Germinal Centers Determine the Prognostic Relevance of Tertiary Lymphoid Structures and Are Impaired by Corticosteroids in Lung Squamous Cell Carcinoma

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.

Genetic profiles of oligometastatic non-small-cell lung cancer and corresponding brain metastases

OBJECTIVES

In patients with oligometastatic non-small-cell lung cancer (NSCLC), systemic therapy in combination with local ablative treatment of the primary tumour and all metastatic sites is associated with improved prognosis. For patient selection and treatment allocation, further knowledge about the molecular characteristics of the oligometastatic state is necessary. Here, we performed a genetic characterization of primary NSCLC and corresponding brain metastases (BM).

METHODS

We retrospectively identified patients with oligometastatic NSCLC and synchronous (<3 months) or metachronous (>3 months) BM who underwent surgical resection of both primary tumour and BM. Mutation profiling of formalin-fixed paraffin-embedded tumour cell blocks was performed by targeted next-generation sequencing using the Oncomine Focus Assay panel.

RESULTS

Sequencing was successful in 46 paired samples. An oncogenic alteration was present in 31 primary tumours (67.4%) and 40 BM (86.9%). The alteration of the primary tumours was preserved in the corresponding BM in 29 out of 31 cases (93.5%). The most prevalent oncogenic driver in both primary tumours and BM was a KRAS (Kirsten rat sarcoma viral oncogene) mutation (s = 21). In 16 patients (34.8%), the BM harboured additional oncogenic alterations. The presence of a private genetic alteration in the BM was an independent predictor of shorter overall survival.

CONCLUSIONS

In oligometastatic NSCLC, BM retain the main genetic alterations of the primary tumours. Patients may profit from targeted inhibition of mutated KRAS. Additional private genetic alterations in the BM are dismal.

Prognostic value of tertiary lymphoid structures in hepatocellular carcinoma: a meta-analysis and systematic review

Background

Multiple investigations and scholarly articles have presented compelling evidence indicating that tertiary lymphoid structures (TLS) play a pivotal role in inhibiting and controlling the advancement of tumors. While there is an abundance of information highlighting the importance of TLS in different cancer types, their prognostic significance specifically in hepatocellular carcinoma (HCC) cancers remains unclear. Thus, this meta-analysis aimed to explore the prognostic relevance of TLS in HCC.

Methods

We conducted a thorough search across four databases, namely Web of Science, PubMed, Embase, and the Cochrane Library, to identify pertinent studies. The search utilized the keywords "tertiary lymphoid structures" and "hepatocellular carcinoma." The primary outcomes of interest encompassed overall survival (OS), recurrence-free survival (RFS), early recurrence, and late recurrence. The statistical effect size for these measures was expressed in terms of hazard ratios (HR).

Results

Six studies were incorporated into the analysis. Among them, four studies, encompassing 6 datasets and involving 1490 patients, and three studies, comprising 5 datasets and involving 656 patients, respectively, investigated the correlation between intratumoral and peritumoral TLSs and the prognosis in HCC patients. The meta-analysis revealed that the presence of intratumoral TLSs is linked to longer RFS and reduced early recurrence (HR, 0.60; 95% CI, 0.50-0.67; p <0.001 and HR, 0.49; 95% CI, 0.36-0.65; p <0.001, respectively). However, no significant association was observed with OS and late recurrence. Sensitivity analysis demonstrated the robustness of these findings, and heterogeneities were minimal. Additionally, the meta-analysis did not detect a relationship between peritumoral TLSs and OS or RFS in HCC patients.

Conclusion

The presence of intratumoral TLSs is correlated with better RFS and reduced early recurrence in HCC patients. Further investigation is warranted to elucidate the roles of peritumoral TLSs in the prognosis of HCC patients.

Systematic review registration

https://www.crd.york.ac.uk/PROSPERO/#recordDetails, identifier CRD42023466793.

Tertiary lymphoid structures in head and neck squamous cell carcinoma

Head and neck squamous cell carcinoma (HNSCC) is the sixth most common malignancy worldwide. Smoking, drinking, and human papillomavirus (HPV) infection are the main risk factors. Early-stage patients can benefit from radical surgery, chemotherapy, and radiotherapy, but the prognosis of locally advanced, recurrent, or metastatic patients is poor. Programmed cell death receptor 1 (PD-1) inhibitor significantly prolongs the survival of these patients, but only about 20 % of the population can benefit significantly. Exploring effective predictive indicators of immunotherapy efficacy and new therapeutic targets is necessary. Tertiary lymphoid structure (TLS) is an ectopic lymphoid organ formed in non-lymphoid tissues, which usually occurs in chronic inflammation including autoimmune diseases, infectious diseases, and tumors. The structure and function of TLS are similar to those of secondary lymphoid organs. The existence of TLS is closely related to the favorable prognosis and immune response of patients. This article will review the formation, prognosis, and predictive value of TLS as well as inducing TLS neogenesis in HNSCC.

A blueprint for tumor-infiltrating B cells across human cancers

B lymphocytes are essential mediators of humoral immunity and play multiple roles in human cancer. To decode the functions of tumor-infiltrating B cells, we generated a B cell blueprint encompassing single-cell transcriptome, B cell-receptor repertoire, and chromatin accessibility data across 20 different cancer types (477 samples, 269 patients). B cells harbored extraordinary heterogeneity and comprised 15 subsets, which could be grouped into two independent developmental paths (extrafollicular versus germinal center). Tumor types grouped into the extrafollicular pathway were linked with worse clinical outcomes and resistance to immunotherapy. The dysfunctional extrafollicular program was associated with glutamine-derived metabolites through epigenetic-metabolic cross-talk, which promoted a T cell-driven immunosuppressive program. These data suggest an intratumor B cell balance between extrafollicular and germinal-center responses and suggest that humoral immunity could possibly be harnessed for B cell-targeting immunotherapy.

Impact of tertiary lymphoid structures on prognosis and therapeutic response in pancreatic ductal adenocarcinoma

BACKGROUND

Pancreatic ductal adenocarcinoma (PDAC) is known to have a heterogeneous desmoplastic tumour microenvironment (TME) with a large number of immunosuppressive cells. Recently, high B-cell infiltration in PDAC has received growing interest as a potential therapeutic target.

METHODS

Our literature review summarises the characteristics of tumour-associated tertiary lymphoid structures (TLSs) and highlight the key studies exploring the clinical outcomes of TLSs in PDAC patients and the direct effect on the TME.

RESULTS

The location, density and maturity stages of TLSs within tumours play a key role in determining the prognosis and is a new emerging target in cancer immunotherapy.

DISCUSSION

TLS development is imperative to improve the prognosis of PDAC patients. In the future, studying the genetics and immune characteristics of tumour infiltrating B cells and TLSs may lead towards enhancing adaptive immunity in PDAC and designing personalised therapies.

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.

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.

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.

Immature central tumor tertiary lymphoid structures are associated with better prognosis in non-small cell lung cancer

BACKGROUND & AIMS

Tertiary lymphoid structures (TLSs) are predictive biomarkers of favorable clinical outcomes and immunotherapy response in several solid malignancies, including non-small cell lung cancer (NSCLC). However, the relationship between TLSs and NSCLC prognosis has not been eludicated from the aspects of location, density, and maturity. This study aimed to investigate the clinicopathological and prognostic significance of TLSs in NSCLC.

METHODS

A collection of 151 resected pulmonary nodules in patients with NSCLC was retrospectively analyzed. Two experienced pathologists reviewed hematoxylin-eosin (H&E) slides and assessed TLS scores at different anatomic subregions. Then, we analyzed their correlation with clinicopathologic parameters and CD8 staining intensity and assessed multiple clinicopathological factors affecting patient prognosis.

RESULTS

CD8 expression was correlated with total (TLS-CT) (P = 0.000), aggregates (Agg) (TLS-CT) (P = 0.001), follicles (FOL)-I (TLS-CT) (P = 0.025), and TLS(overall) (P = 0.013). TLS scores in the central tumor (CT) and invasion margin (IM) areas were negatively correlated with distant metastasis and Union for International Cancer Control (UICC) stage in NSCLC patients, while TLS score in the CT area was positively correlated with CD8 expression. TLS (overall), Agg (TLS-CT), and FOL-I (TLS-CT) were positively correlated with distant metastasis, UICC stage, and CD8 expression in NSCLC patients. Agg (TLS-IM) was positively correlated with distant metastasis and UICC stage. FOL-I (TLS-IM) was positively correlated with UICC stage. FOL-II (TLS-IM) was positively correlated with distant metastasis (P < 0.05). Multivariate Cox regression analysis showed that unfavorable independent prognostic factors were associated with metastasis status and UICC stage. Independent prognostic factors with protective effects included Agg (TLS-CT), FOL-I (TLS-CT), total (TLS-CT), and overall TLS (P < 0.05).

CONCLUSION

Histological score assessment of H&E sections of Agg (TLS-CT), FOL-I (TLS-CT), total (TLS-CT), and overall TLS levels in NSCLC has prognostic value.

Tertiary lymphoid structures and B cells determine clinically relevant T cell phenotypes in ovarian cancer

Intratumoral tertiary lymphoid structures (TLSs) have been associated with improved outcome in various cohorts of patients with cancer, reflecting their contribution to the development of tumor-targeting immunity. Here, we demonstrate that high-grade serous ovarian carcinoma (HGSOC) contains distinct immune aggregates with varying degrees of organization and maturation. Specifically, mature TLSs (mTLS) as forming only in 16% of HGSOCs with relatively elevated tumor mutational burden (TMB) are associated with an increased intratumoral density of CD8+ effector T (TEFF) cells and TIM3+PD1+, hence poorly immune checkpoint inhibitor (ICI)-sensitive, CD8+ T cells. Conversely, CD8+ T cells from immunologically hot tumors like non-small cell lung carcinoma (NSCLC) are enriched in ICI-responsive TCF1+ PD1+ T cells. Spatial B-cell profiling identifies patterns of in situ maturation and differentiation associated with mTLSs. Moreover, B-cell depletion promotes signs of a dysfunctional CD8+ T cell compartment among tumor-infiltrating lymphocytes from freshly isolated HGSOC and NSCLC biopsies. Taken together, our data demonstrate that - at odds with NSCLC - HGSOC is associated with a low density of follicular helper T cells and thus develops a limited number of mTLS that might be insufficient to preserve a ICI-sensitive TCF1+PD1+ CD8+ T cell phenotype. These findings point to key quantitative and qualitative differences between mTLSs in ICI-responsive vs ICI-irresponsive neoplasms that may guide the development of alternative immunotherapies for patients with HGSOC.

Tertiary lymphoid structures predict survival and response to neoadjuvant therapy in locally advanced rectal cancer

Tertiary lymphoid structure (TLS) contributes to the anti-tumor immune response, and predicts the prognosis of colorectal cancer patients. However, the potential impact of TLS in shaping the immune status of rectal adenocarcinoma, and the intrinsic relationship between TLS and neoadjuvant therapies (neoTx) remain unclear. We performed hematoxylin-eosin staining, immunohistochemical and biomolecular analyses to investigate TLS and tumor-infiltrating lymphocytes (TILs) in 221 neoTx-treated and 242 treatment-naïve locally advanced rectal cancer (LARC) patients. High TLS density was significantly associated with the absence of vascular invasion, a lower neutrophil-to-lymphocyte ratio, increased TLS maturity, a longer recurrence-free survival (RFS) (hazard ratio [HR] 0.2985 95% confidence interval [CI] 0.1894-0.4706, p < 0.0001) and enhanced infiltration of adaptive immune cells. Biomolecular analysis showed that high TLS-score was strongly associated with more infiltration of immune cells and increased activation of immune-related pathways. TLS+ tumors in pre-treatment specimens were associated with a higher proportion of good respond (62.5% vs. 29.8%, p < 0.0002) and pathological complete remission (pCR) (40.0% vs. 11.1%, p < 0.0001), and significantly increased RFS (HR 0.3574 95%CI 0.1489-0.8578 p = 0.0213) compared with TLS- tumors in the neoTx cohort, which was confirmed in GSE119409 and GSE150082. Further studies showed that neoTx significantly reduced TLS density and maturity, and abolished the prognostic value of TLS. Our study illustrates that TLS may have a key role in mediating the T-cell-inflamed tumor microenvironment, which also provides a new direction for neoTx, especially neoadjuvant immunotherapy, in LRAC patients.

Intratumor tertiary lymphatic structure evaluation predicts the prognosis and immunotherapy response of patients with colorectal cancer

Background

Immune checkpoint therapy, involving the programmed cell death 1 (PD-1) monoclonal antibody, has revolutionized the treatment of cancer. Tertiary lymphatic structure (TLS) serves as an immune indicator to predict the efficacy of PD-1 antibody therapy. However, there is no clear result whether the distribution, quantity, and maturity of TLS can be effective indicators for predicting the clinical efficacy of anti-PD1 immunotherapy in patients with colorectal cancer (CRC).

Methods

Fifty-seven patients who underwent surgical resection and thirty-nine patients who received anti-PD-1 immunotherapy were enrolled in this retrospective study. Immunohistochemical staining and multiple fluorescence immunohistochemistry were used to evaluate the mismatch repair (MMR) subtypes and TLS distribution, quantity, and maturity, respectively.

Results

A comprehensive patient score system was built based on TLS quantity and maturity. We found that the proportion of patients with score >1 was much higher in the deficient mismatch repair(dMMR) group than in the proficient mismatch repair(pMMR) group, and this difference was mainly due to intratumoral TLS. Patient score, based on the TLS evaluation of whole tumor, peritumor, or intratumor, was used to evaluate the efficacy of anti-PD1 immunotherapy. Based only on the intratumor TLS evaluation, the proportion of patients with a score >1 was higher in the response (PR + CR) group than in the non-response (PD) group. Multivariate analysis revealed that patient scores were positively correlated with the clinical efficacy of immunotherapy. Further analysis of immune-related progression-free survival was performed in patients with CRC who received anti-PD-1 immunotherapy. Patients with score >1 based on the intratumor TLS evaluation had significantly better survival.

Conclusions

These results suggest that the patient score based on intratumor TLS evaluation may be a good immune predictive indicator for PD-1 antibody therapy in patients with CRC.

Can we yet use tertiary lymphoid structures as predictive biomarkers for immunotherapy response in melanoma?

PURPOSE OF REVIEW

In this review, we explore the potential of tertiary lymphoid structures (TLS) as predictive biomarkers in the response to immunotherapy for melanoma patients.

RECENT FINDINGS

The significance of TLS as indicators predicting immunotherapy response becomes particularly pronounced. Melanoma, renowned for its aggressive characteristics, has undergone revolutionary transformations in treatment through immunotherapeutic interventions. Investigations have unveiled a compelling correlation between the presence of TLS in the melanoma tumor microenvironment and favorable responses to immunotherapy. These responses, characterized by heightened survival rates and improved clinical outcomes, imply that TLS might be pivotal in tailoring more efficient and personalized treatments for individuals with melanoma. The ongoing discourse regarding TLS as a predictive biomarker underscores the need for a meticulous examination of its potential in guiding clinical decisions and optimizing therapeutic strategies.

SUMMARY

TLS show great promises as potential biomarkers to melanoma patient's outcomes in ICI treatment; however, more studies are needed to understand their mechanisms of actions and the long-term impact of their functionality.

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.

Regulatory B Cells-Immunopathological and Prognostic Potential in Humans

The aim of the following review is to shed light on the putative role of regulatory B cells (Bregs) in various human diseases and highlight their potential prognostic and therapeutic relevance in humans. Regulatory B cells are a heterogeneous group of B lymphocytes capable of suppressing inflammatory immune reactions. In this way, Bregs contribute to the maintenance of tolerance and immune homeostasis by limiting ongoing immune reactions temporally and spatially. Bregs play an important role in attenuating pathological inflammatory reactions that can be associated with transplant rejection, graft-versus-host disease, autoimmune diseases and allergies but also with infectious, neoplastic and metabolic diseases. Early studies of Bregs identified IL-10 as an important functional molecule, so the IL-10-secreting murine B10 cell is still considered a prototype Breg, and IL-10 has long been central to the search for human Breg equivalents. However, over the past two decades, other molecules that may contribute to the immunosuppressive function of Bregs have been discovered, some of which are only present in human Bregs. This expanded arsenal includes several anti-inflammatory cytokines, such as IL-35 and TGF-β, but also enzymes such as CD39/CD73, granzyme B and IDO as well as cell surface proteins including PD-L1, CD1d and CD25. In summary, the present review illustrates in a concise and comprehensive manner that although human Bregs share common functional immunosuppressive features leading to a prominent role in various human immunpathologies, they are composed of a pool of different B cell types with rather heterogeneous phenotypic and transcriptional properties.

Infiltrating characteristics and prognostic value of tertiary lymphoid structures in resected gastric neuroendocrine neoplasm patients

Objectives

Tertiary lymphoid structures (TLSs) are lymphocyte aggregates that play an anti-tumor role in most solid tumors. However, the functions of TLS in gastric neuroendocrine neoplasms (GNENs) remain unknown. This study aimed to determine the characteristics and prognostic values of TLS in resected GNEN patients.

Methods

Haematoxylin-eosin, immunohistochemistry (IHC) and multiple fluorescent IHC staining were used to assess TLS to investigate the correlation between TLSs and clinicopathological characteristics and its prognostic value.

Results

Tertiary lymphoid structures were identified in 84.3% of patients with GNEN. They were located in the stromal area or outside the tumor tissue and mainly composed of B and T cells. A high density of TLSs promoted an anti-tumor immune response in GNEN. CD15+ TANs and FOXP3+ Tregs in TLSs inhibited the formation of TLSs. High TLS density was significantly associated with prolonged recurrence-free survival (RFS) and overall survival (OS) of GNENs. Univariate and multivariate Cox regression analyses revealed that TLS density, tumor size, tumor-node-metastasis (TNM) stage and World Health Organisation (WHO) classification were independent prognostic factors for OS, whereas TLS density, tumor size and TNM stage were independent prognostic factors for RFS. Finally, OS and RFS nomograms were developed and validated, which were superior to the WHO classification and the TNM stage.

Conclusion

Tertiary lymphoid structures were mainly located in the stromal area or outside the tumor area, and high TLS density was significantly associated with the good prognosis of patients with GNEN. Incorporating TLS density into a nomogram may improve survival prediction in patients with resected GNEN.

Tertiary lymphoid structures in tongue cancer: Association with clinicopathological parameters, preoperative S-1 chemotherapy response, and prognosis

BACKGROUND

Tertiary lymphoid structures (TLSs) are observed in cancer-invasive sites of various organs, and show evidence of tumor-specific B and/or T cells, suggesting an active humoral antitumor response. The aim of this study was to evaluate the relationship between TLSs and prognosis in patients with tongue squamous cell carcinoma (TSCC) after preoperative S-1 chemotherapy.

METHODS

Among 196 TSCC cases, 111 patients who received preoperative S-1 chemotherapy were compared to 85 patients who did not receive chemotherapy. We investigated the incidence of TLSs in both preoperative biopsy and resected specimens.

RESULTS

TLSs were present in 24 (12%) biopsy specimens and 31 (16%) resected specimens. TLSs were associated with clinicopathologically advanced cases and positivity for lymphatic invasion. None of the cases with pStage 0 (i.e., noninvasive cancer) showed TLSs. In preoperative S-1 chemotherapy cases, TLSs were significantly more common in those treated with S-1 for more than 21 days and in those with treatment effects 0, Ia, and Ib. TLSs may not be a favorable prognostic factor by themselves but maybe a prognostic factor when combined with preoperative S-1 treatment.

CONCLUSION

The presence of TLSs was suggested to be a factor indicating a favorable prognosis when considering the indication for preoperative S-1 chemotherapy. The synergistic effect of S-1 by activating antitumor immunity may be associated with a better prognosis in TSCC patients with TLSs.

Translational and oncologic significance of tertiary lymphoid structures in pancreatic adenocarcinoma

Pancreatic adenocarcinoma (PDAC) is an aggressive tumor with poor survival and limited treatment options. PDAC resistance to immunotherapeutic strategies is multifactorial, but partially owed to an immunosuppressive tumor immune microenvironment (TiME). However, the PDAC TiME is heterogeneous and harbors favorable tumor-infiltrating lymphocyte (TIL) populations. Tertiary lymphoid structures (TLS) are organized aggregates of immune cells that develop within non-lymphoid tissue under chronic inflammation in multiple contexts, including cancers. Our current understanding of their role within the PDAC TiME remains limited; TLS are complex structures with multiple anatomic features such as location, density, and maturity that may impact clinical outcomes such as survival and therapy response in PDAC. Similarly, our understanding of methods to manipulate TLS is an actively developing field of research. TLS may function as anti-tumoral immune niches that can be leveraged as a therapeutic strategy to potentiate both existing chemotherapeutic regimens and potentiate future immune-based therapeutic strategies to improve patient outcomes. This review seeks to cover anatomy, relevant features, immune effects, translational significance, and future directions of understanding TLS within the context of PDAC.

Genomic profiling and associated B cell lineages delineate the efficacy of neoadjuvant anti-PD-1-based therapy in oesophageal squamous cell carcinoma

BACKGROUND

Neoadjuvant chemoimmunotherapy has offered novel therapeutic options for patients with locally advanced oesophageal squamous cell carcinoma (ESCC). Depicting the landscape of genomic and immune profiles is critical in predicting therapeutic responses.

METHODS

We integrated whole-exome sequencing, single-cell RNA sequencing, and immunofluorescence data of ESCC samples from 24 patients who received neoadjuvant treatment with PD-1 inhibitors plus paclitaxel and platinum-based chemotherapy to identify correlations with therapeutic responses.

FINDINGS

An elevation of small insertions and deletions was observed in responders. DNA mismatch repair (MMR) pathway alternations were highly frequent in patients with optimal responses and correlated with tumour infiltrating lymphocytes (TILs). Among the TILs in ESCC, dichotomous developing trajectories of B cells were identified, with one lineage differentiating towards LMO2+ germinal centre B cells and another lineage differentiating towards CD55+ memory B cells. While LMO2+ germinal centre B cells were enriched in responding tumours, CD55+ memory B cells were found to correlate with inferior responses to combination therapy, exhibiting immune-regulating features and impeding the cytotoxicity of CD8+ T cells. The comprehensive evaluation of transcriptomic B cell lineage features was validated to predict responses to immunotherapy in patients with cancer.

INTERPRETATION

This comprehensive evaluation of tumour MMR pathway alternations and intra-tumoural B cell features will help to improve the selection and management of patients with ESCC to receive neoadjuvant chemoimmunotherapy.

FUNDING

National Science Foundation of China (82373371, 82330053), Eastern Scholar Program at Shanghai Institutions of Higher Learning, National Science and Technology Major Project of China (2023YFA1800204, 2020YFC2008402), and Science and Technology Commission of Shanghai Municipality (22ZR1410700, 20ZR1410800).

Tertiary lymphoid structures, a historical reappraisal

Tertiary lymphoid structures (TLSs) are accumulations of lymphoid cells within non-lymphoid organs that share the cellular compartments, spatial organization, vasculature, chemokines, and function with secondary lymphoid organs, especially lymph nodes. TLSs are organized into a separate T cell and B cell compartments which contain germinal centers with follicular dendritic cells. In most cases, TLSs contain Peripheral Node addressin (PNAD) expressing high endothelial venules (HEVs). TLSs have been described in various mouse models of inflammation and are associated with a wide range of autoimmune diseases. Other than these, TLSs have been described in chronic allograft rejection and cancer.

Unraveling the complex interplay between anti-tumor immune response and autoimmunity mediated by B cells and autoantibodies in the era of anti-checkpoint monoclonal antibody therapies

The intricate relationship between anti-tumor immunity and autoimmunity is a complex yet crucial aspect of cancer biology. Tumor microenvironment often exhibits autoimmune features, a phenomenon that involves natural autoimmunity and the induction of humoral responses against self-antigens during tumorigenesis. This induction is facilitated by the orchestration of anti-tumor immunity, particularly within organized structures like tertiary lymphoid structures (TLS). Paradoxically, a significant number of cancer patients do not manifest autoimmune features during the course of their illness, with rare instances of paraneoplastic syndromes. This discrepancy can be attributed to various immune-mediated locks, including regulatory or suppressive immune cells, anergic autoreactive lymphocytes, or induction of effector cells exhaustion due to chronic stimulation. Overcoming these locks holds the risk to induce autoimmune mechanisms during cancer progression, a phenomenon notably observed with anti-immune checkpoint therapies, in contrast to more conventional treatments like chemotherapy or radiotherapy. Therefore, the challenge arises in managing immune-related adverse events (irAEs) induced by immune checkpoint inhibitors treatment, as decoupling them from the anti-tumor activity poses a significant clinical dilemma. This review summarizes recent advances in understanding the link between B-cell driven anti-tumor responses and autoimmune reactions in cancer patients, and discusses the clinical implications of this relationship.

B cells in head and neck squamous cell carcinoma: current opinion and novel therapy

Head and neck squamous cell carcinoma (HNSCC) is a common malignant tumour. Despite advancements in surgery, radiotherapy and chemotherapy, which have improved the prognosis of most patients, a subset of patients with poor prognoses still exist due to loss of surgical opportunities, postoperative recurrence, and metastasis, among other reasons. The tumour microenvironment (TME) is a complex organization composed of tumour, stromal, and endothelial cells. Communication and interaction between tumours and immune cells within the TME are increasingly being recognized as pivotal in inhibiting or promoting tumour development. Previous studies on T cells in the TME of HNSCC have yielded novel therapeutic possibilities. However, the function of B cells, another adaptive immune cell type, in the TME of HNSCC patients has yet to be determined. Recent studies have revealed various distinct subtypes of B cells and tertiary lymphoid structures (TLSs) in the TME of HNSCC patients, which are believed to impact the efficacy of immune checkpoint inhibitors (ICIs). Therefore, this paper focuses on B cells in the TME to explore potential directions for future immunotherapy for HNSCC.

Low-dose radiotherapy promotes the formation of tertiary lymphoid structures in lung adenocarcinoma

Purpose

A tertiary lymphoid structure (TLS) refers to an organized infiltration of immune cells that is linked to a positive prognosis and improved response to immunotherapy. However, methods that promote TLS formation are limited and challenging to implement in clinical settings. In this study, we aimed to promote the formation and maturation of TLSs in lung adenocarcinoma (LUAD) by combining low-dose radiotherapy (LDRT) with immunotherapy.

Methods

Tissue sections from 198 patients who had undergone surgery were examined. Risk factors for patient survival were assessed, and the relationship between TLSs and five-year survival was analyzed. The Kras-LSL-G12D spontaneous lung cancer mouse model was used to screen the optimal irradiation dose (0/1/2 Gy whole lung irradiation) for promoting TLS formation. LDRT combined with anti-PD-1 was used to promote the formation and maturation of TLSs.

Results

TLS+, TLSHigh, TLS+GC+ and CD8High within TLS+ were associated with a favorable prognosis. LDRT increased the formation of early TLSs in the Kras-LSL-G12D lung cancer mouse model. In addition, LDRT combined with anti-PD-1 treatment can significantly improve the maturity of TLSs in mouse LUAD, resulting in greater antitumor effects. This antitumor effect was strongly associated with the number of CD8+ T cells within the TLSs.

Conclusion

We successfully applied LDRT combined with PD-1 inhibitor therapy for the first time, which increased both the quantity and maturity of TLSs in lung cancer. This approach achieved a promising antitumor effect.

Tertiary lymphoid structures in autoimmune diseases

Tertiary lymphoid structures (TLSs) are organized lymphoid-like aggregations in non-lymphoid tissues. Tissues with chronic and persistent inflammation infiltration may drive and form ectopic germinal center-like structures, which are very common in autoimmune diseases, chronic infections, and tumor microenvironments. However, the mechanisms governing the formation of TLSs are still being explored. At present, it is not clear whether the formation of TLSs is associated with local uncontrolled immune inflammatory responses. While TLSs suggest a good prognosis in tumors, the opposite is true in autoimmune diseases. This review article will discuss the current views on initiating and maintaining TLSs and the potential therapeutic target in autoimmune diseases.

Multi-resolution deep learning characterizes tertiary lymphoid structures and their prognostic relevance in solid tumors

BACKGROUND

Tertiary lymphoid structures (TLSs) are dense accumulations of lymphocytes in inflamed peripheral tissues, including cancer, and are associated with improved survival and response to immunotherapy in various solid tumors. Histological TLS quantification has been proposed as a novel predictive and prognostic biomarker, but lack of standardized methods of TLS characterization hampers assessment of TLS densities across different patients, diseases, and clinical centers.

METHODS

We introduce an approach based on HookNet-TLS, a multi-resolution deep learning model, for automated and unbiased TLS quantification and identification of germinal centers in routine hematoxylin and eosin stained digital pathology slides. We developed HookNet-TLS using n = 1019 manually annotated TCGA slides from clear cell renal cell carcinoma, muscle-invasive bladder cancer, and lung squamous cell carcinoma.

RESULTS

Here we show that HookNet-TLS automates TLS quantification across multiple cancer types achieving human-level performance and demonstrates prognostic associations similar to visual assessment.

CONCLUSIONS

HookNet-TLS has the potential to be used as a tool for objective quantification of TLS in routine H&E digital pathology slides. We make HookNet-TLS publicly available to promote its use in research.

Unveiling the impact of tertiary lymphoid structures on immunotherapeutic responses of clear cell renal cell carcinoma

Tertiary lymphoid structures (TLS) are organized aggregates of immune cells that form under pathological conditions. However, the predictive value of TLS in clear cell renal cell carcinoma (ccRCC) for immunotherapies remains unclear. We comprehensively assessed the implications for prognosis and immunological responses of the TLS spatial and maturation heterogeneity in 655 ccRCC patients. A higher proportion of early-TLS was found in peritumoral TLS, while intratumoral TLS mainly comprised secondary follicle-like TLS (SFL-TLS), indicating markedly better survival. Notably, presence of TLS, especially intratumoral TLS and SFL-TLS, significantly correlated with better survival and objective reflection rate for ccRCC patients receiving anti-Programmed Cell Death Protein-1 (PD-1)/Programmed Cell Death-Ligand-1 (PD-L1) immunotherapies. In peritumoral TLS cluster, primary follicle-like TLS, the proportion of tumor-associated macrophages, and Treg infiltration in the peritumoral regions increased prominently, suggesting an immunosuppressive tumor microenvironment. Interestingly, spatial transcriptome annotation and multispectral fluorescence showed that an abundance of mature plasma cells within mature TLS has the capacity to produce IgA and IgG, which demonstrate significantly higher objective response rates and a superior prognosis for ccRCC patients subjected to immunotherapy. In conclusion, this study revealed the implications of TLS spatial and maturation heterogeneity on the immunological status and clinical responses, allowing the improvement of precise immunotherapies of ccRCC.

Complete pathological remission and tertiary lymphoid structures are associated with the efficacy of resectable NSCLC receiving neoadjuvant chemoimmunotherapy: A double-center retrospective study

This study aimed to investigate the relationship between complete pathological remission (PCR), tertiary lymphoid structure (TLS) maturation and expression and clinical outcomes of patients with resectable non-small cell lung cancer (NSCLC) receiving neoadjuvant chemoimmunotherapy. Totally 80 patients with resectable NSCLC (stage IB-IIIB) receiving neoadjuvant chemoimmunotherapy were analyzed. We used the Kaplan-Meier method to plot survival curves and the log-rank test to compare differences. Among all patients included, 45 patients (56.25%) achieved major pathological response (MPR), including 30 patients (37.50%) with PCR. The proportion of patients diagnosed with stage IB, II, IIIA and IIIB was 1.25%, 10.00%, 52.50% and 36.25%, respectively. We divided patients into PCR group and non-PCR group respectively according to whether they achieved PCR. We found that patients achieving PCR had significantly improved disease-free survival (DFS) (mDFS: NR vs. 20.24 months, P = .020). TLS expression was low in 43 cases (53.75%) and high in 37 cases (46.25%). TLS maturation was low in 55 cases (68.75%) and high in 25 cases (31.25%). The DFS of patients with TLS high-maturation (34.07 vs. 22.30 months, P = .024) and TLS high-expression (34.07 vs. 22.30 months, P = .041) was significantly longer. In most subgroups, the PCR, TLS high-maturation and TLS high-expression group respectively achieved a better clinical outcome relative to the non-PCR, TLS low-maturation and TLS low-expression group. In patients with resectable NSCLC receiving neoadjuvant chemoimmunotherapy, the acquirement of PCR may predict better DFS. In addition, high expression and maturation of TLS may be prognostic factors.

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.

Immunotherapy-related biomarkers: Confirmations and uncertainties

Immunotherapy profoundly changed oncology treatment, becoming one of the main therapeutical strategies. Remarkable improvement has been achieved in survival outcomes, but the percentage of patients who benefit from immunotherapy is still limited. Only one-third of patients receiving immune checkpoint inhibitors (ICIs) achieve long-term response. Several patients are not responsive to treatment or relapse after an initial response. To date, programmed death-ligand 1, microsatellite instability, and tumor mutational burden are the three biomarkers validated to predict the ICIs response, but a single variable seems still insufficient in the patient's selection. Considering the substantial and increasing use of these drugs, the identification of new predictive biomarkers of ICI response is of paramount importance. We summarize the state of the art and the clinical use of immune biomarkers in oncology, highlighting the strength and weaknesses of currently approved biomarkers, describing the emerging tissues and circulating biomarkers, and outlining future perspectives.

Association of systemic inflammatory markers and tertiary lymphoid structure with pathological complete response in gastric cancer patients receiving preoperative treatment: a retrospective cohort study

BACKGROUND

Assessment of systemic and local immune responses is crucial in determining the efficacy of cancer interventions. The identification of specific factors that correlate with pathological complete response (pCR) is essential for optimizing treatment decisions.

METHODS

In this retrospective study, a total of 521 patients diagnosed with gastric adenocarcinoma who underwent curative gastrectomy following preoperative treatment were reviewed. Of these patients, 463 did not achieve pCR (non-pCR) and 58 achieved pCR. Clinicopathological factors were evaluated to identify predictors for pCR using a logistic regression model. Additionally, a smaller cohort (n=76) was derived using propensity score matching to investigate local immune response, specifically the features of tertiary lymphoid structure (TLS) using H&E staining, immunohistochemistry, and multiplex immunofluorescence.

RESULTS

The multivariate regression analysis demonstrated a significant association between low systemic inflammatory status and pCR, as evidenced by reduced levels of the combined systemic immune-inflammation index (SII) and neutrophil-to-lymphocyte ratio (NLR) (SII+NLR) (odds ratio: 3.33, 95% CI: 1.79-6.17, P<0.001). In the smaller cohort analysis, distinct TLS characteristics were correlated with the presence of pCR. Specifically, a higher density of TLS and a lower proportion of PD1+ cells and CD8+ cells within TLS in the tumor bed were strongly associated with pCR.

CONCLUSION

Both systemic and local immune profile were associated with pCR. A low level of SII+NLR served as an independent predictor of pCR, while distinct TLS features were associated with the presence of pCR. Focusing on the immune profile was crucial for optimal management of gastric cancer patients receiving preoperative treatment.

Prognostic Impact of Tumor-Infiltrating Lymphocytes, Tertiary Lymphoid Structures, and Neutrophil-to-Lymphocyte Ratio in Pulmonary Metastases from Uterine Leiomyosarcoma

BACKGROUND

The presence of tumor-infiltrating lymphocytes (TILs) and tertiary lymphoid structures (TLSs) in tumor tissue has been related to the prognosis in various malignancies. Meanwhile, neutrophil-to-lymphocyte ratio (NLR) as a systemic inflammation marker also has been associated with the prognosis in them. However, few reports have investigated the relationship between pulmonary metastases from sarcoma and these biomarkers.

METHODS

We retrospectively recruited 102 patients undergoing metastasectomy for pulmonary metastases from uterine leiomyosarcoma at Okayama University Hospital from January 2006 to December 2019. TILs and TLSs were evaluated by immunohistochemical staining of surgically resected specimens of pulmonary metastases using anti-CD3/CD8/CD103/Foxp3/CD20 antibodies. NLR was calculated from the blood examination immediately before the most recent pulmonary metastasectomy. We elucidated the relationship between the prognosis and these factors. Because we considered that the status of tumor tissue and systemic inflammation were equally valuable, we also assessed the impact of the combination of TILs or TLSs and NLR on the prognosis.

RESULTS

As for TILs, CD3-positive cells and CD8-positive cells were correlated with the prognosis. The prognosis was significantly better in patients with CD3-high group, CD8-high group, TLSs-high group, and NLR-low group, respectively. The prognosis of CD8-high/NLR-low group and TLSs-high/NLR-low group was significantly better than that of CD8-low/NLR-high group and TLSs-low/NLR-high group, respectively.

CONCLUSIONS

CD3-positive TILs, CD8-positive TILs, TLSs, and NLR are correlated with the prognosis, respectively. The combination of CD8-positive TILs or TLSs and NLR may be the indicators to predict the prognosis of patients with pulmonary metastases from uterine leiomyosarcoma.

Heterogeneity in tertiary lymphoid structures predicts distinct prognosis and immune microenvironment of clear cell renal cell carcinoma

BACKGROUND

Tertiary lymphoid structures (TLS) are organized aggregates of immune cells that develop postnatally in non-lymphoid tissues and are associated with pathological conditions. TLS typically comprise B-cell follicles containing and are encompassed by T- cell zones and dendritic cells. The prognostic and predictive value of TLS in the tumor microenvironment (TME) as potential mediators of antitumor immunity have gained interest. However, the precise relationship between localization and maturation of TLS and the clinical outcome of their presence in clear cell renal cell carcinoma (ccRCC) is yet to be elucidated.

METHODS

Immunohistochemistry and multispectral fluorescence were used to evaluate the TLS heterogeneity along with TME cell-infiltrating characterizations. A thorough investigation of the prognostic implications of the TLS heterogeneity in 395 patients with ccRCC from two independent cohorts was conducted. Associations between TLS heterogeneity and immunologic activity were assessed by quantifying the immune cell infiltration.

RESULTS

Infiltrated TLS were identified in 34.2% of the ccRCC samples (N=395). These TLS were found to be tumor-proximal, tumor-distal, or both in 37.8%, 74.1%, and 11.9% of the TLS-positive cases, respectively. A higher proportion of early TLS was found in tumor-distal TLS (p=0.016), while tumor-proximal TLS primarily comprised secondary follicle-like structures (p=0.004). In the main study cohort (Fudan University Shanghai Cancer Center, N=290), Kaplan-Meier analyses revealed a significant correlation between the presence of tumor-proximal TLS and improved progression-free survival (PFS, p<0.001) and overall survival (OS, p=0.002). Conversely, the presence of tumor-distal TLS was associated with poor PFS (p=0.02) and OS (p=0.021). These findings were further validated in an external validation set of 105 patients with ccRCC. Notably, the presence of mature TLS (namely secondary follicle-like TLS, with CD23+ germinal center) was significantly associated with better clinical outcomes in patients with ccRCC. Furthermore, novel nomograms incorporating the presence of tumor-proximal TLS demonstrated remarkable predictability for the 8-year outcomes of resected ccRCC (area under the curve >0.80). Additionally, ccRCC samples with tumor-distal TLS enriched with primary follicle-like TLS exhibited higher programmed death-ligand 1 tumor-associated macrophages levels and regulatory T cells infiltration in the tumor-distal region, indicative of a suppressive TME.

CONCLUSION

This study for the first time elucidates the impact of TLS localization and maturation heterogeneities on the divergent clinical outcomes of ccRCC. The findings reveal that most TLS in ccRCC are located in the tumor-distal area and are associated with immature, immunosuppressive characterizations. Furthermore, our findings corroborate previous research demonstrating that tumor-proximal TLS were associated with favorable clinical outcomes.

B cells and tertiary lymphoid structures are associated with survival in papillary thyroid cancer

PURPOSE

The function of B cells in papillary thyroid cancer (PTC) is controversial. The role of B-cell-related tertiary lymphoid structures (TLSs) is still unclear. Whether B cells exert their anti-tumor effect through forming TLS in PTC needs further investigation.

METHODS

We detected the percentage of B cells in PTC tissues by multi-parameter flow cytometry. Paraffin-embedded tumor tissues of 125 PTC patients were collected and stained with Haematoxylin-Eosin (H&E) for inflammatory infiltration analysis in combination with clinical features. Multiplexed immunohistochemistry (mIHC) was performed to verify the TLSs in above inflammatory infiltration. Correlation of B cells and TLSs with prognosis was analyzed using the TCGA database.

RESULTS

We observed that PTC patients with higher expression of B lineage cell genes had improved survival and the percentage of B cells in the PTC tumor tissues was variable. Moreover, PTC tumor tissues with more B cells were surrounded by immune cell aggregates of varying sizes. We furtherly confirmed the immune cell aggregates as TLSs with different maturation stages. By analyzing PTC data from TCGA database, we found the maturation stages of TLSs were associated with genders and clinical stages among PTC patients. Moreover, patients with high TLSs survived longer and had a better prognosis.

CONCLUSION

B cells are associated with the existence of TLSs which have different maturation stages in PTC. Both B cells and TLSs are associated with the survival rate of PTC. These observations indicate that the anti-tumor effects of B cells in PTC are associated with TLSs formation.

Deciphering the implications of mitophagy-related signatures in clinical outcomes and microenvironment heterogeneity of clear cell renal cell carcinoma

BACKGROUND

The role of mitophagy in various cancer-associated biological processes is well recognized. Nonetheless, the comprehensive implications of mitophagy in clear cell renal cell carcinoma (ccRCC) necessitate further exploration.

METHODS

Based on the transcriptomic data encompassing 25 mitophagy-related genes (MRGs), we identified the distinct mitophage patterns in 763 ccRCC samples. Subsequently, a mitophage-related predictive signature with machine learning algorithms was constructed, designated as RiskScore, to quantify the individual mitophagy status in ccRCC patients. Employing multispectral immunofluorescence (mIF) and immunohistochemistry (IHC) staining, we detected the effect of PTEN-induced putative kinase 1 (PINK1) in the prognosis and immune microenvironment of ccRCC.

RESULTS

Our analysis initially encompassed a comprehensive assessment of the expression profiling, genomic variations, and interactions among the 25 MRGs in ccRCC. Subsequently, the consensus clustering algorithm was applied to stratify ccRCC patients into three clusters with distinct prognostic outcomes, tumor microenvironment (TME) characteristics, and underlying biological pathways. We screened eight pivotal genes (CLIC4, PTPRB, SLC16A12, ENPP5, FLRT3, HRH2, PDK4, and SCD5) to construct a mitophagy-related predictive signature, which showed excellent prognostic value for ccRCC patients. Moreover, patient subgroups divided by the RiskScore showed contrasting expression levels of immune checkpoints (ICPs), abundance of immune cells, and immunotherapy response. Additionally, a nomogram was established with robust predictive power integrating the RiskScore and clinical features. Notably, we observed that PINK1 expression markedly correlated with favorable treatment response and advanced maturation stages of tertiary lymphoid structures, which potentially shed light on enhancing anti-tumor immunity of ccRCC.

CONCLUSION

Collectively, this study initially developed a signature associated with mitophagy, which demonstrated an excellent ability to predict the clinical prognosis, TME characterization, and responsiveness to targeted therapy and immunotherapy for ccRCC patients. Of particular note is the pivotal role of PINK1 in mediating the treatment response and immune microenvironment for ccRCC patients.

CCF-GNN: A Unified Model Aggregating Appearance, Microenvironment, and Topology for Pathology Image Classification

Pathology images contain rich information of cell appearance, microenvironment, and topology features for cancer analysis and diagnosis. Among such features, topology becomes increasingly important in analysis for cancer immunotherapy. By analyzing geometric and hierarchically structured cell distribution topology, oncologists can identify densely-packed and cancer-relevant cell communities (CCs) for making decisions. Compared to commonly-used pixel-level Convolution Neural Network (CNN) features and cell-instance-level Graph Neural Network (GNN) features, CC topology features are at a higher level of granularity and geometry. However, topological features have not been well exploited by recent deep learning (DL) methods for pathology image classification due to lack of effective topological descriptors for cell distribution and gathering patterns. In this paper, inspired by clinical practice, we analyze and classify pathology images by comprehensively learning cell appearance, microenvironment, and topology in a fine-to-coarse manner. To describe and exploit topology, we design Cell Community Forest (CCF), a novel graph that represents the hierarchical formulation process of big-sparse CCs from small-dense CCs. Using CCF as a new geometric topological descriptor of tumor cells in pathology images, we propose CCF-GNN, a GNN model that successively aggregates heterogeneous features (e.g., appearance, microenvironment) from cell-instance-level, cell-community-level, into image-level for pathology image classification. Extensive cross-validation experiments show that our method significantly outperforms alternative methods on H&E-stained and immunofluorescence images for disease grading tasks with multiple cancer types. Our proposed CCF-GNN establishes a new topological data analysis (TDA) based method, which facilitates integrating multi-level heterogeneous features of point clouds (e.g., for cells) into a unified DL framework.

Of mice and lymphoid aggregates: modeling tertiary lymphoid structures in cancer

Tertiary lymphoid structures (TLS) are lymph node-like aggregates that can form in association with chronic inflammation or cancer. Mature TLS are organized into B and T cell zones, and are not encapsulated but include all cell types necessary for eliciting an adaptive immune response. TLS have been observed in various cancer types and are generally associated with a positive prognosis as well as increased sensitivity to cancer immunotherapy. However, a comprehensive understanding of the roles of TLS in eliciting anti-tumor immunity as well as the mechanisms involved in their formation and function is still lacking. Further studies in orthotopic, immunocompetent cancer models are necessary to evaluate the influence of TLS on cancer therapies, and to develop new treatments that promote their formation in cancer. Here, we review key insights obtained from functional murine studies, discuss appropriate models that can be used to study cancer-associated TLS, and suggest guidelines on how to identify TLS and distinguish them from other antigen-presenting niches.

Immune landscape of tertiary lymphoid structures in hepatocellular carcinoma (HCC) treated with neoadjuvant immune checkpoint blockade

Neoadjuvant immunotherapy is thought to produce long-term remissions through induction of antitumor immune responses before removal of the primary tumor. Tertiary lymphoid structures (TLS), germinal center-like structures that can arise within tumors, may contribute to the establishment of immunological memory in this setting, but understanding of their role remains limited. Here, we investigated the contribution of TLS to antitumor immunity in hepatocellular carcinoma (HCC) treated with neoadjuvant immunotherapy. We found that neoadjuvant immunotherapy induced the formation of TLS, which were associated with superior pathologic response, improved relapse free survival, and expansion of the intratumoral T and B cell repertoire. While TLS in viable tumor displayed a highly active mature morphology, in areas of tumor regression we identified an involuted TLS morphology, which was characterized by dispersion of the B cell follicle and persistence of a T cell zone enriched for ongoing antigen presentation and T cell-mature dendritic cell interactions. Involuted TLS showed increased expression of T cell memory markers and expansion of CD8+ cytotoxic and tissue resident memory clonotypes. Collectively, these data reveal the circumstances of TLS dissolution and suggest a functional role for late-stage TLS as sites of T cell memory formation after elimination of viable tumor.

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.

Exploring the dual role of B cells in solid tumors: implications for head and neck squamous cell carcinoma

In the tumor milieu of head and neck squamous cell carcinoma (HNSCC), distinct B cell subpopulations are present, which exert either pro- or anti-tumor activities. Multiple factors, including hypoxia, cytokines, interactions with tumor cells, and other immune infiltrating lymphocytes (TILs), alter the equilibrium between the dual roles of B cells leading to cancerogenesis. Certain B cell subsets in the tumor microenvironment (TME) exhibit immunosuppressive function. These cells are known as regulatory B (Breg) cells. Breg cells suppress immune responses by secreting a series of immunosuppressive cytokines, including IL-10, IL-35, TGF-β, granzyme B, and adenosine or dampen effector TILs by intercellular contacts. Multiple Breg phenotypes have been discovered in human and mouse cancer models. However, when compartmentalized within a tertiary lymphoid structure (TLS), B cells predominantly play anti-tumor effects. A mature TLS contains a CD20+ B cell zone with several important types of B cells, including germinal-center like B cells, antibody-secreting plasma cells, and memory B cells. They kill tumor cells via antibody-dependent cytotoxicity and phagocytosis, and local complement activation effects. TLSs are also privileged sites for local T and B cell coordination and activation. Nonetheless, in some cases, TLSs may serve as a niche for hidden tumor cells and indicate a bad prognosis. Thus, TIL-B cells exhibit bidirectional immune-modulatory activity and are responsive to a variety of immunotherapies. In this review, we discuss the functional distinctions between immunosuppressive Breg cells and immunogenic effector B cells that mature within TLSs with the focus on tumors of HNSCC patients. Additionally, we review contemporary immunotherapies that aim to target TIL-B cells. For the development of innovative therapeutic approaches to complement T-cell-based immunotherapy, a full understanding of either effector B cells or Breg cells is necessary.

Dendritic Cell Vaccination in Non-Small Cell Lung Cancer: Remodeling the Tumor Immune Microenvironment

Non-small-cell lung cancer (NSCLC) remains one of the leading causes of death worldwide. While NSCLCs possess antigens that can potentially elicit T cell responses, defective tumor antigen presentation and T cell activation hinder host anti-tumor immune responses. The NSCLC tumor microenvironment (TME) is composed of cellular and soluble mediators that can promote or combat tumor growth. The composition of the TME plays a critical role in promoting tumorigenesis and dictating anti-tumor immune responses to immunotherapy. Dendritic cells (DCs) are critical immune cells that activate anti-tumor T cell responses and sustain effector responses. DC vaccination is a promising cellular immunotherapy that has the potential to facilitate anti-tumor immune responses and transform the composition of the NSCLC TME via tumor antigen presentation and cell-cell communication. Here, we will review the features of the NSCLC TME with an emphasis on the immune cell phenotypes that directly interact with DCs. Additionally, we will summarize the major preclinical and clinical approaches for DC vaccine generation and examine how effective DC vaccination can transform the NSCLC TME toward a state of sustained anti-tumor immune signaling.

Hot and cold tumors: Immunological features and the therapeutic strategies

The "hotness" or "coldness" of the tumors are determined by the information of the cancer cells themselves, tumor immune characteristics, tumor microenvironment, and signaling mechanisms, which are key factors affecting cancer patients' clinical efficacy. The switch mechanism of "hotness" and "coldness" and its corresponding pathological characteristics and treatment strategies are the frontier and hot spot of tumor treatment. How to distinguish the "hotness" or "coldness" effectively and clarify the causes, microenvironment state, and characteristics are very important for the tumor response and efficacy treatments. Starting from the concept of hot and cold tumor, this review systematically summarized the molecular characteristics, influencing factors, and therapeutic strategies of "hot and cold tumors," and analyzed the immunophenotypes, the tumor microenvironment, the signaling pathways, and the molecular markers that contribute to "hot and cold tumors" in details. Different therapeutic strategies for "cold and hot tumors" based on clinical efficacy were analyzed with drug targets and proteins for "cold and hot tumors." Furthermore, this review combines the therapeutic strategies of different "hot and cold tumors" with traditional medicine and modern medicine, to provide a basis and guidance for clinical decision-making of cancer treatment.

The role of CD4+ T cells in tumor and chronic viral immune responses

Immunotherapies are mainly aimed to promote a CD8+ T cell response rather than a CD4+ T cell response as cytotoxic T lymphocytes (CTLs) can directly kill target cells. Recently, CD4+ T cells have received more attention due to their diverse roles in tumors and chronic viral infections. In antitumor and antichronic viral responses, CD4+ T cells relay help signals through dendritic cells to indirectly regulate CD8+ T cell response, interact with B cells or macrophages to indirectly modulate humoral immunity or macrophage polarization, and inhibit tumor blood vessel formation. Additionally, CD4+ T cells can also exhibit direct cytotoxicity toward target cells. However, regulatory T cells exhibit immunosuppression and CD4+ T cells become exhausted, which promote tumor progression and chronic viral persistence. Finally, we also outline immunotherapies based on CD4+ T cells, including adoptive cell transfer, vaccines, and immune checkpoint blockade. Overall, this review summarizes diverse roles of CD4+ T cells in the antitumor or protumor and chronic viral responses, and also highlights the immunotherapies based on CD4+ T cells, giving a better understanding of their roles in tumors and chronic viral infections.

Mature tertiary lymphoid structures are key niches of tumour-specific immune responses in pancreatic ductal adenocarcinomas

OBJECTIVE

To better understand the immune microenvironment of pancreatic ductal adenocarcinomas (PDACs), here we explored the relevance of T and B cell compartmentalisation into tertiary lymphoid structures (TLSs) for the generation of local antitumour immunity.

DESIGN

We characterised the functional states and spatial organisation of PDAC-infiltrating T and B cells using single-cell RNA sequencing (scRNA-seq), flow cytometry, multicolour immunofluorescence, gene expression profiling of microdissected TLSs, as well as in vitro assays. In addition, we performed a pan-cancer analysis of tumour-infiltrating T cells using scRNA-seq and sc T cell receptor sequencing datasets from eight cancer types. To evaluate the clinical relevance of our findings, we used PDAC bulk RNA-seq data from The Cancer Genome Atlas and the PRINCE chemoimmunotherapy trial.

RESULTS

We found that a subset of PDACs harbours fully developed TLSs where B cells proliferate and differentiate into plasma cells. These mature TLSs also support T cell activity and are enriched with tumour-reactive T cells. Importantly, we showed that chronically activated, tumour-reactive T cells exposed to fibroblast-derived TGF-β may act as TLS organisers by producing the B cell chemoattractant CXCL13. Identification of highly similar subsets of clonally expanded CXCL13 + tumour-infiltrating T cells across multiple cancer types further indicated a conserved link between tumour-antigen recognition and the allocation of B cells within sheltered hubs in the tumour microenvironment. Finally, we showed that the expression of a gene signature reflecting mature TLSs was enriched in pretreatment biopsies from PDAC patients with longer survival after receiving different chemoimmunotherapy regimens.

CONCLUSION

We provided a framework for understanding the biological role of PDAC-associated TLSs and revealed their potential to guide the selection of patients for future immunotherapy trials.

The Role of CD4 T Cell Help in CD8 T Cell Differentiation and Function During Chronic Infection and Cancer

CD4 and CD8 T cells are key players in the immune response against both pathogenic infections and cancer. CD4 T cells provide help to CD8 T cells via multiple mechanisms, including licensing dendritic cells (DCs), co-stimulation, and cytokine production. During acute infection and vaccination, CD4 T cell help is important for the development of CD8 T cell memory. However, during chronic viral infection and cancer, CD4 helper T cells are critical for the sustained effector CD8 T cell response, through a variety of mechanisms. In this review, we focus on T cell responses in conditions of chronic Ag stimulation, such as chronic viral infection and cancer. In particular, we address the significant role of CD4 T cell help in promoting effector CD8 T cell responses, emerging techniques that can be utilized to further our understanding of how these interactions may take place in the context of tertiary lymphoid structures, and how this key information can be harnessed for therapeutic utility against cancer.

Tertiary lymphoid structures correlate with enhancement of antitumor immunity in esophageal squamous cell carcinoma

BACKGROUND

Tertiary lymphoid structures (TLSs) are associated with a favorable prognosis in several cancers. However, the correlation between TLSs and outcomes of esophageal squamous cell carcinoma (ESCC) and the impact of TLSs on the tumor immune microenvironment (TIME) remain unknown.

METHODS

We pathologically evaluated the significance of TLSs in ESCC focusing on TLS maturation using 180 ESCC specimens and performed single-cell RNA sequencing (scRNA-seq) using 14 ESCC tissues to investigate functional differences of immune cells according to TLS presence.

RESULTS

TLS+ cases had better recurrence-free-survival (RFS) (p < 0.0001) and overall survival (OS) (p = 0.0016) compared with TLS- cases. Additionally, mature TLS+ cases had better RFS and OS compared with immature TLS+ cases (p = 0.019 and p = 0.015) and TLS- cases (p < 0.0001 and p = 0.0002). The scRNA-seq showed that CD8+ T cells in TLS+ tumors expressed high levels of cytotoxic signatures and antigen-presentation of dendritic cells (DCs) was enhanced in TLS+ tumors. Immunohistochemistry showed that the densities of tumor-infiltrating CD8+ T cells and DCs were significantly higher in TLS+ tumors than those in TLS- tumors.

CONCLUSIONS

These data suggest the prognostic and functional significance of TLSs in ESCC and provides new insights into TLSs on the TIME.

ABCB11 accumulated in immature tertiary lymphoid structures participates in xenobiotic metabolic process and predicts resistance to PD-1/PD-L1 inhibitors in head and neck squamous cell carcinoma

Head and neck squamous cell carcinomas (HNSCC) are at a high risk of recurrence and multimodal therapy have not significantly improved survival in recent decades. Although immune checkpoint inhibitors (ICIs) are effective in a small proportion of HNSCC patients, the majority do not respond. In this study, we for the first time revealed that xenobiotic metabolic process was significantly associated with resistance to programmed death-1 (PD-1)/programmed death-ligand 1 (PD-L1) inhibitors in HNSCC and found that ATP binding cassette subfamily B member 11 (ABCB11) accumulated in immature tertiary lymphoid structures (TLSs) predicted worse progression-free survival (PFS) and overall survival (OS) after PD-1/PD-L1 inhibitors therapy. Moreover, the expression of cytochrome P450 1A2 (CYP1A2), a cytochrome P450 (CYP) enzyme that participates in xenobiotic metabolic process, was significantly upregulated in CD45+ABCB11+ tumor-infiltrating lymphocytes (TILs) compared with CD45+ABCB11-TILs in HNSCC tissues. Whole slide scans of 110 HNSCC tissues with hematoxylin-eosin (HE) and multispectral immuno-fluorescent (mIF) staining revealed that ABCB11 had a high co-expression with CYP1A2 in immature TLSs, and colocalization of ABCB11 and CYP1A2 in immature TLs significantly associated with high infiltration of immunosuppressive T-regulatory (Treg). Our study revealed that ABCB11 accumulated in immature TLSs might upregulate CYP1A2 to mediate xenobiotic metabolic process, thus increase the immunosuppressive Treg infiltration, and induce resistance to PD-1/PD-L1 inhibitors in HNSCC.