Stromal and Immune Cell Dynamics in Tumor Associated Tertiary Lymphoid Structures and Anti-Tumor Immune Responses

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.

Characteristics and clinical significance of tertiary lymphoid structures in OSCC

OBJECTIVES

This study aimed to investigate the characteristics of tertiary lymphoid structures (TLSs) in oral squamous cell carcinoma (OSCC) and their association with clinical and pathological features.

MATERIALS AND METHODS

12 TLS-related chemokines in TCGA database were analyzed to investigate the TLSs in OSCC. The density, maturity, and location of TLSs in a large cohort of 189 OSCC patients (114 of which had clinical and prognostic information) were assessed. And the significance between TLSs and clinicopathologic characteristics was analyzed.

RESULTS

Bioinformatics and analysis showed that TLSs were associated with better clinical outcomes in OSCC. Histological staining and analysis showed that the overall survival rate of the high-density group (71/112, 63.4%) was significantly higher (p < 0.0001) than that of the low-density group (41/112, 36.6%), and the high-density group had fewer lymph node metastases (50.0%/68.3%, p = 0.021). And TLSs were divided into 4 types according to the maturity and location. Different types of TLSs are associated with prognosis (OS, p < 0.0001), clinical features (T stage, p = 0.028; degree of differentiation, p = 0.043), and precancerous lesion types (OSF, p = 0.049) of OSCC patients.

CONCLUSION

TLSs were closely associated with better OSCC prognosis, and a more systematic classification may better guide the formulation of further treatment options.

Tertiary lymphoid structures in colorectal cancer - organization and immune cell interactions

Tertiary lymphoid structures (TLS), formerly recognized as Crohn's-like structures, serve as crucial biomarkers for evaluating the progression of colorectal cancer (CRC). Understanding their spatial distribution, cellular composition, and interactions within CRC is paramount for comprehending the immune response in the tumor microenvironment (TME). TLS are comprised of a T-cellular compartment and a B-cellular compartment, the latter encompassing follicular dendritic cells (FDCs), high endothelial venules (HEVs), and lymphatic vessels. While T helper cells predominate in cancer TLS, the specific functions of their subpopulations remain inadequately understood. Notably, T follicular helper (Tfh) cells play a central role in the activation of CD8+ T cells, and both Tfh cells and Tfh-associated genes have been linked to enhanced CRC survival. In stage II CRC TLS, an escalation in the number of FoxP3+ T regulatory cells (Tregs) is regarded as a negative prognostic factor. Moreover, within TLS, T lymphocytes shield B lymphocytes from the immunosuppressive effects of the TME. B lymphocyte activation is succeeded by class recombination (CSR) and somatic hypermutation (SHM). Dendritic cells (DCs) constitute a vital cellular component of the TLS T compartment. During steady state and early stages of CRC, specialized antigen-presenting cells such as DCs migrate to regional lymph nodes through afferent lymphatics. They deliver MHC antigen-derived peptide complexes (tumor antigens) to naïve CD4+ and CD8+ T cells, which subsequently infiltrate the tumor site as antigen-specific T cells. Key DC markers studied in TLS include CD83 and DC-LAMP. Research has indicated that the DC-LAMP gene signature in tumor TLS reflects Th1 cell targeting, cytotoxicity, and T cell activation. This review comprehensively outlines the functions performed by distinct cell subsets within tertiary lymphoid structures (TLS) in tumors.

SDePER: a hybrid machine learning and regression method for cell-type deconvolution of spatial barcoding-based transcriptomic data

Spatial barcoding-based transcriptomic (ST) data require deconvolution for cellular-level downstream analysis. Here we present SDePER, a hybrid machine learning and regression method to deconvolve ST data using reference single-cell RNA sequencing (scRNA-seq) data. SDePER tackles platform effects between ST and scRNA-seq data, ensuring a linear relationship between them while addressing sparsity and spatial correlations in cell types across capture spots. SDePER estimates cell-type proportions, enabling enhanced resolution tissue mapping by imputing cell-type compositions and gene expressions at unmeasured locations. Applications to simulated data and four real datasets showed SDePER's superior accuracy and robustness over existing methods.

Macrophages and tertiary lymphoid structures as indicators of prognosis and therapeutic response in cancer patients

Tertiary lymphoid structures (TLS) can reflect cancer prognosis and clinical outcomes in various tumour tissues. Tumour-associated macrophages (TAMs) are indispensable components of the tumour microenvironment and play crucial roles in tumour development and immunotherapy. TAMs are associated with TLS induction via the modulation of the T cell response, which is a major component of the TLS. Despite their important roles in cancer immunology, the subtypes of TAMs that influence TLS and their correlation with prognosis are not completely understood. Here, we provide novel insights into the role of TAMs in regulating TLS formation. Furthermore, we discuss the prognostic value of these TAM subtypes and TLS, as well as the current antitumour therapies for inducing TLS. This study highlights an entirely new field of TLS regulation that may lead to the development of an innovative perspective on immunotherapy for cancer treatment.

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.

Tertiary lymphoid structures: new immunotherapy biomarker

Immunotherapy shows substantial advancement in cancer and is becoming widely used in clinical practice. A variety of biomarkers have been proposed to predict the efficacy of immunotherapy, but most of them have low predictive ability. Tertiary lymphoid structures (TLSs), the aggregation of multiple lymphocytes, have been found to exist in various tumor tissues. TLSs have been shown to correlate with patient prognosis and immunotherapy response. This review summarizes the characteristics of TLSs and the inducing factors of TLS formation, presents available evidence on the role of TLSs in predicting immunotherapy response in different cancers, and lastly emphasizes their predictive potential for neoadjuvant immunotherapy efficacy.

Identifying specific TLS-associated genes as potential biomarkers for predicting prognosis and evaluating the efficacy of immunotherapy in soft tissue sarcoma

Background

The tertiary lymphatic structure (TLS) is an important component of the tumor immune microenvironment and has important significance in patient prognosis and response to immune therapy. However, the underlying mechanism of TLS in soft tissue sarcoma remains unclear.

Methods

A total of 256 RNAseq and 7 single-cell sequencing samples were collected from TCGA-SARC and GSE212527 cohorts. Based on published TLS-related gene sets, four TLS scores were established by GSVA algorithm. The immune cell infiltration was calculated via TIMER2.0 and "MCPcounter" algorithms. In addition, the univariate, LASSO, and multivariate-Cox analyses were used to select TLS-related and prognosis-significant hub genes. Single-cell sequencing dataset, clinical immunohistochemical, and cell experiments were utilized to validate the hub genes.

Results

In this study, four TLS-related scores were identified, and the total-gene TLS score more accurately reflected the infiltration level of TLS in STS. We further established two hub genes (DUSP9 and TNFSF14) prognosis markers and risk scores associated with soft tissue sarcoma prognosis and immune therapy response. Flow cytometry analysis showed that the amount of CD3, CD8, CD19, and CD11c positive immune cell infiltration in the tumor tissue dedifferentiated liposarcoma patients was significantly higher than that of liposarcoma patients. Cytological experiments showed that soft tissue sarcoma cell lines overexpressing TNFSF14 could inhibit the proliferation and migration of sarcoma cells.

Conclusion

This study systematically explored the TLS and related genes from the perspectives of bioinformatics, clinical features and cytology experiments. The total-gene TLS score, risk score and TNFSF14 hub gene may be useful biomarkers for predicting the prognosis and immunotherapy efficacy of soft tissue sarcoma.

Epigenetic targets to enhance antitumor immune response through the induction of tertiary lymphoid structures

Tertiary lymphoid structures (TLS) are ectopic lymphoid aggregates found in sites of chronic inflammation such as tumors and autoimmune diseases. The discovery that TLS formation at tumor sites correlated with good patient prognosis has triggered extensive research into various techniques to induce their formation at the tumor microenvironment (TME). One strategy is the exogenous induction of specific cytokines and chemokine expression in murine models. However, applying such systemic chemokine expression can result in significant toxicity and damage to healthy tissues. Also, the TLS formed from exogenous chemokine induction is heterogeneous and different from the ones associated with favorable prognosis. Therefore, there is a need to optimize additional approaches like immune cell engineering with lentiviral transduction to improve the TLS formation in vivo. Similarly, the genetic and epigenetic regulation of the different phases of TLS neogenesis are still unknown. Understanding these molecular regulations could help identify novel targets to induce tissue-specific TLS in the TME. This review offers a unique insight into the molecular checkpoints of the different stages and mechanisms involved in TLS formation. This review also highlights potential epigenetic targets to induce TLS neogenesis. The review further explores epigenetic therapies (epi-therapy) and ongoing clinical trials using epi-therapy in cancers. In addition, it builds upon the current knowledge of tools to generate TLS and TLS phenotyping biomarkers with predictive and prognostic clinical potential.

Systems immunology spanning tumors, lymph nodes, and periphery

The immune system defines a complex network of tissues and cell types that orchestrate responses across the body in a dynamic manner. The local and systemic interactions between immune and cancer cells contribute to disease progression. Lymphocytes are activated in lymph nodes, traffic through the periphery, and impact cancer progression through their interactions with tumor cells. As a result, therapeutic response and resistance are mediated across tissues, and a comprehensive understanding of lymphocyte dynamics requires a systems-level approach. In this review, we highlight experimental and computational methods that can leverage the study of leukocyte trafficking through an immunomics lens and reveal how adaptive immunity shapes cancer.

Localization and density of tertiary lymphoid structures associate with molecular subtype and clinical outcome in colorectal cancer liver metastases

BACKGROUND

Tertiary lymphoid structures (TLSs) have been proposed to assess the prognosis of patients with cancer. Here, we investigated the prognostic value and relevant mechanisms of TLSs in colorectal cancer liver metastases (CRCLM).

METHODS

603 patients with CRCLM treated by surgical resection from three cancer centers were included. The TLSs were categorized according to their anatomic subregions and quantified, and a TLS scoring system was established for intratumor region (T score) and peritumor region (P score). Differences in relapse-free survival (RFS) and overall survival (OS) between groups were determined. Multiplex immunohistochemical staining (mIHC) was used to determine the cellular composition of TLSs in 40 CRCLM patients.

RESULTS

T score positively correlated with superior prognosis, while P score negatively associated with poor survival (all p<0.05). Meanwhile, T score was positively associated with specific mutation subtype of KRAS. Furthermore, TLSs enrichment gene expression was significantly associated with survival and transcriptomic subtypes of CRCLM. Subsequently, mIHC showed that the densities of Treg cells, M2 macrophages and Tfh cells were significantly higher in intratumor TLSs than in peritumor TLSs (p=0.029, p=0.047 and p=0.041, respectively), and the frequencies of Treg cells and M2 macrophages were positively correlated with P score, while the frequencies of Tfh cells were positively associated with T scores in intratumor TLSs (all p<0.05). Next, based on the distribution and abundance of TLSs, an Immune Score combining T score and P score was established which categorized CRCLM patients into four immune classes with different prognosis (all p<0.05). Among them, patients with higher immune class have more favorable prognoses. The C-index of Immune Class for RFS and OS was higher than Clinical Risk Score statistically. These results were also confirmed by the other two validation cohorts.

CONCLUSIONS

The distribution and abundance of TLSs is significantly associated with RFS and OS of CRCLM patients, and a novel immune class was proposed for predicting the prognosis of CRCLM patients.