Targeting Tertiary Lymphoid Structures for Tumor Immunotherapy

Simultaneous immunomodulation and epithelial-to-mesenchymal transition drives lung adenocarcinoma progression

Lung cancer remains the deadliest cancer in the United States, with lung adenocarcinoma (LUAD) as its most prevalent subtype. While computed tomography (CT)-based screening has improved early detection and enabled curative surgeries, the molecular and cellular dynamics driving early-stage LUAD progression remain poorly understood, limiting non-surgical treatment options. To address this gap, we profiled 2.24 million cells from 122 early-stage LUAD patients using multiplexed imaging mass cytometry (IMC). This analysis revealed the molecular, spatial, and temporal dynamics of LUAD development. Our findings uncover a binary progression model. LUAD advances through either inflammation, driven by a balance of cytotoxic and regulatory immune activity, or fibrosis, characterized by stromal activation. Surprisingly, tumor cell populations did not increase significantly. Instead, they displayed a mixed phenotypic profile consistent with epithelial-to-mesenchymal transition (EMT), effectively masking the expansion of malignant cells. Furthermore, we addressed discrepancies between CT-based and histology-based subtyping. CT scans, while non-invasive, often mischaracterize invasive fibrotic tumors-which account for 20.5% of LUAD cases-as mild, non-solid ground glass opacities (GGOs). Using high-content IMC imaging, we demonstrate that these tumors harbor significant risks and advocate for improved diagnostic strategies. These strategies should integrate molecular profiling to refine patient stratification and therapeutic decision-making. Altogether, our study provides a high-resolution, systems-level view of the tumor microenvironment in early-stage LUAD. We characterize key transitions in oncogenesis and propose a precision-driven framework to enhance the detection and management of aggressive disease subtypes.

The Presence of Tertiary Lymphoid Structures Provides New Insight Into the Clinicopathological Features and Prognosis of Patients With Breast Cancer

Background

Tertiary lymphoid structures (TLSs) have been proven to be predictive biomarkers of favorable clinical outcomes and response to immunotherapies in several solid malignancies. Nevertheless, the effect of TLSs in patients with breast cancer (BC) remains controversial. The objective of the current study is to investigate the clinicopathological and prognostic significance of TLSs in BC. Given the unique difficulties for detecting and quantifying TLSs, a TLS-associated gene signature based on The Cancer Genome Atlas (TCGA) BC cohort was used to validate and supplement our results.

Methods

Electronic platforms (PubMed, Web of Science, EMBASE, the Cochrane Library, CNKI, and Wanfang) were searched systematically to identify relevant studies as of January 11, 2022. We calculated combined odds ratios (ORs) with 95% confidence intervals (CIs) to determine the relationship between clinicopathological parameters and TLSs. The pooled hazard ratios (HRs) and 95% CIs were also calculated to evaluate the prognostic significance of TLSs. The TLS signature based on the TCGA BC cohort was applied to validate and supplement our results.

Results

Fifteen studies with 3,898 patients were eligible for enrollment in our study. The combined analysis indicated that the presence of TLSs was related to improved disease-free survival (DFS) (HR = 0.61, 95% CI: 0.41-0.90, p < 0.05) and overall survival (OS) (HR = 1.66, 95% CI: 1.26-2.20, p < 0.001). Additionally, the presence of TLSs was positively correlated with early tumor TNM stage and high tumor-infiltrating lymphocytes. TLS presence was positively related to human epidermal growth factor receptor 2 (HER-2) and Ki-67 but inversely correlated with the status of estrogen and progesterone receptor. Simultaneously, our study found that tumor immune microenvironment was more favorable in the high-TLS signature group than in the low-TLS signature group. Consistently, BC patients in the high-TLS signature group exhibited better survival outcomes compared to those in the low-TLS signature group, suggesting that TLSs might be favorable prognostic biomarkers.

Conclusions

TLS presence provides new insight into the clinicopathological features and prognosis of patients with BC, whereas the factors discussed limited the evidence quality of this study. We look forward to consistent methods to define and characterize TLSs, and more high-quality prospective clinical trials designed to validate the value of TLSs alone or in combination with other markers.

Tertiary lymphoid structure and B-cell-related pathways: A potential target in tumor immunotherapy

The tertiary lymphoid structure (TLS), also referred to as the ectopic lymphoid structure, has recently become a focus of attention. The TLS consists of T-cell and B-cell-rich regions, as well as plasma cells, follicular helper T cells, follicular dendritic cells (FDCs), germinal centers (GCs) and high endothelial venules. TLSs can be divided into different subtypes and mature stages according to the density of FDCs and GCs. The TLS serves as an effective site in which an antitumor inflammatory response is generated through infiltrating immune cells. B-cell-related pathways, known as the CXC chemokine ligand 13/CXC chemokine receptor type 5 axis and the CC chemokine ligand (CCL)19/CCL21/CC-chemokine receptor 7 axis, play a key role in the generation and formation of TLSs. The aim of the present review was to systematically summarize updated research progress on the formation, subtypes, evaluation and B-cell-related pathways of TLSs. Furthermore, researchers have previously reported that TLSs are present in several types of solid cancers and that they are associated with survival outcomes. Therefore, studies on TLS in breast, lung, colorectal and ovarian cancers and melanoma were summarized and compared. The TLS and B-cell-related pathways require further investigation as important immune signals and promising new immunotherapy targets in the era of T-cell therapy revolution.

Tertiary lymphoid structures are associated with favorable survival outcomes in patients with endometrial cancer

Immunotherapy has experienced remarkable growth recently. Tertiary lymphoid structures (TLSs) and B cells may play a key role in the immune response and have a survival benefit in some solid tumors, but there have been no reports about their role in endometrial cancer (EC). We investigated the clinicopathological and pathobiological characteristics of the tumor microenvironment (TME) in EC. Patients with EC at Kyoto University Hospital during 2006–2011 were retrospectively included. In 104 patients with EC who met study inclusion criteria, 81 (77.9%) had TLSs, which consisted of areas rich in CD20⁺ B cells, CD8⁺ T cells, CD4⁺ T cells, and CD38⁺ plasma cells. The absence of TLS was independently associated with tumor progression (HR, 0.154; 95% CI, 0.044–0.536; P = 0.003). Patients with TLSs that included CD23⁺ germinal centers had better PFS. All tumor infiltrating lymphocytes were counted in the intratumor site. The number of CD20⁺ B cells was significantly larger in patients with TLSs than in those without TLS (P < 0.001). CD20⁺ B cells numbers were positively correlated with other TLSs. The larger number of CD20⁺ B cell was associated with better PFS (P = 0.015). TLSs and B cell infiltration into tumors are associated with favorable survival outcomes in patients with EC. They may represent an active immune reaction of the TME in endometrial cancer.

New insights into the interaction of the immune system with non-small cell lung carcinomas

The basis of current and future lung cancer immunotherapy depends mainly on our knowledge of the molecular mechanisms of interactions between cancer and immune cells (ICs), as well as on interactions occurring between the different populations of intra-tumor ICs. These interactions are very complex, as virtually all immune cell types, including macrophages, neutrophils, mast cells, natural killer (NK) cells, dendritic cells and T and B lymphocytes can infiltrate lung cancer tissues at the same time. Moreover these interactions lead to progressive emergence of an imbalance in ICs. Initially ICs have an anti-tumor effect but then induce immune tolerance and eventually tumor progression and dissemination. All the cells of innate and adaptive intra-tumor immunity engage in this progressive phenotypic switch. A majority of non-small cell lung carcinoma (NSCLC) patients do not benefit from the expected positive responses associated with current immunotherapy. Thus, there is urgent need to better understand the different roles of the associated cancer ICs. This review summarizes some of the new insights into this domain, with particular focus on: the myeloid cell population associated with tumors, the tertiary lymphoid structures (TLSs), the role of the P2 purinergic receptors (P2R) and ATP, and the new concept of the “liquid microenvironment” implying blood circulating ICs.

Like a Rolling Stone: Sting-Cgas Pathway and Cell-Free DNA as Biomarkers for Combinatorial Immunotherapy

Combining immune checkpoint inhibitors with other treatments likely to harness tumor immunity is a rising strategy in oncology. The exact modalities of such a combinatorial regimen are yet to be defined, and most attempts have relied so far on concomitant dosing, rather than sequential or phased administration. Because immunomodulating features are likely to be time-, dose-, and-schedule dependent, the need for biomarkers providing real-time information is critical to better define the optimal time-window to combine immune checkpoint inhibitors with other drugs. In this review, we present the various putative markers that have been investigated as predictive tools with immune checkpoint inhibitors and could be used to help further combining treatments. Whereas none of the current biomarkers, such as the PDL1 expression of a tumor mutational burden, is suitable to identify the best way to combine treatments, monitoring circulating tumor DNA is a promising strategy, in particular to check whether the STING-cGAS pathway has been activated by cytotoxics. As such, circulating tumor DNA could help defining the best time-window to administrate immune checkpoint inhibitors after that cytotoxics have been given.

Biological mechanisms of ectopic lymphoid structure formation and their pathophysiological significance

Ectopic lymphoid structures (ELS) or tertiary lymphoid organs are structures with the organization similar to the one of secondary lymphoid organs, formed in non-lymphoid tissues. They are considered to be an important site for the lymphocytic physiological and pathological role in conditions such are chronic infections, autoimmune diseases, cancer, and allograft rejection. Although similar to the secondary lymphoid tissues, the initiation of ELS formation is not preprogramed and requires chronic inflammation, expression of homeostatic chemokines, and lymphotoxin beta receptor activation. Importantly, while ELS formation may be considered beneficiary in antimicrobial and antitumor immunity, the persistence of these active lymphoid structures within the tissue increase the chance for development of autoimmunity and lymphoma. This paper is providing an overview of biological mechanisms involved in ELS formation, as well as the overview of the pathophysiological role of these structures. In addition, the paper discusses the possibility to therapeutically target ELS formation, bearing in mind their bivalent nature and role in different pathophysiological conditions.

Adaptive Immunity and the Tumor Microenvironment

The adaptive immune response is a 500-million-year-old (the "Big Bang" of Immunology) collective set of rearranged and/or selected receptors capable of recognizing soluble and cell surface molecules or shape (B cells, antibody), endogenous and extracellular peptides presented by Major Histocompatibility (MHC) molecules including Class I and Class II (conventional αβ T cells), lipid in the context of MHC-like molecules of the CD1 family (NKT cells), metabolites and B7 family molecules/butyrophilins with stress factors (γδT cells), and stress ligands and absence of MHC molecules (natural killer, NK cells). What makes tumor immunogenic is the recruitment of initially innate immune cells to sites of stress or tissue damage with release of Damage-Associated Molecular Pattern (DAMP) molecules. Subsequent maintenance of a chronic inflammatory state, representing a balance between mature, normalized blood vessels, innate and adaptive immune cells and the tumor provides a complex tumor microenvironment serving as the backdrop for Darwinian selection, tumor elimination, tumor equilibrium, and ultimately tumor escape. Effective immunotherapies are still limited, given the complexities of this highly evolved and selected tumor microenvironment. Cytokine therapies and Immune Checkpoint Blockade (ICB) enable immune effector function and are largely dependent on the shape and size of the B and T cell repertoires (the "adaptome"), now accessible by Next-Generation Sequencing (NGS) and dimer-avoidance multiplexed PCR. How immune effectors access the tumor (infiltrated, immune sequestered, and immune desserts), egress and are organized within the tumor are of contemporary interest and substantial investigation.

Oral cancer-associated tertiary lymphoid structures: gene expression profile and prognostic value

Tertiary lymphoid structure (TLS) provides a local and critical microenvironment for both cellular and humoral immunity and supports effective antigen presentation and lymphocyte activation. However, the gene expression profile and prognostic significance of TLS in oral cancer remain largely unrevealed. In this study, we found the presence of both intratumoral and peritumoral TLSs in a series of 65 patients with oral cancer treated by surgical resection, with positive detection rates of 33.8 and 75.4%, respectively. The presence of intratumoral TLSs, but not peritumoral TLSs, was significantly associated with decreased P53 and Ki67 scores (P = 0·027 and 0·047, respectively). The survival analyses revealed that oral cancer patients with higher grades of TLSs was associated with improved disease-free survival (DFS) and overall survival (OS) (P = 0·037 and 0·031, respectively). Gene expression profiling analysis of the cytokines and chemokines responsible for lymph-node neogenesis identified a three-up-regulated-gene set, i.e. IL7, LTB and CXCL13, which was shown to be correlated with human oral cancer-associated TLSs. This study provides a framework for better understanding of oral cancer-associated TLSs and for delineating future innovative prognostic biomarkers and immune therapeutic strategies for oral cancer.