Heterogeneity of tertiary lymphoid structures in cancer

ScRNA+TCR-seq Reveals the Proportion and Characteristics of Dual TCR T Cells in Tertiary Lymphoid Structures(TLS) in Pemphigus

The origin, characteristics, and the effects/mechanisms of lymphocytes within tertiary lymphoid structures (TLS) in pemphigus pathological skin tissue, as well as their role in pemphigus pathogenesis, remain unclear. Using scRNA+TCR-seq analysis, this study revealed that pemphigus TLS (P_TLS) contain a higher proportion of dual T-cell receptor (TCR) T cells compared to chronic idiopathic erythroderma (CIE) and healthy control (HC) skin tissues. Notably, P_TLS exhibit a unique enrichment of clonally expanded dual TCR CXCL13+CD4+ T cells, while the proportions of dual TCR Treg and dual TCR CD8+ T cells are reduced. However, CXCR5 is significantly upregulated in dual TCR Treg cells within P_TLS. The dual TCR T cells within P_TLS exhibit significant heterogeneity in their top 10 mRNA expressions compared to HC and CIE. For instance, P_TLS shows high expression of IL-17F, among others. There is also substantial heterogeneity in shared CDR3 (Complementarity Determining Region 3) sequences and V gene usage among single and dual TCR T cells across HC, P_TLS, and CIE. These findings provide insights and a basis for further exploring TLS formation, the origin, effects, and mechanisms of potential novel T-cell subsets in pemphigus pathogenesis.

Tertiary lymphoid structures in gliomas: impact on tumour immunity and progression

Tertiary lymphoid structures (TLSs) are ectopic lymphoid formations that develop in chronically inflamed tissues, including various solid tumours. In the context of gliomas, the presence of TLSs has recently attracted considerable attention because of their potential implications in tumour immunology and therapy. The tumour immune microenvironment (TIME) plays a crucial role in cancer progression, and tumour-infiltrating immune cells (TILs) are key players in this environment. These immune cell aggregates, known as TLSs, display distinct characteristics across different solid tumours. However, central nervous system (CNS) tumours are highly heterogeneous, and the immune environment within these tumours is often more deficient than that of peripheral tissue tumours. This leads to differences in the formation and function of TLSs in CNS tumours. These variations are particularly relevant in the context of glioma immunotherapy and could have important implications for treatment strategies. This review focuses on the composition and function of TLSs, examines the complexity of the glioblastoma (GBM) immune microenvironment, and highlights the unique characteristics of TLSs in GBM, providing new theoretical insights and practical foundations for targeting TLSs in glioma immunotherapy.

Spatial transcriptomic characteristics of gastric cancer in young and the expression and role of TMEM176B in gastric cancer cells

BACKGROUND

Gastric cancer in young (GCY) is increasing in incidence with poor prognosis. Current screening and molecular methods are inadequate, necessitating new approaches to explore its pathogenesis. This study used spatial transcriptomic sequencing (ST-seq) to analyze the cellular composition of gastric cancer (GC) tumors, compare gene expression patterns, explore signaling pathways, and investigate the role of the differentially expressed gene (DEG) TMEM176B in GCY.

METHODS

The surgical specimens of six patients with GCY were included to construct a tissue microarray containing the tumor core region (TCR), cancer-adjacent tissue (CAT), and normal gastric tissue (NGT). ST-seq was performed to obtain the transcript expression levels at different spatial locations. After quality control, normalization, standardization, clustering, dimensionality reduction, and cell-type prediction analyses were carried out to identify the DEGs. Gene Ontology and Kyoto Encyclopedia of Genes and Genomes pathway analyses were used to clarify the underlying mechanisms of GC. Based on the results, TMEM176B was selected for functional analysis. Western blotting was used to assess TMEM176B expression in normal gastric cells and cancerous cells. shRNA-mediated TMEM176B knockdown in cancer cells was used for phenotypic analysis, proliferation assays, and apoptosis experiments.

RESULTS

This study identified heterogeneous cell populations in GCY tissues. Exactly 18,082 DEGs were found between the TCR and CAT, mainly enriched in the IL-17, AGE-RAGE, and relaxin pathways. Moreover, 17,586 DEGs were identified between the TCR and NGT, primarily related to the HIF-1 and apoptosis pathways. TMEM176B was a key DEG in the TCR vs. CAT and TCR vs. NGT comparisons. It was highly expressed in GCY tissues and GC cell lines. Further analysis using The Cancer Genome Atlas database confirmed its oncogenic effects. TMEM176B knockdown in GC cell lines inhibited cell proliferation (reduced CCK8 and colony formation), increased apoptosis (higher Bax/Bcl2 ratio), and arrested the cell cycle in the G0/G1 phase.

CONCLUSIONS

This study used ST-seq to map the transcriptomic profiles of the TCR, CAT, and NGT in patients with GCY, investigating gene spatial expression patterns and tumor heterogeneity. We identified TMEM176B's role in GC development and progression, offering molecular targets and a foundation for future treatments.

Tumor Heterogeneity and the Immune Response in Non-Small Cell Lung Cancer: Emerging Insights and Implications for Immunotherapy

Resistance to immune checkpoint inhibitors (ICIs) represents a major challenge for the effective treatment of non-small cell lung cancer (NSCLC). Tumor heterogeneity has been identified as an important mechanism of treatment resistance in cancer and has been increasingly implicated in ICI resistance. The diversity and clonality of tumor neoantigens, which represent the target epitopes for tumor-specific immune cells, have been shown to impact the efficacy of immunotherapy. Advances in genomic techniques have further enhanced our understanding of clonal landscapes within NSCLC and their evolution in response to therapy. In this review, we examine the role of tumor heterogeneity during immune surveillance in NSCLC and highlight its spatial and temporal evolution as revealed by modern technologies. We explore additional sources of heterogeneity, including epigenetic and metabolic factors, that have come under greater scrutiny as potential mediators of the immune response. We finally discuss the implications of tumor heterogeneity on the efficacy of ICIs and highlight potential strategies for overcoming therapeutic resistance.

Exploring effects of gut microbiota on tertiary lymphoid structure formation for tumor immunotherapy

Anti-tumor immunity, including innate and adaptive immunity is critical in inhibiting tumorigenesis and development of tumor. The adaptive immunity needs specific lymph organs such as tertiary lymphoid structures (TLSs), which are highly correlated with improved survival outcomes in many cancers. In recent years, with increasing attention on the TLS in tumor microenvironment, TLSs have emerged as a novel target for anti-tumor therapy. Excitingly, studies have shown the contribution of TLSs to the adaptive immune responses. However, it is unclear how TLSs to form and how to more effectively defense against tumor through TLS formation. Recent studies have shown that the inflammation plays a critical role in TLS formation. Interestingly, studies have also found that gut microbiota can regulate the occurrence and development of inflammation. Therefore, we here summarize the potential effects of gut microbiota- mediated inflammation or immunosuppression on the TLS formation in tumor environments. Meanwhile, this review also explores how to manipulate mature TLS formation through regulating gut microbiota/metabolites or gut microbiota associated signal pathways for anti-tumor immunity, which potentially lead to a next-generation cancer immunotherapy.

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.

Phosphatidylserine externalization as immune checkpoint in cancer

Cancer is the second leading cause of mortality worldwide. Despite recent advances in cancer treatment including immunotherapy with immune checkpoint inhibitors, new unconventional biomarkers and targets for the detection, prognosis, and treatment of cancer are still in high demand. Tumor cells are characterized by mutations that allow their unlimited growth, program their local microenvironment to support tumor growth, and spread towards distant sites. While a major focus has been on altered tumor genomes and proteomes, crucial signaling molecules such as lipids have been underappreciated. One of these molecules is the membrane phospholipid phosphatidylserine (PS) that is usually found at cytosolic surfaces of cellular membranes but can be rapidly and massively shuttled to the extracellular leaflet of the plasma membrane during apoptosis to serve as a limiting factor for immune responses. These immunosuppressive interactions are exploited by tumor cells to evade the immune system. In this review, we describe mechanisms of immune regulation in tumors, discuss if PS may constitute an inhibitory immune checkpoint, and describe current and future strategies for targeting PS to reactivate the tumor-associated immune system.

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.

Heterogeneity of Cervical Cancer-Associated Tertiary Lymphoid Structures (TLSs) and Their Specific Interrelation With Clinicopathological Parameters

OBJECTIVE

The study investigates morphological variants of tertiary lymphoid structures (TLSs) in relation to cervical cancer development, from intraepithelial neoplastic lesions to invasive carcinomas with locoregional lymph node metastases.

MATERIALS AND METHODS

This retrospective analysis comprised 100 cervical cancer cases who had had total hysterectomy with lymphadenectomy in the Obstetrics and Gynecology Clinic of the Municipal Emergency Clinical Hospital of Timisoara, Romania, from 2020 to 2023. Bilateral ilio obturator lymphadenectomy and total hysterectomy were used to acquire biopsy samples. The presence of germinal centers, other stromal structures, TLS density, topography relative to the tumor lesion, and malignant cell islets are used to evaluate and classify TLS.

RESULTS

We first globally evaluated the total number of TLSs (TLS.T). We observed topographically two places in the cervical stroma: TLS immediately peritumorally positioned and TLS away from tumor lesions. Invasive carcinomas have bigger superficial TLSs with a well-defined germinal center. As they approached the tumor, TLSs increased in size and density. We also detected a special type of TLS associated with nerve fibers, which we named tertiary lymphoid structures associated with nerves (TLS.N). The total number of TLSs did not correlate with age, but 85.71% of patients presenting TLS.N were aged between 59 and 72 years old. Our findings showed a strong correlation between age (postmenopausal, p = 0.005) and TLS-N presence. Similarly, TLS parameters evolved with tumor differentiation. Only in the TLS.N group did the tumoral grading (G) 3 correlate with TLS (p = 0.041), while TLS.T did not correlate with G. All TLS.N. patients, except one, had lymphovascular invasion and massive histiocytosis. On the first point, TLS.N correlated with lymphovascular invasion (p = 0.032).

CONCLUSION

Tertiary lymphoid structures associated with nerves have not been previously reported in cervical cancer, and their effects on prognosis and aggression are unknown. There was a substantial association between TLSs.N presence and age over 60, suggesting it is exclusive to menopausal women. They were also substantially connected with lymphovascular invasion and G3, suggesting they may be a poor cervical cancer prognostic factor.

Distinct roles for interleukin-23 receptor signaling in regulatory T cells in sporadic and inflammation-associated carcinogenesis

Introduction

The pro-inflammatory cytokine interleukin-23 (IL-23) has been implicated in colorectal cancer (CRC). Yet, the cell-specific contributions of IL-23 receptor (IL-23R) signaling in CRC remain unknown. One of the cell types that highly expresses IL-23R are colonic regulatory T cells (Treg cells). The aim of this study was to define the contribution of Treg cell-specific IL-23R signaling in sporadic and inflammation-associated CRC.

Methods

In mice, the role of IL-23R in Treg cells in colitis-associated cancer (CAC) was investigated using azoxymethane/dextran sodium sulphate in wild-type Treg cell reporter mice (WT, Foxp3 YFP-iCre), and mice harboring a Treg cell-specific deletion of IL-23 (Il23r ΔTreg). The role of IL-23R signaling in Treg cells in sporadic CRC was examined utilizing orthotopic injection of the syngeneic colon cancer cell line MC-38 submucosally into the colon/rectum of mice. The function of macrophages was studied using clodronate. Finally, single-cell RNA-seq of a previously published dataset in human sporadic cancer was reanalyzed to corroborate these findings.

Results

In CAC, Il23r ΔTreg mice had increased tumor size and increased dysplasia compared to WT mice that was associated with decreased tumor-infiltrating macrophages. In the sporadic cancer model, Il23r ΔTreg mice had increased survival and decreased tumor size compared to WT mice. Additionally, MC-38 tumors of Il23r ΔTreg mice exhibited a higher frequency of pro-inflammatory macrophages and IL-17 producing CD4+ T cells. The decreased tumor size in Il23r ΔTreg mice was macrophage-dependent. These data suggest that loss of IL-23R signaling in Treg cells permits IL-17 production by CD4+ T cells that in turn promotes pro-inflammatory macrophages to clear tumors. Finally, analysis of TCGA data and single-cell RNA-seq analysis of a previously published dataset in human sporadic cancer, revealed that IL23R was highly expressed in CRC compared to other cancers and specifically in tumor-associated Treg cells.

Conclusion

Inflammation in colorectal carcinogenesis differs with respect to the contribution of IL-23R signaling in regulatory T cells.