Regulatory T cells infiltrate the tumor-induced tertiary lymphoïd structures and are associated with poor clinical outcome in NSCLC

Tertiary lymphoid structures and clinicopathological characteristics in pT1b Esophageal squamous cell carcinoma

PURPOSE

The objective of the current study is to investigate the clinicopathological and prognostic significance of Tertiary lymphoid structures (TLSs) in T1b ESCC.

METHODS

A total of 291 T1b ESCC patients who underwent esophagectomy and regional lymphadenectomy between 2008 and 2017 were included. Hematoxylin and eosin staining slides were used to evaluate TLSs and pathological features.

RESULTS

Intratumoral TLSs (iTLSs), mature iTLSs, peritumoral TLSs (pTLSs), mature pTLSs, distal TLSs (dTLSs), mature dTLSs, high grade dysplasia TLSs (HGD TLSs), and mature HGD TLSs were found in 51.2 %, 21.3 %, 86.9 %, 55.7 %, 58.8 %, 7.2 %, 95.5 %, and 68.1 % patients, respectively. There were significant correlation between iTLSs and mature iTLSs (P < 0.001), iTLSs and pTLSs (P = 0.025), pTLSs and mature pTLSs (P < 0.001), pTLSs and dTLSs (P = 0.048), dTLSs and mature dTLSs (P < 0.001), HGD TLSs and mature HGD TLSs (P < 0.001). High iTLSs or mature iTLSs correlated positively with INFc, lymphovascular invasion, high tumor stroma (P < 0.05). Multivariate Cox regression analyses identified tumor budding (P = 0.040) and differentiation (P = 0.016) as independent prognostic factors for disease-free survival (DFS), and tumor size (P = 0.049) and differentiation (P = 0.001) as independent indicators for overall survival (OS).

CONCLUSIONS

TLSs and mature TLSs, especially in peritumoural dysplasia tissues, were common in T1b ESCC, which couldn't predict prognosis for these patients. Tumor budding and differentiation reflect the biological activity of the tumor and may be useful prognostic indicators in T1b ESCC.

Multimodal diagnostic models and subtype analysis for neoadjuvant therapy in breast cancer

Background

Breast cancer, a heterogeneous malignancy, comprises multiple subtypes and poses a substantial threat to women's health globally. Neoadjuvant therapy (NAT), administered prior to surgery, is integral to breast cancer treatment strategies. It aims to downsize tumors, optimize surgical outcomes, and evaluate tumor responsiveness to treatment. However, accurately predicting NAT efficacy remains challenging due to the disease's complexity and the diverse responses across different molecular subtypes.

Methods

In this study, we harnessed multimodal data, including proteomic, genomic, MRI imaging, and clinical information, sourced from multiple cohorts such as I-SPY2, TCGA-BRCA, GSE161529, and METABRIC. Post data preprocessing, Lasso regression was utilized for feature extraction and selection. Five machine learning algorithms were employed to construct diagnostic models, with pathological complete response (pCR) as the predictive endpoint.

Results

Our results revealed that the multi-omics Ridge regression model achieved the optimal performance in predicting pCR, with an AUC of 0.917. Through unsupervised clustering using the R package MOVICS and nine clustering algorithms, we identified four distinct multimodal breast cancer subtypes associated with NAT. These subtypes exhibited significant differences in proteomic profiles, hallmark cancer gene sets, pathway activities, tumor immune microenvironments, transcription factor activities, and clinical characteristics. For instance, CS1 subtype, predominantly ER-positive, had a low pCR rate and poor response to chemotherapy drugs, while CS4 subtype, characterized by high immune infiltration, showed a better response to immunotherapy. At the single-cell level, we detected significant heterogeneity in the tumor microenvironment among the four subtypes. Malignant cells in different subtypes displayed distinct copy number variations, differentiation levels, and evolutionary trajectories. Cell-cell communication analysis further highlighted differential interaction patterns among the subtypes, with implications for tumor progression and treatment response.

Conclusion

Our multimodal diagnostic model and subtype analysis provide novel insights into predicting NAT efficacy in breast cancer. These findings hold promise for guiding personalized treatment strategies. Future research should focus on experimental validation, in-depth exploration of the underlying mechanisms, and extension of these methods to other cancers and treatment modalities.

Prognostic Factors for Intravesical Recurrence in NMIBC: Evaluating the Role of Pyuria, Bacteriuria, and Comorbidities

Background: The discovery of risk factors that might predict the recurrence of non-muscle invasive bladder cancer (NMIBC) is essential. Objectives: Therefore, this prospective cohort study aimed at examining the association between bacteriuria and pyuria before bacillus Calmette-Guérin (BCG) installation and the occurrence of intravesical recurrence (IVR) in patients diagnosed with NMIBC. Methods: A total of 73 NMIBC patients undergoing transurethral resection of bladder tumor (TURBT) and BCG treatment were included. Pre-instillation urine samples were analyzed for pyuria and bacteriuria. Results: The findings of this study indicated that preoperative pyuria was present in 31 (42.5%) of the studied patients. Furthermore, a statistically significant association was detected between preoperative pyuria and preoperative proteinuria (P < 0.001), preoperative hematuria (P = 0.023), preoperative bacteriuria (P = 0.001), and muscle invasion (MI) (P = 0.028). The results of the univariate analysis indicated substantial associations between the variables of smoking, diabetes, carcinoma in situ (CIS), age, and IVR. Subsequently, a multivariate analysis indicated that diabetes (HR = 18.11, P = 0.004) and CIS (HR = 14.69, P = 0.039) had a statistically significant link with IVR. Conclusions: In conclusion, our study demonstrated that diabetes, CIS, and younger age were the sole independent prognostic factors for IVR. Furthermore, no statistically significant association was observed between pyuria, bacteriuria, and smoking with bladder tumor recurrence. The analyses revealed that pyuria emerged as a statistically significant predictive factor for IVR only among individuals without pre-instillation proteinuria.

Prognostic Factors for Intravesical Recurrence in NMIBC: Evaluating the Role of Pyuria, Bacteriuria, and Comorbidities

Background: The discovery of risk factors that might predict the recurrence of non-muscle invasive bladder cancer (NMIBC) is essential. Objectives: Therefore, this prospective cohort study aimed at examining the association between bacteriuria and pyuria before bacillus Calmette-Guérin (BCG) installation and the occurrence of intravesical recurrence (IVR) in patients diagnosed with NMIBC. Methods: A total of 73 NMIBC patients undergoing transurethral resection of bladder tumor (TURBT) and BCG treatment were included. Pre-instillation urine samples were analyzed for pyuria and bacteriuria. Results: The findings of this study indicated that preoperative pyuria was present in 31 (42.5%) of the studied patients. Furthermore, a statistically significant association was detected between preoperative pyuria and preoperative proteinuria (P < 0.001), preoperative hematuria (P = 0.023), preoperative bacteriuria (P = 0.001), and muscle invasion (MI) (P = 0.028). The results of the univariate analysis indicated substantial associations between the variables of smoking, diabetes, carcinoma in situ (CIS), age, and IVR. Subsequently, a multivariate analysis indicated that diabetes (HR = 18.11, P = 0.004) and CIS (HR = 14.69, P = 0.039) had a statistically significant link with IVR. Conclusions: In conclusion, our study demonstrated that diabetes, CIS, and younger age were the sole independent prognostic factors for IVR. Furthermore, no statistically significant association was observed between pyuria, bacteriuria, and smoking with bladder tumor recurrence. The analyses revealed that pyuria emerged as a statistically significant predictive factor for IVR only among individuals without pre-instillation proteinuria.

From heterogeneity to prognosis: understanding the complexity of tertiary lymphoid structures in tumors

Tertiary lymphoid structures (TLSs) are aberrant lymphoid tissues found in persistent inflammatory settings, including malignancies, autoimmune disorders, and transplanted organs. The organization and architecture of TLS closely resemble that of secondary lymphoid organs (SLOs). The formation of TLS is an ongoing process, with varying structural features observed at different stages of maturation. The tumor microenvironment (TME) is a multifaceted milieu comprising cells, molecules, and extracellular matrix components in close proximity to the neoplasm. TLS within the TME have the capacity to actively elicit anti-tumor immune responses. TLSs exhibit tumor-specific and individual-specific characteristics, leading to varying immune responses towards tumor immunity based on their distinct cellular components, maturity levels, and spatial distribution. Cell interaction is the foundational elements of tumor immunity. Despite differences in the cellular composition of TLS, B cells and T cells are the main components of tumor-associated TLS。Recent research has highlighted the significance of diverse subtypes of B cells and T cells within TLSs in influencing the therapeutic outcomes and prognostic indicators of individual tumors. This review elucidates the diversity of TLS in terms of cellular composition, developmental stage, anatomical location, and the influence of cytokines on their initiation and progression. Furthermore, the article examines the involvement of B and T cells within TLS and the significance of TLS in relation to tumor prognosis.

The prognostic significance of tertiary lymphoid structures in oral squamous cell carcinomas: a systematic review

Introduction

Upper aerodigestive tract cancers are prevalent, with a global incidence surpassing 500,000 new cases in 2018. Among these, oral squamous cell carcinomas (OSCC) constitute the majority. OSCC has a low 5-year survival rate due to late-stage diagnosis. Risk factors include alcohol and tobacco use. However, non-smokers and non-drinkers are also affected, especially young patients with tongue cancer. The impact of tumor microenvironment (TME) and tumor-infiltrating lymphocytes (TILs) on OSCC prognosis remains debated. Remarkably, Tertiary Lymphoid Structures (TLS) identified in solid tumors have shown associations with favorable outcomes, yet their prognostic significance in OSCC remains understudied.

Objective

Thus, this systematic review aims to explore the value of TLS in OSCC reported in the literature.

Method

A scoping review was conducted and six retrospective cohort studies involving 1,203 patients met the inclusion criteria.

Results

Predominantly male patients, with an average age of 49.3 years were included. Immunohistochemistry was the primary method to identify TLS, present in 21% up to 100% of cases. TLS were predominantly located in the peri-tumoral area (75.4%-84.8%) compared to the intra-tumoral area (33.8%-33.9%). Our review shows that the presence of TLS is associated with improved survival in OSCC.

Discussion

However, variations in TLS detection and classification methods across studies introduce potential biases, hindering direct comparisons between findings. For instance, reports that are based solely on examining HES-stained slides for TLS identification may raise reliability concerns. Standardization of methodologies is imperative to ensure consistency in criteria utilization, thereby facilitating meaningful data comparisons.

Systematic Review Registration

https://www.crd.york.ac.uk/prospero/display_record.php?ID=CRD42023428010, PROSPERO (CRD42023428010).

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.

Exploring the Role of Tertiary Lymphoid Structures Using a Mouse Model of Bacteria-Infected Lungs

Animal models can be helpful tools for deciphering the generation, maintenance, and role of tertiary lymphoid structures (TLS) during infections or tumor development. We describe here the establishment of a persistent lung infection in immune-competent mice by intratracheal instillation of agarose beads containing Pseudomonas aeruginosa or Staphylococcus aureus bacteria. After instillation, animals develop a chronic pulmonary infection, marked by the presence of TLS. This experimental setting allows the study of the function of TLS induced by bacteria encountered in patients with cystic fibrosis (CF) as P. aeruginosa and S. aureus are the two main bacterial strains that infect the bronchi of adult CF patients. Additionally, we describe also how to manipulate the immune response in these infected animals by targeting immune cells involved in TLS function. Overall, this approach makes it possible to explore the role of chronic inflammation in the induction and maintenance of TLS in infected tissues.

Advancement of Techniques for Precise Visualization and Quantification of Tertiary Lymphoid Structure-Associated Immune Cells in Tissue Samples

Tertiary Lymphoid Structures (TLS) are considered as genuine markers of inflammation. Their presence within inflamed tissues or the tumor microenvironment has been associated with the local development of an active immune response. While high densities of TLS are correlated with disease severity in autoimmune diseases or during graft rejection, it has been associated with longer patient survival in many cancer types and more recently with positive responses to anti-PD-1 immunotherapy. Their efficient visualization and quantification within human tissues may represent new tools for helping clinicians in adjusting their therapeutic strategy. In clinical settings, the use of single-marker immunohistochemistry (IHC) protocols prevails in immune cell infiltration in formalin-fixed, paraffin-embedded (FFPE) tissues. In contrast, the development of automated multiplex immunofluorescence markings, i.e., 40-plex, requires very costly investments in equipment and analysis stations. Yet, employing two or more markers can enhance the characterization of immune infiltrates, particularly in the context of TLS. Besides the growing development of multiplex labeling approaches, imaging can also be used to overcome some technical difficulties encountered during the immunolabeling of tissues with several markers.This chapter describes IHC methods to visualize in human tissue (tumoral or not) the presence of TLS. These methods are based on the immunostaining of four TLS-associated immune cell populations, namely, follicular B cells, follicular dendritic Cells (FDCs), mature Dendritic Cells (mDCs), and Follicular Helper T cells (TFH), together with non-TFH T cells. Methodologies for subsequent quantification of TLS density are also proposed, as well as a virtual multiplexing method based on image registration using the open-source software ImageJ (IJ), aiming at co-localizing several immune cell populations from different IHC stainings performed on serial tissue sections.

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).

Mouse Models Enable the Functional Investigation of Tertiary Lymphoid Structures in Cancer

Tertiary lymphoid structures (TLSs) are organized lymphoid aggregates that form within nonlymphoid tissue, including tumors, in response to persistent inflammatory stimulation. In cancer patients, TLSs are generally associated with positive clinical outcomes. However, the cellular composition and spatial distribution of TLSs can vary depending on the underlying disease state, complicating interpretations of their prognostic significance. Murine models are indispensable for providing a deeper insight into the mechanisms involved in TLS formation and function. Studies using these models can complement current clinical efforts to characterize TLSs via genetic sequencing and histopathology of human samples. Several features of TLSs resemble that of secondary lymphoid organs (SLOs). Consequently, vascular system components and structural support elements are important for TLS formation and maintenance. Furthermore, TLSs in different tissue environments can exhibit distinct characteristics, necessitating careful consideration when selecting mouse models for study. Herein, we discuss critical aspects to consider when modeling TLSs and describe recent findings of TLS studies in the mouse lung and intestinal gut environments as examples to highlight the importance of considering tissue-specific regulatory mechanisms for TLSs. In this chapter, we also summarize the mechanistic insights derived from murine models on the formation and function of TLSs, which may translate to the future therapeutic modulation of TLS in disease.

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.

Tertiary Lymphoid Structures and Immunotherapy: Challenges and Opportunities

Tertiary lymphoid structures (TLS) are accumulations of lymphoid cells that arise in ectopic sites through the process of lymphoid neogenesis in chronic inflammation in autoimmunity, microbial infections, organ rejection, aging, and cancer. Their cellular composition and function and regulation via members of the lymphotoxin (LT)/tumor necrosis factor (TNF) family resemble that of secondary lymphoid organs (SLOs). Tumor-associated (TA)-TLS can be associated with favorable clinical outcomes. Immunotherapy in the form of immune checkpoint inhibitors (ICI) has contributed to tremendous advances in cancer therapy. However, ICI are effective in only some tumors, can give rise to resistance, and can precipitate immune-related adverse events (irAEs), many of which appear to have hallmarks of autoimmunity and can resemble TLS. TA-TLS correlate with a positive response to immunotherapy, but they can also be associated with susceptibility to irAEs, suggesting that TA-TLS in combination with ICI could lead to uncontrolled autoimmunity. The tumor environment can be manipulated to ensure that, not only the number of TLS, but also their cellular composition and appropriate function allow for judicious combinations of TLS and immunotherapy that can synergize and contribute to better outcomes with a minimum of destructive irAEs. Strategies include directed delivery of lymphoneogenic cytokines and chemokines or vascular growth factors directly, via transgenes or via adenovirus vectors.

Simultaneous Epigenetic and Gene Expression Profiling at Single Cell Resolution Uncovers Stem-Like Treg Subsets Induced With Oligonucleotide Expansion in Humans

Tregs play a central role in maintaining immune tolerance. Recent progress in the clinical application of Tregs underscores their potential for cell therapy. Nevertheless, a notable hurdle remains in producing functional Tregs in vitro. There is also a lack of detailed studies evaluating the function of Tregs during their ex vivo expansion process. Our prior investigation showed that the ex vivo expansion with oligonucleotides produces FoxP3highHelioshigh subsets. To investigate how oligonucleotides in culture media influence on gene expression and epigenetic states at single cell resolution, we sorted Tregs from healthy individuals and profiled in vitro oligonucleotide-expanded and non-expanded Tregs. We discovered a subset of Tregs, specifically enriched in expanded Tregs (seTregs), through oligonucleotide-induced expansion. seTregs showed an enhancement in both stem-like characteristics and functional attributes. Through analysis of histone modification data and gene regulatory networks, we elucidated IKZF2 (Helios) as a pivotal transcription factor in generating these cell subsets. We believe these findings offer insights into evaluating functional regulation of in vitro expanded Tregs aimed at manufacturing Treg-based cell therapies.

Global trends in tertiary lymphoid structures: a bibliometric analysis from 2014 to 2023

AIM AND BACKGROUND

Tertiary lymphoid structures (TLS) are increasingly recognized for their role in immunity. Despite growing interest, a systematic bibliometric analysis of TLS-related research has been lacking. To provide a comprehensive overview of current research trends and hotspots, we conducted a bibliometric analysis using data from the Web of Science Core Collection.

METHODS

We retrieved TLS-related publications from the Science Citation Index Expanded within the Web of Science Core Collection from January 2014 to December 2023. Co-occurrence analysis with "VOSviewer" identified current status and research hotspots, while "CiteSpace" was used for co-citation analysis to assess knowledge evolution and bursts. Thematic evolution was explored using bibliometrics to identify emerging keyword trends. Additionally, we examined country/region, institutional, and author contributions and collaborations. Tables were created using Microsoft Word.

RESULTS

A total of 785 publications were analyzed, showing a continuous growth trend from 2017 to 2023, indicating escalating interest in TLS among researchers. Leading countries in TLS research were China (231 publications), the United States (212 publications), and France (89 publications). The most productive institution and author were the "Institut national de la santé et de la recherche médicale" (70 publications) and Catherine Sautes-Fridman (21 publications), respectively. Key topics included TLS, B cells, and immunotherapy. Recent research has focused on mechanisms linking TLS with cancers, such as immunotherapy, tumor microenvironment, tumor-infiltrating lymphocytes, prognosis, and immune checkpoint inhibitors, highlighting an expanding area of study. Additionally, TLS' potential as a biomarker for predicting immunotherapy efficacy across different cancer types remains a burgeoning research direction.

CONCLUSIONS

This study provides a comprehensive analysis of global TLS-related publications, revealing key literature metrics and identifying influential articles and emerging research concerns. These findings contribute valuable insights into the role of TLS in immunotherapy and suggest future directions for this dynamic field.

A multidimensional analysis reveals distinct immune phenotypes and the composition of immune aggregates in pediatric acute myeloid leukemia

Because of the low mutational burden and consequently, fewer potential neoantigens, children with acute myeloid leukemia (AML) are thought to have a T cell-depleted or 'cold' tumor microenvironment and may have a low likelihood of response to T cell-directed immunotherapies. Understanding the composition, phenotype, and spatial organization of T cells and other microenvironmental populations in the pediatric AML bone marrow (BM) is essential for informing future immunotherapeutic trials about targetable immune-evasion mechanisms specific to pediatric AML. Here, we conducted a multidimensional analysis of the tumor immune microenvironment in pediatric AML and non-leukemic controls. We demonstrated that nearly one-third of pediatric AML cases has an immune-infiltrated BM, which is characterized by a decreased ratio of M2- to M1-like macrophages. Furthermore, we detected the presence of large T cell networks, both with and without colocalizing B cells, in the BM and dissected the cellular composition of T- and B cell-rich aggregates using spatial transcriptomics. These analyses revealed that these aggregates are hotspots of CD8+ T cells, memory B cells, plasma cells and/or plasmablasts, and M1-like macrophages. Collectively, our study provides a multidimensional characterization of the BM immune microenvironment in pediatric AML and indicates starting points for further investigations into immunomodulatory mechanisms in this devastating disease.

Associations between tertiary lymphoid structure density and immune checkpoint inhibitor efficacy in solid tumors: systematic review and meta-analysis

Background

Tertiary lymphoid structures (TLS) play a crucial role in tumor immunity, yet their relationship with the efficacy of immune checkpoint inhibitors (ICI) in cancer therapy is not fully understood. This study aims to systematically evaluate how TLS density influences treatment outcomes in cancer patients receiving ICI therapy.

Methods

The PubMed, Embase, Cochrane Library, and Web of Science databases were searched for eligible studies published before January 22, 2024. Our analysis encompassed odds ratios (ORs) for response rates (RRs) and hazard ratios (HRs) for progression-free survival (PFS), each with their respective 95% confidence intervals (CIs).

Results

Our meta-analysis, including 19 clinical trials with 1,752 patients, identified a strong correlation between high TLS density and increased RR to ICIs (OR= 2.99, 95% CI: 2.14-4.18, P < 0.001). Furthermore, a higher TLS density was associated with prolonged PFS (HR=0.75, 95% CI: 0.63-0.88, P < 0.001). Specifically, in the context of non-small cell lung cancer (NSCLC), breast cancer (BC), renal cell carcinoma (RCC), esophageal cancer (EC), and urothelial carcinoma (UC), a significant relationship was observed between high TLS density and better ICI efficacy. Publication bias did not affect the integrity of our conclusions. Sensitivity analysis further reinforced the reliability of our aggregated outcomes.

Conclusion

Our meta-analysis underscores the predictive role of TLS density in determining the RR and PFS among cancer patients undergoing ICI therapy. These results highlight the prognostic significance of TLS, suggesting its potential as a biomarker for guiding treatment decisions, even in tumor types traditionally considered ICI-resistant. Clinicians are recommended to assess TLS density as a part of patient evaluation to optimize ICI therapy initiation.

Systematic review registration

https://www.crd.york.ac.uk/prospero/, identifier CRD42023439875.

Radiation drives tertiary lymphoid structures to reshape TME for synergized antitumour immunity

Radiotherapy (RT) plays a key role in the tumour microenvironment (TME), impacting the immune response via cellular and humoral immunity. RT can induce local immunity to modify the TME. It can stimulate dendritic cell maturation and T-cell infiltration. Moreover, B cells, macrophages and other immune cells may also be affected. Tertiary lymphoid structure (TLS) is a unique structure within the TME and a class of aggregates containing T cells, B cells and other immune cells. The maturation of TLS is determined by the presence of mature dendritic cells, the density of TLS is determined by the number of immune cells. TLS maturation and density both affect the antitumour immune response in the TME. This review summarized the recent research on the impact and the role of RT on TLS, including the changes of TLS components and formation conditions and the mechanism of how RT affects TLS and transforms the TME. RT may promote TLS maturation and density to modify the TME regarding enhanced antitumour immunity.

The role of dendritic cells in tertiary lymphoid structures: implications in cancer and autoimmune diseases

Tertiary Lymphoid Structures (TLS) are organized aggregates of immune cells such as T cells, B cells, and Dendritic Cells (DCs), as well as fibroblasts, formed postnatally in response to signals from cytokines and chemokines. Central to the function of TLS are DCs, professional antigen-presenting cells (APCs) that coordinate the adaptive immune response, and which can be classified into different subsets, with specific functions, and markers. In this article, we review current data on the contribution of different DC subsets to TLS function in cancer and autoimmunity, two opposite sides of the immune response. Different DC subsets can be found in different tumor types, correlating with cancer prognosis. Moreover, DCs are also present in TLS found in autoimmune and inflammatory conditions, contributing to disease development. Broadly, the presence of DCs in TLS appears to be associated with favorable clinical outcomes in cancer while in autoimmune pathologies these cells are associated with unfavorable prognosis. Therefore, it is important to analyze the complex functions of DCs within TLS in order to enhance our fundamental understanding of immune regulation but also as a possible route to create innovative clinical interventions designed for the specific needs of patients with diverse pathological diseases.

Prognostic value of tumour-associated regulatory T-cells as a biomarker in non-small cell lung cancer: a systematic review and meta-analysis

BACKGROUND

Tumour, nodes, and metastases (TNM) staging has been deficient in prognosticating in patients suffering from non-small cell lung cancer (NSCLC). To supplement TNM staging, this systematic review and meta-analysis aimed to evaluate the prognostic value of the regulatory T cells (Treg).

METHODS

A keyword search was conducted in MEDLINE and EMBASE for full-text original human studies from any region published in English during the last 12 years. Eligible for inclusion were studies evaluating the prognostic value of the number of Treg cells in NSCLC except case studies, case series, systematic reviews, and meta-analyses. Two reviewers (one reviewer used an automation tool) independently screened the studies and assessed risk-of-bias using the Quality in Prognosis Studies (QUIPS) tool. Meta-analysis was done for studies reporting significant multivariate hazard ratio (HR).

RESULTS

Out of 809 retrievals, 24 studies were included in the final review. The low number of Treg cells was found significantly associated with improved overall survival (pooled log OR, 1.646; 95% CI, 1.349, 1.944; p (2-tailed) < .001; SE, 0.1217), improved recurrence-free survival (HR, 1.99; 95% CI, 1.15, 3.46; p = .01), improved progression-free survival (pooled log OR, 2.231; 95% CI, 0.424, 4.038; p (2-tailed) .034; SE, 0.4200), and worse disease-free survival (pooled log OR, 0.992; 95% CI, 0.820, 1.163; p (2-tailed) .009; SE, 0.0135), especially when identified by forkhead box P3 (FOXP3), in any stage or non-metastatic NSCLC.

CONCLUSION

A low number of Treg cells indicated better survival, suggesting its potential use as a prognostic biomarker in NSCLC.

SYSTEMATIC REVIEW REGISTRATION

The protocol of this review was prospectively registered on PROSPERO on August 28, 2021, and was assigned the registration number CRD42021270598. The protocol can be accessed from PROSPERO website.

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.

Tertiary lymphoid structures in diseases: immune mechanisms and therapeutic advances

Tertiary lymphoid structures (TLSs) are defined as lymphoid aggregates formed in non-hematopoietic organs under pathological conditions. Similar to secondary lymphoid organs (SLOs), the formation of TLSs relies on the interaction between lymphoid tissue inducer (LTi) cells and lymphoid tissue organizer (LTo) cells, involving multiple cytokines. Heterogeneity is a distinguishing feature of TLSs, which may lead to differences in their functions. Growing evidence suggests that TLSs are associated with various diseases, such as cancers, autoimmune diseases, transplant rejection, chronic inflammation, infection, and even ageing. However, the detailed mechanisms behind these clinical associations are not yet fully understood. The mechanisms by which TLS maturation and localization affect immune function are also unclear. Therefore, it is necessary to enhance the understanding of TLS development and function at the cellular and molecular level, which may allow us to utilize them to improve the immune microenvironment. In this review, we delve into the composition, formation mechanism, associations with diseases, and potential therapeutic applications of TLSs. Furthermore, we discuss the therapeutic implications of TLSs, such as their role as markers of therapeutic response and prognosis. Finally, we summarize various methods for detecting and targeting TLSs. Overall, we provide a comprehensive understanding of TLSs and aim to develop more effective therapeutic strategies.

A multidimensional analysis reveals distinct immune phenotypes and the composition of immune aggregates in pediatric acute myeloid leukemia

Because of the low mutational burden and consequently, fewer potential neoantigens, children with acute myeloid leukemia (AML) are thought to have a T cell-depleted or 'cold' tumor microenvironment and may have a low likelihood of response to T cell-directed immunotherapies. Understanding the composition, phenotype, and spatial organization of T cells and other microenvironmental populations in the pediatric AML bone marrow (BM) is essential for informing future immunotherapeutic trials about targetable immune-evasion mechanisms specific to pediatric AML. Here, we conducted a multidimensional analysis of the tumor immune microenvironment in pediatric AML and non-leukemic controls. We demonstrated that nearly one-third of pediatric AML cases has an immune-infiltrated BM, which is characterized by a decreased ratio of M2-to M1-like macrophages. Furthermore, we detected the presence of large T cell networks, both with and without colocalizing B cells, in the BM and dissected the cellular composition of T- and B cell-rich aggregates using spatial transcriptomics. These analyses revealed that these aggregates are hotspots of CD8 + T cells, memory B cells, plasma cells and/or plasmablasts, and M1-like macrophages. Collectively, our study provides a multidimensional characterization of the BM immune microenvironment in pediatric AML and indicates starting points for further investigations into immunomodulatory mechanisms in this devastating disease.

Mapping the complexity and diversity of tertiary lymphoid structures in primary and peritoneal metastatic gastric cancer

BACKGROUND

Tertiary lymphoid structures (TLSs) are thought to stimulate antitumor immunity and positively impact prognosis and response to immune checkpoint blockade. In gastric cancers (GCs), however, TLSs are predominantly found in GC with poor prognosis and limited treatment response. We, therefore, hypothesize that immune cell composition and function of TLS depends on tumor location and the tumor immune environment.

METHODS

Spatial transcriptomics and immunohistochemistry were used to characterize the phenotype of CD45+ immune cells inside and outside of TLS using archival resection specimens from GC primary tumors and peritoneal metastases.

RESULTS

We identified significant intrapatient and interpatient diversity of the cellular composition and maturation status of TLS in GC. Tumor location (primary vs metastatic site) accounted for the majority of differences in TLS maturity, as TLS in peritoneal metastases were predominantly immature. This was associated with higher levels of tumor-infiltrating macrophages and Tregs and less plasma cells compared with tumors with mature TLS. Furthermore, mature TLSs were characterized by overexpression of antitumor immune pathways such as B cell-related pathways, MHC class II antigen presentation while immature TLS were associated with protumor pathways, including T cell exhaustion and enhancement of DNA repair pathways in the corresponding cancer.

CONCLUSION

The observation that GC-derived peritoneal metastases often contain immature TLS which are associated with immune suppressive regulatory tumor-infiltrating leucocytes, is in keeping with the lack of response to immune checkpoint blockade and the poor prognostic features of peritoneal metastatic GC, which needs to be taken into account when optimizing immunomodulatory strategies for metastatic GC.

To explore the prognostic characteristics of colon cancer based on tertiary lymphoid structure-related genes and reveal the characteristics of tumor microenvironment and drug prediction

In order to construct a prognostic evaluation model of TLS features in COAD and better realize personalized precision medicine in COAD. Colon adenocarcinoma (COAD) is a common malignant tumor of the digestive system. At present, there is no effective prognostic marker to predict the prognosis of patients. Tertiary lymphoid structure (TLS) affects cancer progression by regulating immune microenvironment. Mining COAD biomarkers based on TLS-related genes helps to improve the prognosis of patients. In order to construct a prognostic evaluation model of TLS features in COAD and better realize personalized precision medicine in COAD. The mRNA expression data and clinical information of COAD and adjacent tissues were downloaded from the Cancer Genome Atlas database. The differentially expressed TLS-related genes of COAD relative to adjacent tissues were obtained by differential analysis. TLS gene co-expression analysis was used to mine genes highly related to TLS, and the intersection of the two was used to obtain candidate genes. Univariate, LASSO, and multivariate Cox regression analysis were performed on candidate genes to screen prognostic markers to construct a risk assessment model. The differences of immune characteristics were evaluated by ESTIMATE, ssGSEA and CIBERSORT in high and low risk groups of prognostic model. The difference of genomic mutation between groups was evaluated by tumor mutation burden score. Screening small molecule drugs through the GDSC library. Finally, a nomogram was drawn to evaluate the clinical value of the prognostic model. Seven TLS-related genes ADAM8, SLC6A1, PAXX, RIMKLB, PTH1R, CD1B, and MMP10 were screened to construct a prognostic model. Survival analysis showed that patients in the high-risk group had significantly lower overall survival rates. Immune microenvironment analysis showed that patients in the high-risk group had higher immune indicators, indicating higher immunity. The genomic mutation patterns of the high-risk and low-risk groups were significantly different, especially the KRAS mutation frequency was significantly higher in the high-risk group. Drug sensitivity analysis showed that the low-risk group was more sensitive to Erlotinib, Savolitinib and VE _ 822, which may be used as a potential drug for COAD treatment. Finally, the nomogram constructed by pathological features combined with RiskScore can accurately evaluate the prognosis of COAD patients. This study constructed and verified a TLS model that can predict COAD. More importantly, it provides a reference standard for guiding the prognosis and immunotherapy of COAD patients.

Associations between immune cell phenotypes and lung cancer subtypes: insights from mendelian randomization analysis

INTRODUCTION

Lung cancer is a common malignant tumor, and different types of immune cells may have different effects on the occurrence and development of lung cancer subtypes, including lung squamous cell carcinoma (LUSC) and lung adenocarcinoma (LUAD). However, the causal relationship between immune phenotype and lung cancer is still unclear.

METHODS

This study utilized a comprehensive dataset containing 731 immune phenotypes from the European Bioinformatics Institute (EBI) to evaluate the potential causal relationship between immune phenotypes and LUSC and LUAD using the inverse variance weighted (IVW) method in Mendelian randomization (MR). Sensitivity analyses, including MR-Egger intercept, Cochran Q test, and others, were conducted for the robustness of the results. The study results were further validated through meta-analysis using data from the Transdisciplinary Research Into Cancer of the Lung (TRICL) data. Additionally, confounding factors were excluded to ensure the robustness of the findings.

RESULTS

Among the final selection of 729 immune cell phenotypes, three immune phenotypes exhibited statistically significant effects with LUSC. CD28 expression on resting CD4 regulatory T cells (OR 1.0980, 95% CI: 1.0627-1.1344, p < 0.0001) and CD45RA + CD28- CD8 + T cell %T cell (OR 1.0011, 95% CI: 1.0007; 1.0015, p < 0.0001) were associated with increased susceptibility to LUSC. Conversely, CCR2 expression on monocytes (OR 0.9399, 95% CI: 0.9177-0.9625, p < 0.0001) was correlated with a decreased risk of LUSC. However, no significant causal relationships were established between any immune cell phenotypes and LUAD.

CONCLUSION

This study demonstrates that specific immune cell types are associated with the risk of LUSC but not with LUAD. While these findings are derived solely from European populations, they still provide clues for a deeper understanding of the immunological mechanisms underlying lung cancer and may offer new directions for future therapeutic strategies and preventive measures.

Tertiary lymphoid structures in cancer: maturation and induction

Tertiary lymphoid structure (TLS) is an ectopic lymphocyte aggregate formed in peripheral non-lymphoid tissues, including inflamed or cancerous tissue. Tumor-associated TLS serves as a prominent center of antigen presentation and adaptive immune activation within the periphery, which has exhibited positive prognostic value in various cancers. In recent years, the concept of maturity regarding TLS has been proposed and mature TLS, characterized by well-developed germinal centers, exhibits a more potent tumor-suppressive capacity with stronger significance. Meanwhile, more and more evidence showed that TLS can be induced by therapeutic interventions during cancer treatments. Thus, the evaluation of TLS maturity and the therapeutic interventions that induce its formation are critical issues in current TLS research. In this review, we aim to provide a comprehensive summary of the existing classifications for TLS maturity and therapeutic strategies capable of inducing its formation in tumors.

Exploiting Tertiary Lymphoid Structures to Stimulate Antitumor Immunity and Improve Immunotherapy Efficacy

Tumor-associated tertiary lymphoid structures (TLS) have been associated with favorable clinical outcomes and response to immune checkpoint inhibitors in many cancer types, including non-small cell lung cancer. Although the detailed cellular and molecular mechanisms underlying these clinical associations have not been fully elucidated, growing preclinical and clinical studies are helping to elucidate the mechanisms at the basis of TLS formation, composition, and regulation of immune responses. However, a major challenge remains how to exploit TLS to enhance naïve and treatment-mediated antitumor immune responses. Here, we discuss the current understanding of tumor-associated TLS, preclinical models that can be used to study them, and potential therapeutic interventions to boost TLS formation, with a particular focus on lung cancer research.

Tertiary lymphoid structural heterogeneity determines tumour immunity and prospects for clinical application

Tertiary lymphoid structures (TLS) are clusters of immune cells that resemble and function similarly to secondary lymphoid organs (SLOs). While TLS is generally associated with an anti-tumour immune response in most cancer types, it has also been observed to act as a pro-tumour immune response. The heterogeneity of TLS function is largely determined by the composition of tumour-infiltrating lymphocytes (TILs) and the balance of cell subsets within the tumour-associated TLS (TA-TLS). TA-TLS of varying maturity, density, and location may have opposing effects on tumour immunity. Higher maturity and/or higher density TLS are often associated with favorable clinical outcomes and immunotherapeutic response, mainly due to crosstalk between different proportions of immune cell subpopulations in TA-TLS. Therefore, TLS can be used as a marker to predict the efficacy of immunotherapy in immune checkpoint blockade (ICB). Developing efficient imaging and induction methods to study TA-TLS is crucial for enhancing anti-tumour immunity. The integration of imaging techniques with biological materials, including nanoprobes and hydrogels, alongside artificial intelligence (AI), enables non-invasive in vivo visualization of TLS. In this review, we explore the dynamic interactions among T and B cell subpopulations of varying phenotypes that contribute to the structural and functional diversity of TLS, examining both existing and emerging techniques for TLS imaging and induction, focusing on cancer immunotherapies and biomaterials. We also highlight novel therapeutic approaches of TLS that are being explored with the aim of increasing ICB treatment efficacy and predicting prognosis.

CD137+ and regulatory T cells as independent prognostic factors of survival in advanced non-oncogene addicted NSCLC patients treated with immunotherapy as first-line

BACKGROUND

Immune checkpoint inhibitors (ICIs), administered alone or combined with chemotherapy, are the standard of care in advanced non-oncogene addicted Non-Small Cell Lung Cancer (NSCLC). Despite these treatments' success, most long-term survival benefit is restricted to approximately 20% of patients, highlighting the need to identify novel biomarkers to optimize treatment strategies. In several solid tumors, immune soluble factors, the activatory CD137+ Tcells, and the immunosuppressive cell subsets Tregs and MDSCs (PMN(Lox1+)-MDSC and M-MDSCs) correlated with responses to ICIs and clinical outcomes thus becoming appealing predictive and prognostic factors. This study investigated the role of distinct CD137+ Tcell subsets, Tregs, MDSCs, and immune-soluble factors in NSCLC patients as possible biomarkers.

METHODS

The levels of T cells, MDSCs and soluble factors were evaluated in 89 metastatic NSCLC patients who underwent ICIs as first- or second-line treatment. T cell analysis was performed by cytoflurimetry evaluating Tregs and different CD137+ Tcell subsets also combined with CD3+, CD8+, PD1+, and Ki67+ markers. Circulating cytokines and immune checkpoints were also evaluated by Luminex analysis. All these parameters were correlated with several clinical factors (age, sex, smoking status, PS and TPS), response to therapy, PFS , and OS . The analyses were conducted in the overall population and in patients treated with ICIs as first-line (naïve patients).

RESULTS

In both groups of patients, high levels of circulating CD137+ and CD137+PD1+ T cells (total, CD4 and CD8) and the soluble factor LAG3 positively correlated with response to therapy. In naïve patients, PMN(Lox1+)-MDSCs negatively correlated with clinical response, and a high percentage of Tregs was associated with favorable survival. Moreover, the balance between Treg/CD137+ Tcells or PMN(Lox1+)-MDSC/CD137+ Tcells was higher in non-responding patients and was associated with poor survival. CD137+ Tcells and Tregs resulted as two positive independent prognostic factors.

CONCLUSION

High levels of CD137+, CD137+PD1+ Tcells and sLAG3 could predict the response to ICIs in NSCLC patients independently by previous therapy. Combining the evaluation of CD137+ Tcells and Tregs also as Treg/CD137+ T cells ratio it is possible to identify naive patients with longer survival.

Tertiary lymphoid structures in cancer: immune mechanisms and clinical implications

Cancer is a major cause of death globally, and traditional treatments often have limited efficacy and adverse effects. Immunotherapy has shown promise in various malignancies but is less effective in tumors with low immunogenicity or immunosuppressive microenvironment, especially sarcomas. Tertiary lymphoid structures (TLSs) have been associated with a favorable response to immunotherapy and improved survival in cancer patients. However, the immunological mechanisms and clinical significance of TLS in malignant tumors are not fully understood. In this review, we elucidate the composition, neogenesis, and immune characteristics of TLS in tumors, as well as the inflammatory response in cancer development. An in-depth discussion of the unique immune characteristics of TLSs in lung cancer, breast cancer, melanoma, and soft tissue sarcomas will be presented. Additionally, the therapeutic implications of TLS, including its role as a marker of therapeutic response and prognosis, and strategies to promote TLS formation and maturation will be explored. Overall, we aim to provide a comprehensive understanding of the role of TLS in the tumor immune microenvironment and suggest potential interventions for cancer treatment.

CD8+ T cell priming that is required for curative intratumorally anchored anti-4-1BB immunotherapy is constrained by Tregs

Although co-stimulation of T cells with agonist antibodies targeting 4-1BB (CD137) improves antitumor immune responses in preclinical studies, clinical success has been limited by on-target, off-tumor activity. Here, we report the development of a tumor-anchored ɑ4-1BB agonist (ɑ4-1BB-LAIR), which consists of a ɑ4-1BB antibody fused to the collagen-binding protein LAIR. While combination treatment with an antitumor antibody (TA99) shows only modest efficacy, simultaneous depletion of CD4+ T cells boosts cure rates to over 90% of mice. Mechanistically, this synergy depends on ɑCD4 eliminating tumor draining lymph node regulatory T cells, resulting in priming and activation of CD8+ T cells which then infiltrate the tumor microenvironment. The cytotoxic program of these newly primed CD8+ T cells is then supported by the combined effect of TA99 and ɑ4-1BB-LAIR. The combination of TA99 and ɑ4-1BB-LAIR with a clinically approved ɑCTLA-4 antibody known for enhancing T cell priming results in equivalent cure rates, which validates the mechanistic principle, while the addition of ɑCTLA-4 also generates robust immunological memory against secondary tumor rechallenge. Thus, our study establishes the proof of principle for a clinically translatable cancer immunotherapy.

Prognostic Factors and Construction of Nomogram Prediction Model of Lung Cancer Patients Using Clinical and Blood Laboratory Parameters

Objective

This work aimed to explore the prognostic risk factors of lung cancer (LC) patients and establish a line chart prediction model.

Methods

A total of 322 LC patients were taken as the study subjects. They were randomly divided into a training set (n = 202) and a validation set (n = 120). Basic information and laboratory indicators were collected, and the progression-free survival (PFS) and overall survival (OS) were followed up. Single-factor and cyclooxygenase (COX) multivariate analyses were performed on the training set to construct a Nomogram prediction model, which was validated with 120 patients in the validation set, and Harrell's consistency was analyzed.

Results

Single-factor analysis revealed significant differences in PFS (P<0.05) between genders, body mass index (BMI), carcinoembryonic antigen (CEA), cancer antigen 125 (CA125), squamous cell carcinoma antigen (SCCA), treatment methods, treatment response evaluation, smoking status, presence of pericardial effusion, and programmed death ligand 1 (PD-L1) at 0 and 1-50%. Significant differences in OS (P<0.05) were observed for age, tumor location, treatment methods, White blood cells (WBC), uric acid (UA), CA125, pro-gastrin-releasing peptide (ProGRP), SCCA, cytokeratin fragment 21 (CYFRA21), and smoking status. COX analysis identified male gender, progressive disease (PD) as treatment response, and SCCA > 1.6 as risk factors for LC PFS. The consistency indices of the line chart models for predicting PFS and OS were 0.782 and 0.772, respectively.

Conclusion

Male gender, treatment response of PD, and SCCA > 1.6 are independent risk factors affecting the survival of LC patients. The PFS line chart model demonstrates good concordance.

The impact of Foxp3+ regulatory T-cells on CD8+ T-cell dysfunction in tumour microenvironments and responses to immune checkpoint inhibitors

Immune checkpoint inhibitors (ICIs) have been a breakthrough in cancer therapy, inducing durable remissions in responding patients. However, they are associated with variable outcomes, spanning from disease hyperprogression to complete responses with the onset of immune-related adverse events. The consequences of checkpoint inhibition on Foxp3+ regulatory T (Treg ) cells remain unclear but could provide key insights into these variable outcomes. In this review, we first cover the mechanisms that underlie the development of hot and cold tumour microenvironments, which determine the efficacy of immunotherapy. We then outline how differences in tumour-intrinsic immunogenicity, T-cell trafficking, local metabolic environments and inhibitory checkpoint signalling differentially impair CD8+ T-cell function in tumour microenvironments, all the while promoting Treg -cell suppressive activity. Finally, we focus on the mechanisms that enable the induction of polyfunctional CD8+ T-cells upon checkpoint blockade and discuss the role of ICI-induced Treg -cell reactivation in acquired resistance to treatment.

Heterogeneity of tertiary lymphoid structures in cancer

The success of immunotherapy approaches, such as immune checkpoint blockade and cellular immunotherapy with genetically modified lymphocytes, has firmly embedded the immune system in the roadmap for combating cancer. Unfortunately, the majority of cancer patients do not yet benefit from these therapeutic approaches, even when the prognostic relevance of the immune response in their tumor entity has been demonstrated. Therefore, there is a justified need to explore new strategies for inducing anti-tumor immunity. The recent connection between the formation of ectopic lymphoid aggregates at tumor sites and patient prognosis, along with an effective anti-tumor response, suggests that manipulating the occurrence of these tertiary lymphoid structures (TLS) may play a critical role in activating the immune system against a growing tumor. However, mechanisms governing TLS formation and a clear understanding of their substantial heterogeneity are still lacking. Here, we briefly summarize the current state of knowledge regarding the mechanisms driving TLS development, outline the impact of TLS heterogeneity on clinical outcomes in cancer patients, and discuss appropriate systems for modeling TLS heterogeneity that may help identify new strategies for inducing protective TLS formation in cancer patients.

Tertiary lymphoid structures and B cells: An intratumoral immunity cycle

The generation of anti-tumor immunity in the draining lymph nodes is known as the cancer immunity cycle. Accumulating evidence supports the occurrence of such a cycle at tumor sites in the context of chronic inflammation. Here, we review the role of tertiary lymphoid structures (TLS) in the generation of T and B cell immunities, focusing on the impact of B cells that undergo full maturation, resulting in the generation of plasma cells (PCs) producing high-affinity IgG and IgA antibodies. In this context, we propose that antibodies binding to tumor cells induce macrophage or natural killer (NK)-cell-dependent apoptosis. Subsequently, released antigen-antibody complexes are internalized and processed by dendritic cells (DCs), amplifying antigen presentation to T cells. Immune complexes may also be fixed by follicular DCs (FDCs) in TLS, thereby increasing memory B cell responses. This amplification loop creates an intra-tumoral immunity cycle, capable of increasing sensitivity of tumors to immunotherapy even in cancers with low mutational burden.

Lung tumor-infiltrating Treg have divergent transcriptional profiles and function linked to checkpoint blockade response

Regulatory T cells (Treg) are conventionally viewed as suppressors of endogenous and therapy-induced antitumor immunity; however, their role in modulating responses to immune checkpoint blockade (ICB) is unclear. In this study, we integrated single-cell RNA-seq/T cell receptor sequencing (TCRseq) of >73,000 tumor-infiltrating Treg (TIL-Treg) from anti-PD-1-treated and treatment-naive non-small cell lung cancers (NSCLC) with single-cell analysis of tumor-associated antigen (TAA)-specific Treg derived from a murine tumor model. We identified 10 subsets of human TIL-Treg, most of which have high concordance with murine TIL-Treg subsets. Only one subset selectively expresses high levels of TNFRSF4 (OX40) and TNFRSF18 (GITR), whose engangement by cognate ligand mediated proliferative programs and NF-κB activation, as well as multiple genes involved in Treg suppression, including LAG3. Functionally, the OX40hiGITRhi subset is the most highly suppressive ex vivo, and its higher representation among total TIL-Treg correlated with resistance to PD-1 blockade. Unexpectedly, in the murine tumor model, we found that virtually all TIL-Treg-expressing T cell receptors that are specific for TAA fully develop a distinct TH1-like signature over a 2-week period after entry into the tumor, down-regulating FoxP3 and up-regulating expression of TBX21 (Tbet), IFNG, and certain proinflammatory granzymes. Transfer learning of a gene score from the murine TAA-specific TH1-like Treg subset to the human single-cell dataset revealed a highly analogous subcluster that was enriched in anti-PD-1-responding tumors. These findings demonstrate that TIL-Treg partition into multiple distinct transcriptionally defined subsets with potentially opposing effects on ICB-induced antitumor immunity and suggest that TAA-specific TIL-Treg may positively contribute to antitumor responses.

CCL21-Ser expression in melanoma cells recruits CCR7+ naïve T cells to tumor tissues and promotes tumor growth

CCL21-Ser, a chemokine encoded by the Ccl21a gene, is constitutively expressed in the thymic epithelial cells and stromal cells of secondary lymphoid organs. It regulates immune cell migration and survival through its receptor CCR7. Herein, using CCL21-Ser-expressing melanoma cells and the Ccl21a-deficient mice, we demonstrated the functional role of cancer cell-derived CCL21-Ser in melanoma growth in vivo. The B16-F10 tumor growth was significantly decreased in Ccl21a-deficient mice compared with that in wild-type mice, indicating that host-derived CCL21-Ser contributes to melanoma proliferation in vivo. In Ccl21a-deficient mice, tumor growth of melanoma cells expressing CCL21-Ser was significantly enhanced, suggesting that CCL21-Ser from melanoma cells promotes tumor growth in the absence of host-derived CCL21-Ser. The increase in tumor growth was associated with an increase in the CCR7+ CD62L+ T cell frequency in the tumor tissue but was inversely correlated with Treg frequency, suggesting that naïve T cells primarily promote tumor growth. Adoptive transfer experiments demonstrated that naïve T cells are preferentially recruited from the blood into tumors with melanoma cell-derived CCL21-Ser expression. These results suggest that CCL21-Ser from melanoma cells promotes the infiltration of CCR7+ naïve T cells into the tumor tissues and creates a tumor microenvironment favorable for melanoma growth.

Harnessing the power of oncolytic virotherapy and tertiary lymphoid structures to amplify antitumor immune responses in cancer patients

Tertiary lymphoid structures (TLS) are ectopic aggregates of immune cells that develop in non-lymphoid tissues under persistent inflammation. Since their presence has been associated with a better prognosis in cancer patients, modulating TLS formation is being part of new challenges in immunotherapy. Although mechanisms underlying TLS genesis are still not fully understood, different strategies have been developed in preclinical models to induce their formation and ultimately enhance antitumor responses. Herein, we will discuss a new approach that would consist in using oncolytic viruses (OV). These viruses have the unique feature to preferentially infect, replicate in and kill cancer cells. Their immunoadjuvant property, their use as a vector of therapeutic molecules and their selectivity for cancer cells, make them an attractive strategy to induce TLS in the tumor microenvironment. This review will examine the current knowledge about TLS neogenesis, approaches for inducing them, and relevance of using OV for this purpose, especially in combination with immunotherapy such as immune checkpoint blockade.

HEV-associated dendritic cells are observed in metastatic tumor-draining lymph nodes of cutaneous melanoma patients with longer distant metastasis-free survival after adjuvant immunotherapy

Introduction

Tissue biomarkers that aid in identifying cutaneous melanoma (CM) patients who will benefit from adjuvant immunotherapy are of crucial interest. Metastatic tumor-draining lymph nodes (mTDLN) are the first encounter site between the metastatic CM cells and an organized immune structure. Therefore, their study may reveal mechanisms that could influence patients´ outcomes.

Methods

Twenty-nine stage-III CM patients enrolled in clinical trials to study the vaccine VACCIMEL were included in this retrospective study. After radical mTDLN dissection, patients were treated with VACCIMEL (n=22) or IFNα-2b (n=6), unless rapid progression (n=1). Distant Metastasis-Free Survival (DMFS) was selected as an end-point. Two cohorts of patients were selected: one with a good outcome (GO) (n=17; median DMFS 130.0 months), and another with a bad outcome (BO) (n=12; median DMFS 8.5 months). We analyzed by immunohistochemistry and immunofluorescence the expression of relevant biomarkers to tumor-cell biology and immune cells and structures in mTDLN, both in the tumor and peritumoral areas.

Results

In BO patients, highly replicating Ki-67+ tumor cells, low tumor HLA-I expression and abundant FoxP3+ lymphocytes were found (p=0.037; p=0.056 and p=0.021). In GO patients, the most favorable biomarkers for prolonged DMFS were the abundance of peri- and intra-tumoral CD11c+ cells (p=0.0002 and p=0.001), peri-tumoral DC-LAMP+ dendritic cells (DCs) (p=0.001), and PNAd+ High Endothelial Venules (HEVs) (p=0.004). Most strikingly, we describe in GO patients a peculiar, heterogeneous structure that we named FAPS (Favoring Antigen-Presenting Structure), a triad composed of DC, HEV and CD62L+ naïve lymphocytes, whose postulated role would be to favor tumor antigen (Ag) priming of incoming naïve lymphocytes. We also found in GO patients a preferential tumor infiltration of CD8+ and CD20+ lymphocytes (p=0.004 and p=0.027), as well as peritumoral CD20+ aggregates, with no CD21+ follicular dendritic cells detected (p=0.023). Heterogeneous infiltration with CD64+CD68-CD163-, CD64+CD68+CD163- and CD64+CD68+CD163+ macrophages were observed in both cohorts.

Discussion

The analysis of mTDLN in GO and BO patients revealed marked differences. This work highlights the importance of analyzing resected mTDLN from CM patients and suggests a correlation between tumor and immune characteristics that may be associated with a spontaneous or vaccine-induced long DMFS. These results should be confirmed in prospective studies.

Construction of stemness gene score by bulk and single-cell transcriptome to characterize the prognosis of breast cancer

Breast cancer (BC) is a heterogeneous disease characterized by significant differences in prognosis and therapy response. Numerous prognostic tools have been developed for breast cancer. Usually these tools are based on bulk RNA-sequencing (RNA-Seq) and ignore tumor heterogeneity. Consequently, the goal of this study was to construct a single-cell level tool for predicting the prognosis of BC patients. In this study, we constructed a stemness-risk gene score (SGS) model based on single-sample gene set enrichment analysis (ssGSEA). Patients were divided into two groups based on the median SGS. Patients with a high SGS scores had a significantly worse prognosis than those with a low SGS, and these groups exhibited differences in several tumor characteristics, such as immune infiltration, gene mutations, and copy number variants. Our results indicate that the SGS is a reliable tool for predicting prognosis and response to immunotherapy in BC patients.

Both intratumoral regulatory T cell depletion and CTLA-4 antagonism are required for maximum efficacy of anti-CTLA-4 antibodies

Anti-CTLA-4 antibodies have successfully elicited durable tumor regression in the clinic; however, long-term benefit is limited to a subset of patients for select cancer indications. The incomplete understanding of their mechanism of action has hindered efforts at improvement, with conflicting hypotheses proposing either antagonism of the CTLA-4:B7 axis or Fc effector-mediated regulatory T cell (Treg) depletion governing efficacy. Here, we report the engineering of a nonantagonistic CTLA-4 binding domain (b1s1e2) that depletes intratumoral Tregs as an Fc fusion. Comparison of b1s1e2-Fc to 9d9, an antagonistic anti-CTLA-4 antibody, allowed for interrogation of the separate contributions of CTLA-4 antagonism and Treg depletion to efficacy. Despite equivalent levels of intratumoral Treg depletion, 9d9 achieved more long-term cures than b1s1e2-Fc in MC38 tumors, demonstrating that CTLA-4 antagonism provided additional survival benefit. Consistent with prior reports that CTLA-4 antagonism enhances priming, treatment with 9d9, but not b1s1e2-Fc, increased the percentage of activated T cells in the tumor-draining lymph node (tdLN). Treg depletion with either construct was restricted to the tumor due to insufficient surface CTLA-4 expression on Tregs in other compartments. Through intratumoral administration of diphtheria toxin in Foxp3-DTR mice, we show that depletion of both intratumoral and nodal Tregs provided even greater survival benefit than 9d9, consistent with Treg-driven restraint of priming in the tdLN. Our data demonstrate that anti-CTLA-4 therapies require both CTLA-4 antagonism and intratumoral Treg depletion for maximum efficacy-but that potential future therapies also capable of depleting nodal Tregs could show efficacy in the absence of CTLA-4 antagonism.

Development and function of FOXP3+ regulators of immune responses

The Forkhead Box P3 (FOXP3) protein is an essential transcription factor for the development and function of regulatory T cells (Tregs), involved in the maintenance of immunological tolerance. Although extensive research over the last decade has investigated the critical role of FOXP3+ cells in preserving immune homeostasis, our understanding of their specific functions remains limited. Therefore, unveiling the molecular mechanisms underpinning the up- and downstream transcriptional regulation of and by FOXP3 is crucial for developing Treg-targeted therapeutics. Dysfunctions in FOXP3+ Tregs have also been found to be inherent drivers of autoimmune disorders and have been shown to exhibit multifaceted functions in the context of cancer. Recent research suggests that these cells may also be involved in tissue-specific repair and regeneration. Herein, we summarize current understanding of the thymic-transcriptional regulatory landscape of FOXP3+ Tregs, their epigenetic modulators, and associated signaling pathways. Finally, we highlight the contributions of FOXP3 on the functional development of Tregs and reflect on the clinical implications in the context of pathological and physiological immune responses.

Characterization of intratumoral tertiary lymphoid structures in pancreatic ductal adenocarcinoma: cellular properties and prognostic significance

BACKGROUND

Tumor-associated tertiary lymphoid structures (TLSs) are functional immune-responsive niches that are not fully understood in pancreatic ductal adenocarcinoma (PDAC).

METHODS

Fluorescent multiplex immunohistochemistry was performed on sequential sections of surgically resected tumor tissues from 380 PDAC patients without preoperative treatment (surgery alone (SA)) and 136 patients pretreated with neoadjuvant treatment (NAT). Multispectral images were processed via machine learning and image processing platforms, inForm V.2.4 and HALO V.3.2; TLS regions were segmented, and the cells were identified and quantified. The cellular composition and immunological properties of TLSs and their adjacent tissues in PDAC were scored and compared, and their association with prognosis was further examined.

RESULTS

Intratumoral TLSs were identified in 21.1% (80/380) of patients in the SA group and 15.4% (21/136) of patients in the NAT group. In the SA group, the presence of intratumoral TLSs was significantly associated with improved overall survival (OS) and progression-free survival. The existence of intratumoral TLSs was correlated with elevated levels of infiltrating CD8+T, CD4+T, B cells and activated immune cells in adjacent tissues. A nomogram model was generated with TLS presence as a variable, which successfully predicted PDAC patient OS in an external validation cohort (n=123). In the NAT group, samples exhibited a lower proportion of B cells and a higher proportion of regulatory T cells within intratumoral TLSs. Additionally, these TLSs were smaller in size, with a lower overall maturation level and reduced immune cell activation, and the prognostic value of TLS presence was insignificant in the NAT cohort.

CONCLUSION

Our study systematically revealed the cellular properties and prognostic values of intratumoral TLSs in PDAC and described the potential impact of NAT on TLS development and function.

Advances in efficacy prediction and monitoring of neoadjuvant immunotherapy for non-small cell lung cancer

The use of immune checkpoint inhibitors (ICIs) has become mainstream in the treatment of non-small cell lung cancer (NSCLC). The idea of harnessing the immune system to fight cancer is fast developing. Neoadjuvant treatment in NSCLC is undergoing unprecedented change. Chemo-immunotherapy combinations not only seem to achieve population-wide treating coverage irrespective of PD-L1 expression but also enable achieving a pathological complete response (pCR). Despite these recent advancements in neoadjuvant chemo-immunotherapy, not all patients respond favorably to treatment with ICIs plus chemo and may even suffer from severe immune-related adverse effects (irAEs). Similar to selection for target therapy, identifying patients most likely to benefit from chemo-immunotherapy may be valuable. Recently, several prognostic and predictive factors associated with the efficacy of neoadjuvant immunotherapy in NSCLC, such as tumor-intrinsic biomarkers, tumor microenvironment biomarkers, liquid biopsies, microbiota, metabolic profiles, and clinical characteristics, have been described. However, a specific and sensitive biomarker remains to be identified. Recently, the construction of prediction models for ICI therapy using novel tools, such as multi-omics factors, proteomic tests, host immune classifiers, and machine learning algorithms, has gained attention. In this review, we provide a comprehensive overview of the different positive prognostic and predictive factors in treating preoperative patients with ICIs, highlight the recent advances made in the efficacy prediction of neoadjuvant immunotherapy, and provide an outlook for joint predictors.

Relationship between Preoperative Pyuria and Bacille Calmette-Guerin Treatment in Intravesical Recurrence after Transurethral Resection of High-Risk, Non-Muscle Invasive, Bladder Carcinoma: A Retrospective Study of Human Data

Some researchers have found that preoperative pyuria is a risk factor for recurrence after transurethral resection of high-risk non-muscle invasive bladder cancer. However, to our knowledge, none have clarified the risks associated with pyuria according to bacille Calmette-Guerin (BCG) treatment status. We retrospectively selected patients with high-risk non-muscle invasive bladder cancer according to Japanese Urological Association guidelines. Pyuria was defined as ≥10 white blood cells per high-powered field. We analyzed recurrence-free rates (RFS) in 424 patients who had and had not undergone BCG treatment. The median duration of follow-up was 45.2 months. According to multivariate analysis, postoperative intravesical BCG induction and preoperative pyuria were independent risk factors for intravesical recurrence in the whole study cohort. We found no significant risk factors for recurrence in the BCG-treated group (n = 179). In the non-BCG-treated group (n = 245), patients with pyuria were much more frequently female and more often had T1 disease than patients without pyuria. According to univariate and multivariate analysis, preoperative pyuria is an independent risk factor for intravesical recurrence. There was no significant difference in the severity of pyuria between the BCG and non-BCG-treated groups. Aggressive BCG treatment may need to be considered in patients with high-risk NMIBC and pyuria.

Tregs constrain CD8+ T cell priming required for curative intratumorally anchored anti-4-1BB immunotherapy

Although co-stimulation of T cells with agonist antibodies targeting 4-1BB (CD137) improves antitumor immune responses in preclinical studies, clinical development has been hampered by on-target, off-tumor toxicity. Here, we report the development of a tumor-anchored ɑ4-1BB agonist (ɑ4-1BB-LAIR), which consists of an ɑ4-1BB antibody fused to the collagen binding protein LAIR. While combination treatment with an antitumor antibody (TA99) displayed only modest efficacy, simultaneous depletion of CD4+ T cells boosted cure rates to over 90% of mice. We elucidated two mechanisms of action for this synergy: ɑCD4 eliminated tumor draining lymph node Tregs, enhancing priming and activation of CD8+ T cells, and TA99 + ɑ4-1BB-LAIR supported the cytotoxic program of these newly primed CD8+ T cells within the tumor microenvironment. Replacement of ɑCD4 with ɑCTLA-4, a clinically approved antibody that enhances T cell priming, produced equivalent cure rates while additionally generating robust immunological memory against secondary tumor rechallenge.