Characteristics of tertiary lymphoid structures in primary cancers

Tumor-associated tertiary lymphoid structures in cancer: implications for immunotherapy

INTRODUCTION

Tertiary lymphoid structures (TLS) arise at chronic inflammatory sites where they function as miniature lymph nodes to generate immune responses, which can be beneficial or detrimental, in diseases as diverse as autoimmunity, chronic infections and cancer. A growing number of studies show that a TLS presence in tumors from cancer patients treated with immune checkpoint inhibitors is closely linked with improved clinical outcomes. TLS may foster the generation of specific anti-tumor immune responses and immunological memory that recognizes a patient's own tumor. Due to repeated rounds of chronic inflammation, some tumor-associated TLS may be immunologically inactive, with immune checkpoint inhibitors functioning to revitalize them through pathway activation.

AREAS COVERED

This review summarizes work on TLS and how they mediate immune responses in human tumors. We also explore TLS as potential prognostic and predictive biomarkers for immunotherapy.

EXPERT OPINION

The presence of TLS in human tumors has been linked with a better clinical prognosis, response to treatment(s) and overall survival. TLS provide a structured microenvironment for the activation, expansion and maturation of immune cells at the tumor site. These activities can enhance the efficacy of immunotherapeutic treatments such as checkpoint inhibitors and cancer vaccines by revitalizing local anti-tumor immunity.

Baseline Blood CD8+ T Cell Activation Potency Discriminates Responders from Non-Responders to Immune Checkpoint Inhibition Combined with Stereotactic Radiotherapy in Non-Small-Cell Lung Cancer

BACKGROUND

Tumor-infiltrating immune cells have been correlated with prognosis for patients treated with immune checkpoint inhibitor (ICI) treatment of various cancers. However, no robust biomarker has been described to predict treatment response yet. We hypothesized that the activation potency of circulating T cells may predict response to ICI treatment.

METHODS

An exploratory analysis was conducted to investigate the association between the response to immune checkpoint inhibition (ICI) combined with stereotactic radiotherapy (SBRT) and the potency of circulating T cells to be activated. Blood-derived lymphocytes from 14 patients were stimulated ex vivo with, among others, Staphylococcal enterotoxin B (SEB) and compared to healthy controls (HCs). Patients were grouped into responders (>median progression free survival (PFS)) and non-responders (

RESULTS

At baseline, a higher percentage of activated CD8+ T cells (15.8% vs. 3.5% (p = <0.01)) and IL-2+CD69+CD8+ T cells (8.8% vs. 2.9% (p = 0.02)) was observed in responders compared to non-responders upon ex vivo stimulation with SEB. The concurrently measured serum cytokine levels were not different between responders and non-responders.

CONCLUSION

Baseline blood CD8+ T cell activation potency, measured by intracellular cytokine production after ex vivo stimulation, is a potential biomarker to discriminate responders from non-responders to SBRT combined with ICI.

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Key Words

• NSCLC
• T cell function assay
• biomarker
• cytokines
• immune checkpoint inhibition
• immunotherapy
• liquid biopsy

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MESH Headings Collapse

Grants

• ESR 16-12461 / D4191C00075 AstraZeneca (Netherlands)

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Affiliation(s)

Hanneke Kievit Department of Pulmonology, University of Groningen, University Medical Center Groningen, 9713 GZ Groningen, The Netherlands (H.A.M.K.)
M. Benthe Muntinghe-Wagenaar Department of Pulmonology, University of Groningen, University Medical Center Groningen, 9713 GZ Groningen, The Netherlands (H.A.M.K.)
Wayel H. Abdulahad Department of Rheumatology and Clinical Immunology, University of Groningen, University Medical Center Groningen, 9713 GZ Groningen, The Netherlands
Abraham Rutgers Department of Rheumatology and Clinical Immunology, University of Groningen, University Medical Center Groningen, 9713 GZ Groningen, The Netherlands
Lucie B. M. Hijmering-Kappelle Department of Pulmonology, University of Groningen, University Medical Center Groningen, 9713 GZ Groningen, The Netherlands (H.A.M.K.)
Birgitta I. Hiddinga Department of Pulmonology, University of Groningen, University Medical Center Groningen, 9713 GZ Groningen, The Netherlands (H.A.M.K.)
J. Fred Ubbels Department of Radiation Oncology, University of Groningen, University Medical Center Groningen, 9713 GZ Groningen, The Netherlands
Robin Wijsman Department of Radiation Oncology, University of Groningen, University Medical Center Groningen, 9713 GZ Groningen, The Netherlands
Marcel J. van der Leij Department of Laboratory Medicine, Medical Immunology Laboratory, University of Groningen, University Medical Center Groningen, 9713 GZ Groningen, The Netherlands
Johan Bijzet Department of Rheumatology and Clinical Immunology, University of Groningen, University Medical Center Groningen, 9713 GZ Groningen, The Netherlands
Harry J. M. Groen Department of Pulmonology, University of Groningen, University Medical Center Groningen, 9713 GZ Groningen, The Netherlands (H.A.M.K.)
Huib A. M. Kerstjens Department of Pulmonology, University of Groningen, University Medical Center Groningen, 9713 GZ Groningen, The Netherlands (H.A.M.K.)
Anthonie J. van der Wekken Department of Pulmonology, University of Groningen, University Medical Center Groningen, 9713 GZ Groningen, The Netherlands (H.A.M.K.)
Bart-Jan Kroesen Department of Laboratory Medicine, Medical Immunology Laboratory, University of Groningen, University Medical Center Groningen, 9713 GZ Groningen, The Netherlands
T. Jeroen N. Hiltermann Department of Pulmonology, University of Groningen, University Medical Center Groningen, 9713 GZ Groningen, The Netherlands (H.A.M.K.)

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Tertiary lymphoid structures: new immunotherapy biomarker

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

Whole-body cellular mapping in mouse using standard IgG antibodies

Whole-body imaging techniques play a vital role in exploring the interplay of physiological systems in maintaining health and driving disease. We introduce wildDISCO, a new approach for whole-body immunolabeling, optical clearing and imaging in mice, circumventing the need for transgenic reporter animals or nanobody labeling and so overcoming existing technical limitations. We identified heptakis(2,6-di-O-methyl)-β-cyclodextrin as a potent enhancer of cholesterol extraction and membrane permeabilization, enabling deep, homogeneous penetration of standard antibodies without aggregation. WildDISCO facilitates imaging of peripheral nervous systems, lymphatic vessels and immune cells in whole mice at cellular resolution by labeling diverse endogenous proteins. Additionally, we examined rare proliferating cells and the effects of biological perturbations, as demonstrated in germ-free mice. We applied wildDISCO to map tertiary lymphoid structures in the context of breast cancer, considering both primary tumor and metastases throughout the mouse body. An atlas of high-resolution images showcasing mouse nervous, lymphatic and vascular systems is accessible at http://discotechnologies.org/wildDISCO/atlas/index.php .

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.

High endothelial venules proportion in tertiary lymphoid structure is a prognostic marker and correlated with anti-tumor immune microenvironment in colorectal cancer

BACKGROUND

High endothelial venules (HEV) and tertiary lymphoid structures (TLS) are associated with clinical outcomes of patients with colorectal cancer (CRC). However, because HEV are components of TLS, there have been few studies of the role of the HEV proportion in TLS (HEV/TLS). This study investigated the role of the HEV/TLS and its relationship with the tumor immune microenvironment in CRC.

METHODS

A retrospective analysis of 203 cases of tissue pathologically diagnosed as CRC after general surgery was performed at the First Affiliated Hospital of Jinan University from January 2014 to July 2017. Paraffin sections were obtained from the paracancerous intestinal mucosal tissues. The area of HEV and TLS and immune cells were detected by immunohistochemistry. We further divided the positive HEV expression group into the high HEV/TLS group and the low HEV/TLS group by the average area of HEV/TLS. After grouping, the data were also analyzed using the chi-square test, Kaplan-Meier method, and univariate and multivariate Cox proportional risk regression analyses. A correlation analysis of the HEV/TLS and immune cells as well as angiogenesis was performed.

RESULTS

Patients with a high HEV/TLS in CRC tissue were associated with longer OS, DFS and lower TNM stage. Meanwhile, CRC tissue with a high HEV/TLS showed a greater ability to recruit the CD3+ T cells, CD8+ T cells and M1 macrophages and correlated with less angiogenesis. Conclusively, high HEV/TLS links to the favorable prognosis of CRC patients and correlated with anti-tumor immune microenvironment, which can be a potential biomarker for prognosis of CRC patients.

CONCLUSION

A high HEV/TLS is associated with a favorable prognosis for CRC and is correlated with the anti-tumor immune microenvironment. Therefore, it is a potential biomarker of the CRC prognosis.KEY MESSAGESHigh HEV/TLS is associated with a favorable prognosis for CRC.High HEV/TLS correlated with the anti-tumor immune microenvironment of CRC and can serve as a novel prognostic biomarker.

Prognostic and predictive values of the grading system of lymph node status in patients with advanced-stage gastric cancer

Background

Lymph node metastasis is one of the most important prognostic factors of gastric cancer. However, the effect of germinal centers in lymph nodes on the prognosis of patients with gastric cancer has not been reported. This study aimed to investigate the contribution of germinal center generation to prognostic parameters and clinicopathological significance in gastric cancer.

Methods

We retrospectively reviewed gastric cancer patients who underwent surgery from October 2012 to June 2022. We analyzed 5484 lymph nodes (210 patients) and calculated the lymph node metastasis rate (LNMR) and the proportion of non-metastatic lymph nodes containing three or more germinal centers (NML-GCP).

Results

Using a grading system that incorporated LNMR and NML-GCP. The tumors were classified into three groups based on this system, which was found to be significantly associated with prognosis. The TNM stage and grading system of lymph node status were independent risk factors for overall survival (OS) and disease-free survival (DFS). The 5-year OS rates for patients with advanced gastric cancer were 85.07% (n=50), 58.34% (n=42), and 24.44% (n=21) for Grades 1, 2, and 3, respectively (p<0.0001). The 5-year DFS rates were 65.32% (n=58), 40.85% (n=51), and 5.88% (n=34), respectively (p<0.0001). Patients with Grade 1 advanced gastric cancer had higher 5-year OS and DFS rates compared to those with Grade 2 or 3 in TNM stage II and III. Furthermore, the 5-year OS and DFS rates differed significantly among patients with different grades of advanced gastric cancer who received chemotherapy (p<0.0001).

Conclusion

These findings suggest that the grading system may be valuable for predicting prognosis and guiding clinical management in patients with gastric cancer, and provides good prognostic stratification for OS and DFS in patients with TNM stage II and III.

Defining and using immune archetypes to classify and treat cancer

Tumours are surrounded by a host immune system that can suppress or promote tumour growth. The tumour microenvironment (TME) has often been framed as a singular entity, suggesting a single type of immune state that is defective and in need of therapeutic intervention. By contrast, the past few years have highlighted a plurality of immune states that can surround tumours. In this Perspective, we suggest that different TMEs have 'archetypal' qualities across all cancers - characteristic and repeating collections of cells and gene-expression profiles at the level of the bulk tumour. We discuss many studies that together support a view that tumours typically draw from a finite number (around 12) of 'dominant' immune archetypes. In considering the likely evolutionary origin and roles of these archetypes, their associated TMEs can be predicted to have specific vulnerabilities that can be leveraged as targets for cancer treatment with expected and addressable adverse effects for patients.

Understanding the Tumor Immune Microenvironment in Renal Cell Carcinoma

Scientific understanding of how the immune microenvironment interacts with renal cell carcinoma (RCC) has substantially increased over the last decade as a result of research investigations and applying immunotherapies, which modulate how the immune system targets and eliminates RCC tumor cells. Clinically, immune checkpoint inhibitor therapy (ICI) has revolutionized the treatment of advanced clear cell RCC because of improved outcomes compared to targeted molecular therapies. From an immunologic perspective, RCC is particularly interesting because tumors are known to be highly inflamed, but the mechanisms underlying the inflammation of the tumor immune microenvironment are atypical and not well described. While technological advances in gene sequencing and cellular imaging have enabled precise characterization of RCC immune cell phenotypes, multiple theories have been suggested regarding the functional significance of immune infiltration in RCC progression. The purpose of this review is to describe the general concepts of the anti-tumor immune response and to provide a detailed summary of the current understanding of the immune response to RCC tumor development and progression. This article describes immune cell phenotypes that have been reported in the RCC microenvironment and discusses the application of RCC immunophenotyping to predict response to ICI therapy and patient survival.

Nanovaccines Fostering Tertiary Lymphoid Structure to Attack Mimicry Nasopharyngeal Carcinoma

Tertiary lymphoid structures (TLSs) are formed in inflamed tissues, and recent studies demonstrated that the appearance of TLSs in tumor sites is associated with a good prognosis for tumor patients. However, the process of natural TLSs' formation was slow and uncontrollable. Herein, we developed a nanovaccine consisting of Epstein-Barr virus nuclear antigen 1 (EBNA1) and a bi-adjuvant of Mn²⁺ and cytosine-phosphate-guanine (CpG) formulated with tannic acid that significantly inhibited the development of mimicry nasopharyngeal carcinoma by fostering TLS formation. The nanovaccine activated LT-α and LT-β pathways, subsequently enhancing the expression of downstream chemokines, CCL19/CCL21, CXCL10 and CXCL13, in the tumor microenvironment. In turn, normalized blood and lymph vessels were detected in the tumor tissues of the nanovaccine group, correlated with increased infiltration of lymphocytes. Especially, the proportion of the B220⁺ CD8⁺ T, which was produced via trogocytosis between T and B cells during activation of T cells, was increased in tumors of the nanovaccine group. Furthermore, the intratumoral effector memory T cells (Tem), CD45⁺, CD3⁺, CD8⁺, CD44⁺, and CD62L^-, did not decrease after blocking the egress of T cells from tumor-draining lymph nodes by FTY-720. These results demonstrated that the nanovaccine can foster TLS formation, which thus enhances local immune responses significantly, delays tumor outgrowth, and prolongs the median survival time of murine models of mimicry nasopharyngeal carcinoma, demonstrating a promising strategy for nanovaccine development.

Tertiary lymphoid structures in desmoplastic melanoma have increased lymphocyte density, lymphocyte proliferation, and immune cross talk with tumor when compared to non-desmoplastic melanomas

Tertiary lymphoid structures (TLS) are ectopic lymphoid structures that can arise in human cancers and are associated with improved overall survival (OS) and response to immune checkpoint blockade (ICB) in several cancers, including non-desmoplastic metastatic melanoma (NDMM). Desmoplastic melanoma (DM) has one of the highest response rates to ICB, and we previously identified that primary DM (PDM) contains TLS. Despite the association of TLS with survival and ICB response, it is unknown whether TLS or associated markers of immune activity can differ between PDM and NDMM. We hypothesized that PDM would contain higher frequencies of TLS than NDMM, that T and B-cell densities and proliferation would be greater in TLS of PDM than TLS of NDMM, and that proliferation rates of T and B-cells in PDM TLS would be concordant with those of intratumoral lymphocytes. We found that four features of TLS in PDM distinguish them from TLS in NDMM. TLS were peritumoral in NDMM but intratumoral in PDM. CD8⁺ T-cell and CD20⁺ B-cell densities and proliferative fractions were higher in PDM TLS than NDMM TLS. Additionally, the proliferative fractions of T- and B-cells were concordant between the TLS and tumor site in PDM and discordant in NDMM. Collectively, these data suggest that TLS and associated immune markers can differ across melanoma subsets and suggest that PDM TLS may be more immunologically active and have enhanced immune cell trafficking between tumor and TLS compared to NDMM.

The impact of tertiary lymphoid structures on clinicopathological, genetic and gene expression characteristics in lung adenocarcinoma

INTRODUCTION

Tertiary lymphoid structures (TLS) are observed in several cancers and are associated with favorable prognosis. This study aimed to examine the clinicopathological, genetic, and gene expression profiles of lung adenocarcinoma patients with TLS.

METHODS

A total of 112 patients with pathological stage IB lung adenocarcinoma who underwent complete resection between 2011 and 2015 were enrolled in this study. We investigated whether TLS correlated with prognosis and programmed death-ligand 1 (PD-L1) expression. Furthermore, the correlation of TLS with tumor mutation burden (TMB) and genetic mutations was evaluated in patients for whom whole-exon sequencing data were available. In addition, using the Cancer Genome Atlas Lung Adenocarcinoma (TCGA-LUAD) dataset, gene expression analysis according to the TLS status was performed.

RESULTS

Among the 112 patients, 49 were TLS-positive (TLS+). TLS+ correlated with longer recurrence-free survival (RFS) than TLS-negative cases (TLS-) (hazard ratio [HR], 0.47; 95 % confidence interval [CI]: 0.23-0.88, p = 0.02). In the multivariate analysis, TLS was a better independent prognostic factor for RFS (HR 0.37, 95 %CI 0.18-0.72, p < 0.01). PD-L1 expression was not significantly different between TLS+ and TLS- patients (p = 0.54). TMB in TLS+ was similar to that in TLS- patients (p = 0.39); however, it tended to be lower than that in TLS- especially among smokers (p = 0.07). In gene expression analysis, RNA expression of chemokines related to lymph node formation, such as CXCL13, CCL19 and CCL21, was significantly higher, and biological processes such as positive regulation of humoral immune response and regulation of antigen receptor-mediated signaling pathway were enhanced in TLS+.

CONCLUSIONS

TLS was a favorable prognostic factor and was not associated with PD-L1 expression in patients with lung adenocarcainoma. Moreover, gene expression analysis indicated that TLS is a site for the generation and regulation of antitumor immune responses.

Longitudinal Modulation of Loco-Regional Immunity in Ovarian Cancer Patients Receiving Intraperitoneal Chemotherapy

The immune tumor microenvironment (TME) of epithelial ovarian cancer (EOC) carries both effector and suppressive functions. To define immune correlates of chemotherapy-induced tumor involution, we performed longitudinal evaluation of biomarker expression on serial biological specimens collected during intraperitoneal (IP) platinum-based chemotherapy. Serial biological samples were collected at several time points during IP chemotherapy. RNA from IP fluid cells and tumor tissue was analyzed via NanoString. Meso Scale Discovery (MSD) multiplex assay and ELISA for MUC1 antibodies were performed on plasma and IP fluid. Differentially expressed genes in IP fluid demonstrate an upregulation of B cell function and activation of Th2 immune response along with dampening of Th1 immunity during chemotherapy. MSD analysis of IP fluid and gene expression analysis of tumor tissue revealed activation of Th2 immunity and the complement system. Anti-MUC1 antibodies were detected in IP fluid samples. IP fluid analysis in a secondary cohort also identified chemotherapy-induced B cell function genes. This study shows that serial IP fluid sampling is an effective method to capture changes in the immune TME during chemotherapy and reveals treatment induced changes in B cell function and Th2 immunity.

Sensory nerves impede the formation of tertiary lymphoid structures and development of protective anti-melanoma immune responses

Peripheral neurons comprise a critical component of the tumor microenvironment (TME). The role of the autonomic innervation in cancer has been firmly established. However, the effect of the afferent (sensory) neurons on tumor progression remains unclear. Utilizing surgical and chemical skin sensory denervation methods, we showed that afferent neurons supported the growth of melanoma tumors in vivo and demonstrated that sensory innervation limited the activation of effective anti-tumor immune responses. Specifically, sensory ablation led to improved leukocyte recruitment into tumors, with decreased presence of lymphoid and myeloid immunosuppressive cells and increased activation of T-effector cells within the TME. Cutaneous sensory nerves hindered maturation of intratumoral high endothelial venules (HEVs) and limited formation of mature tertiary lymphoid-like structures containing organized clusters of CD4+ T cells and B cells. Denervation further increased T-cell clonality and expanded the B-cell repertoire in the TME. Importantly, CD8a depletion prevented denervation-dependent anti-tumor effects. Finally, we observed that gene signatures of inflammation and the content of neuron-associated transcripts inversely correlated in human primary cutaneous melanomas, with the latter representing a negative prognostic marker of patient overall survival. Our results suggest that tumor-associated sensory neurons negatively regulate the development of protective anti-tumor immune responses within the TME, thereby defining a novel target for therapeutic intervention in the melanoma setting.

Tertiary lymphoid structures in cancer

Ectopic lymphoid aggregates, termed tertiary lymphoid structures (TLSs), are formed in numerous cancer types, and, with few exceptions, their presence is associated with superior prognosis and response to immunotherapy. In spite of their presumed importance, the triggers that lead to TLS formation in cancer tissue and the contribution of these structures to intratumoral immune responses remain incompletely understood. Here, we discuss the present knowledge on TLSs in cancer, focusing on (i) the drivers of TLS formation, (ii) the function and contribution of TLSs to the antitumor immune response, and (iii) the potential of TLSs as therapeutic targets in human cancers.

The relationship of the tertiary lymphoid structures with the tumor-infiltrating lymphocytes and its prognostic value in gastric cancer

Introduction

To explore the relationship between the tertiary lymphoid structures (TLSs) and tumor-infiltrating lymphocytes (TILs), and their distribution characteristics as well as the prognostic value in gastric cancer (GC).

Material and methods

The TLSs and four subtypes of TILs were assessed by immunohistochemical (IHC) staining. The presence of MECA-79 positive high endothelial venules (HEVs) identified among the ectopic lymphocyte aggregation area in the GC tissue was defined as valid TLSs. The number of labeled TILs was observed in 5 fields of the most positive cells in the tumor center, invasive edge and within the TLSs, at a field of vision ×40.

Results

The TLS distribution was significantly higher in the tumor invasive edge than the tumor center (p < 0.001). Similarly, the infiltrating density of CD8+ T cells and GrB+ T cells was statistically significantly higher in the tumor infiltrating edge than the tumor center. The total number of TILs and FOXP3+ T cells showed a contrary distribution. There was a positive correlation of the density of TLSs and TILs with both the location and the immune phenotype. A higher frequency of TILs and TLSs is often associated with favorable clinicopathologic parameters. Higher numbers of peri-TLSs (p = 0.007), peri-CD8+ (p = 0.019) and peri-GrB+TILs (p = 0.032) were significantly correlated with the favorable overall survival. Multivariate analysis revealed that the densities of TILs (p = 0.019) and TLSs (p = 0.037) were independent prognostic predictor for GC patients.

Conclusions

We provide evidence that TLSs were positively associated with lymphocyte infiltration in GC. Thus, the formation of TLSs predicts advantageous immune system function and can be considered as a novel biomarker to stratify the overall survival risk of untreated GC patients.

Molecular mechanism study of HGF/c-MET pathway activation and immune regulation for a tumor diagnosis model

Background

Hepatocyte growth factor (HGF) binds to the c-mesenchymal-epithelial transition (C-MET) receptor and activates downstream signaling pathways, playing an essential role in the development of various cancers. Given the role of this signaling pathway, the primary therapeutic direction focuses on identifying and designing HGF inhibitors, antagonists and other molecules to block the binding of HGF to C-MET, thereby limiting the abnormal state of other downstream genes.

Methods

This study focuses on the analysis of immune-related genes and corresponding immune functions that are significantly associated with the HGF/c-MET pathway using transcriptome data from 11 solid tumors.

Results

We systematically analyzed 11 different cancers, including expression correlation, immune infiltration, tumor diagnosis and survival prognosis from HGF/c-MET pathway and immune regulation, two biological mechanisms having received extensive attention in cancer analysis.

Conclusion

We found that the HGF/c-MET pathway affected the tumor microenvironment mainly by interfering with expression levels of other genes. Immune infiltration is another critical factor involved in changes to the tumor microenvironment. The downstream immune-related genes activated by the HGF/c-MET pathway regulate immune-related pathways, which in turn affect the degree of infiltration of immune cells. Immune infiltration is significantly associated with cancer development and prognosis.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12935-021-02051-2.

Prognostic Value of Tumor-Infiltrating Lymphocytes and Tertiary Lymphoid Structures in Epstein-Barr Virus-Associated and -Negative Gastric Carcinoma

Background

Tumor-infiltrating lymphocytes (TILs) are considered a manifestation of the host immune response against cancer and tertiary lymphoid structures (TLS) may contribute to lymphocytes recruitment. Both of them have been reported as potential prognostic parameters in some human malignancies. However, the roles of TILs, TLS, and their correlation in Epstein-Barr Virus-associated gastric carcinoma (EBVaGC) and EBV-negative gastric carcinoma (EBVnGC) are largely unknown.

Methods

To observe the correlation among TILs, TLS, and clinicopathological characteristics and their prognostic significance in EBVaGC and EBVnGC, respectively. TILs and TLS were assessed by morphology and/or immunohistochemistry, and accompanied by clinicopathological analysis from 846 gastric cancer patients in multiple institutions.

Results

Forty-two (5.0%) cases of EBVaGC and 804 cases of EBVnGC were identified by in situ hybridization, respectively. For EBVnGC, higher TILs grade was correlated with TLS-present. EBVnGC patients with high TILs grade and TLS-present exhibited survival benefits. TILs (P = 0.001) and TLS (P = 0.003), especially TILs & TLS (P < 0.001) were independent prognostic factors in EBVnGC. A nomogram was constructed and validated for predicting the probability of overall survival and performed well with a good calibration. No significant prognostic value was detected in EBVaGC.

Conclusion

TILs and TLS, especially TILs & TLS were promising prognostic indicators for overall survival in EBVnGC. TILs and TLS were highly overlapping in their extent and prognostic abilities, and may be considered as a coindicator of prognosis of gastric cancer. The evaluations of TILs and TLS are simple and can be assessed routinely in pathological diagnosis.

Inducible Tertiary Lymphoid Structures: Promise and Challenges for Translating a New Class of Immunotherapy

Tertiary lymphoid structures (TLS) are ectopically formed aggregates of organized lymphocytes and antigen-presenting cells that occur in solid tissues as part of a chronic inflammation response. Sharing structural and functional characteristics with conventional secondary lymphoid organs (SLO) including discrete T cell zones, B cell zones, marginal zones with antigen presenting cells, reticular stromal networks, and high endothelial venues (HEV), TLS are prominent centers of antigen presentation and adaptive immune activation within the periphery. TLS share many signaling axes and leukocyte recruitment schemes with SLO regarding their formation and function. In cancer, their presence confers positive prognostic value across a wide spectrum of indications, spurring interest in their artificial induction as either a new form of immunotherapy, or as a means to augment other cell or immunotherapies. Here, we review approaches for inducible (iTLS) that utilize chemokines, inflammatory factors, or cellular analogues vital to TLS formation and that often mirror conventional SLO organogenesis. This review also addresses biomaterials that have been or might be suitable for iTLS, and discusses remaining challenges facing iTLS manufacturing approaches for clinical translation.

Relationship between Tertiary Lymphoid Structure and the Prognosis and Clinicopathologic Characteristics in Solid Tumors

Background: An increasing number of studies had shown that tertiary lymphoid structure (TLS) plays an important role in tumor progression. However, the prognostic role of TLS in various tumors remains controversial. This meta-analysis aims to investigate the clinicopathological and prognostic values of TLS in solid tumors. Methods: A systematic search was conducted in PubMed, EMBASE and Cochrane Library undated to November 2, 2020. Odds ratios of clinical parameters, hazard ratio (HR) of overall survival (OS), relapse-free survival (RFS), disease-free survival (DFS) and relapse rate were calculated in order to evaluate the relationship between TLS expression and clinicopathological or prognostic values in different tumors. Result: 27 eligible studies including 6647 patients with different types of tumors were analyzed. High TLS expression was associated with a longer OS (HR = 0.66, 95% CI: 0.50 - 0.86, P = 0.002) and RFS (HR = 0.61, 95% CI: 0.47 - 0.79, P = 0.0001). Moreover, high TLS levels in tumor were associated with a low risk of recurrence (HR = 0.43, 95% CI: 0.32 - 0.57, P < 0.0001). However, there was no relationship between TLS expression and DFS. Meanwhile, high TLS expression was associated with smaller tumor size (P < 0.00001) and higher tumor infiltrating lymphocytes (TILs). Furthermore, the subgroup analysis showed high TLS expression that may be associated with a lower clinical grading and N stage in breast cancer and colorectal cancer. Conclusion: High TLS expression is associated with the longer OS and RFS in solid tumors, and a lower risk of cancer relapse. Meanwhile, high TLS expression is also associated with a smaller tumor size, higher infiltration of TILs, lower clinical grading and N stage in the tumor. Therefore, high TLS expression in the tumor is a favorable prognostic biomarker for solid tumor patients.

Tumor-infiltrating plasmacytoid dendritic cells are associated with survival in human colon cancer

Background

Plasmacytoid dendritic cells (pDCs) play a key role in the induction and maintenance of antitumor immunity. Conversely, they can act as tolerogenic DCs by inhibiting tumor-directed immune responses. Therefore, pDCs may profoundly influence tumor progression. To gain novel insights into the role of pDCs in colon cancer, we investigated the frequency and clinical relevance of pDCs in primary tumor tissues from patients with colon cancer with different clinicopathological characteristics.

Methods

Immunohistochemical stainings were performed to explore the frequency of tumor-infiltrating BDCA-2⁺ pDCs in patients with colon cancer. Statistical analyses were conducted to determine an association between the pDC density and clinicopathological characteristics of the patients. Furthermore, we used multiplex immunofluorescence stainings to evaluate the localization and phenotype of pDCs in stroma and tertiary lymphoid structures (TLS) of colon cancer tissues.

Results

An increased density of infiltrating pDCs was associated with lower Union for International Cancer Control (UICC) stages. Furthermore, a higher pDC frequency was significantly correlated with increased progression-free and overall survival of patients with colon cancer. Moreover, a lower number of coloncancer-infiltrating pDCs was significantly and independently linked to worse prognosis. In addition, we found that a proportion of pDCs shows a nuclear expression of the transcription factor interferon regulatory factor 7 (IRF7), which is characteristic for an activated phenotype. In various tumor stroma regions, IRF7⁺ pDCs were located in the neighborhood of granzyme B-expressing CD8⁺ T cells. Moreover, pDCs were identified as a novel component of the T cell zone of colon cancer-associated TLS, which are major regulators of adaptive antitumor immunity. A proportion of TLS-associated pDCs displayed a nuclear IRF7 expression and was preferentially located close to CD4⁺ T cells.

Conclusions

These results indicate that higher densities of tumor-infiltrating pDCs are associated with prolonged survival of patients with colon cancer. Moreover, colon cancer-infiltrating pDCs may represent a novel prognostic factor. The colocalization of activated pDCs and T cells in tumor stroma and within TLS may contribute to the correlation between higher pDC densities and better prognosis. In addition, our findings may have implications for the design of novel immunotherapeutic strategies that are based on targeting colon cancer-infiltrating pDCs.

Next Generation Imaging Techniques to Define Immune Topographies in Solid Tumors

In recent years, cancer immunotherapy experienced remarkable developments and it is nowadays considered a promising therapeutic frontier against many types of cancer, especially hematological malignancies. However, in most types of solid tumors, immunotherapy efficacy is modest, partly because of the limited accessibility of lymphocytes to the tumor core. This immune exclusion is mediated by a variety of physical, functional and dynamic barriers, which play a role in shaping the immune infiltrate in the tumor microenvironment. At present there is no unified and integrated understanding about the role played by different postulated models of immune exclusion in human solid tumors. Systematically mapping immune landscapes or "topographies" in cancers of different histology is of pivotal importance to characterize spatial and temporal distribution of lymphocytes in the tumor microenvironment, providing insights into mechanisms of immune exclusion. Spatially mapping immune cells also provides quantitative information, which could be informative in clinical settings, for example for the discovery of new biomarkers that could guide the design of patient-specific immunotherapies. In this review, we aim to summarize current standard and next generation approaches to define Cancer Immune Topographies based on published studies and propose future perspectives.

Multiplex Immunofluorescence Histology for Immune Cell Infiltrates in Melanoma-Associated Tertiary Lymphoid Structures

The presence of tertiary lymphoid structures (TLS) is correlated with prolonged patient survival in a variety of solid cancers, including melanoma. However, few methods have been described that could enable a more comprehensive understanding of the organization and functionality of TLS in solid cancers. In this chapter, we describe multiplex immunohistochemistry and microscopy approaches for identifying, characterizing, and quantifying TLS and intra-tumoral immune infiltrates in melanoma. The described methods are not limited to melanoma alone and could be used to evaluate tertiary lymphoid structures in a wide variety of human cancers.

Vaccine-Induced Intratumoral Lymphoid Aggregates Correlate with Survival Following Treatment with a Neoadjuvant and Adjuvant Vaccine in Patients with Resectable Pancreatic Adenocarcinoma

PURPOSE

Immunotherapy is currently ineffective for nearly all pancreatic ductal adenocarcinomas (PDAC), largely due to its tumor microenvironment (TME) that lacks antigen-experienced T effector cells (Teff). Vaccine-based immunotherapies are known to activate antigen-specific Teffs in the peripheral blood. To evaluate the effect of vaccine therapy on the PDAC TME, we designed a neoadjuvant and adjuvant clinical trial of an irradiated, GM-CSF-secreting, allogeneic PDAC vaccine (GVAX).

PATIENTS AND METHODS

Eighty-seven eligible patients with resectable PDAC were randomly assigned (1:1:1) to receive GVAX alone or in combination with two forms of low-dose cyclophosphamide. Resected tumors following neoadjuvant immunotherapy were assessed for the formation of tertiary lymphoid aggregates (TLA) in response to treatment. The clinical endpoints are disease-free survival (DFS) and overall survival (OS).

RESULTS

The neoadjuvant treatment with GVAX either alone or with two forms of low-dose cyclophosphamide is safe and feasible without adversely increasing the surgical complication rate. Patients in Arm A who received neoadjuvant and adjuvant GVAX alone had a trend toward longer median OS (35.0 months) than that (24.8 months) in the historical controls who received adjuvant GVAX alone. However, Arm C, who received low-dose oral cyclophosphamide in addition to GVAX, had a significantly shorter DFS than Arm A. When comparing patients with OS > 24 months to those with OS < 15 months, longer OS was found to be associated with higher density of intratumoral TLA.

CONCLUSIONS

It is safe and feasible to use a neoadjuvant immunotherapy approach for PDACs to evaluate early biologic responses. In-depth analysis of TLAs is warranted in future neoadjuvant immunotherapy clinical trials.

The immune contexture and Immunoscore in cancer prognosis and therapeutic efficacy

The international American Joint Committee on Cancer/Union for International Cancer Control (AJCC/UICC) tumour-node-metastasis (TNM) staging system provides the current guidelines for the classification of cancer. However, among patients within the same stage, the clinical outcome can be very different. More recently, a novel definition of cancer has emerged, implicating at all stages a complex and dynamic interaction between tumour cells and the immune system. This has enabled the definition of the immune contexture, representing the pre-existing immune parameters associated with patient survival. Even so, the role of distinct immune cell types in modulating cancer progression is increasingly emerging. An immune-based assay named the 'Immunoscore' was defined to quantify the in situ T cell infiltrate and was demonstrated to be superior to the AJCC/UICC TNM classification for patients with colorectal cancer. This Review provides a broad overview of the main immune parameters positively or negatively shaping cancer development, including the Immunoscore, and their prognostic and predictive value. The importance of the immune system in cancer control is demonstrated by the requirement for a pre-existing intratumour adaptive immune response for effective immunotherapies, such as checkpoint inhibitors. Finally, we discuss how the combination of multiple immune parameters, rather than individual ones, might increase prognostic and/or predictive power.

Nicotinamide combined with gemcitabine is an immunomodulatory therapy that restrains pancreatic cancer in mice

BACKGROUND

Treatments for pancreatic ductal adenocarcinoma are poorly effective, at least partly due to the tumor's immune-suppressive stromal compartment. New evidence of positive effects on immune responses in the tumor microenvironment (TME), compelled us to test the combination of gemcitabine (GEM), a standard chemotherapeutic for pancreatic cancer, with nicotinamide (NAM), the amide form of niacin (vitamin B3), in mice with pancreatic cancer.

METHODS

Various mouse tumor models of pancreatic cancer, that is, orthotopic Panc-02 and KPC (KrasG12D, p53R172H, Pdx1-Cre) grafts, were treated alternately with NAM and GEM for 2 weeks, and the effects on efficacy, survival, stromal architecture and tumor-infiltrating immune cells was examined by immunohistochemistry (IHC), flow cytometry, Enzyme-linked immunospot (ELISPOT), T cell depletions in vivo, Nanostring analysis and RNAscope.

RESULTS

A significant reduction in tumor weight and number of metastases was found, as well as a significant improved survival of the NAM+GEM group compared with all control groups. IHC and flow cytometry showed a significant decrease in tumor-associated macrophages and myeloid-derived suppressor cells in the tumors of NAM+GEM-treated mice. This correlated with a significant increase in the number of CD4 and CD8 T cells of NAM+GEM-treated tumors, and CD4 and CD8 T cell responses to tumor-associated antigen survivin, most likely through epitope spreading. In vivo depletions of T cells demonstrated the involvement of CD4 T cells in the eradication of the tumor by NAM+GEM treatment. In addition, remodeling of the tumor stroma was observed with decreased collagen I and lower expression of hyaluronic acid binding protein, reorganization of the immune cells into lymph node like structures and CD31 positive vessels. Expression profiling for a panel of immuno-oncology genes revealed significant changes in genes involved in migration and activation of T cells, attraction of dendritic cells and epitope spreading.

CONCLUSION

This study highlights the potential of NAM+GEM as immunotherapy for advanced pancreatic cancer.

Immune parameters associated with survival in metaplastic breast cancer

Background

Metaplastic breast carcinoma (MBC) is a rare histological type of breast cancer, which commonly shows resistance to standard therapies and is associated with poor prognosis. The immune microenvironment in MBC and its significance has not been well established due to its low incurrence rate and complex components. We aimed to investigate the diversity of immune parameters including subsets of TILs and PDL1/PD1 expression in MBC, as well as its correlation with prognosis.

Methods

A total of 60 patients diagnosed with MBC from January 2006 to December 2017 were included in our study. The percentage (%) and quantification (per mm²) of TILs and presence of tertiary lymphoid structures (TLS) were evaluated by hematoxylin and eosin staining (HE). The quantification of CD4+, CD8+ TILs (per mm²), and PD-1/PDL1 expression were evaluated through immunohistochemistry and analyzed in relation to clinicopathological characteristics. A ≥ 1% membranous or cytoplasmatic expression of PD1 and PDL1 was considered a positive expression.

Results

We found squamous cell carcinoma MBC (33/60, 55%) exhibiting most TILs of all the MBC subtypes (p = 0.043). Thirty-three of 60 (50%) of the patients had coexisting invasive ductal carcinoma of no special type (IDC-NST), and the average percentage of TILs in MBC components was lower compared with NST components (p < 0.001). Thirty (50%) patients exhibited positive (≥ 1%) PDL1 expression in their tumor cells, while 36 (60%) had positive (≥ 1%) PDL1 expression in their TILs. Twenty-seven (45%) of all the patients had positive (≥ 1%) PD1 expression in their tumor cells and 33 (55%) had PD1-positive (≥ 1%) stromal TILs. More CD8+ TILs were associated with positive PDL1 expression of tumor cells as well as positive PD1 expression in stromal cells. Greater number of stromal TILS (> 300/mm², 20%), CD4+ TILs (> 250/mm²), and CD8+ TILs (> 70/mm²) in MBC were found associated with longer disease-free survival. Positive expression of PDL1 in tumor cells (≥ 1%) and PD1 in stromal cells (≥ 1%) were also associated with longer survival.

Conclusions

The immune characteristics differ in various subtypes as well as components of MBC. Immune parameters are key predictive factors of MBC and provide the clinical significance of applying immune checkpoint therapies in patients with MBC.

Immune cells as tumor drug delivery vehicles

This review article describes the use of immune cells as potential candidates to deliver anti-cancer drugs deep within the tumor microenvironment. First, the rationale of using drug carriers to target tumors and potentially decrease drug-related side effects is discussed. We further explain some of the current limitations when using nanoparticles for this purpose. Next, a comprehensive step-by-step description of the migration cascade of immune cells is provided as well as arguments on why immune cells can be used to address some of the limitations associated with nanoparticle-mediated drug delivery. We then describe the benefits and drawbacks of using red blood cells, platelets, granulocytes, monocytes, macrophages, myeloid-derived suppressor cells, T cells and NK cells for tumor-targeted drug delivery. An additional section discusses the versatility of nanoparticles to load anti-cancer drugs into immune cells. Lastly, we propose increasing the circulatory half-life and development of conditional release strategies as the two main future pillars to improve the efficacy of immune cell-mediated drug delivery to tumors.

Cancer systems immunology

Tumor immunology is undergoing a renaissance due to the recent profound clinical successes of tumor immunotherapy. These advances have coincided with an exponential growth in the development of -omics technologies. Armed with these technologies and their associated computational and modeling toolsets, systems biologists have turned their attention to tumor immunology in an effort to understand the precise nature and consequences of interactions between tumors and the immune system. Such interactions are inherently multivariate, spanning multiple time and size scales, cell types, and organ systems, rendering systems biology approaches particularly amenable to their interrogation. While in its infancy, the field of 'Cancer Systems Immunology' has already influenced our understanding of tumor immunology and immunotherapy. As the field matures, studies will move beyond descriptive characterizations toward functional investigations of the emergent behavior that govern tumor-immune responses. Thus, Cancer Systems Immunology holds incredible promise to advance our ability to fight this disease.

CD8+ T cells located in tertiary lymphoid structures are associated with improved prognosis in patients with gastric cancer

The presence of tumor infiltrating lymphocytes (TILs) and tertiary lymphoid structures (TLSs) in tumor tissues are of great prognostic significance in several types of human cancer. The present study investigated the density of TILs and TLSs in gastric cancer (GC) tissues and their association with pathological parameters. Moreover, the clinical significance of follicular CD8⁺ cytotoxic T cells present within the germinal centers of the tumor-associated TLSs was investigated. Immunohistochemistry and H&E staining were used to examine the infiltration and distribution patterns of TILs, TLSs and germinal center (gc) CD8⁺ TILs in tumor tissues obtained from 63 patients with GC. The number of TILs, TLSs, combination of TILs and TLSs (TILs-TLSs) and gcCD8⁺ TILs were used to define tumoral immune parameters, and the prognostic value of these parameters was assessed. The analysis revealed that patients with GC with increased levels of TILs, TLSs, or gcCD8⁺ TILs exhibited improved overall survival. In addition, gcCD8⁺ TILs levels were significantly associated with patient age, histological grade and pTN stage. Increased levels of TILs-TLSs were positively associated with nerve invasion, tumor thrombus, nodal metastasis and histological grade. Multivariate Cox regression analysis revealed that TILs-TLSs and gcCD8⁺ TILs were independent prognostic factors. The data obtained in the present study demonstrated that high levels of tumoral immune parameters are important independent prognostic predictors for human GC. The results also suggested a possible role of gcCD8⁺ TILs in tumor immune surveillance.

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.

TNFSF14: LIGHTing the Way for Effective Cancer Immunotherapy

Tumor necrosis factor superfamily member 14 (LIGHT) has been in pre-clinical development for over a decade and shows promise as a modality of enhancing treatment approaches in the field of cancer immunotherapy. To date, LIGHT has been used to combat cancer in multiple tumor models where it can be combined with other immunotherapy modalities to clear established solid tumors as well as treat metastatic events. When LIGHT molecules are delivered to or expressed within tumors they cause significant changes in the tumor microenvironment that are primarily driven through vascular normalization and generation of tertiary lymphoid structures. These changes can synergize with methods that induce or support anti-tumor immune responses, such as checkpoint inhibitors and/or tumor vaccines, to greatly improve immunotherapeutic strategies against cancer. While investigators have utilized multiple vectors to LIGHT-up tumor tissues, there are still improvements needed and components to be found within a human tumor microenvironment that may impede translational efforts. This review addresses the current state of this field.

Existence of intratumoral tertiary lymphoid structures is associated with immune cells infiltration and predicts better prognosis in early-stage hepatocellular carcinoma

Tumor-associated tertiary lymphoid structures (TLS) play a critical role in the progression of various tumors. However, the dynamics of lymphocyte recruitment during hepatocellular carcinoma (HCC) clinical progression have not been fully elucidated. In the present study, tissue microarrays and hematoxylin-eosin staining were used to evaluate the existence and degree of TLS in HCC patients. Nine immune biomarkers in intratumoral tissues were examined by immunohistochemical staining. A total of 462 patients were recruited for the study. Kaplan-Meier analysis showed that TLS was inversely correlated with the risk of early tumor recurrence (P=0.014), whereas no association was found between TLS and overall survival. Cox regression analysis identified TLS as an independent prognostic factor for early HCC recurrence (P=0.005). In addition, TLS was associated with increased intratumoral CD3+, CD8+, CD20+, and decreased infiltration of Foxp3+ and CD68+ cells. A lower density of PD1+, TIM3+, and LAG3+ were found in TLS+ cases. Sub-analysis revealed the prognostic value of TLS on early-stage HCC (BCLC 0-A, TNM stage I-II) and HCC with solitary nodule. The validation cohort verified the prognostic value of TLS in early-stage HCC patients. These results suggest that TLS-targeted immune-modulating therapies may be a potential strategy for effective immune-mediated tumor suppression.

Immunological Complexity of the Prostate Cancer Microenvironment Influences the Response to Immunotherapy

Prostate cancer is one of the most common cancers in men and a leading cause of cancer-related death. Recent advances in the treatment of advanced prostate cancer, including the use of more potent and selective inhibitors of the androgen signaling pathway, have provided significant clinical benefit for men with metastatic castration-resistant prostate cancer (mCRPC). However, most patients develop progressive lethal disease, highlighting the need for more effective treatments. One such approach is immunotherapy, which harness the power of the patient's immune system to identify and destroy cancer cells through the activation of cytotoxic CD8 T cells specific for tumor antigens. Although immunotherapy, particularly checkpoint blockade, can induce significant clinical responses in patients with solid tumors or hematological malignancies, minimal efficacy has been observed in men with mCRPC. In the current review, we discuss our current understanding of the immunological complexity of the immunosuppressive prostate cancer microenvironment, preclinical models of prostate cancer, and recent advances in immunotherapy clinical trials to improve outcomes for men with mCRPC.

The Role of the Immune Infiltrate in Distinct Cancer Types and Its Clinical Implications : Lymphocytic Infiltration in Colorectal Cancer

Colorectal cancer (CRC) represents a major public health challenges, with one of the highest incidences worldwide. The two affected anatomical sites in CRC, i.e. the colon and the rectum, share important underlying features, but often differ in terms of therapeutic management. Current guidelines for CRC define its clinical stratification according to classical, tumor cell-based and pathological parameters. Novel ground-breaking findings in the recent years revealed the prominent role of the immune system in shaping CRC development. This chapter provides a detailed overview of the main genomic and immune features driving (or hampering) CRC progression, with a focus on the main immune cells and factors shaping its evolution. Furthermore, we discuss how tumor-infiltrating immunity could be leveraged both for therapeutic and stratification purposes.

Deconvolution of the immunological contexture of mouse tumors with multiplexed immunohistochemistry

In a variety of solid tumors, the presence of higher densities of tumor-infiltrating lymphocytes or tertiary lymphoid structures (TLS) are correlated with prolonged patient survival. Murine studies are usually required to define mechanisms that govern immunologic infiltrate in tumors. However, few methods have been described that could enable a more comprehensive understanding of the functionality of intratumoral immune infiltrate and TLS in solid murine cancers. In this chapter, we describe multiplex immunohistochemistry and microscopy approaches for identifying, characterizing, and quantifying intratumoral immune infiltrate and TLS in murine tumor models.

Histopathological and microbiological findings in buffalo chronic mastitis: evidence of tertiary lymphoid structures

Buffalo mastitis is an important economic problem in southern Italy, causing qualitative/quantitative alterations in milk and resulting in economic losses due to the sub-clinical course and chronic evolution. We investigated 50 udders of slaughtered buffaloes and subjected them to effectual microbiological screening to evaluate macro and microscopic mammary gland changes, immune-characterize the cell infiltrates, and compare the degree of tissue inflammation with somatic cell counts. Numerous Gram-positive and Gram-negative bacteria were isolated from all samples, majority of which were environmental mastitis pathogens. Histological features referable to chronic mastitis were observed in 92% udders. Lymphocytes, plasma cells and macrophages were found to evolve into aggregates in 48% udders, which often organized to form tertiary lymphoid structures (TLSs). A predominance of interstitial CD8+ over CD4+ lymphocytes and, in TLSs, scattered CD8+ lymphocytes in the mantle cells and CD79+ lymphocytes in germinal centers, were evidenced. Environmental pathogens are known to persist and cause chronic inflammatory changes in buffaloes, where CD8+ lymphocytes play an important role by controlling the local immune response. Moreover, the TLSs evidenced here for the first time in buffalo mastitis, could play a role in maintaining immune responses against persistent antigens, thereby contributing in determining the chronic course of mastitis.

Tumor-associated B cells and humoral immune response in head and neck squamous cell carcinoma

B lymphocytes are important players in immune responses to cancer. However, their composition and function in head and neck squamous cell carcinoma (HNSCC) has not been well described. Here, we analyzed B cell subsets in HNSCC (n = 38), non-cancerous mucosa (n = 14) and peripheral blood from HNSCC patients (n = 38) and healthy controls (n = 20) by flow cytometry. Intratumoral B cells contained high percentages of activated (CD86+), antigen-presenting (CD86+/CD21-) and memory B cells (IgD-/CD27+). T follicular helper cells (CD4+/CXCR5+/CD45RA-/CCR7-) as key components of tertiary lymphoid structures and plasma cells made up high percentages of the lymphocyte infiltrate. Percentages of regulatory B cell varied depending on the regulatory phenotype. Analysis of humoral immune responses against 23 tumor-associated antigens (TAA) showed reactivity against at least one antigen in 56% of HNSCC patients. Reactivity was less frequent in human papillomavirus associated (HPV+) patients and healthy controls compared to HPV negative (HPV-) HNSCC. Likewise, patients with early stage HNSCC or MHC-I loss on tumor cells had low TAA responses. Patients with TAA responses showed CD4+ dominated T cell infiltration compared to mainly CD8+ T cells in tumors without detected TAA response. To summarize, our data demonstrates different immune infiltration patterns in relation to serological TAA response detection and the presence of B cell subpopulations in HNSCC that can engage in tumor promoting and antitumor activity. In view of increasing use of immunotherapeutic approaches, it will be important to include B cells into comprehensive phenotypic and functional analyses of tumor-associated lymphocytes.

The requirement for immune infiltration and organization in the tumor microenvironment for successful immunotherapy in prostate cancer

Immunotherapy-particularly immune checkpoint blockade-has seen great success in many tumor types. However, checkpoint-based therapies have not demonstrated high levels of success in prostate cancer, and there is much to be learned from both the successes and failures of these treatments. Here we review the evidence that composition of infiltrating immune cells in the tumor microenvironment is fundamental to the response to immunotherapy. Additionally, we discuss the emerging idea that the organization of these immune cells may also be crucial to this response. In prostate cancer, the composition and organization of the tumor immune microenvironment are preeminent topics of discussion and areas of important future investigation.

Neutrophils and Snail Orchestrate the Establishment of a Pro-tumor Microenvironment in Lung Cancer

Understanding the immune compartment of tumors facilitates the development of revolutionary new therapies. We used a Kras(G12D)-driven mouse model of lung cancer to establish an immune signature and identified a contribution of Gr1⁺ neutrophils to disease progression. Depletion experiments showed that Gr1⁺ cells (1) favor tumor growth, (2) reduce T cell homing and prevent successful anti-PD1 immunotherapy, and (3) alter angiogenesis, leading to hypoxia and sustained Snail expression in lung cancer cells. In turn, Snail accelerated disease progression and increased intratumoral Cxcl2 secretion and neutrophil infiltration. Cxcl2 was produced mainly by neutrophils themselves in response to a factor secreted by Snail-expressing tumor cells. We therefore propose a vicious cycle encompassing neutrophils and Snail to maintain a deleterious tumor microenvironment.

Cellular Composition and Contribution of Tertiary Lymphoid Structures to Tumor Immune Infiltration and Modulation by Radiation Therapy

Immune-based anti-cancer strategies combined with radiation therapy (RT) are actively being investigated but many questions remain, such as the ideal treatment scheme and whether a potent immune response can be generated both locally and systemically. In this context, tumor-associated tertiary lymphoid structures (TLS) have become a subject of research. While TLS are present in several types of cancer with strong similarities, they are especially relevant in medullary breast carcinoma (MBC). This suggests that MBC patients are ideally suited for investigating this question and may benefit from adapted therapeutic options. As RT is a corner-stone of MBC treatment, investigating interactions between RT and TLS composition is also clinically relevant. We thus first characterized the lymphoid structures associated with MBC in a patient case report and demonstrated that they closely resemble the TLS observed in a genetical mouse model. In this model, we quantitatively and qualitatively investigated the cellular composition of the tumor-associated TLS. Finally, we investigated TLS regulation after hypo-fractionated RT and showed that RT induced their acute and transient depletion, followed by a restoration phase. This study is the first work to bring a comprehensive and timely characterization of tumor-associated TLS in basal conditions and after RT. It highlights cellular targets (i.e., Tregs) that could be selectively modulated in subsequent studies to optimize anti-tumor immune response. The study of TLS modulation is worth further investigation in the context of RT and personalized medicine.

Transcriptomic immune profiling of ovarian cancers in paraneoplastic cerebellar degeneration associated with anti-Yo antibodies

BACKGROUND

Paraneoplastic neurological syndromes are rare conditions where an autoimmune reaction against the nervous system appears in patients suffering from a tumour, but not linked to the spreading of the tumour. A break in the immune tolerance is thought to be the trigger.

METHODS

The transcriptomic profile of 12 ovarian tumours (OT) from patients suffering from paraneoplastic cerebellar degeneration (PCD) linked to anti-Yo antibodies (anti-Yo PCD OT) was compared with 733 ovarian tumours (OT control) from different public databases using linear model analysis.

RESULTS

A prominent significant transcriptomic over-representation of CD8+ and Treg cells was found in anti-Yo PCD OT, as compared to the OT control. However, the overall degree of immune cell infiltration was similar, according to the ESTIMATE immune score. We also found an under-representation of M2 macrophages in anti-Yo PCD OT. Furthermore, the differentially expressed genes were enriched for AIRE-related genes, a well-known transcription factor associated with a broad range of autoimmune diseases. Finally, we found that the differentially expressed genes were correlated to the transcriptomic profiling of the cerebellar structures.

CONCLUSIONS

Our data pinpointed the enrichment of acquired immune response, particularly high density of CD8+ lymphocytes, and high-level expression of CDR-related antigens in anti-Yo PCD OT.

Role of chemokines in ectopic lymphoid structures formation in autoimmunity and cancer

Ectopic (or tertiary) lymphoid structures (ELS) are organized aggregates of lymphocytes resembling secondary lymphoid organs and developing in chronically inflamed nonlymphoid tissues during persistent infections, graft rejection, autoimmune conditions, and cancer. In this review, we will first depict the mechanisms regulating ELS generation, focusing on the role played by lymphoid chemokines. We will then characterize ELS forming in target organs during autoimmune conditions, here exemplified by rheumatoid arthritis, and cancer, highlighting the relevance of the tissue-specific factors. Finally, we will discuss the clinical significance of ELS and the therapeutic potential of their inhibition and/or enhancement depending on the disease considered.

Lymphoid aggregates in desmoplastic melanoma have features of tertiary lymphoid structures

Desmoplastic melanomas (DM) have unique and challenging clinical presentations and histomorphology. A characteristic feature is the presence of scattered lymphoid aggregates. However, the nature of these aggregates is not defined. We hypothesized that they may be tertiary lymphoid structures (TLS), and may be associated with programmed death ligand 1 (PD-L1) expression. We searched our tissue database for 'pure' DMs and for scars as control tissues, collected clinical information, and reviewed H&E histology. We performed multispectral imaging after staining for CD8, CD20, PNAd, FoxP3, CD83, and Ki67, and assessed PD-L1 expression by immunohistochemistry. Pure DM samples were evaluable in 11 patients. All had desmoplastic stroma and lymphoid aggregates on H&E. The lymphoid aggregates of eight of the 11 (72%) DM samples and only three of the 11 scars contained features of TLS, defined as distinct clusters of B cells and CD8 T cells, CD83 dendritic cells in T-cell zones, and PNAd vasculature resembling high endothelial venules. PD-L1 was expressed by at least 1% of melanoma cells in six and by at least 5% of immune cells in 10 of the 11 DM samples. We found that most lymphoid aggregates in DM are organized, classical TLS. PD-L1 expression was detected in most cases and was highest in two cases of DM with TLS. However, low PD-L1 expression in some cases suggests that some DM cells may be unresponsive to interferon-γ. TLS support antigen presentation and T-cell responses in chronic inflammation and cancer. Their presence in DM likely reflects an adaptive immune response, which may be enhanced with immune therapies.

The heterogeneity of tumor-infiltrating CD8+ T cells in metastatic melanoma distorts their quantification: how to manage heterogeneity?

CD8 T-cell infiltration of metastatic melanoma may be a useful biomarker for prediction of prognosis and response to therapy. The heterogeneous distribution of CD8 T cells within a single tumor, and across different tumors within a single patient, may complicate quantification of infiltration. However, the impact of heterogeneity has not been quantified sufficiently. To address this, we have assessed intratumoral heterogeneity of CD8 T-cell counts, as well as intertumoral heterogeneity for synchronous and metachronous metastases. In a tissue microarray containing 189 melanoma metastases from 147 patients, the density of CD8 T cells per sample was determined by immunohistochemistry. The mean density and coefficient of variation were calculated for each tumor and the rates of discordant values were determined. CD8 counts varied widely among different core samples of the same tumors (average coefficient of variation=0.77, 95% confidence interval: 0.70-0.85), with discordance occurring in 40% of tumors. CD8 densities were similar among pairs of simultaneous tumors; however, significant changes in CD8 densities were observed among 35 pairs of metachronous tumors. CD8 T-cell density is not well represented by a single 1 mm diameter sample. Differences in CD8 T-cell counts, observed in clinical trials, from pretreatment to post-treatment specimens may be explained by the spatial and temporal heterogeneity of CD8 distribution, especially if the assessed samples are small (i.e. 1 mm). A sufficiently large biopsy of one of several synchronous tumors may be representative of CD8 T-cell infiltration of a patient's disease.

Identification and Characterization of Tertiary Lymphoid Structures in Murine Melanoma

Tertiary lymphoid structures (TLS) are transient ectopic lymphoid aggregates that often share structural similarities to conventional secondary lymphoid organs. In a variety of solid cancers, the presence of these structures commonly correlates with high densities of tumor-infiltrating T lymphocytes and prolonged patient survival. These observations suggest that TLS act as sites for the development of beneficial antitumor immune responses. However, few murine tumor models have been described that could enable a more comprehensive understanding of the functionality of TLS in solid cancers. We previously reported that murine B16-F1 melanoma or Lewis lung carcinoma cells transfected to express the model antigen ovalbumin form intratumoral TLS after implantation into the peritoneal cavity of C57BL/6 mice. In this chapter, we describe immunofluorescent microscopy and flow cytometry approaches for identifying and characterizing intratumoral TLS. Additionally, we describe an adoptive transfer method for demonstrating the infiltration of naïve T cells into B16-OVA melanoma tumors via the lymph node-like vasculature, which is an essential functional feature of tumor-associated TLS.

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

In solid tumors, the presence of lymph node-like structures called tertiary lymphoid structures (TLS) is associated with improved patient survival. However, little is known about how TLS develop in cancer, how their function affects survival, and whether they are affected by cancer therapy. In this study, we used multispectral microscopy, quantitative pathology, and gene expression profiling to analyze TLS formation in human lung squamous cell carcinoma (LSCC) and in an experimental model of lung TLS induction. We identified a niche of CXCL13⁺ perivascular and CXCL12⁺LTB⁺ and PD-L1⁺ epithelial cells supporting TLS formation. We also characterized sequential stages of TLS maturation in LSCC culminating in the formation of germinal centers (GC). In untreated patients, TLS density was the strongest independent prognostic marker. Furthermore, TLS density correlated with GC formation and expression of adaptive immune response-related genes. In patients treated with neoadjuvant chemotherapy, TLS density was similar, but GC formation was impaired and the prognostic value of TLS density was lost. Corticosteroids are coadministered with chemotherapy to manage side effects in LSCC patients, so we evaluated whether they impaired TLS development independently of chemotherapy. TLS density and GC formation were each reduced in chemotherapy-naïve LSCC patients treated with corticosteroids before surgery, compared with untreated patients, a finding that we confirmed in the experimental model of lung TLS induction. Overall, our results highlight the importance of GC formation in TLS during tumor development and treatment.Significance: Corticosteroid treatment during chemotherapy negatively affects the development of tertiary lymphoid structures and abrogates their prognostic value in patients with lung cancer. Cancer Res; 78(5); 1308-20. ©2018 AACR.

Tertiary Lymphoid Structures in Cancer: Drivers of Antitumor Immunity, Immunosuppression, or Bystander Sentinels in Disease?

Secondary lymphoid organs are integral to initiation and execution of adaptive immune responses. These organs provide a setting for interactions between antigen-specific lymphocytes and antigen-presenting cells recruited from local infected or inflamed tissues. Secondary lymphoid organs develop as a part of a genetically preprogrammed process during embryogenesis. However, organogenesis of secondary lymphoid tissues can also be recapitulated in adulthood during de novo lymphoid neogenesis of tertiary lymphoid structures (TLSs). These ectopic lymphoid-like structures form in the inflamed tissues afflicted by various pathological conditions, including cancer, autoimmunity, infection, or allograft rejection. Studies are beginning to shed light on the function of such structures in different disease settings, raising important questions regarding their contribution to progression or resolution of disease. Data show an association between the tumor-associated TLSs and a favorable prognosis in various types of human cancer, attracting the speculation that TLSs support effective local antitumor immune responses. However, definitive evidence for the role for TLSs in fostering immune responses in vivo are lacking, with current data remaining largely correlative by nature. In fact, some more recent studies have even demonstrated an immunosuppressive, tumor-promoting role for cancer-associated TLSs. In this review, we will discuss what is known about the development of cancer-associated TLSs and the current understanding of their potential role in the antitumor immune response.

Myc Cooperates with Ras by Programming Inflammation and Immune Suppression

The two oncogenes KRas and Myc cooperate to drive tumorigenesis, but the mechanism underlying this remains unclear. In a mouse lung model of KRasG12D-driven adenomas, we find that co-activation of Myc drives the immediate transition to highly proliferative and invasive adenocarcinomas marked by highly inflammatory, angiogenic, and immune-suppressed stroma. We identify epithelial-derived signaling molecules CCL9 and IL-23 as the principal instructing signals for stromal reprogramming. CCL9 mediates recruitment of macrophages, angiogenesis, and PD-L1-dependent expulsion of T and B cells. IL-23 orchestrates exclusion of adaptive T and B cells and innate immune NK cells. Co-blockade of both CCL9 and IL-23 abrogates Myc-induced tumor progression. Subsequent deactivation of Myc in established adenocarcinomas triggers immediate reversal of all stromal changes and tumor regression, which are independent of CD4+CD8+ T cells but substantially dependent on returning NK cells. We show that Myc extensively programs an immune suppressive stroma that is obligatory for tumor progression.

Tumor microenvironment and noncoding RNAs as co-drivers of epithelial-mesenchymal transition and cancer metastasis

Reciprocal interactions between cancer cells and tumor microenvironment (TME) are crucial events in tumor progression and metastasis. Pervasive stromal reprogramming of TME modifies numerous cellular functions, including extracellular matrix (ECM) stiffness, inflammation, and immunity. These environmental factors allow selection of more aggressive cells that develop adaptive strategies associating plasticity and epithelial-mesenchymal transition (EMT), stem-like phenotype, invasion, immunosuppression, and resistance to therapies. EMT is a morphomolecular process that endows epithelial tumor cells with mesenchymal properties, including reduced adhesion and increased motility. Numerous studies have demonstrated involvement of noncoding RNAs (ncRNAs), such as miRNAs and lncRNAs, in tumor initiation, progression, and metastasis. NcRNAs regulate every hallmark of cancer and have now emerged as new players in induction and regulation of EMT. The reciprocal regulatory interactions between ncRNAs, TME components, and cancer cells increase the complexity of gene expression and protein translation in cancer. Thus, deeper understanding of molecular mechanisms controlling EMT will not only shed light on metastatic processes of cancer cells, but enhance development of new therapies targeting metastasis. In this review, we will provide recent findings on the role of known ncRNAs relevant to EMT and cancer metastasis and discuss the role of the interaction between ncRNAs and TME as co-drivers of EMT. Developmental Dynamics 247:405-431, 2018. © 2017 Wiley Periodicals, Inc.