The roles of tertiary lymphoid structures in chronic diseases

Hierarchical protein nano-crystalline hydrogel with extracellular vesicles for ectopic lymphoid structure formation

Among cancer therapies, immune checkpoint blockade (ICB) has emerged as a prominent approach, substantially enhancing anti-tumor immune responses. However, the efficacy of ICB is often limited in the absence of a pre-existing immune response within the tumor microenvironment. Here, we introduce a novel hierarchical protein hydrogel platform designed to facilitate the formation of artificial tertiary lymphoid structures (aTLS), thereby improving ICB efficacy. Through the integration of self-assembling ferritin protein nanocages, rec1-resilin protein, and CP05 peptide, our hierarchical hydrogels provide a structurally supportive and functionally adaptive scaffold capable of on-demand self-repair in response to mild thermal treatments. The effective encapsulation of extracellular vesicles (EVs) via the CP05 peptide ensures the formation of aTLS with germinal center-like structures within the hierarchical hydrogel. We demonstrate that, combined with ICB therapy, EV-loaded hierarchical hydrogels also induce the TLS within the tumor, markedly promoting immune responses against ICB-resistant tumor. This bioactive hydrogel platform offers a versatile tool for enhancing a broad range of immunotherapies, with potential applications extending beyond TLS to other frameworks that support complex tissue architectures.

Artery tertiary lymphoid organs in atherosclerosis: A review

Atherosclerosis (AS) is the common pathological basis for many cardiovascular diseases. Initial investigations into AS predominantly centered on endothelial immune responses associated with plaque formation. However, recent studies increasingly underscore the salutary immune modulation occurring on the aorta adventitia as the atheromatous plaque progresses. The immune responses extend from the intima of the vessel to the adventitia, and the artery tertiary lymphoid organ (ATLO) assumes a major immune role in advanced stages of AS, according to available studies conducted on ApoE-/- mice. In this review, we collate the history of studies on the participation of ATLOs in immunity to AS, detailing its structure, classification, cellular composition, and formation mechanisms. We elucidate the distinct roles of ATLO components in immune regulation, emphasizing unique features such as territorial organization, T cell-driven autoimmunity, and the T follicular helper-germinal center B cell axis, which distinguish ATLOs from conventional lymphoid responses. Furthermore, based on the latest research, we propose that ATLOs cooperate with the nervous system to regulate the progression of AS. Moreover, we highlight that aging has a great impact on the deterioration of AS and this impact is related to ATLOs. We conclude by suggesting that a focus on ATLOs is important for the clinical management of AS, and we offer a perspective for further research on ATLO and suggest whether it will be beneficial or detrimental to ATLOs.

Coordinated Regulation of Extrafollicular B Cell Responses by IL-12 and IFNγ

Upon activation, B cells undergo either the germinal center (GC) or extrafollicular (EF) response. While GC are known to generate high-affinity memory B cells and long-lived plasma cells, the role of the EF response is less well understood. Initially, it was thought to be limited to that of a source of fast but lower-quality antibodies until the GC can form. However, recent evidence strongly supports the EF response as an important component of the humoral response to infection. EF responses are now also recognized as a source of pathogenic B cells in autoimmune diseases. The EF response itself is dynamic and regulated by pathways that are only recently being uncovered. We have identified that the cytokine IL-12 acts as a molecular switch, enhancing the EF response and suppressing GC through multiple mechanisms. These include direct effects on both B cells themselves and the coordinated differentiation of helper CD4 T cells. Here, we explore this pathway in relation to other recent advancements in our understanding of the EF response's role and highlight areas for future research. A better understanding of how the EF response forms and is regulated is essential for advancing treatments for many disease states.

Spatial genomics: Mapping the landscape of fibrosis

Organ fibrosis causes major morbidity and mortality worldwide. Treatments for fibrosis are limited, with organ transplantation being the only cure. Here, we review how various state-of-the-art spatial genomics approaches are being deployed to interrogate fibrosis across multiple organs, providing exciting insights into fibrotic disease pathogenesis. These include the detailed topographical annotation of pathogenic cell populations and states, detection of transcriptomic perturbations in morphologically normal tissue, characterization of fibrotic and homeostatic niches and their cellular constituents, and in situ interrogation of ligand-receptor interactions within these microenvironments. Together, these powerful readouts enable detailed analysis of fibrosis evolution across time and space.

Characterisation and Clinical Relevance of Tertiary Lymphoid Structures in Primary Biliary Cholangitis

BACKGROUND AND AIMS

The pathological characteristics of lymphocyte infiltration in the hepatic portal tracts of patients with primary biliary cholangitis (PBC) remain unclear. Tertiary lymphoid structures (TLSs) are ectopic lymphoid tissues associated with the exacerbation of autoimmune reactions. Here, we evaluate the role of TLSs in PBC and investigate their potential therapeutic value.

METHODS

We recruited 75 patients with PBC and 53 control patients with liver biopsies who were followed more than 2 years. TLSs and their maturity were identified by the amount and spatial distribution of immune cells. Bulk RNA sequencing of liver was performed in PBC patients with different TLS maturity. The sphingosine-1-phosphate receptor (S1PRs) modulator FTY720 was administered to dnTGFβRII mice to assess the role of TLSs on cholangitis.

RESULTS

TLSs presented in 61.3% (46/75) of liver tissues from patients with PBC, including 26 patients with mature TLS (mTLS) and 20 patients with immature TLS (imTLS). The proportion of mTLS was higher in PBC compared with chronic hepatitis B and autoimmune hepatitis. PBC patients with mTLS exhibited the highest serum levels of biochemical indicators, immune globulin and proportions of liver cirrhosis. Gene sets for lymphocyte migration and chemokine signalling pathways were enriched in patients with PBC presenting with TLS. FTY720 inhibited TLS formation and relieved cholangitis and fibrosis in dnTGFβRII mice.

CONCLUSION

TLSs are characteristics of lymphocyte accumulation in the portal tracts of PBC, of which the maturity of TLSs correlates with the inflammation and fibrosis of PBC. Targeting TLSs formation is a potential treatment of PBC.

Multi-stain deep learning prediction model of treatment response in lupus nephritis based on renal histopathology

The response of the kidney after induction treatment is one of the determinants of prognosis in lupus nephritis, but effective predictive tools are lacking. Here, we sought to apply deep learning approaches on kidney biopsies for treatment response prediction in lupus nephritis. Patients who received cyclophosphamide or mycophenolate mofetil as induction treatment were included, and the primary outcome was 12-month treatment response, complete response defined as 24-h urinary protein under 0.5 g with normal estimated glomerular filtration rate or within 10% of normal range. The model development cohort included 245 patients (880 digital slides), and the external test cohort had 71 patients (258 digital slides). Deep learning models were trained independently on hematoxylin and eosin-, periodic acid-Schiff-, periodic Schiff-methenamine silver- and Masson's trichrome-stained slides at multiple magnifications and integrated to predict the primary outcome of complete response to therapy at 12 months. Single-stain models showed area under the curves of 0.813, 0.841, 0.823, and 0.862, respectively. Further, integration of the four models into a multi-stain model achieved area under the curves of 0.901 and 0.840 on internal validation and external testing, respectively, which outperformed conventional clinicopathologic parameters including estimated glomerular filtration rate, chronicity index and reduction in proteinuria at three months. Decisive features uncovered by visualization for model prediction included tertiary lymphoid structures, glomerulosclerosis, interstitial fibrosis and tubular atrophy. Our study demonstrated the feasibility of utilizing deep learning on kidney pathology to predict treatment response for lupus patients. Further validation is required before the model could be implemented for risk stratification and to aid in making therapeutic decisions in clinical practice.

Matrix stiffening from collagen fibril density and alignment modulates YAP-mediated T-cell immune suppression

T-cells are essential components of the immune system, adapting their behavior in response to the mechanical environments they encounter within the body. In pathological conditions like cancer, the extracellular matrix (ECM) often becomes stiffer due to increased density and alignment of collagen fibrils, which can have a significant impact on T-cell function. In this study, we explored how these ECM properties-density and fibrillar alignment-affect T-cell behavior using three-dimensional (3D) collagen matrices that mimic these conditions. Our results show that increased matrix stiffness, whether due to higher density or alignment, significantly suppresses T-cell activation, reduces cytokine production, and limits proliferation, largely through enhanced YAP signaling. Individually, matrix alignment appears to lower actin levels in activated T-cells and changes migration behavior in both resting and activated T-cells, an effect not observed in matrices with randomly oriented fibrils. Notably, inhibiting YAP signaling was able to restore T-cell activation and improve immune responses, suggesting a potential strategy to boost the effectiveness of immunotherapy in stiff ECM environments. Overall, this study provides new insights into how ECM characteristics influence T-cell function, offering potential avenues for overcoming ECM-induced immunosuppression in diseases such as cancer.

Uncovering the Role of Tertiary Lymphoid Organs in the Inflammatory Landscape: A Novel Immunophenotype of Diabetic Foot Ulcers

Diabetes foot ulcers (DFU) are the most common foot injuries leading to lower extremity amputation. Our study aimed to provide the first representative analysis highlighting the vital role of Tertiary Lymphoid Organs (TLO) inflammatory landscape in diabetic foot ulcers. The study explores mechanisms of TLO formation and the disease-specific roles of TLOs in regulating peripheral inflammatory and immune responses. Additionally, comprehensive analysis of clinical data from DFU cases, focused on TLO pathophysiology and systemic immune-inflammation landscape, is documented, aiming to identify the risk factors contributing to the development of DFUs. Our experimental results showed very significant differences were observed among the IL-17 and IFN-γ cytokine levels between the DFU vs. Control and DFU vs. NIDFU (Non-Infectious Diabetic Foot Ulcers) groups, while minimal differences were observed in IL-6 and TNF-α cytokine levels. Immunohistochemistry staining or Immunophenotyping of DFU patient-derived wound samples for TLO inflammatory stratification showed remarkable differences between DFU, NIDFU, and control groups both in CD3+ T Cells and CD20+ B cells. Overall, our study findings highlight the perspective role of TLO in DFU mechanisms and its prudent role in regulating peripheral inflammatory-immune responses. TLO study-related significant findings might be one of the important mechanisms, and its effective unveil might be a valuable treatment modality for DFU-complications.

Ectopic germinal centers in the nasal turbinates contribute to B cell immunity to intranasal viral infection and vaccination

The nasal mucosa is the first immunologically active site that respiratory viruses encounter and establishing immunity at the initial point of pathogen contact is essential for preventing viral spread. Influenza A virus (IAV) in humans preferentially replicates in the upper respiratory tract (URT) but mouse models of infection result in lower respiratory tract infection. Here, we optimize IAV inoculation to enhance replication in the nasal turbinate (NT) and study local B cell immunity. We demonstrate that URT-targeted IAV infection stimulates robust local B cell responses, including germinal center (GC) B cell formation in the NT, outside of classical nasal-associated lymphoid tissues. NT GC contributes to local tissue-resident B cell generation and enhances local antibody production. Furthermore, URT-focused immunization also induces significant GC formation in the NT. Finally, we detect steady-state GC in the NT of both mice and healthy humans, suggesting continuous immune surveillance triggered by environmental stimuli. These findings highlight the pivotal role of the NT in local and systemic immunity, with important implications for future mucosal vaccines targeting the upper airways.

Spatial Correlation of the Extracellular Matrix to Immune Cell Phenotypes in the Tumor Boundary of Clear Cell Renal Cell Carcinoma Revealed by Cyclic Immunohistochemistry

The significance of the tumor microenvironment (TME) in predicting immunotherapy efficacy is increasingly acknowledged. However, the complexity of the TME necessitates novel technological approaches for the precise characterization of individual cell types, functional phenotypes, and heterocellular spatial interactions. This study utilizes a streamlined multiplex cyclic immunohistochemistry (cycIHC) protocol for detailed TME annotation. Unlike proprietary methods, cycIHC relies on iterative cycles of conventional immunohistochemistry, using off-the-shelf antibodies and reagents, followed by digitalization, chromogen removal, and antibody stripping. The method was combined with open-source tools for the coregistration of individual staining cycles. Using clear cell renal cell carcinoma (ccRCC) as a model, the protocol was applied for granular annotation of cellular and acellular structures in the tumor boundary zone. Our results demonstrate that the tumor periphery, particularly the pseudocapsule of ccRCC, is homogeneously organized across the 3D scale, yet exhibits distinct cellular distribution gradients of T and B cells. These patterns correspond to deposited extracellular matrix proteins, especially collagen types I and VI. Our findings indicate an instructive impact of extracellular matrix proteins on defining the spatial organization of immune cells in the TME of ccRCC. The developed cycIHC method facilitates detailed characterization of the TME and may enhance the understanding of tumor-immune cell interactions.

The correlation of tertiary lymphoid structures with tumor spread through air spaces and prognosis in lung adenocarcinoma: focusing on pathological spatial features

Lung adenocarcinoma (LADC) exhibits high spatial heterogeneity, with distinct spatial variations in pathological features. The distribution of tertiary lymphoid structures (TLS) in LADC is uneven, and different TLS characteristics play unique roles. To investigate the correlation between TLS features and other pathological characteristics, particularly tumor spread through air spaces (STAS), we analyzed TLS and other pathological features on whole-slide images stained with HE and CD20/CD23. Additionally, the 14-Gene assay was used to assess prognostic risk. Among 388 enrolled LADC patients, 226 (58.2%) were TLS-positive. TLS showed a negative correlation with various adverse pathological features, with boundary-area TLS demonstrating the strongest correlation with STAS quantity (r= -0.324, P < 0.001). Multivariate Cox analysis identified boundary-area TLS as an independent prognostic factor for recurrence-free survival (HR = 0.856, 95% CI = 0.759-0.966, P = 0.026), while mature TLS was an independent factor for overall survival (HR = 0.841, 95% CI = 0.717-0.988, P = 0.035). High-density TLS at the tumor boundary was associated with low-risk stratification by the 14-Gene assay (P = 0.013). This study highlights the negative correlation between TLS and STAS, especially in boundary areas, and emphasizes the impact of tumor microenvironment spatial characteristics on clinical outcomes. Assessment of spatial heterogeneity in LADC facilitates precise risk stratification for patients.

Adding insult to injury: the spectrum of tubulointerstitial responses in acute kidney injury

Acute kidney injury (AKI) encompasses pathophysiology ranging from glomerular hypofiltration to tubular cell injury and outflow obstruction. This Review will focus on the tubulointerstitial processes that underlie most cases of AKI. Tubular epithelial cell (TEC) injury can occur via distinct insults, including ischemia, nephrotoxins, sepsis, and primary immune-mediated processes. Following these initial insults, tubular cells can activate survival and repair responses or they can develop mitochondrial dysfunction and metabolic reprogramming, cell-cycle arrest, and programmed cell death. Developing evidence suggests that the fate of individual tubular cells to survive and proliferate or undergo cell death or senescence is frequently determined by a biphasic immune response with initial proinflammatory macrophage, neutrophil, and lymphocyte infiltration exacerbating injury and activating programmed cell death, while alternatively activated macrophages and specific lymphocyte subsets subsequently modulate inflammation and promote repair. Functional recovery requires that this reparative phase supports proteolytic degradation of tubular casts, proliferation of surviving TECs, and restoration of TEC differentiation. Incomplete resolution or persistence of inflammation can lead to failed tubular repair, fibrosis, and chronic kidney disease. Despite extensive research in animal models, translating preclinical findings to therapies remains challenging, emphasizing the need for integrated multiomic approaches to advance AKI understanding and treatment.

Cross-Talk Between Cancer and Its Cellular Environment-A Role in Cancer Progression

The tumor microenvironment is a dynamic and complex three-dimensional network comprising the extracellular matrix and diverse non-cancerous cells, including fibroblasts, adipocytes, endothelial cells and various immune cells (lymphocytes T and B, NK cells, dendritic cells, monocytes/macrophages, myeloid-derived suppressor cells, and innate lymphoid cells). A constantly and rapidly growing number of studies highlight the critical role of these cells in shaping cancer survival, metastatic potential and therapy resistance. This review provides a synthesis of current knowledge on the modulating role of the cellular microenvironment in cancer progression and response to treatment.

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

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

Tertiary Lymphoid Structures in Pancreatic Cancer are Structurally Homologous, Share Gene Expression Patterns and B-cell Clones with Secondary Lymphoid Organs, but Show Increased T-cell Activation

Tertiary lymphoid structures (TLS) in cancer are considered ectopic hotspots for immune activation that are similar to lymphoid follicles in secondary lymphoid organs (SLO). This study elucidates shared and TLS/SLO-specific features in pancreatic ductal adenocarcinoma (PDAC). TLS abundance was related to superior survival and T-cell abundance in 110 treatment-naïve PDAC samples, underlining their clinical relevance. Immunofluorescence microscopy identified structural homologies between TLSs and SLOs. In RNA expression analyses of laser-microdissected TLSs and paired SLOs, we observed largely overlapping expression patterns of immune-related gene clusters but distinct expression patterns of T-cell and complement-associated genes. Immune cells in TLS expressed essential markers of germinal center formation. Increased activation of tumor-draining lymph nodes in patients with high numbers of TLSs highlights the relevance of these tumor-related structures to systemic immune response. In line with this, we identified an overlap of expanded B-cell receptor clonotypes in TLSs and SLOs, which suggests a vivid cross-talk between the two compartments. We conclude that combined therapeutic approaches exploiting TLS-mediated antitumor immune responses may improve susceptibility of PDAC to immunotherapy.

Antigen-presenting cancer associated fibroblasts enhance antitumor immunity and predict immunotherapy response

Cancer-associated fibroblasts (CAF) play a crucial role in tumor progression and immune regulation. However, the functional heterogeneity of CAFs remains unclear. Here, we identify antigen-presenting CAFs (apCAF), characterized by high MHC II expression, in gastric cancer (GC) tumors and find that apCAFs are preferentially located near tertiary lymphoid structures. Both in vivo and in vitro experiments demonstrate that apCAFs promote T cell activation and enhances its cytotoxic and proliferative capacities, thereby strengthening T cell-mediated anti-tumor immunity. Additionally, apCAFs facilitate the polarization of macrophages toward a pro-inflammatory phenotype. These polarized macrophages, in turn, promote the formation of apCAFs, creating a positive feedback loop that amplifies anti-tumor immune responses. Notably, baseline tumors in immunotherapy responders across various cancer types exhibit higher levels of apCAFs infiltration. This study advances the understanding of CAFs heterogeneity in GC and highlights apCAFs as a potential biomarker for predicting immunotherapy response in pan-cancer.

Parenchymal and inflammatory responses to ozone exposure in the aging healthy and surfactant protein C mutant lung

Ozone (O3) is a ubiquitous pollutant known to produce acute, transient inflammation through oxidative injury and inflammation. These effects are exacerbated in susceptible populations, such as the elderly and those exhibiting genetic mutations in central nodes of pulmonary function. To comprehend the impact of these predisposing factors, the present study examines structural, mechanical, and immunological responses to single acute O3 exposure (0.8 ppm, 3 h) in young (8-14-wk old), middle-aged (44-52-wk old), and old (>80-wk old) mice. Furthermore, this work compares the impact of a clinically relevant mutation in the gene encoding for the alveolar epithelial type 2 specific surfactant protein C. Aging was associated with reduced lung resistance and increases in respiratory elastic properties, the latter of which was exacerbated in SP-C mutant mice. Ozone exposure produced focal injury localized at the terminal bronchiole-to-alveolar junctions and enlarged alveoli in aged SP-C mutant lungs. Flow cytometric analysis revealed increases in mononuclear myeloid abundance in aged SP-C mutant lungs, paired with a contraction in CD8+ expressing cells. Expansion of tertiary lymphoid tissues was also noted in aged groups, more evident in the mutant mice. Spatial transcriptomics of CD68+ macrophages and CD45- nonimmune parenchymal cells highlighted age-dependent shifts in inflammatory and extracellular matrix organization signaling, and enrichment in senescence and chromatin remodeling pathways. These results illustrate the structural and immunological impact of O3 in the aging wild-type and mutant lung and emphasize the significance of modeling environmental exposure in at-risk populations.NEW & NOTEWORTHY Environmental stress and genetic mutations in key functional nodes are linked to the pathogenesis and exacerbation of respiratory pathologies. These responses are exacerbated by aging, though the impact of these factors in combination is not clearly defined. Using a surfactant protein-C mutant line, our studies describe structural changes and phenotypic responses triggered by acute ozone exposure in the young/middle-aged/old lung. Spatial transcriptomics also found regionally distinct and enhanced activation in the aged lung.

Tertiary lymphoid structure formation induced by LIGHT-engineered and photosensitive nanoparticles-decorated bacteria enhances immune response against colorectal cancer

Tertiary lymphoid structures (TLSs) are known to enhance the prognosis of patients with colorectal cancer (CRC) by fostering an immunologically active tumor microenvironment (TME). Inducing TLS formation therapeutically holds promise for treating immunologically cold CRC, though it poses technical challenges. Here, we design and fabricate a photosensitive bacterial system named E@L-P/ICG. This system is engineered bacteria internally loaded with the cytokine LIGHT and surface-modified with PLGA/ICG nanoparticles (P/ICG NPs). Once accumulated in orthotopic colonic tumors in mice, E@L-P/ICG generates a mild photothermal effect under laser irradiation due to the photosensitive P/ICG NPs. This photothermal effect triggers the self-rupture of E@L-P/ICG and the death of surrounding tumor cells to release adjuvants and antigens, respectively, which in turn synergistically activate the adaptive immune responses. Furthermore, the cytokine LIGHT released from ruptured E@L-P/ICG stimulates the generation of high endothelial vessels (HEVs), promoting lymphocyte recruitment within the TME. These mechanisms lead to the TLS formation in CRC, which further boosts adaptive immune responses through effective infiltration of T cells and B cells, resulting in effectively inhibited tumor growth and extended survival of mice. Our study shows the potential of the E@L-P/ICG system in photosensitively inducing the TLS formation to treat CRC in clinic.

The immunological pathogenesis of IgG4-related disease categorized by clinical characteristics

IgG4-related disease (IgG4-RD) is an immune disorder characterized by organ enlargement and fibrosis leading to functional impairment. Key immune cell subsets contributing to the pathogenesis of IgG4-RD include T follicular helper 2 cells (Tfh2), Tfh1, CX3CR1 + cytotoxic T cells (CX3CR1 + CTLs), Tregs and IgG4 + B cells. Tfh2 and Tregs are commonly involved in inducing IgG4 class-switching in this disease. Importantly, IgG4-RD can be classified into four clinical phenotypes based on the distribution of affected organs, with each phenotype showing different dominant immune cell subsets involved in its pathogenesis. Specifically, the clinical phenotype of retroperitoneal fibrosis/aortitis is characterized by CX3CR1 + CTLs as the dominant key immune cell subset, while Mikulicz disease with systemic involvement is dominated by Tfh2. In addition to classification based on organ distribution, IgG4-RD can also be categorized into phenotypes associated with malignancy or allergy. The malignancy phenotype is characterized by an increase in CXCR5 + CD2-double negative T cells compared to the allergy phenotype, along with a decrease in naive CD8 + T cells. Moreover, several autoantigens have been identified, and the presence of autoimmune phenotype has been revealed. Due to the pathogenicity of IgG1-type autoantibodies, Tfh1 may be important inducing IgG1 class-switching by IFNγ in autoimmune phenotype. In IgG4-RD with hypocomplementemia, activation of the complement pathway is thought to be induced by IgG1 or IgG2 antibodies, suggesting the involvement of Tfh1 in the disease pathogenesis. Therefore, elucidating the immunological features specific to each clinical characteristic is believed to lead to a deeper understanding of the pathogenesis of IgG4-RD and the discovery of novel therapeutic targets. This review provides an overview of the immunological mechanisms common to IgG4-RD as well as those specific to each clinical characteristic.

TLR Agonist Nano Immune Therapy Clears Peritoneal and Systemic Ovarian Cancer

Intraperitoneal (IP) administration of immunogenic mesoporous silica nanoparticles (iMSN) in a mouse model of metastatic ovarian cancer promotes the development of tumor-specific CD8+ T cells and protective immunity. IP delivery of iMSN functionalized with the Toll-like receptor (TLR) agonists polyethyleneimine (PEI), CpG oligonucleotide, and monophosphoryl lipid A (MPLA) stimulated rapid uptake by all peritoneal myeloid subsets. Myeloid cells quickly transported iMSN to milky spots and fat-associated lymphoid clusters (FALCs) present in tumor-burdened adipose tissues, leading to a reduction in suppressive T cells and an increase in activated memory T cells. Two doses of iMSN cleared or reduced ovarian and colorectal cancer and protected against future tumor engraftment. In contrast, subcutaneous (SC) and intravenous (IV) delivery of iMSN were without therapeutic effect in mice with peritoneal metastases, supporting the need for activation of regional immune cells. Remarkably, intraperitoneal delivery of iMSN cleared subcutaneously implanted ovarian cancer, supporting homing of antigen specific T cells to extraperitoneal tumor sites.

Aligning cellular and molecular components in age-dependent tertiary lymphoid tissues of kidney and liver

Tertiary lymphoid tissues (TLTs) are ectopic lymphoid structures induced by multiple stimuli, including infection and tissue injuries; however, their clinical relevance in disease progression has remained unclear. We demonstrated previously that TLTs develop in mouse and human kidneys with aging and can be a potential marker of kidney injury and prognosis, and therapeutic targets. In addition, we found that two types of unique lymphocytes that emerge with aging, senescence-associated T cells and age-associated B cells, are essential for TLT formation in the kidney. Although TLTs develop with aging in other organs as well, their cellular and molecular components, and clinical significance remain unclear. In the present study, we found that TLTs developed in the liver with aging, and that their cellular and molecular components were similar to those in the kidneys. Notably, senescence-associated T cells and age-associated B cells were also present in hepatic TLTs. Furthermore, analysis of publicly available data on human liver biopsy transcriptomes revealed that the expression of TLT-related genes was elevated in the liver biopsy samples from hepatitis C virus (HCV)-infected patients compared with those without HCV infection and was associated with liver injury and fibrosis. Therefore, we analyzed liver biopsy samples from 47 HCV patients and found that TLTs were present in 87.2% of cases and that the numbers and stages of TLTs were higher in aged patients and cellular and molecular components of TLTs in humans were similar to those in mice. Our findings suggesting that age-dependent TLT formation is a systemic phenomenon across the tissues and aging is also a predisposing factor for TLT formation across organs.

[Chinese Expert Consensus on Assessment and Clinical Application of Tertiary Lymphoid Structure for Non-small Cell Lung Cancer (2025 Version)]

The tertiary lymphoid structure (TLS) plays a crucial role in the tumor microenvironment, influencing tumor development and progression. As an emerging biomarker for predicting the prognosis and treatment response in cancer patients, TLS has received increasing attention. However, there is currently a lack of standardized evaluation criteria for TLS, and significant differences exist in TLS across different tumor tissues. This poses challenges for the clinical application of this biomarker in translation. To meet the clinical diagnosis and treatment needs of non-small cell lung cancer (NSCLC), this consensus focuses on the definition, clinical significance, testing components, and assessment methods of TLS in NSCLC. Combining relevant research and Chinese clinical practice, it provides standardized and normalized suggestions for the clinical assessment and application of TLS, so as to improve the understanding of TLS among clinicians and pathologists, and provide a reference basis for the clinical application of the detection of TLS in NSCLC. 
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Integrated control of leukocyte compartments as a feature of adaptive physiology

As a highly diverse and mobile organ, the immune system is uniquely equipped to participate in tissue responses in a tunable manner, depending on the number, type, and nature of cells deployed to the respective organ. Most acute organismal stressors that threaten survival-predation, infection, poisoning, and others-induce pronounced redistribution of immune cells across tissue compartments. Here, we review the current understanding of leukocyte compartmentalization under homeostatic and noxious conditions. We argue that leukocyte shuttling between compartments is a function of local tissue demands, which are linked to the organ's contribution to adaptive physiology at steady state and upon challenge. We highlight the neuroendocrine signals that relay and organize this trafficking behavior and outline mechanisms underlying the functional diversification of leukocyte responses. In this context, we discuss important areas of future inquiry and the implications of this scientific space for clinical medicine in the era of targeted immunomodulation.

Non-small cell lung cancer and the tumor microenvironment: making headway from targeted therapies to advanced immunotherapy

Over the past decades, significant progress has been made in the understanding of non-small cell lung cancer (NSCLC) biology and tumor progression mechanisms, resulting in the development of novel strategies for early detection and wide-ranging care approaches. Since their introduction, over 20 years ago, targeted therapies with tyrosine kinase inhibitors (TKIs) have revolutionized the treatment landscape for NSCLC. Nowadays, targeted therapies remain the gold standard for many patients, but still they suffer from many adverse effects, including unexpected toxicity and intrinsic acquired resistance mutations, which lead to relapse. The adoption of immune checkpoint inhibitors (ICIs) in 2015, has offered exceptional survival benefits for patients without targetable alterations. Despite this notable progress, challenges remain, as not all patients respond favorably to ICIs, and resistance to therapy can develop over time. A crucial factor influencing clinical response to immunotherapy is the tumor microenvironment (TME). The TME is pivotal in orchestrating the interactions between neoplastic cells and the immune system, influencing tumor growth and treatment outcomes. In this review, we discuss how the understanding of this intricate relationship is crucial for the success of immunotherapy and survey the current state of immunotherapy intervention, with a focus on forthcoming and promising chimeric antigen receptor (CAR) T cell therapies in NSCLC. The TME sets major obstacles for CAR-T therapies, creating conditions that suppress the immune response, inducing T cell exhaustion. To enhance treatment efficacy, specific efforts associated with CAR-T cell therapy in NSCLC, should definitely focus TME-related immunosuppression and antigen escape mechanisms, by combining CAR-T cells with immune checkpoint blockades.

B cells in non-lymphoid tissues

B cells have long been understood to be drivers of both humoral and cellular immunity. Recent advances underscore this importance but also indicate that in infection, inflammatory disease and cancer, B cells function directly at sites of inflammation and form tissue-resident memory populations. The spatial organization and cellular niches of tissue B cells have profound effects on their function and on disease outcome, as well as on patient response to therapy. Here we review the role of B cells in peripheral tissues in homeostasis and disease, and discuss the newly identified cellular and molecular signals that are involved in regulating their activity. We integrate emerging data from multi-omic human studies with experimental models to propose a framework for B cell function in tissue inflammation and homeostasis.

Toward curing neurological autoimmune disorders: Biomarkers, immunological mechanisms, and therapeutic targets

Autoimmune neurology is a rapidly expanding field driven by the discovery of neuroglial autoantibodies and encompassing a myriad of conditions affecting every level of the nervous system. Traditionally, autoantibodies targeting intracellular antigens are considered markers of T cell-mediated cytotoxicity, while those targeting extracellular antigens are viewed as pathogenic drivers of disease. However, recent advances highlight complex interactions between these immune mechanisms, suggesting a continuum of immunopathogenesis. The breakdown of immune tolerance, central to these conditions, is affected by modifiable and non-modifiable risk factors such as genetic predisposition, infections, and malignancy. While significant therapeutic advancements have revolutionized treatment of certain diseases, such as neuromyelitis optica, our understanding of many others, particularly T cell-mediated conditions, remains limited, with fewer treatment options available. Future research should focus on improving effector function modeling and deepening our understanding of the factors influencing immune tolerance, with the goal of providing novel treatment options and improving patient care.

Senescence-associated T cells in immunosenescence and diseases

Age-related changes in the immune system, referred to as immunosenescence, appear to evolve with rather paradoxical manifestations, a diminished adaptive immune capacity, and an increased propensity for chronic inflammation often with autoimmunity, which may underlie the development of diverse disorders with age. Immunosenescent phenotypes are associated with the emergence of unique lymphocyte subpopulations of both T and B lineages. We report that a CD153+ programmed cell death protein 1 (PD-1)+ CD4+ T-cell subpopulation with severely attenuated T-cell receptor (TCR)-responsiveness, termed senescence-associated T (SAT) cells, co-evolve with potentially autoreactive CD30+ B cells, such as spontaneous germinal center B cells and age-associated B cells, in aging mice. SAT cells and CD30+ B cells are reciprocally activated with the aid of the interaction of CD153 with CD30 in trans and with the TCR complex in cis, resulting in the restoration of TCR-mediated proliferation and secretion of abundant pro-inflammatory cytokines in SAT cells and the activation and production of autoantibodies by CD30+ B cells. Besides normal aging, the development of SAT cells coupled with counterpart B cells may be robustly accelerated and accumulated in the relevant tissues of lymphoid or extra-lymphoid organs under chronic inflammatory conditions, including autoimmunity, and may contribute to the pathogenesis and aggravation of the disorders. This review summarizes and discusses recent advances in the understanding of SAT cells in the contexts of immunosenescent phenotypes, as well as autoimmune and chronic inflammatory diseases, and it provides a novel therapeutic clue.

Lymph node or lymphoid aggregate? Impact on cancer resection quality, clinical prognosis, and tumor staging

The clinical outcome of most cancer patients depends on the stage of the primary tumor, the lymph node status, and if distant metastases are present. According to the Union for International Cancer Control (UICC) and the American Joint Committee on Cancer (AJCC), the Tumor Node Metastasis (TNM) classification of malignant tumors requires the examination of a minimum number of regional lymph nodes for each type of cancer to fulfill the criteria of high-quality surgical oncology. Due to the daily challenge of collecting an appropriate number of lymph nodes and time constraints when processing and assessing tissue samples, pathologists may be tempted to identify every histological lymphoid structure mimicking a lymph node as a "true" lymph node. Faced with this issue, we propose to resolve it by specifying histological characteristics to differentiate lymphoid aggregates from "true" lymph nodes. To find a minimum consensus, we suggest defining as lymph nodes only those lymphoid structures composed of lymphoid cells encapsulated by a complete or incomplete fibrous capsule.

GZMK-expressing CD8+ T cells promote recurrent airway inflammatory diseases

Inflammatory diseases are often chronic and recurrent, and current treatments do not typically remove underlying disease drivers1. T cells participate in a wide range of inflammatory diseases such as psoriasis2, Crohn's disease3, oesophagitis4 and multiple sclerosis5,6, and clonally expanded antigen-specific T cells may contribute to disease chronicity and recurrence, in part by forming persistent pathogenic memory. Chronic rhinosinusitis and asthma are inflammatory airway diseases that often present as comorbidities7. Chronic rhinosinusitis affects more than 10% of the general population8. Among these patients, 20-25% would develop nasal polyps, which often require repeated surgical resections owing to a high incidence of recurrence9. Whereas abundant T cells infiltrate the nasal polyps tissue10,11, T cell subsets that drive the disease pathology and promote recurrence are not fully understood. By comparing T cell repertoires in nasal polyp tissues obtained from consecutive surgeries, here we report that persistent CD8+ T cell clones carrying effector memory-like features colonize the mucosal tissue during disease recurrence, and these cells characteristically express the tryptase Granzyme K (GZMK). We find that GZMK cleaves many complement components, including C2, C3, C4 and C5, that collectively contribute to the activation of the complement cascade. GZMK-expressing CD8+ T cells participate in organized tertiary lymphoid structures, and tissue GZMK levels predict the disease severity and comorbidities better than well-established biomarkers such as eosinophilia and tissue interleukin-5. Using a mouse asthma model, we further show that GZMK-expressing CD8+ T cells exacerbate the disease in a manner dependent on the proteolytic activity of GZMK and complements. Genetic ablation or pharmacological inhibition of GZMK after the disease onset markedly alleviates tissue pathology and restores lung function. Our work identifies a pathogenic CD8+ memory T cell subset that promotes tissue inflammation and recurrent airway diseases by the effector molecule GZMK and suggests GZMK as a potential therapeutic target.

Biofabrication Directions in Recapitulating the Immune System-on-a-Chip

Ever since the implementation of microfluidics in the biomedical field, in vitro models have experienced unprecedented progress that has led to a new generation of highly complex miniaturized cell culture platforms, known as Organs-on-a-Chip (OoC). These devices aim to emulate biologically relevant environments, encompassing perfusion and other mechanical and/or biochemical stimuli, to recapitulate key physiological events. While OoCs excel in simulating diverse organ functions, the integration of the immune organs and immune cells, though recent and challenging, is pivotal for a more comprehensive representation of human physiology. This comprehensive review covers the state of the art in the intricate landscape of immune OoC models, shedding light on the pivotal role of biofabrication technologies in bridging the gap between conceptual design and physiological relevance. The multifaceted aspects of immune cell behavior, crosstalk, and immune responses that are aimed to be replicated within microfluidic environments, emphasizing the need for precise biomimicry are explored. Furthermore, the latest breakthroughs and challenges of biofabrication technologies in immune OoC platforms are described, guiding researchers toward a deeper understanding of immune physiology and the development of more accurate and human predictive models for a.o., immune-related disorders, immune development, immune programming, and immune regulation.

Infiltration and subtype analysis of CD3 + CD20 + T cells in lung cancer

BACKGROUND

CD3 + CD20 + T cells (TB cells) are a subset of lymphocytes in the human body that are associated with inflammation. They originate from T cells interacting with B cells, and their levels are abnormally elevated in individuals with immune disorders, as well as in some cancer patients. The interplay between tumor immunity and inflammation is intricate, yet the specific involvement of TB cells in local tumor immunity remains uncertain, with limited research on their subtypes.

METHODS

Lung cancer surgical samples were stained using multi-color immunofluorescence to study the subtypes and distribution patterns of TB cells.

RESULTS

TB cells were confirmed to exist in a scattered pattern within tertiary lymphoid structures (TLS) in lung cancer tissues, with higher abundance in mature TLS. In subtype analysis, the CD4-CD8- double-negative TB cell subtype was predominant, comprising over 90% in samples with abundant TLS infiltration and over 60% in samples with poor infiltration. This was followed by the CD4 + CD8- and CD4-CD8 + single-positive TB cell subtypes, while the CD4 + CD8 + double-positive TB cell subtype was nearly absent. During the maturation of TLS, the proportion of B cells gradually increased, while the proportion of CD4-CD8- T cell subtype decreased.

CONCLUSIONS

TB cells extensively infiltrate the TLS regions in tumor tissues, with the double-negative subtype being predominant, potentially playing a crucial regulatory role in the local tumor immune microenvironment. This finding could facilitate the advancement of novel cancer treatment strategies.

Kidney immunology from pathophysiology to clinical translation

Kidney diseases are widespread and represent a considerable medical, social and economic burden. However, there has been marked progress in understanding the immunological aspects of kidney disease. This includes the identification of distinct intrarenal immunological niches and characterization of kidney disease endotypes according to the underlying molecular immunopathology, as well as a better understanding of the pathological roles for T cells, mononuclear phagocytes and B cells and the renal elements they target. These insights have improved the diagnosis of kidney disease. Here, we discuss new developments in our understanding of kidney immunology, focusing on immune mechanisms of disease and their translational implications for the diagnosis and treatment of kidney disease. We also describe the immune-mediated crosstalk between the kidney and other organs that influences kidney disease and extrarenal inflammation.

Toll-like receptor agonists promote the formation of tertiary lymphoid structure and improve anti-glioma immunity

BACKGROUND

Glioma, characterized by limited lymphocytic infiltration, constitutes an "immune-desert" tumor displaying insensitivity to various immunotherapies. This study aims to explore therapeutic strategies for inducing tertiary lymphoid structure (TLS) formation within the glioma microenvironment (GME) to transition it from an immune resistant to an activated state.

METHODS

TLS formation in GME was successfully induced by intracranial administration of Toll-like receptor (TLR) agonists (OK-432, TLR2/4/9 agonist) and glioma antigens (i.c. αTLR-mix). We employed staining analysis, antibody neutralization, single-cell RNA sequencing (scRNA-Seq), and BCR/TCR sequencing to investigate the underlying mechanisms of TLS formation and its role in anti-glioma immunity. Additionally, a preliminary translational clinical study was conducted.

RESULTS

TLS formation correlated with increased lymphocyte infiltration in GME and led to improved prognosis in glioma-bearing mice. In the study of TLS induction mechanisms, certain macrophages/microglia and Th17 displayed markers of "LTo" and "LTi" cells, respectively, interaction through LTα/β-LTβR promoted TLS induction. Post-TLS formation, CD4 + and CD8 + T cells but not CD19 + B cells contributed to anti-glioma immunity. Comparative analysis of B/T cells between brain and lymph node showed that brain B/T cells unveiled the switch from naïve to mature, some B cells highlighted an enrichment of class switch recombination (CSR)-associated genes, V gene usage, and clonotype bias were observed. In related clinical studies, i.c. αTLR-mix treatment exhibited tolerability, and chemokines/cytokines assay provided preliminary evidence supporting TLS formation in GME.

CONCLUSIONS

TLS induction in GME enhanced anti-glioma immunity, improved the immune microenvironment, and controlled glioma growth, suggesting potential therapeutic avenues for treating glioma in the future.

Silica-mediated exacerbation of inflammatory arthritis: A novel murine model

Objective

The mucosal origin hypothesis in rheumatoid arthritis (RA) posits that inhalant exposures, such as cigarette smoke and crystalline silica (c-silica), trigger immune responses contributing to disease onset. Despite the established risk posed by these exposures, the mechanistic link between inhalants, lung inflammation, and inflammatory arthritis remains poorly understood, partly from the lack of a suitable experimental model. As c-silica accelerates autoimmune phenotypes in lupus models and is a recognized risk factor for several autoimmune diseases, we investigated whether c-silica exposure could induce RA-like inflammatory arthritis in mice.

Methods

Two arthritis-prone mouse strains, BXD2/TyJ and HLA-DR4 transgenic (DR4-Tg), were exposed to c-silica or PBS via oropharyngeal instillation. Arthritis was evaluated by clinical signs and histopathology. Autoimmunity was further evaluated by serological analysis, including autoantibodies and cytokines and chemokines. Lung pathology was evaluated by histopathology and immunofluorescent staining for lymphocyte and macrophages.

Results

C-silica exposure induced chronic pulmonary silicosis in all mice. In BXD2 mice, this was associated with rapid arthritis development, marked by synovitis, bone erosion, and elevated serum autoantibody levels targeting various antigens, including snRNP and citrullinated protein. Additionally, BXD2 mice exhibited inducible bronchus-associated lymphoid tissue (iBALT) formation and elevated autoantibodies in bronchoalveolar lavage fluid (BALF). Conversely, DR4-Tg mice had no significant arthritis, negligible autoantibody responses, and milder lung inflammation lacking iBALT.

Conclusion

We introduce a novel model of c-silica-mediated inflammatory arthritis, creating a novel platform to unravel the molecular and cellular underpinnings of RA and advance understanding of the mucosal origin hypothesis.

Role of tertiary lymphoid structures and B cells in clinical immunotherapy of gastric cancer

Gastric cancer is a common malignant tumor of the digestive tract, and its treatment remains a significant challenge. In recent years, the role of various immune cells in the tumor microenvironment in cancer progression and treatment has gained increasing attention. Immunotherapy, primarily based on immune checkpoint inhibitors, has notably improved the prognosis of patients with gastric cancer; however, challenges regarding therapeutic efficacy persist. Histological features within the tumor microenvironment, such as tertiary lymphoid structures (TLSs), tumor-infiltrating lymphocytes, and the proportion of intratumoral stroma, are emerging as potentially effective prognostic factors. In gastric cancer, TLSs may serve as local immune hubs, enhancing the ability of immune cells to interact with and recognize tumor antigens, which is closely linked to the effectiveness of immunotherapy and improved survival rates in patients. However, the specific cell type driving TLS formation in tumors has not yet been elucidated. Mature TLSs are B-cell regions containing germinal centers. During germinal center formation, B cells undergo transformations to become mature cells with immune function, exerting anti-tumor effects. Therefore, targeting B cells within TLSs could provide new avenues for gastric cancer immunotherapy. This review, combined with current research on TLSs and B cells in gastric cancer, elaborates on the relationship between TLSs and B cells in the prognosis and immunotherapy of patients with gastric cancer, aiming to provide effective guidance for precise immunotherapy.

Tertiary Lymphoid Structures in Central Nervous System Disorders

The central nervous system (CNS) constitutes a tightly regulated milieu, where immune responses are strictly controlled to prevent neurological damage. This poses considerable challenges to the therapeutic management of CNS pathologies, such as autoimmune disorders and cancer. Tertiary lymphoid structures (TLS) are ectopic, lymph node-like structures containing B- and T-cells, often associated with chronic inflammation or cancer, which have been shown to be detrimental in autoimmunity but beneficial in cancer. In-depth studies of TLS induction in CNS disorders, as well as their precise role in regulating adaptive immune responses in this context, will be paramount to the development of novel TLS-targeting therapies. In the present chapter, we review the anatomical and physiological peculiarities shaping TLS formation in the CNS, their relevance in autoimmunity and cancer, as well as their implications for the development of novel therapeutic modalities for these patients.

Cancer-Associated Lymphoid Aggregates in Histology Images: Manual and Deep Learning-Based Quantification Approaches

Quantification of lymphoid aggregates including tertiary lymphoid structures (TLS) with germinal centers in histology images of cancer is a promising approach for developing prognostic and predictive tissue biomarkers. In this article, we provide recommendations for identifying lymphoid aggregates in tissue sections from routine pathology workflows such as hematoxylin and eosin staining. To overcome the intrinsic variability associated with manual image analysis (such as subjective decision-making, attention span), we recently developed a deep learning-based algorithm called HookNet-TLS to detect lymphoid aggregates and germinal centers in various tissues. Here, we additionally provide a guideline for using manually annotated images for training and implementing HookNet-TLS for automated and objective quantification of lymphoid aggregates in various cancer types.

Histopathologic Analysis of Human Kidney Spatial Transcriptomics Data: Toward Precision Pathology

The application of spatial transcriptomics (ST) technologies is booming and has already yielded important insights across many different tissues and disease models. In nephrology, ST technologies have helped to decipher the cellular and molecular mechanisms in kidney diseases and have allowed the recent creation of spatially anchored human kidney atlases of healthy and diseased kidney tissues. During ST data analysis, the computationally annotated clusters are often superimposed on a histologic image without their initial identification being based on the morphologic and/or spatial analyses of the tissues and lesions. Herein, histopathologic ST data from a human kidney sample were modeled to correspond as closely as possible to the kidney biopsy sample in a health care or research context. This study shows the feasibility of a morphology-based approach to interpreting ST data, helping to improve our understanding of the lesion phenomena at work in chronic kidney disease at both the cellular and the molecular level. Finally, the newly identified pathology-based clusters could be accurately projected onto other slides from nephrectomy or needle biopsy samples. Thus, they serve as a reference for analyzing other kidney tissues, paving the way for the future of molecular microscopy and precision pathology.

Proteomic signatures of healthy dietary patterns are associated with lower risks of major chronic diseases and mortality

Healthy dietary patterns have been linked to a decreased risk of chronic diseases. However, it remains uncertain whether proteomic signatures can reflect proteome response to healthy diet patterns, and whether these proteomic signatures are associated with health outcomes. Using data from the UK Biobank including Olink plasma proteins, we identified substantial proteomic variation in relation to adherence to eight healthy dietary patterns. The proteomic signatures, reflecting adherence and proteome response to healthy dietary patterns, were prospectively associated with lower risks of diabetes, cardiovascular diseases, chronic respiratory diseases, chronic kidney diseases and cancers, along with longer life expectancy, even after adjusting for corresponding dietary patterns. These findings suggest proteomic signatures have the potential to complement traditional dietary assessments and deepen our understanding of the relationships between dietary patterns and chronic diseases.

Generation of antagonistic biparatopic anti-CD30 antibody from an agonistic antibody by precise epitope determination and utilization of structural characteristics of CD30 molecule

Background

CD30 is a member of the tumor necrosis factor receptor superfamily. Recently, blocking CD30-dependent intracellular signaling has emerged as potential strategy for immunological regulation. Development of antibody-based CD30 antagonists is therefore of significant interest. However, a key challenge is that the bivalent form of natural antibody can crosslink CD30 molecules, leading to signal transduction even in the absence of specific ligand, CD153. Biparatopic antibodies (BpAbs) offer a solution, using two different variable fragments (Fvs) to bind distinct epitopes on a single antigen molecule. BpAbs format is an attractive alternative of natural antibody by potentially avoiding unwanted crosslinking and signaling induction.

Methods

We systematically characterized 36 BpAbs, each designed with pairs of Fvs binding to nine distinct epitopes across the CD30 extracellular domain. We first identified the precise epitope sites of the nine antibodies by assessing the binding to multiple orthologous CD30 proteins and mutants. We then produced the 36 BpAbs and analyzed their biological activities and binding modes.

Results

Among 36 BpAbs, we identified both potent ligand-independent agonists and ligand-blocking antagonists, with many displayed reduced signal activation, including 1:1-binding antagonists derived from AC10, a strong agonist developed for lymphoma therapy. Epitope dependency in reduced signaling activity was observed and associated with the flexible nature of CD30 protein.

Conclusions

We successfully developed antagonistic BpAbs against CD30 by controlling the stoichiometry of antibody-antigen binding mode. This study elucidated the mechanism of signaling induction, informing the design strategies of the development of biparatopic antibodies.

Homebuilt Imaging-Based Spatial Transcriptomics: Tertiary Lymphoid Structures as a Case Example

Spatial transcriptomics methods provide insight into the cellular heterogeneity and spatial architecture of complex, multicellular systems. Combining molecular and spatial information provides important clues to study tissue architecture in development and disease. Here, we present a comprehensive do-it-yourself (DIY) guide to perform such experiments at reduced costs leveraging open-source approaches. This guide spans the entire life cycle of a project, from its initial definition to experimental choices, wet lab approaches, instrumentation, and analysis. As a concrete example, we focus on tertiary lymphoid structures (TLS), which we use to develop typical questions that can be addressed by these approaches.

Maturation of Tertiary Lymphoid Structures

Tertiary lymphoid structures (TLS) are organized collections of B and T lymphocytes that arise in nonlymphoid tissue in response to chronic, unresolved inflammation. TLS have structural and functional similarities to germinal centers found in lymph nodes and are believed to support the establishment of lymph node-like adaptive immune responses at local sites of inflammation. However, understanding of the underlying biology of these structures remains limited, particularly the different stages of TLS life cycle and the signals governing the initiation, maturation, and termination of TLS. Here, we review current understanding of the maturation of TLS and the signals and cell types involved in various stages of development with particular emphasis on recent studies of TLS in cancer, where evidence suggests that TLS may play an important role in supporting antitumor immune responses in solid tumors.

An Introduction to Tertiary Lymphoid Structures in Cancer

Immunotherapy has revolutionized therapeutics for cancer patients, which signifies the importance of effective antitumor immunity in combatting cancer. However, the benefit of immunotherapies is limited to specific patient populations and tumor types, suggesting the overt need for new immunotherapeutic targets. Tertiary lymphoid structures (TLS) are ectopic lymph node-like structures that develop at the sites of chronic inflammation such as cancer. TLS are correlated with favorable clinical outcomes across multiple solid tumors and are associated with increased tumor-infiltrating lymphocytes (TILs), particularly effector memory CD8+ T cells. Despite strong clinical data in humans, there are still major knowledge gaps on the function of TLS in cancer. Herein, we highlight the known biology and clinical impact of TLS, which offer further evidence to harness TLS for improved immunotherapeutics.

Oncolytic herpes simplex virus propagates tertiary lymphoid structure formation via CXCL10/CXCR3 to boost antitumor immunity

Inducing tertiary lymphoid structure (TLS) formation can fuel antitumor immunity. It is necessary to create mouse models containing TLS to explore strategies of TLS formation. Oncolytic herpes simplex virus-1 (oHSV) exhibited intense effects in preclinical and clinical trials. However, the role of oHSV in TLS formation remains to be elucidated. Here, we observed the presence of TLS in 4MOSC1 and MC38 subcutaneous tumour models. Interestingly, oHSV evoked TLS formation, and increased infiltration of B cells and stem-like TCF1+CD8+ T cells proliferation. Mechanistically, oHSV increased the expression of TLS-related chemokines, along with upregulated CXCL10/CXCR3 to facilitate TLS formation. Notably, CXCL10 and CXCR3 were favourable prognostic factors for cancer patients, and closely related with immune cells infiltration. Inhibiting CXCL10/CXCR3 reduced TCF1+CD8+ T cells and granzyme B expression, and impaired oHSV-mediated TLS formation. Furthermore, oHSV-mediated TLS formation revealed superior response and survival rate when combined with αPD-1 treatment. Collectively, these findings indicate that oHSV recruits stem-like TCF1+CD8+ T cells through CXCL10/CXCR3 pathway to propagate TLS formation, and warrants future antitumor immunity development.

Single-Cell Analysis Provides New Insights into the Roles of Tertiary Lymphoid Structures and Immune Cell Infiltration in Kidney Injury and Chronic Kidney Disease

Chronic kidney disease (CKD) is a global health concern with high morbidity and mortality. Acute kidney injury (AKI) is a pivotal risk factor for the progression of CKD, and the rate of AKI-to-CKD progression increases with aging. Intrarenal inflammation is a fundamental mechanism underlying AKI-to-CKD progression. Tertiary lymphoid structures (TLSs), ectopic lymphoid aggregates formed in nonlymphoid organs, develop in aged injured kidneys, but not in young kidneys, with prolonged inflammation and maladaptive repair, which potentially exacerbates AKI-to-CKD progression in aged individuals. Dysregulated immune responses are involved in the pathogenesis of various kidney diseases, such as IgA nephropathy, lupus nephritis, and diabetic kidney diseases, thereby deteriorating kidney function. TLSs also develop in several kidney diseases, including transplanted kidneys and renal cell carcinoma. However, the precise immunologic mechanisms driving AKI-to-CKD progression and development of these kidney diseases remain unclear, which hinders the development of novel therapeutic approaches. This review aims to describe recent findings from single-cell analysis of cellular heterogeneity and complex interactions among immune and renal parenchymal cells, which potentially contribute to the pathogenesis of AKI-to-CKD progression and other kidney diseases, highlighting the mechanisms of formation and pathogenic roles of TLSs in aged injured kidneys.

Tertiary Lymphoid Structure in Dental Pulp: The Role in Combating Bacterial Infections

Tertiary lymphoid structure (TLS) is associated with various pathologies, including those of cancers and chronic infections. Depending on the organ, multiple factors regulate the formation of TLS. However, the role of TLS in immune response and the molecules that drive its formation remain uncertain. The dental pulp, includes a few immune cells surrounded by rigid mineralized tissue, and opens to the outside through the apical foramen. Owing to this special organization, the dental pulp generates a directional immune response to bacterial infection. Considering this aspect, the dental pulp is an ideal model for comprehensively studying the TLS. In the present study, single-cell RNA sequencing of healthy and inflamed human dental pulp reveals known markers of TLS, including C-C motif chemokine ligand 19 (CCL19), lysosome-associated membrane glycoprotein 3 (LAMP3), CC chemokine receptor 7 (CCR7), and CD86, present in inflamed dental pulp. Compared with the healthy pulp, types and proportions of immune cells increase, along with enhanced cellular communication. Multiple immunofluorescence staining reveals that typical TLS emerges in dental pulp with pulpitis, consistent with the high expression of CC chemokine ligand 3 (CCL3), which may be a key driver of TLS formation. Moreover, TLS is also observed in a mouse model of pulpitis. These findings collectively offer insights into the formation and function of TLS in response to infection.

Methods for Selective Gene Expression Profiling in Single Tertiary Lymphoid Structure Using Laser Capture Microdissection

Tertiary lymphoid structures (TLS) are de novo lymphoid formations that are induced within tissues during inflammatory episodes. TLS have been reported at various anatomic sites and in many different contexts like cancer, infections, autoimmunity, graft rejection, and idiopathic diseases. These inducible, ectopic, and transient lymphoid structures exhibit the prototypical architecture found within secondary lymphoid organs (SLO) and have been increasingly recognized as a major driver of local adaptive immune reaction. As TLS emerge within tissues, the isolation in situ and the molecular characterization of these structures are challenging to perform. Laser capture microdissection (LCM) is a powerful tool to isolate selective structural components and cells from frozen or paraffin-embedded tissues. We and other groups previously applied LCM to decipher the molecular network within TLS and uncover their intrinsic connection with the local microenvironment. In this chapter, we describe a detailed LCM method for selecting and isolating TLS in situ to perform comprehensive downstream molecular analyses.

Prognostic value of tertiary lymphoid structures in triple-negative breast cancer: integrated analysis with the tumor microenvironment and clinicopathological features

Background

In triple-negative breast cancer (TNBC), the most immunogenic breast cancer type, tumor-infiltrating lymphocytes (TILs) are an independent prognostic factor. Tertiary lymphoid structures (TLS) are an important TILs source, but they are not integrated in the current prognostic criteria.

Methods

In this retrospective study, TLS were assessed in hematein-eosin-saffron-stained (HES) histological sections from 397 early, chemotherapy-naive TNBC samples after primary surgical resection. Their association with i) classical clinicopathological features, ii) TILs and CD3+, CD8+, CD20+ lymphoid populations, iii) CD68+, CD163+, CD11b+, CD66b+ myeloid populations, and iv) expression of the PD1/PD-L1 and PVR/TIGIT axis immune checkpoint components and their prognostic significance were evaluated.

Results

TLS were observed in 88.2% of samples, mainly in peritumoral areas (86.1%). Increased amount of peritumoral TLS (PT-TLS) was significantly associated with younger age (p<0.001), smaller tumor size and higher tumor grade (both, p<0.001), HER2null tumors (versus HER2low tumors, p<0.002), and non-lobular histological type (p<0.016). TNBC with higher PT-TLS abundance displayed more often a basal-like (p<0.001) and not molecular-apocrine phenotype (p<0.001). TLS abundance was associated with TILs and hot tumor inflammatory pattern (both, p<0.001). Remarkably, PT-TLS abundance was positively associated with the density of the analyzed lymphoid (CD3+, CD8+, CD20+) and myeloid (CD68+, CD163+, CD11b+) cell populations (all p<0.001), with the exception of CD66b+ cells, as well as with expression of the PD1/PD-L1 and TIGIT/PVR immune checkpoint markers. In univariate analysis, beside the classical clinicopathological factors (tumor size, node involvement and adjuvant chemotherapy), TILs, hot tumors and PT-TLS were significantly associated with clinical outcome. Moreover, the risk of relapse was inversely correlated with PT-TLS abundance (Kaplan-Meier analysis). In multivariate analysis, pathological stage, adjuvant chemotherapy and PT-TLS remained correlated with relapse-free survival.

Conclusion

Our results suggest that TLS are a frequent feature in early TNBC and that their presence, particularly at the tumor periphery, recapitulates the tumor immune microenvironment. In our series, their prognostic value outperformed that of TILs. Therefore, their easy quantification on routine HES sections and their integration into the factors classically analyzed by pathologists could improve the clinical management of TNBC, a breast cancer type whose prognosis remains too poor.

Artificial Tertiary Lymphoid Structures: Exploring Mesenchymal Stromal Cells as a Platform for Immune Niche Formation

Constructing artificial tertiary lymphoid structures (TLSs) opens new avenues for advancing cancer immunotherapy and personalized medicine by creating controllable immune niches. Mesenchymal stromal cells (MSCs) offer an ideal stromal source for such constructs, given their potent immunomodulatory abilities and accessibility. In this study, we explored the potential of adipose-derived MSCs to adopt TLS-supportive phenotypes and facilitate lymphocyte organization. Single-cell RNA sequencing revealed a distinct subpopulation of MSCs expressing key fibroblastic reticular cell (FRC)-associated markers, including IL-7, PDPN, and IL-15, though lacking follicular dendritic cell (FDC) markers. TNF-α stimulation, but not LTα2β1, further enhanced FRC marker expression (IL-7, PDPN, and ICAM1). Notably, in 3D spheroid co-culture with lymphocytes, MSCs upregulated additional FRC markers, specifically CCL21. Upon implantation into adipose tissue, MSC-lymphocyte organoids maintained structural integrity and showed extensive T-cell infiltration and partial vascularization after 15 days in vivo, although organized B-cell follicles and FDC markers were still lacking. These findings highlight MSCs' intrinsic ability to adopt an FRC-like phenotype that supports T-cell and HEV organization, suggesting that further optimization, including genetic modification, may be needed to achieve an FDC phenotype and replicate the full architectural and functional complexity of TLSs.

Hidradenitis suppurativa: TLSs take the center stage

Hidradenitis suppurativa (HS) is a severe chronic inflammatory skin disease with limited response to therapy. In this issue of Immunity, Yu et al.1 identify skin tertiary lymphoid structures (TLSs) as primary sites for lymphocyte clonal expansion and autoantibody production, driving disease progression, and provide insight into how formation and maintenance of TLS impact therapeutic outcomes.