adjacent stroma and assess how normal mesenchymal stem cells MSCs (nMSCs) may support B cell function and TLS, contrary to cancer-educated MSCs (CA-MSCs) which negate the prognostic benefit of our TLS signature, suggesting that pro-tumorigenic stroma could limit TLS formation.

Tertiary lymphoid structures in ovarian cancer

Ovarian cancer (OC) is a significant cause of cancer-related mortality in women worldwide. Despite advances in treatment modalities, including surgery and chemotherapy, the overall prognosis for OC patients remains poor, particularly for patients with advanced or recurrent disease. Immunotherapy, particularly immune checkpoint blockade (ICB), has revolutionized cancer treatment in various malignancies but has shown limited efficacy in treating OC, which is primarily attributed to the immunologically. Tertiary lymphoid structures (TLSs), which are ectopic aggregates of immune cells, have emerged as potential mediators of antitumor immunity. This review explores the composition, formation, and induction of tumor associated TLS (TA-TLS) in OC, along with their role and therapeutic implications in disease development and treatment. By elucidating the roles TA-TLSs and their cellular compositions played in OC microenvironment, novel therapeutic targets may be identified to overcome immune suppression and enhance immunotherapy efficacy in ovarian cancer.

Tertiary lymphoid structures in endometriosis

OBJECTIVE

To determine whether tertiary lymphoid structures (TLSs), which reflect organized immune cell aggregates present in non-lymphoid tissues, are consistent features of endometriosis lesions.

DESIGN

Detailed histopathological analysis of endometrial and lesion tissue from patients with endometriosis and controls was performed. Multiplex immunofluorescence on select samples was then conducted to identify canonical cell populations present within TLSs: CD3+ and CD8+ T-cells, CD79a+ B-cells, CD208+ dendritic cells, CD21+ follicular dendritic cells, and PNAd+ high endothelial venules.

PATIENT(S)

Patients with histologically confirmed endometriosis (N = 113; 44.3 ± 6.0) and control individuals (N = 110; 44.6 ± 7.1).

INTERVENTION

Not applicable.

MAIN OUTCOME MEASURE(S)

Detection of TLSs as characterized by the presence of all canonical cell types that constitute TLS and structure morphology.

RESULT(S)

Of the selected samples (N = 18; 6 ectopic/eutopic/control), mature TLSs were identified in 3 ectopic tissue samples present on the ovary and fallopian tube, with immature TLSs (lacking follicular dendritic cell networks and high endothelial venules) present throughout eutopic and control endometrial samples.

CONCLUSION

These findings demonstrate the presence of TLSs across various endometriosis phenotypes, prompting further research into their significance within disease pathophysiology and the prognostic implications for patients.

Lymphoid Aggregates in Canine Cutaneous and Subcutaneous Sarcomas: Immunohistochemical and Gene Expression Evidence for Tertiary Lymphoid Structures

Canine cutaneous/subcutaneous soft-tissue sarcomas (STS) are diversely derived mesenchymal neoplasms with a risk of recurrence and/or metastasis depending on the extent of surgical excision and histologic grade. Lymphoid aggregates (LAs) are often described in these tumours but not characterised. In humans, LA characterised as tertiary lymphoid structures (TLSs) improve the prognosis of many tumours, including sarcomas. We sought to determine if LA meeting a size criterion (> 700 cells) in canine sarcomas met the criteria of TLS and the overall prevalence of LA of any size. RNA expression in large LAs versus aggregate-adjacent sarcoma tissue (AAS) was measured in laser capture microdissected tissue and compared to curl-derived RNA from aggregate-free sarcomas and lymph nodes. CD3, CD20, MUM-1 and PNAd expressions were measured using immunohistochemistry. CD20 and CD3 mRNA were more highly expressed in LA versus AAS (13.8 fold, p = 0.0003 and 2.3 fold, p = 0.043). This was supported by the IHC findings. The large LAs were also enriched in chemokine RNA expression characteristic of TLS (CXCR5 5.8 fold, p < 00001, CCL19 3.68 fold, p = 0.0209, CCL21 6.87 fold, p = 0.0209 and CXCL13 2.68 fold, p = 0.0924). Plasma cells and high endothelial venules were identified in LA containing tumours but not in control tissue. Large LAs were present in 12% of tumours, and LA of any size in 30%. We conclude that large LAs in canine STS are consistent with TLS.

Tertiary lymphoid structures as potential biomarkers for cancer prediction and prognosis

Tertiary lymphoid structures (TLSs) are ectopic lymphocyte aggregates formed in non-lymphoid tissues, including cancers, and are loci for the generation of in situ anti-tumor immune responses, which play a crucial role in cancer control. The state of TLS presence in cancer and its composition can significantly impact the treatment response and prognosis of patients. TLSs have the potential to serve as predictive and prognostic biomarkers for cancer. However, the mechanisms underlying TLS formation in cancer and how the essential components of TLSs affect cancer are not fully understood. In this review, we summarized TLS formation in cancer, the value of the TLS in different states of existence, and its key constituents for cancer prediction and prognosis. Finally, we discussed the impact of cancer treatment on TLSs.

Proteomic and transcriptomic analyses identify apo-transcobalamin-II as a biomarker of overall survival in osteosarcoma

Background

The large-scale proteomic platform known as the SomaScan® assay is capable of simultaneously measuring thousands of proteins in patient specimens through next-generation aptamer-based multiplexed technology. While previous studies have utilized patient peripheral blood to suggest serum biomarkers of prognostic or diagnostic value in osteosarcoma (OSA), the most common primary pediatric bone cancer, they have ultimately been limited in the robustness of their analyses. We propose utilizing this aptamer-based technology to describe the systemic proteomic milieu in patients diagnosed with this disease.

Methods

To determine novel biomarkers associated with overall survival in OSA, we deployed the SomaLogic SomaScan® 7k assay to investigate the plasma proteomic profile of naive primary, recurrent, and metastatic OSA patients. Following identification of differentially expressed proteins (DEPs) between 2-year deceased and survivor cohorts, publicly available databases including Survival Genie, TIGER, and KM Plotter Immunotherapy, among others, were utilized to investigate the significance of our proteomic findings.

Results

Apo-transcobalamin-II (APO-TCN2) was identified as the most DEP between 2-year deceased and survivor cohorts (Log2 fold change = 6.8, P-value = 0.0017). Survival analysis using the Survival Genie web-based platform indicated that increased intratumoral TCN2 expression was associated with better overall survival in both OSA (TARGET-OS) and sarcoma (TCGA-SARC) datasets. Cell-cell communication analysis using the TIGER database suggested that TCN2+ Myeloid cells likely interact with marginal zone and immunoglobin-producing B lymphocytes expressing the TCN2 receptor (CD320) to promote their proliferation and survival in both non-small cell lung cancer and melanoma tumors. Analysis of publicly available OSA scRNA-sequencing datasets identified similar populations in naive primary tumors. Furthermore, circulating APO-TCN2 levels in OSA were then associated with a plasma proteomic profile likely necessary for robust B lymphocyte proliferation, infiltration, and formation of intratumoral tertiary lymphoid structures for improved anti-tumor immunity.

Conclusions

Overall, APO-TCN2, a circulatory protein previously described in various lymphoproliferative disorders, was associated with 2-year survival status in patients diagnosed with OSA. The relevance of this protein and apparent immunological function (anti-tumor B lymphocyte responses) was suggested using publicly available solid tumor RNA-sequencing datasets. Further studies characterizing the biological function of APO-TCN2 and its relevance in these diseases is warranted.

Unlocking the potential of immunotherapy in platinum-resistant ovarian cancer: rationale, challenges, and novel strategies

Ovarian cancer is a significant global health challenge, with cytoreductive surgery and platinum-based chemotherapy serving as established primary treatments. Unfortunately, most patients relapse and ultimately become platinum-resistant, at which point there are limited effective treatment options. Given the success of immunotherapy in inducing durable treatment responses in several other cancers, its potential in platinum-resistant ovarian cancer (PROC) is currently being investigated. However, in unselected advanced ovarian cancer populations, researchers have reported low response rates to immune checkpoint inhibition, and thus far, no validated biomarkers are predictive of response. Understanding the intricate interplay between platinum resistance, immune recognition, and the tumour microenvironment (TME) is crucial. In this review, we examine the research challenges encountered thus far, the biological rationale for immunotherapy, the underlying mechanisms of immune resistance, and new strategies to overcome resistance.

Tertiary Lymphoid Structures in Microorganism-Related Cancer

Tertiary lymphoid structures (TLSs) are ectopic lymphoid tissues formed by the accumulation of lymphocytes and other components outside lymphoid organs. They have been shown to be widespread in cancers and have predictive effects on prognosis and immunotherapy efficacy; however, there is no standardized measurement guide. This paper provides a reference for future research. Moreover, the induction strategy for the formation mechanism of TLSs is a new direction for future cancer treatment, such as cancer vaccines for microorganisms. The effects of microorganisms on cancer are dual. The role of microorganisms, including bacteria, parasites, viruses, and fungi, in promoting cancer has been widely confirmed. However, the specific mechanism of their tumor suppressor effect, particularly the promotion of TLS formation, is currently unknown. In this review, we summarize the role of TLSs in cancer related to microbial infection and provide new ideas for further understanding their mechanisms of action in cancer.

Genomic instability as a driver and suppressor of anti-tumor immunity

Genomic instability is a driver and accelerator of tumorigenesis and influences disease outcomes across cancer types. Although genomic instability has been associated with immune evasion and worsened disease prognosis, emerging evidence shows that genomic instability instigates pro-inflammatory signaling and enhances the immunogenicity of tumor cells, making them more susceptible to immune recognition. While this paradoxical role of genomic instability in cancer is complex and likely context-dependent, understanding it is essential for improving the success rates of cancer immunotherapy. In this review, we provide an overview of the underlying mechanisms that link genomic instability to pro-inflammatory signaling and increased immune surveillance in the context of cancer, as well as discuss how genomically unstable tumors evade the immune system. A better understanding of the molecular crosstalk between genomic instability, inflammatory signaling, and immune surveillance could guide the exploitation of immunotherapeutic vulnerabilities in cancer.

The Immune Microenvironment in Prostate Cancer: A Comprehensive Review

BACKGROUND

Prostate cancer (PCa) is a malignancy with significant immunosuppressive properties and limited immune activation. This immunosuppression is linked to reduced cytotoxic T cell activity, impaired antigen presentation, and elevated levels of immunosuppressive cytokines and immune checkpoint molecules. Studies demonstrate that cytotoxic CD8+ T cell infiltration correlates with improved survival, while increased regulatory T cells (Tregs) and tumor-associated macrophages (TAMs) are associated with worse outcomes and therapeutic resistance. Th1 cells are beneficial, whereas Th17 cells, producing interleukin-17 (IL-17), contribute to tumor progression. Tumor-associated neutrophils (TANs) and immune checkpoint molecules, such as PD-1/PD-L1 and T cell immunoglobulin-3 (TIM-3) are also linked to advanced stages of PCa. Chemotherapy holds promise in converting the "cold" tumor microenvironment (TME) to a "hot" one by depleting immunosuppressive cells and enhancing tumor immunogenicity.

SUMMARY

This comprehensive review examines the immune microenvironment in PCa, focusing on the intricate interactions between immune and tumor cells in the TME. It highlights how TAMs, Tregs, cytotoxic T cells, and other immune cell types contribute to tumor progression or suppression and how PCa's low immunogenicity complicates immunotherapy.

KEY MESSAGES

The infiltration of cytotoxic CD8+ T cells and Th1 cells correlates with better outcomes, while elevated T regs and TAMs promote tumor growth, metastasis, and resistance. TANs and natural killer (NK) cells exhibit dual roles, with higher NK cell levels linked to better prognoses. Immune checkpoint molecules like PD-1, PD-L1, and TIM-3 are associated with advanced disease. Chemotherapy can improve tumor immunogenicity by depleting T regs and myeloid-derived suppressor cells, offering therapeutic promise.

Digital assessment of tertiary lymphoid structures and therapeutic responses in gastric cancer: a multicentric retrospective study

BACKGROUND

Tertiary lymphoid structures (TLSs) are associated with favorable prognosis and enhanced response to anticancer therapy. A digital assessment of TLSs could provide an objective alternative that mitigates variability inherent in manual evaluation. This study aimed to develop and validate a digital gene panel based on biological prior knowledge for assessment of TLSs, and further investigate its associations with survival and multiple anticancer therapies.

MATERIALS AND METHODS

The present study involved 1704 patients with gastric cancer from seven cancer centers. TLSs were identified morphologically through hematoxylin-and-eosin staining. The authors further developed a digital score based on targeted gene expression profiling to assess TLSs status, recorded as gene signature of tertiary lymphoid structures (gsTLS). For enhanced interpretability, we employed the SHapley Additive exPlanation (SHAP) analysis to elucidate its contribution to the prediction. The authors next evaluated the signature's associations with prognosis, and investigated its predictive accuracy for multiple anticancer therapies, including adjuvant chemotherapy and immunotherapy.

RESULTS

The gsTLS panel with nine gene features achieved high accuracies in predicting TLSs status in the training, internal, and external validation cohorts (area under the curve, range: 0.729-0.791). In multivariable analysis, gsTLS remained an independent predictor of disease-free and overall survival (hazard ratio, range: 0.346-0.743, all P <0.05) after adjusting for other clinicopathological variables. SHAP analysis highlighted gsTLS as the strongest predictor of TLSs status compared with clinical features. Importantly, patients with high gsTLS (but not those with low gsTLS) exhibited substantial benefits from adjuvant chemotherapy ( P <0.05). Furthermore, the authors found that the objective response rate to antiprogrammed cell death protein 1 (anti-PD-1) immunotherapy was significantly higher in the high-gsTLS group (40.7%) versus the low-gsTLS group (5.6%, P =0.036), and the diagnosis was independent from Epstein-Barr virus, tumor mutation burden, and programmed cell death-ligand 1 (PD-L1) expression.

CONCLUSION

The gsTLS digital panel enables accurate assessment of TLSs status, and provides information regarding prognosis and responses to multiple therapies for gastric cancer.

Atypical B Cells Promote Cancer Progression and Poor Response to Bacillus Calmette-Guérin in Non-Muscle Invasive Bladder Cancer

Poor response to Bacillus Calmette-Guérin (BCG) immunotherapy remains a major barrier in the management of patients with non-muscle invasive bladder cancer (NMIBC). Multiple factors are associated with poor outcomes, including biological aging and female sex. More recently, it has emerged that a B-cell-infiltrated pretreatment immune microenvironment of NMIBC tumors can influence the response to intravesically administered BCG. The mechanisms underlying the roles of B cells in NMIBC are poorly understood. Here, we show that B-cell-dominant tertiary lymphoid structures (TLSs), a hallmark feature of the chronic mucosal immune response, are abundant and located close to the epithelial compartment in pretreatment tumors from BCG non-responders. Digital spatial proteomic profiling of whole tumor sections from male and female patients with NMIBC who underwent treatment with intravesical BCG, revealed higher expression of immune exhaustion-associated proteins within the tumor-adjacent TLSs in both responders and non-responders. Chronic local inflammation, induced by the N-butyl-N-(4-hydroxybutyl) nitrosamine carcinogen, led to TLS formation with recruitment and differentiation of the immunosuppressive atypical B-cell (ABC) subset within the bladder microenvironment, predominantly in aging female mice compared to their male counterparts. Depletion of ABCs simultaneous to BCG treatment delayed cancer progression in female mice. Our findings provide evidence indicating a role for ABCs in BCG response and will inform future development of therapies targeting the B-cell-exhaustion axis.

Panoramic tumor microenvironment in pancreatic ductal adenocarcinoma

Pancreatic ductal adenocarcinoma (PDAC) is notorious for its resistance to various treatment modalities. The genetic heterogeneity of PDAC, coupled with the presence of a desmoplastic stroma within the tumor microenvironment (TME), contributes to an unfavorable prognosis. The mechanisms and consequences of interactions among different cell types, along with spatial variations influencing cellular function, potentially play a role in the pathogenesis of PDAC. Understanding the diverse compositions of the TME and elucidating the functions of microscopic neighborhoods may contribute to understanding the immune microenvironment status in pancreatic cancer. As we delve into the spatial biology of the microscopic neighborhoods within the TME, aiding in deciphering the factors that orchestrate this intricate ecosystem. This overview delineates the fundamental constituents and the structural arrangement of the PDAC microenvironment, highlighting their impact on cancer cell biology.

Linking FOXM1 and PD-L1 to CDK4/6-MEK targeted therapy resistance in malignant peripheral nerve sheath tumors

Malignant peripheral nerve sheath tumors (MPNSTs) are aggressive, Ras-driven sarcomas characterized by loss of the NF1 tumor suppressor gene and hyperactivation of MEK and CDK4/6 kinases. MPNSTs lack effective therapies. We recently demonstrated remarkable efficacy of dual CDK4/6-MEK inhibition in mice with de novo MPNSTs, which was heightened by combined targeting of the immune checkpoint protein, PD-L1. The triple combination therapy targeting CDK4/6, MEK, and PD-L1 led to extended MPNST regression and improved survival, although most tumors eventually acquired drug resistance. Here, we consider the immune activation phenotype caused by CDK4/6-MEK inhibition in MPNSTs that uniquely involved intratumoral plasma cell accumulation. We discuss how PD-L1 and FOXM1, a tumor-promoting transcription factor, are functionally linked and may be key mediators of resistance to CDK4/6-MEK targeted therapies. Finally, the role of FOXM1 in suppressing anti-tumor immunity and potentially thwarting immune-based therapies is considered. We suggest that future therapeutic strategies targeting the oncogenic network of CDK4/6, MEK, PD-L1, and FOXM1 represent exciting future treatment options for MPNST patients.

Spatial multiplexed immunofluorescence analysis reveals coordinated cellular networks associated with overall survival in metastatic osteosarcoma

Patients diagnosed with advanced osteosarcoma, often in the form of lung metastases, have abysmal five-year overall survival rates. The complexity of the osteosarcoma immune tumor microenvironment has been implicated in clinical trial failures of various immunotherapies. The purpose of this exploratory study was to spatially characterize the immune tumor microenvironment of metastatic osteosarcoma lung specimens. Knowledge of the coordinating cellular networks within these tissues could then lead to improved outcomes when utilizing immunotherapy for treatment of this disease. Importantly, various cell types, interactions, and cellular neighborhoods were associated with five-year survival status. Of note, increases in cellular interactions between T lymphocytes, positive for programmed cell death protein 1, and myeloid-derived suppressor cells were observed in the 5-year deceased cohort. Additionally, cellular neighborhood analysis identified an Immune-Cold Parenchyma cellular neighborhood, also associated with worse 5-year survival. Finally, the Osteosarcoma Spatial Score, which approximates effector immune activity in the immune tumor microenvironment through the spatial proximity of immune and tumor cells, was increased within 5-year survivors, suggesting improved effector signaling in this patient cohort. Ultimately, these data represent a robust spatial multiplexed immunofluorescence analysis of the metastatic osteosarcoma immune tumor microenvironment. Various communication networks, and their association with survival, were described. In the future, identification of these networks may suggest the use of specific, combinatory immunotherapeutic strategies for improved anti-tumor immune responses and outcomes in osteosarcoma.

Exploring the impact of tertiary lymphoid structures maturity in NSCLC: insights from TLS scoring

Tertiary Lymphoid Structures (TLS) are lymphoid structures commonly associated with improved survival of cancer patients and response to immunotherapies. However, conflicting reports underscore the need to consider TLS heterogeneity and multiple features such as TLS size, composition, and maturation status, when assessing their functional impact. With the aim of gaining insights into TLS biology and evaluating the prognostic impact of TLS maturity in Non-Small Cell Lung Carcinoma (NSCLC), we developed a multiplex immunofluorescent (mIF) panel including T cell (CD3, CD8), B cell (CD20), Follicular Dendritic cell (FDC) (CD21, CD23) and mature dendritic cell (DC-LAMP) markers. We deployed this panel across a cohort of primary tumor resections from NSCLC patients (N=406) and established a mIF image analysis workstream to specifically detect TLS structures and evaluate the density of each cell phenotype. We assessed the prognostic significance of TLS size, number, and composition, to develop a TLS scoring system representative of TLS biology within a tumor. TLS relative area, (total TLS area divided by the total tumor area), was the most prognostic TLS feature (C-index: 0.54, p = 0.04). CD21 positivity was a marker driving the favorable prognostic impact, where CD21+ CD23- B cells (C-index: 0.57, p = 0.04) and CD21+ CD23- FDC (C-index: 0.58, p = 0.01) were the only prognostic cell phenotypes in TLS. Combining the three most robust prognostic TLS features: TLS relative area, the density of B cells, and FDC CD21+ CD23- we generated a TLS scoring system that demonstrated strong prognostic value in NSCLC when considering the effect of age, sex, histology, and smoking status. This TLS Score also demonstrated significant association with Immunoscore, EGFR mutational status and gene expression-based B-cell and TLS signature scores. It was not correlated with PD-L1 status in tumor cells or immune cells. In conclusion, we generated a prognostic TLS Score representative of the TLS heterogeneity and maturity undergoing within NSCLC tissues. This score could be used as a tool to explore how TLS presence and maturity impact the organization of the tumor microenvironment and support the discovery of spatial biomarker surrogates of TLS maturity, that could be used in the clinic.

Evaluation of the Immune Response within the Tumor Microenvironment in African American and Non-Hispanic White Patients with Non-Small Cell Lung Cancer

BACKGROUND

African Americans have higher incidence and mortality from lung cancer than non-Hispanic Whites, but investigations into differences in immune response have been minimal. Therefore, we compared components of the tumor microenvironment among African Americans and non-Hispanic Whites diagnosed with non-small cell lung cancer based on PDL1 or tertiary lymphoid structure (TLS) status to identify differences of translational relevance.

METHODS

Using a cohort of 280 patients with non-small cell lung cancer from the Inflammation, Health, Ancestry, and Lung Epidemiology study (non-Hispanic White: n = 155; African American: n = 125), we evaluated PDL1 tumor proportion score (<1% vs. ≥1%) and TLS status (presence/absence), comparing differences within the tumor microenvironment based on immune cell distribution and differential expression of genes.

RESULTS

Tumors from African Americans had a higher proportion of plasma cell signatures within the tumor microenvironment than non-Hispanic Whites. In addition, gene expression patterns in African American PDL1-positive samples suggest that these tumors contained greater numbers of γδ T cells and resting dendritic cells, along with fewer CD8+ T cells after adjusting for age, sex, pack-years, stage, and histology. Investigation of differential expression of B cell/plasma cell-related genes between the two patient populations revealed that two immunoglobulin genes (IGKV2-29 and IGLL5) were associated with decreased mortality risk in African Americans.

CONCLUSIONS

In the first known race-stratified analysis of tumor microenvironment components in lung cancer based on PDL1 expression or TLS status, differences within the immune cell composition and transcriptomic signature were identified that may have therapeutic implications.

IMPACT

Future investigation of racial variation within the tumor microenvironment may help direct the use of immunotherapy.

Tertiary lymphoid structures in anticancer immunity

Tertiary lymphoid structures (TLS) are transient ectopic lymphoid aggregates where adaptive antitumour cellular and humoral responses can be elaborated. Initially described in non-small cell lung cancer as functional immune lymphoid structures associated with better clinical outcome, TLS have also been found in many other carcinomas, as well as melanomas and sarcomas, and associated with improved response to immunotherapy. The manipulation of TLS as a therapeutic strategy is now coming of age owing to the likely role of TLS in the improved survival of patients with cancer receiving immune checkpoint inhibitor treatment. TLS have also garnered considerable interest as a predictive biomarker of the response to antitumour therapies, including immune checkpoint blockade and, possibly, chemotherapy. However, several important questions still remain regarding the definition of TLS in terms of both their cellular composition and functions. Here, we summarize the current views on the composition of TLS at different stages of their development. We also discuss the role of B cells and T cells associated with TLS and their dialogue in mounting antibody and cellular antitumour responses, as well as some of the various mechanisms that negatively regulate antitumour activity of TLS. The prognostic value of TLS to the clinical outcome of patients with cancer and the relationship between TLS and the response to therapy are then addressed. Finally, we present some preclinical evidence that favours the idea that manipulating the formation and function of TLS could lead to a potent next-generation cancer immunotherapy.

CCL19-producing fibroblasts promote tertiary lymphoid structure formation enhancing anti-tumor IgG response in colorectal cancer liver metastasis

Tertiary lymphoid structures (TLSs) are associated with enhanced immunity in tumors. However, their formation and functions in colorectal cancer liver metastasis (CRLM) remain unclear. Here, we reveal that intra- and peri-tumor mature TLSs (TLS+) are associated with improved clinical outcomes than TLS- tumors. Using single-cell-RNA-sequencing and spatial-enhanced-resolution-omics-sequencing (Stereo-seq), we reveal that TLS+ tumors are enriched with IgG+ plasma cells (PCs), while TLS- tumors are characterized with IgA+ PCs. By generating TLS-associated PC-derived monoclonal antibodies in vitro, we show that TLS-PCs secrete tumor-targeting antibodies. As the proof-of-concept, we demonstrate the anti-tumor activities of TLS-PC-mAb6 antibody in humanized mouse model of colorectal cancer. We identify a fibroblast lineage secreting CCL19 that facilitates lymphocyte trafficking to TLSs. CCL19 treatment promotes TLS neogenesis and prevents tumor growth in mice. Our data uncover the central role of CCL19+ fibroblasts in TLS formation, which in turn generates therapeutic antibodies to restrict CRLM.

The roles of tertiary lymphoid structures in genitourinary cancers: molecular mechanisms, therapeutic strategies, and clinical applications

The presence of tertiary lymphoid structures (TLSs) associated with distinct treatment efficacy and clinical prognosis has been identified in various cancer types. However, the mechanistic roles and clinical implications of TLSs in genitourinary (GU) cancers remain incompletely explored. Despite their potential role as predictive markers described in numerous studies, it is essential to comprehensively evaluate the characteristics of TLSs, including drivers of formation, structural foundation, cellular compositions, maturation stages, molecular features, and specific functionality to maximize their positive impacts on tumor-specific immunity. The unique contributions of these structures to cancer progression and biology have fueled interest in these structures as mediators of antitumor immunity. Emerging data are trying to explore the effects of therapeutic interventions targeting TLSs. Therefore, a better understanding of the molecular and phenotypic heterogeneity of TLSs may facilitate the development of TLSs-targeting therapeutic strategies to obtain optimal clinical benefits for GU cancers in the setting of immunotherapy. In this review, the authors focus on the phenotypic and functional heterogeneity of TLSs in cancer progression, current therapeutic interventions targeting TLSs and the clinical implications and therapeutic potential of TLSs in GU cancers.

Multi-dimensional characterization of apoptosis in the tumor microenvironment and therapeutic relevance in melanoma

PURPOSE

Melanoma is widely utilized as a prominent model for the development of immunotherapy, thought an inadequate immune response can occur. Moreover, the development of apoptosis-related therapies and combinations with other therapeutic strategies is impeded by the limited understanding of apoptosis's role within diverse tumor immune microenvironments (TMEs).

METHODS

Here, we constructed an apoptosis-related tumor microenvironment signature (ATM) and employ multi-dimensional analysis to understand the roles of apoptosis in tumor microenvironment. We further assessed the clinical applications of ATM in nine independent cohorts, and anticipated the impact of ATM on cellular drug response in cultured cells.

RESULTS

Our ATM model exhibits robust performance in survival prediction in multiple melanoma cohorts. Different ATM groups exhibited distinct molecular signatures and biological processes. The low ATM group exhibited significant enrichment in B cell activation-related pathways. What's more, plasma cells showed the lowest ATM score, highlighting their role as pivotal contributors in the ATM model. Mechanistically, the analysis of the interplay between plasma cells and other immune cells elucidated their crucial role in orchestrating an effective anti-tumor immune response. Significantly, the ATM signature exhibited associations with therapeutic efficacy of immune checkpoint blockade and the drug sensitivity of various agents, including FDA-approved and clinically utilized drugs targeting the VEGF signaling pathway. Finally, ATM was associated with tertiary lymphoid structures (TLS), exhibiting stronger patient stratification ability compared to classical "hot tumors".

CONCLUSION

Our findings indicate that ATM is a prognostic factor and is associated with the immune response and drug sensitivity in melanoma.

Association Between MRI Radiomics and Intratumoral Tertiary Lymphoid Structures in Intrahepatic Cholangiocarcinoma and Its Prognostic Significance

BACKGROUND

Tertiary lymphoid structures (TLSs) have prognostic value in intrahepatic cholangiocarcinoma (ICC) patients. Noninvasive tool to preoperatively evaluate TLSs is still lacking.

PURPOSE

To explore the association between TLSs status of ICC and preoperative MRI radiomics analysis.

STUDY TYPE

Retrospective.

SUBJECTS

One hundred and ninety-two patients with ICC, divided into training (T = 105), internal validation groups (V1 = 46), and external validation group (V2 = 41).

SEQUENCE

Coronal and axial single-shot fast spin-echo T2-weighted, diffusion-weighted imaging, T1-weighted, and T1WI fat-suppressed spoiled gradient-recall echo LAVA sequence at 3.0 T.

ASSESSMENT

The VOIs were drawn manually within the visible borders of the tumors using ITK-SNAP version 3.8.0 software in the axial T2WI, DWI, and portal vein phase sequences. Radiomics features were subjected to least absolute shrinkage and selection operator regression to select the associated features of TLSs and construct the radiomics model. Univariate and multivariate analyses were used to identify the clinical radiological variables associated with TLSs. The performances were evaluated by the area under the receiver operator characteristic curve (AUC).

STATISTICAL TESTS

Logistic regression analysis, ROC and AUC, Hosmer-Lemeshow test, Kaplan-Meier method with the log-rank test, calibration curves, and decision curve analysis. P < 0.05 was considered statistically significant.

RESULTS

The AUCs of arterial phase diffuse hyperenhancement were 0.59 (95% confidence interval [CI], 0.50-0.67), 0.52 (95% CI, 0.43-0.61), and 0.66 (95% CI, 0.52-0.80) in the T, V1, and V2 cohorts. The AUCs of Rad-score were 0.85 (95% CI, 0.77-0.92), 0.81 (95% CI, 0.67-0.94), and 0.84 (95% CI, 0.71-0.96) in the T, V1, and V2 cohorts, respectively. In cohort T, low-risk group showed significantly better median recurrence-free survival (RFS) than that of the high-risk group, which was also confirmed in cohort V1 and V2.

DATA CONCLUSION

A preoperative MRI radiomics signature is associated with the intratumoral TLSs status of ICC patients and correlate significantly with RFS.

LEVEL OF EVIDENCE

3 TECHNICAL EFFICACY: Stage 2.

Characterization of latently infected EBV+ antibody-secreting B cells isolated from ovarian tumors and malignant ascites

Introduction

Intra-tumoral B cells mediate a plethora of immune effector mechanisms with key roles in anti-tumor immunity and serve as positive prognostic indicators in a variety of solid tumor types, including epithelial ovarian cancer (EOC). Several aspects of intra-tumoral B cells remain unclear, such as their state of activation, antigenic repertoires, and capacity to mature into plasma cells.

Methods

B lymphocytes were isolated from primary EOC tissue and malignant ascites and were maintained in cell culture medium. The stably maintained cell lines were profiled with flow cytometry and B cell receptor sequencing. Secreted antibodies were tested with a human proteome array comprising more than 21,000 proteins, followed by ELISA for validation. Originating tumor samples were used for spatial profiling with chip cytometry.

Results

Antibody-secreting B lymphocytes were isolated from the ovarian tumor microenvironment (TME) of four different EOC patients. The highly clonal cell populations underwent spontaneous immortalization in vitro, were stably maintained in an antibody-secreting state, and showed presence of Epstein-Barr viral (EBV) proteins. All originating tumors had high frequency of tumor-infiltrating B cells, present as lymphoid aggregates, or tertiary lymphoid structures. The antigens recognized by three of the four cell lines are coil-coil domain containing protein 155 (CCDC155), growth factor receptor-bound protein 2 (GRB2), and pyruvate dehydrogenase phosphatase2 (PDP2), respectively. Anti-CCDC155 circulating IgG antibodies were detected in 9 of 20 (45%) of EOC patients' sera. Tissue analyses with multiparameter chip cytometry shows that the antibodies secreted by these novel human B cell lines engage their cognate antigens on tumor cells.

Discussion

These studies demonstrate that within the tumor-infiltrating lymphocyte population in EOC resides a low frequency population of antibody-secreting B cells that have been naturally exposed to EBV. Once stably maintained, these novel cell lines offer unique opportunities for future studies on intratumor B cell biology and new target antigen recognition, and for studies on EBV latency and/or viral reactivation in the TME of non-EBV related solid tumors such as the EOC.