B cells sustain inflammation and predict response to immune checkpoint blockade in human melanoma

Gut microbiota in melanoma: Effects and pathogeneses

The gut microbiota exhibits intricate connections with the body's immune system and holds significant implications for various diseases and cancers. Currently, accumulating evidence suggests a correlation between the composition of the gut microbiota and the development, treatment, and prognosis of melanoma. However, the underlying pathogenesis remains incompletely elucidated. In this comprehensive review, we present an in-depth review of the role played by gut microbiota in melanoma tumorigenesis, growth, metastasis, treatment response, and prognosis. Furthermore, we discuss the potential utility of gut microbiota as a promising prognostic marker. Lastly, we summarize three routes through which gut microbiota influences melanoma: immunity, aging, and the endocrine system. By modulating innate and adaptive immunity in patients with melanoma across different age groups and genders, the gut microbiota plays a crucial role in anti-tumor immune regulation from tumorigenesis to prognosis management, thereby impacting tumor growth and metastasis. This review also addresses current study limitations while highlighting future research prospects.

RORc-expressing immune cells negatively regulate tertiary lymphoid structure formation and support their pro-tumorigenic functions

BACKGROUND & AIMS

RORc-expressing immune cells play important roles in inflammation, autoimmune disease and cancer. They are required for lymphoid organogenesis and have been implicated in tertiary lymphoid structure (TLS) formation. TLSs are formed in many cancer types and have been correlated with better prognosis and response to immunotherapy. In liver cancer, some TLSs are pro-tumorigenic as they harbor tumor progenitor cells and support their growth. The processes involved in TLS development and acquisition of pro- or anti-tumorigenic roles are largely unknown. This study aims to explore the role of RORc-expressing cells in TLS development in the context of inflammation-associated liver cancer.

METHODS

IKKβ(EE)Hep mice, exhibiting chronic liver inflammation, TLS formation and liver cancer, were crossed with RORc knockout mice to explore RORc's effect on TLS and tumor formation. TLS phenotypes were analyzed using transcriptional, proteomic, and immunohistochemical techniques. CD4, CD8, and B-cell depletions were used to assess their contribution to liver TLS and tumor formation.

RESULTS

RORc-expressing cells are detected within TLSs of both human patients and mice developing intrahepatic cholangiocarcinoma. In mice, these cells negatively regulate TLS formation, as excess TLSs form in their absence. CD4 cells are essential for liver TLS formation, while B cells are required for TLS formation specifically in the absence of RORc-expressing cells. Importantly, in chronically inflamed livers lacking RORc-expressing cells, TLSs become anti-tumorigenic, reducing tumor load. Anti-tumorigenic TLSs revealed enrichment of exhausted CD8 cells with effector functions, germinal center B cells and plasma cells. B cells are key in limiting tumor development, possibly via tumor-directed antibodies.

CONCLUSIONS

RORc-expressing cells negatively regulate B-cell responses and facilitate the pro-tumorigenic functions of hepatic TLSs.

IMPACT AND IMPLICATIONS

RORc-expressing immune cells play critical roles in immune regulation, yet their specific influence on tertiary lymphoid structures (TLSs) in liver pathology and cancer has not been elucidated. Our study reveals that RORc-expressing cells act as negative regulators of TLS formation and shape the immune microenvironment in a manner that promotes tumor development. In the absence of RORc-expressing cells, TLSs not only increase in number but also acquire anti-tumorigenic properties. These findings suggest that RORc-expressing cells serve as key modulators of liver immune dynamics, with potential implications for the use of RORc as a biomarker to differentiate between pro- and anti-tumorigenic immune environments and as a target for manipulating TLS abundance and phenotype in liver cancer.

Circulating immunoregulatory B cell and autoreactive antibody profiles predict lack of toxicity to anti-PD-1 checkpoint inhibitor treatment in advanced melanoma

BACKGROUND

The majority of patients with melanoma develop immune-related adverse events (irAEs), and over half do not respond to anti-PD-1 (Programmed cell death protein 1) checkpoint inhibitor (CPI) immunotherapy. Accurate predictive biomarkers for both response to therapy and development of irAEs are currently lacking in clinical practice. Here, we conduct deep immunophenotyping of circulating regulatory and class-switched B cell and antibody immune states in patients with advanced stage III/IV melanoma prior to and longitudinally during CPI.

METHODS

Mass cytometry, serum antibody isotyping and immuno-mass spectrometry proteome-wide screening evaluations to identify autoreactive antibodies were undertaken to profile circulating humoral immunity features in patients and healthy subjects and interrogate pretreatment B cell and antibody signatures that predict toxicity and response to anti-PD-1 therapy. In paired blood samples pretreatment and post-treatment, these humoral immune response profiles were monitored and correlated with the onset of toxicity.

RESULTS

We found increased circulating IL-10+ (Interleukin-10+) plasmablasts and double-negative (DN) B cell frequencies, higher PD-L1 (programmed death ligand 1), TGFβ (Transforming Growth Factorβ) and CD95 expression by B cells, alongside higher IgG4 and IgE serum levels in patients with stage III/IV melanoma. This suggests enhanced B regulatory and Th2 (Thelper2)-driven responses in advanced disease. Increased baseline frequency of DN2 B cells, plasmablasts, and serum IgE, IgA and antibody autoreactivity were observed in patients who did not develop irAE. During treatment, higher IL-10+class-switched memory B cell, plasmablast and IgG1, IgG3 and IgE, alongside reduced IgG2, IgG4, IgA and IgM levels, were observed. A reduction in autoantibodies targeting tubulins was observed during treatment. Increased frequency of class-switched memory B cells predicted improved survival, while reduced transitional and PD-L1+TGFβ+ naive B cell frequencies and higher IgG4 and IgE levels predicted lower survival, on anti-PD-1 therapy.

CONCLUSIONS

Distinct B cell and antibody reactivities in patients with advanced melanoma share features with extrafollicular B cell responses in autoimmune diseases, may be protective from irAE and help predict outcomes to anti-PD-1.

Induced B cell receptor diversity predicts PD-1 blockade immunotherapy response

Immune checkpoint inhibitors such as anti-Programmed Death-1 antibodies (aPD-1) can be effective in treating advanced cancers. However, many patients do not respond, and the mechanisms underlying these differences remain incompletely understood. In this study, we profile a cohort of patients with locally advanced or metastatic basal cell carcinoma undergoing aPD-1 therapy using single-cell RNA sequencing, high-definition spatial transcriptomics in tumors and draining lymph nodes, and spatial immunoreceptor profiling, with long-term clinical follow-up. We find that successful responses to PD-1 inhibition are characterized by an induction of B cell receptor (BCR) clonal diversity after treatment initiation. These induced BCR clones spatially colocalize with T cell clones, facilitate their activation, and traffic alongside them between tumor and draining lymph nodes to enhance tumor clearance. Furthermore, we validated aPD-1-induced BCR diversity as a predictor of clinical response in a larger cohort of glioblastoma, melanoma, and head and neck squamous cell carcinoma patients, suggesting that this is a generalizable predictor of treatment response across many types of cancers. We find that pretreatment tumors harbor a characteristic gene expression signature that portends a higher probability of inducing BCR clonal diversity after aPD-1 therapy, and we develop a machine learning model that predicts PD-1-induced BCR clonal diversity from baseline tumor RNA sequencing. These findings underscore a dynamic role of B cell diversity during immunotherapy, highlighting its importance as a prognostic marker and a potential target for intervention in non-responders.

Generalizable AI predicts immunotherapy outcomes across cancers and treatments

Immune checkpoint inhibitors have become standard care across many cancers, but most patients do not respond. Predicting response remains challenging due to complex tumor-immune interactions and the poor generalizability of current biomarkers and models. Predictors such as tumor mutational burden, PD-L1 expression, and transcriptomic signatures often fail across cancer types, therapies, and clinical settings. There is a clear need for a robust, interpretable model that captures shared immune response principles and adapts to diverse clinical contexts. We present Compass, a foundation model for predicting immunotherapy response from pan-cancer transcriptomic data using a concept bottleneck architecture. Compass encodes tumor gene expression through 44 biologically grounded immune concepts representing immune cell states, tumor-microenvironment interactions, and signaling pathways. Trained on 10,184 tumors across 33 cancer types, Compass outperforms 22 baseline methods in 16 independent clinical cohorts spanning seven cancers and six immune checkpoint inhibitors, increasing precision by 8.5%, Matthews correlation coefficient by 12.3%, and area under the precision-recall curve by 15.7%, with minimal or no additional training. The model generalizes to unseen cancer types and treatments, supporting indication selection and patient stratification in early-phase clinical trials. Survival analysis shows that Compass-stratified responders have significantly longer overall survival (hazard ratio = 4.7, p < 0.0001). Personalized response maps link gene expression to immune concepts, revealing distinct mechanisms of response and resistance. For example, among immune-inflamed non-responders, Compass identifies distinct resistance programs involving TGF- β signaling, endothelial exclusion, CD4+ T cell dysfunction, and B cell deficiency. By combining mechanistic interpretability with transfer learning, Compass provides mechanistic insights into treatment response variability, supports clinical decision-making, and informs trial design.

Tumor-infiltrating and circulating B cells mediate local and systemic immunomodulatory mechanisms in Glioblastoma

BACKGROUND

Glioblastoma (GBM) demonstrates extensive immunomodulatory mechanisms that challenge effective therapeutic interventions. These phenomena extend well beyond the tumor microenvironment (TME) and are reflected in the circulating immunophenotype. B lymphocytes (B cells) have received limited attention in GBM studies despite their emerging importance in mediating both local and systemic immune responses. Recent findings highlight the complex regulatory interactions between B cells and other immune cell populations, including tumor-infiltrating macrophages (TAMs), myeloid-derived suppressor cells (MDSCs), and other infiltrating lymphocytes (TILs). B cells are believed to hinder the efficacy of modern immunotherapy strategies focusing on T cells.

METHODS

This is a focused review of available evidence regarding B cells in GBM through January 2025.

RESULTS

Peripheral blood reflects a systemically dampened immune response, with sustained lymphopenia, increased plasma cells, and dysfunctional memory B cells. The tumor immune landscape is enriched in cells of B-lineage. Subsets of poorly characterized B regulatory cells (Bregs) populate the TME, developing their phenotype due to their proximity to MDSCs, TAMs, and tumoral cells. The Bregs inhibit CD8+ T activity and may have potential prognostic significance.

CONCLUSION

Understanding the role of B cells, how they are recruited, and their differentiation shifted towards an immunomodulatory role could inform better therapeutic strategies and unleash their full antitumoral potential in GBM.

The pathogenesis of neurological immune-related adverse events following immune checkpoint inhibitor therapy

Cancer is a leading cause of morbidity and mortality worldwide. The development of immune checkpoint inhibitors (ICI) has revolutionised cancer therapy, and patients who were previously incurable can now have excellent responses. These therapies work by blocking inhibitory immune pathways, like cytotoxic T lymphocyte-associated protein 4 (CTLA-4), programmed cell death-1 (PD-1), its ligand PD-L1, and lymphocyte activation gene 3 (LAG-3); which leads to increased anti-tumour immune responses. However, their use can lead to the development of immune-related adverse events (irAEs), which may result in severe disability, interruption of cancer therapy, and even death. Neurological autoimmune sequelae occur in 1-10 % of patients treated with ICIs and can be fatal. They encompass a broad spectrum of diseases, may affect the central and the peripheral nervous system, and include syndromes like encephalitis, cerebellitis, neuropathy, and myositis. In some cases, neurological irAEs can be associated with autoantibodies recognising neuronal or glial targets. In this review, we first describe the key targets in ICI therapy, followed by a formulation of irAEs and their clinical presentations, where we focus on neurological syndromes. We comprehensively formulate the current literature evaluating cell surface and intracellular autoantibodies, cytokines, chemokines, leukocyte patterns, other blood derived biomarkers, and immunogenetic profiles; and highlight their impact on our understanding of the pathogenesis of neurological irAEs. Finally, we describe therapeutic pathways and patient outcomes, and provide an overview on future aspects of ICI cancer therapy.

Exploring predictive biomarkers of efficacy and survival with nivolumab treatment for unresectable/recurrent esophageal squamous cell carcinoma

BACKGROUND

Programmed cell death protein-1 (PD-1) blockade has improved survival for patients with esophageal squamous cell carcinoma (ESCC), but response rates are low. Biomarkers to predict who will benefit from PD-1 blockade are urgently needed.

METHODS

This multicenter study involved 250 patients with recurrent/unresectable advanced ESCC receiving nivolumab as second- or later-line therapy. We assessed tumor-infiltrating T lymphocytes (TILs) and tertiary lymphoid structure (TLS) density using immunohistochemistry and hematoxylin/eosin staining in surgical specimens and pre-nivolumab endoscopic biopsies.

RESULTS

In surgical specimens, clinical response (vs. non-response) to nivolumab correlated significantly with CD8+ lymphocyte count (160 vs. 95.2 cells/field, P = 0.0494), CD8/Foxp3 ratio (6.52 vs. 2.72, P = 0.0053), and TLS density (0.21/mm2 vs. 0.10/mm2, P = 0.0005). In terms of overall survival, multivariate analysis identified CD8/Foxp3 ratio (hazard ratio [HR] = 1.83, P = 0.0050) and TLS density (HR = 1.67, P = 0.0171 as independent prognostic parameters in surgical specimens. Similarly, in endoscopic biopsies, clinical response (vs. non-response) to nivolumab correlated significantly with CD8+ counts (254 cells/mm2 vs. 124 cells/mm2, P = 0.0344), CCR8+ lymphocyte count (62.6 cells/mm2 vs. 140 cells/mm2, P = 0.0355), CD8/Foxp3 ratio (2.09 vs. 0.89, P = 0.040), and CD8/CCR8 ratio (2.34 vs. 0.89, P = 0.0020). Multivariate analysis also identified CD8/CCR8 ratio in endoscopic biopsies (HR = 1.66, P = 0.0313) as an independent prognostic parameter.

CONCLUSIONS

CD8+ and CCR8+ cell counts, CD8/Foxp3 and CD8/CCR8 ratios, and TLS density may be predictive biomarkers of therapeutic efficacy and survival with PD-1 blockade for ESCC.

Immunocytes in the tumor microenvironment: recent updates and interconnections

The tumor microenvironment (TME) is a complex, dynamic ecosystem where tumor cells interact with diverse immune and stromal cell types. This review provides an overview of the TME's evolving composition, emphasizing its transition from an early pro-inflammatory, immune-promoting state to a later immunosuppressive milieu characterized by metabolic reprogramming and hypoxia. It highlights the dual roles of key immunocytes-including T lymphocytes, natural killer cells, macrophages, dendritic cells, and myeloid-derived suppressor cells-which can either inhibit or support tumor progression based on their phenotypic polarization and local metabolic conditions. The article further elucidates mechanisms of immune cell plasticity, such as the M1/M2 macrophage switch and the balance between effector T cells and regulatory T cells, underscoring their impact on tumor growth and metastasis. Additionally, emerging therapeutic strategies, including checkpoint inhibitors and chimeric antigen receptor (CAR) T and NK cell therapies, as well as approaches targeting metabolic pathways, are discussed as promising avenues to reinvigorate antitumor immunity. By integrating recent molecular insights and clinical advancements, the review underscores the importance of deciphering the interplay between immunocytes and the TME to develop more effective cancer immunotherapies.

Navigating established and emerging biomarkers for immune checkpoint inhibitor therapy

Immune checkpoint inhibitors (ICIs) have improved outcomes of patients with many different cancers. These antibodies target molecules such as programmed cell death 1 (PD-1) or cytotoxic T lymphocyte associated protein 4 (CTLA-4) which normally function to limit immune activity. Treatment with ICIs reactivates T cells to destroy tumor cells in a highly specific manner, which in some patients, results in dramatic remissions and durable disease control. Over the last decade, much effort has been directed at characterizing factors that drive efficacy and resistance to ICI therapy. Food and Drug Administration (FDA)-approved biomarkers for ICI therapy have facilitated more judicious treatment of cancer patients and transformed the field of precision oncology. Yet, adaptive immunity against cancers is complex, and newer data have revealed the potential utility of other biomarkers. In this review, we discuss the utility of currently approved biomarkers and highlight how emerging biomarkers can further improve the identification of patients who benefit from ICIs.

CD40L stimulates tumor-infiltrating B-cells and improves ex vivo TIL expansion

BACKGROUND

Adoptive transfer of tumor-infiltrating lymphocytes (TIL) is now a Food and Drug Administration (FDA)-approved treatment for melanoma. While this is a major milestone, there is room for improvement to increase clinical response rates and to further optimize the manufacturing of TIL products. In this study, we characterized the association of tumor-infiltrating B-cells (TIL-B) and tertiary lymphoid structures (TLSs) with clinical response to TIL therapy and tested whether the presence of B-cells in the tumor can be leveraged to optimize TIL manufacture.

METHODS

Tumor sections from TIL responders (R, n=9) and non-responders (NR, n=11) were analyzed by RNA sequencing, and immune cell content was estimated in silico. To study the association between B-cells and TIL expansion, we quantified B-cell subsets and TIL phenotype by flow cytometry. CD40L-induced effects on melanoma-infiltrating B-cells were analyzed by flow cytometry and scRNA-sequencing.

RESULTS

Tumors from TIL clinical responders had greater abundance of class-switched B-cells (p=0.007) and a greater TLS score (p=0.03) than those of NRs. In addition, greater abundance of B-cells (p≤0.05) and switched memory B-cells (CD27+ IgD-, p≤0.05) in the tumors were associated with greater TIL expansion. Stimulation of TIL-B through addition of CD40L during TIL ex vivo culture improved their expansion success rate from 33% to 67% (p=0.03). Similarly, the addition of CD40L to non-small cell lung cancer (NSCLC) TIL cultures shortened the manufacturing period by 1 week. Moreover, CD40L-enhanced TIL showed more stem-like T-cells (CD39- CD69-, p≤0.05) and an enrichment of neoantigen-reactive T-cell clones in NSCLC TIL. Gene expression analysis showed that CD40L induced gene expression changes in TIL-B after 48 hours in culture (126 differentially expressed genes (DEGs)), with minimal to no changes observed in other immune cell types (including 12 DEG in macrophages, 10 DEG in dendritic cells, and none in monocytes). B-cell DEGs included upregulated co-stimulatory ligands (CD83, CD58), chemokines (CCL22, CCL17), among others. CD40L-induced upregulation of CD58 by melanoma infiltrating B-cells was associated with successful TIL expansion.

CONCLUSIONS

Our results show that CD40L-stimulated B-cells can be leveraged to enhance the quality and quantity of TIL. Clinical trial NCT05681780 is currently testing this concept applied to NSCLC TIL.

Multifaceted function of B cells in tumorigenesis

B lymphocytes (B cells) play a complex and paradoxical role in tumorigenesis. They can recognize tumor-associated antigens, present these antigens to T cells, and produce antibodies that directly target and eliminate tumor cells. This makes B cells a potentially powerful ally in combating cancer. However, B cells also exhibit immunosuppressive functions, secreting cytokines like IL-10 or generating tumor-promoting antibodies that dampen the anti-tumor immune response, and some tumor cells have even been shown to exploit B cells to promote their growth and metastasis. This dual nature of B cells presents both opportunities and challenges for tumor immunotherapy. In this review, we summarize the mechanisms underlying the multifaceted functions of B cells and their current applications in cancer immunotherapy. Furthermore, we also explore the key issues and future directions in this field, emphasizing the need for further research to fully harness the anti-tumor potential of B cells in the fight against cancer.

m6A eraser ALKBH5/treRNA1/DDX46 axis regulates BCR expression

Epitranscriptomic modifications, particularly N6-methyladenosine (m6A), have emerged as critical regulators of RNA stability, localization, and translation, shaping immune responses and tumor progression. In B-cell biology, m6A modifications influence germinal center formation and antigen-driven differentiation, underscoring their importance in immune regulation. Among m6A regulators, ALKBH5 (RNA demethylase) is pivotal in removing methylation marks and modulating gene expression in diverse cellular contexts. Despite advancements in understanding m6A dynamics, the mechanistic interplay between m6A demethylation and B-cell receptor (BCR) signaling pathways still needs to be explored. This study reveals a novel regulatory axis involving ALKBH5, treRNA1 (Translation Regulatory Long Non-Coding RNA 1), and DDX46 (RNA helicase). Upon activation signals, ALKBH5 and treRNA1 translocate to the nucleus, forming a functional complex with DDX46 to orchestrate the removal of m6A modifications on key transcripts, including those involved in BCR signaling. This demethylation enhances transcript stability and facilitates cytoplasmic export through interaction with the RNA-binding protein HuR, promoting efficient translation. Disruption of this axis, via loss of ALKBH5, DDX46, or treRNA1, led to impaired transcript processing and diminished BCR-related gene expression, highlighting the critical role of m6A demethylation in maintaining RNA dynamics. These findings uncover a previously unrecognized epitranscriptomic mechanism driven by the ALKBH5-treRNA1-DDX46 complex, with significant implications for B-cell functionality, immune regulation, and oncogenic pathways. Targeting this axis offers a promising avenue for developing therapeutic strategies in cancer and immune-related disorders where m6A dysregulation plays a central role.

Description of lymphocyte and cytokine profiles in individuals with acute myeloid leukemia associated with FLT3-ITD and NPM1 mutation status

The pathogenesis of acute myeloid leukemia (AML) involves mutations in genes such as FLT3 and NPM1 , which are also associated with the prognosis of the disease. The immune system influences disease progression, but the mechanisms underlying the interaction between the immune system and AML are not clear. In this study, the profiles of lymphocytes and cytokines were described in individuals with AML stratified by molecular changes associated with prognosis. The participants included in this study were newly diagnosed AML patients ( n  = 43) who were about to undergo chemotherapy. Subtypes of lymphocytes in peripheral blood, including B cells, T cells, and natural killer cells, and serum concentrations of cytokines, including Th1, Th2, and Th17, were studied by flow cytometry assays (BD FACSCanto II). The correlations between lymphocyte subsets, cytokines, and genetic/prognostic risk stratification (based on the FLT3 and NPM1 genes) were analyzed. The differences in B lymphocytes (%), T lymphocytes (%), plasmablasts (%), leukocytes (cells/µl), and tumor necrosis factor (pg/ml) were determined between groups with FLT3-ITD+ and FLT3-ITD- mutations. The presence of mutations in NPM1 and FLT3-ITD and age suggested changes in the lymphocyte and cytokine profile in individuals with AML.

Comprehensive Breslow thickness (BT)-based analysis to identify biological mechanisms associated with melanoma pathogenesis

Breslow thickness (BT), a parameter measuring the depth of invasion of abnormally proliferating melanocytes, is a key indicator of melanoma severity and prognosis. However, the mechanisms underlying the increase in BT remain elusive. Utilizing data from The Cancer Genome Atlas (TCGA) human skin cutaneous melanoma (SKCM), we identified a set of BT-related molecules and analyzed their expression and genomic heterogeneity across pan-cancerous and normal tissues. Through consensus clustering, we identified two distinct BT phenotypes in melanoma, which exhibited significant differences in clinical, genomic, and immune infiltration characteristics. High BT molecular expression was associated with reduced CD8+ T cell infiltration and poor immunotherapy response, potentially mediated by the Macrophage Migration Inhibitory Factor (MIF) signaling pathway. In vitro experiments confirmed that BT molecules, including TRIM29, SERPINB5, and RAB25, promoted melanoma development through distinct mechanisms. Notably, fibroblast-derived TRIM29 and B-cell-derived RAB25 interacted with SPP1+ monocytes/macrophages via different pathways. Our findings suggest that genomic variations leading to imbalanced expression of BT molecules across cancers contribute to increased BT, which is closely linked to an immunosuppressive microenvironment. The involvement of multiple cell types and complex intercellular interactions underscores the importance of evaluating dynamic cellular crosstalk in the tumor microenvironment to better understand BT increases and develop more effective immunotherapeutic strategies.

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.

Triple-negative breast cancer modifies the systemic immune landscape and alters neutrophil functionality

Cancer disrupts intratumoral innate-adaptive immune crosstalk, but how the systemic immune landscape evolves during breast cancer progression remains unclear. We profiled circulating immune cells in stage I-III and stage IV triple-negative breast cancer (TNBC) patients and healthy donors (HDs). Metastatic TNBC (mTNBC) patients had reduced T cells, dendritic cells, and differentiated B cells compared to non-metastatic TNBC patients and HDs, partly linked to prior chemotherapy. Vδ1 γδ T cells from mTNBC patients produced more IL17 than those from HDs. Chemotherapy-naïve mTNBC patients showed increased classical monocytes and neutrophils. Transcriptional, proteomic, and functional analyses revealed that neutrophils in mTNBC exhibited enhanced migratory capacity, elevated granule proteins, and higher ROS production. Some immune changes, such as reduced non-switched B cells and heightened neutrophil migration, were evident in earlier TNBC stages. This study comprehensively maps systemic immunity in TNBC, guiding future research on patient stratification and immunomodulation strategies.

B cells enhance IL-1 beta driven invasiveness in triple negative breast cancer

Triple-negative breast cancer (TNBC) is an aggressive subtype often characterized by high lymphocyte infiltration, including tumor-infiltrating B cells (TIBs). These cells are present even in early stages of TNBC and associated with microinvasion. This study shows that co-culturing TNBC cells with B cells increases Interleukin-1β (IL-1β) expression and secretion. We further show that B cell-induced IL-1β activates NFκB signaling, leading to higher expression of target genes and promoting IL-1β-dependent increases in matrix metalloproteinase (MMP) activity, invasion, and migration. Immunohistochemical analysis of IL-1β and TIBs in triple-negative ductal carcinoma in situ (DCIS, n = 90) and invasive TNBC (n = 171) revealed that in DCIS, TIBs correlated with IL-1β expression and microinvasion, with IL-1β also linked to recurrence. In invasive TNBC, IL-1β expression correlated with TIB density and stage, with high IL-1β levels associated with poorer survival outcomes. These findings suggest that early B cell presence in TNBC can induce IL-1β secretion, enhancing invasion and mobility through IL-1β-NFκB signaling. This highlights the potential of IL-1 inhibitors as preventive and therapeutic options for hormone receptor-negative DCIS and TNBC.

Identification of Immune Infiltration-Associated CC Motif Chemokine Ligands as Biomarkers and Targets for Colorectal Cancer Prevention and Immunotherapy

Colorectal cancer (CRC) is the third most common cancer globally, with limited effective biomarkers and sensitive therapeutic targets. An increasing number of studies have highlighted the critical role of tumor microenvironment (TME) imbalances, particularly immune escape due to impaired chemokine-mediated trafficking, in tumorigenesis and progression. Notably, CC chemokines (CCLs) have been shown to either promote or inhibit angiogenesis, metastasis, and immune responses in tumors, thereby influencing cancer development and patient outcomes. However, the diagnostic and prognostic significance of CCLs in CRC remains unclear. In this study, multiple online tools for bioinformatics analyses were utilized. The findings revealed that the mRNA expression levels of CCL3, CCL4, and CCL26 were significantly elevated in CRC tissues compared to normal tissues, whereas CCL2, CCL5, CCL11, CCL21, and CCL28 mRNA levels were markedly downregulated. Additionally, dysregulation of CCL4, CCL5, and CCL21 was strongly associated with clinical staging, and elevated levels of CCL4, CCL11, and CCL28 were linked to significantly prolonged survival in CRC patients. Functional enrichment analysis indicated that the cellular roles of CCLs were predominantly associated with the chemokine, Wnt, and Toll-like receptor signaling pathways, as well as protein kinase activity. Furthermore, transcriptional regulation of most CCLs involved RELA and NFKB1. Key downstream targets included members of the SRC family of tyrosine kinases (HCK, LYN, and LCK), serine/threonine kinases (ATR and ATM), and others such as CSNK1G2, NEK2, and CDK2. Moreover, CCLs (CCL2, CCL3, CCL4, CCL5, CCL11, CCL21, and CCL28) exhibited strong correlations with major infiltration-related immune cells, including B cells, CD8+ T cells, CD4+ T cells, macrophages, neutrophils, and dendritic cells. In conclusion, our study provides novel insights into the potential utility of CCLs as biomarkers and therapeutic targets for CRC prevention and immunotherapy.

EZH2 inhibition enhances T cell immunotherapies by inducing lymphoma immunogenicity and improving T cell function

T cell-based immunotherapies have demonstrated effectiveness in treating diffuse large B cell lymphoma (DLBCL) and follicular lymphoma (FL) but predicting response and understanding resistance remains a challenge. To address this, we developed syngeneic models reflecting the genetics, epigenetics, and immunology of human FL and DLBCL. We show that EZH2 inhibitors reprogram these models to re-express T cell engagement genes and render them highly immunogenic. EZH2 inhibitors do not harm tumor-controlling T cells or CAR-T cells. Instead, they reduce regulatory T cells, promote memory chimeric antigen receptor (CAR) CD8 phenotypes, and reduce exhaustion, resulting in a decreased tumor burden. Intravital 2-photon imaging shows increased CAR-T recruitment and interaction within the tumor microenvironment, improving lymphoma cell killing. Therefore, EZH2 inhibition enhances CAR-T cell efficacy through direct effects on CAR-T cells, in addition to rendering lymphoma B cells immunogenic. This approach is currently being evaluated in two clinical trials, NCT05934838 and NCT05994235, to improve immunotherapy outcomes in B cell lymphoma patients.

Tertiary lymphoid structures and cancer immunotherapy: From bench to bedside

Tertiary lymphoid structures (TLSs) are organized ectopic lymphoid aggregates within the tumor microenvironment that serve as crucial sites for the development of adaptive antitumor cellular and humoral immunity. TLSs have been consistently documented in numerous cancer types, correlating with improved prognosis and enhanced responses to immunotherapy, especially immune-checkpoint blockade (ICB). Given the potential role of TLSs as predictive biomarkers for the efficacy of ICB in cancer patients, the therapeutic manipulation of TLSs is gaining significant attention as a promising avenue for cancer treatment. Herein, we comprehensively review the composition, definition, and detection methods of TLSs in humans. We also discuss the contributions of TLSs to antitumor immunity, their prognostic value in cancer patients, and their association with therapeutic response to ICB-based immunotherapy. Finally, we present preclinical data supporting the potential of therapeutically manipulating TLSs as a promising approach for innovative cancer immunotherapy.

B cells and tertiary lymphoid structures in tumors: immunity cycle, clinical impact, and therapeutic applications

Tumorigenesis involves a multifaceted and heterogeneous interplay characterized by perturbations in individual immune surveillance. Tumor-infiltrating lymphocytes, as orchestrators of adaptive immune responses, constitute the principal component of tumor immunity. Over the past decade, the functions of tumor-specific T cells have been extensively elucidated, whereas current understanding and research regarding intratumoral B cells remain inadequate and underexplored. The delineation of B cell subsets is contingent upon distinct surface proteins and the specific transcription factors that define these subsets have yet to be fully described. Consequently, there is a pressing need for extensive and comprehensive exploration into tumor-infiltrating B cells and their cancer biology. Notably, B cells and other cellular entities assemble within the tumor milieu to establish tertiary lymphoid structures that facilitate localized immune activation and furnish novel insights for tumor research. It is of great significance to develop therapeutic strategies based on B cells, antibodies, and tertiary lymphoid structures. In this review, we address the role of B cells and tertiary lymphoid structures in tumor microenvironment, with the highlight on their spatiotemporal effect, prognostic value and therapeutic applications in tumor immunity.

Efficacy and tolerability of neoadjuvant therapy with Talimogene laherparepvec in cutaneous basal cell carcinoma: a phase II trial (NeoBCC trial)

We present a single-arm, phase II, neoadjuvant trial with the oncolytic virus talimogene laherparepvec (T-VEC) in 18 patients with difficult-to-resect cutaneous basal cell carcinomas. The primary end point, defined as the proportion of patients, who after six cycles of T-VEC (13 weeks), become resectable without the need for plastic reconstructive surgery, was already achieved after stage I (9 of 18 patients; 50.0%); thus the study was discontinued for early success. The objective response rate was 55.6% and the complete pathological response rate was 33.3%. Secondary end points included safety, relapse-free survival and overall survival, time to occurrence of new basal cell carcinomas and biological read outs. Only mild adverse events occurred. The 6-month relapse-free survival and overall survival rates were 100%. In two patients a new basal cell carcinoma was diagnosed. T-VEC led to a significant increase in cytotoxic T cells (P = 0.0092), B cells (P = 0.0004) and myeloid cells (P = 0.0042) and a decrease in regulatory T cells (P = 0.0290) within the tumor microenvironment. Together, neoadjuvant T-VEC represents a viable treatment option for patients with difficult-to-resect basal cell carcinomas (EudraCT no. 2018-002165-19).

Differentiating multiple sclerosis with predominant spinal cord and optic nerve involvement from other autoimmune demyelinating diseases using B cell immunophenotyping and gene expression profiling

OBJECTIVE

Multiple sclerosis (MS) may present with predominant involvement of the spinal cord and optic nerve (MS/w-SCON) and mimic other autoimmune inflammatory demyelinating disorders (AIDD) such as neuromyelitis optica spectrum disorder (NMOSD), and relapsing inflammatory optic neuritis (RION). Thus, biomarkers are required for effective differential diagnosis of AIDD.

METHODS

Patients with MS/w-SCON (n = 20), MS without involvement of SCON (MS/wo-SCON) (n = 22), NMOSD (n = 16), RION (n = 15) and healthy individuals (n = 21) were included. Peripheral blood cell immunophenotypes were analyzed by flow cytometry and gene expression levels of isolated B cells were assessed by microarray analysis and quantitative real-time PCR.

RESULTS

Significantly increased Breg, plasmablast, and plasma cell ratios distinguished MS/w-SCON from other groups. Most differentially expressed B cell genes were subjected to protein-protein interaction yielding a network of 13 immune mediators (IL18, IL18R1, P2RY12, CSF3R, TNFSF4, TNFRSF13C, TNFRSF1A, CCL20, CCL5, CCR4, CCL4L2, CXCL5, CXCL10). CCL4L2 and CCR4 expression levels distinguished MS/w-SCON. IL18/IL18R1 and CCL5 were distinguishing factors for NMOSD and RION, respectively.

CONCLUSION

Peripheral blood B cell expression levels of CCL4L2, CCR4, IL18, IL18R1 and CCL5 are candidate biomarkers for differential diagnosis of AIDD of CNS. Our results substantiate the significance of B cells in the pathogenesis of these disorders.

Efficacy and pharmacodynamic effect of anti-CD73 and anti-PD-L1 monoclonal antibodies in combination with cytotoxic therapy: observations from mouse tumor models

CD73 is a cell surface 5'nucleotidase (NT5E) and key node in the catabolic process generating immunosuppressive adenosine in cancer. Using a murine monoclonal antibody surrogate of Oleclumab, we investigated the effect of CD73 inhibition in concert with cytotoxic therapies (chemotherapies as well as fractionated radiotherapy) and PD-L1 blockade. Our results highlight improved survival in syngeneic tumor models of colorectal cancer (CT26 and MC38) and sarcoma (MCA205). This therapeutic outcome was in part driven by cytotoxic CD8 T-cells, as evidenced by the detrimental effect of CD8 depleting antibody treatment of MCA205 tumor bearing mice treated with anti-CD73, anti-PD-L1 and 5-Fluorouracil+Oxaliplatin (5FU+OHP). We hypothesize that the improved responses are tumor microenvironment (TME)-driven, as suggested by the lack of anti-CD73 enhanced cytopathic effects mediated by 5FU+OHP on cell lines in vitro. Pharmacodynamic analysis, using imaging mass cytometry and RNA-sequencing, revealed noteworthy changes in specific cell populations like cytotoxic T cells, B cells and NK cells in the CT26 TME. Transcriptomic analysis highlighted treatment-related modulation of gene profiles associated with an immune response, NK and T-cell activation, T cell receptor signaling and interferon (types 1 & 2) pathways. Inclusion of comparator groups representing the various components of the combination allowed deconvolution of contribution of the individual therapeutic elements; highlighting specific effects mediated by the anti-CD73 antibody with respect to immune-cell representation, chemotaxis and myeloid biology. These pre-clinical data reflect complementarity of adenosine blockade with cytotoxic therapy, and T-cell checkpoint inhibition, and provides new mechanistic insights in support of combination therapy.

B cells enhance IL-1 beta driven invasiveness in triple-negative breast cancer

Triple-negative breast cancer (TNBC) is an aggressive subtype often characterized by high lymphocyte infiltration, including tumor-infiltrating B cells (TIBs). These cells are present even in early stages of TNBC and associated with microinvasion. This study shows that co-culturing TNBC cells with B cells increases Interleukin-1β (IL-1β) expression and secretion. We further show that B cell-induced IL-1β activates NFκB signaling, leading to higher expression of target genes and promoting IL-1β-dependent increases in matrix metalloproteinase (MMP) activity, invasion, and migration. Immunohistochemical analysis of IL-1β and TIBs in triple-negative ductal carcinoma in situ (DCIS, n=90) and invasive TNBC (n=171) revealed that in DCIS, TIBs correlated with IL-1β expression and microinvasion, with IL-1β also linked to recurrence. In invasive TNBC, IL-1β expression correlated with TIB density and stage, with high IL-1β levels associated with poorer survival outcomes. These findings suggest that early B cell presence in TNBC can induce IL-1β secretion, enhancing invasion and mobility through IL-1β-NFκB signaling. This highlights the potential of IL-1 inhibitors as preventive and therapeutic options for hormone receptor-negative DCIS and TNBC.

Induced B-Cell Receptor Diversity Predicts PD-1 Blockade Immunotherapy Response

Immune checkpoint inhibitors such as anti-PD-1 antibodies (aPD1) can be effective in treating advanced cancers. However, many patients do not respond and the mechanisms underlying these differences remain incompletely understood. In this study, we profile a cohort of patients with locally-advanced or metastatic basal cell carcinoma undergoing aPD-1 therapy using single-cell RNA sequencing, high-definition spatial transcriptomics in tumors and draining lymph nodes, and spatial immunoreceptor profiling, with long-term clinical follow-up. We find that successful responses to PD-1 inhibition are characterized by an induction of B-cell receptor (BCR) clonal diversity after treatment initiation. These induced BCR clones spatially co-localize with T-cell clones, facilitate their activation, and traffic alongside them between tumor and draining lymph nodes to enhance tumor clearance. Furthermore, we validated aPD1-induced BCR diversity as a predictor of clinical response in a larger cohort of glioblastoma, melanoma, and head and neck squamous cell carcinoma patients, suggesting that this is a generalizable predictor of treatment response across many types of cancers. We discover that pre-treatment tumors harbor a characteristic gene expression signature that portends a higher probability of inducing BCR clonal diversity after aPD-1 therapy, and we develop a machine learning model that predicts PD-1-induced BCR clonal diversity from baseline tumor RNA sequencing. These findings underscore a dynamic role of B cell diversity during immunotherapy, highlighting its importance as a prognostic marker and a potential target for intervention in non-responders.

Immune Checkpoints in B Cells: Unlocking New Potentials in Cancer Treatment

B cells are crucial component of humoral immunity, and their role in the tumor immune microenvironment (TME) has garnered significant attention in recent years. These cells hold great potential and application prospects in the field of tumor immunotherapy. Research has demonstrated that the TME can remodel various B cell functions, including proliferation, differentiation, antigen presentation, and antibody production, thereby invalidating the anti-tumor effects of B cells. Concurrently, numerous immune checkpoints (ICs) on the surface of B cells are upregulated. Aberrant B-cell IC signals not only impair the function of B cells themselves, but also modulate the tumor-killing effects of other immune cells, ultimately fostering an immunosuppressive TME and facilitating tumor immune escape. Blocking ICs on B cells is beneficial for reversing the immunosuppressive TME and restoring anti-tumor immune responses. In this paper, the intricate connection between B-cell ICs and the TME is delved into, emphasizing the critical role of targeting B-cell ICs in anti-tumor immunity, which may provide valuable insights for the future development of tumor immunotherapy based on B cells.

B cell c-Maf signaling promotes tumor progression in animal models of pancreatic cancer and melanoma

BACKGROUND

The role of B cells in antitumor immunity remains controversial, with studies suggesting the protumor and antitumor activity. This controversy may be due to the heterogeneity in B cell populations, as the balance among the subtypes may impact tumor progression. The immunosuppressive regulatory B cells (Breg) release interleukin 10 (IL-10) but only represent a minor population. Additionally, tumor-specific antibodies (Abs) also exhibit antitumor and protumor functions dependent on the Ab isotype. Transcription factor c-Maf has been suggested to contribute to the regulation of IL-10 in Breg, but the role of B cell c-Maf signaling in antitumor immunity and regulating Ab responses remains unknown.

METHODS

Conditional B cell c-Maf knockout (KO) and control mice were used to establish a KPC pancreatic cancer model and B16.F10 melanoma model. Tumor progression was evaluated. B cell and T cell phenotypes were determined by flow cytometry, mass cytometry, and cytokine/chemokine profiling. Differentially expressed genes in B cells were examined by using RNA sequencing (RNA-seq). Peripheral blood samples were collected from healthy donors and patients with melanoma for B cell phenotyping.

RESULTS

Compared with B cells from the spleen and lymph nodes (LN), B cells in the pancreas exhibited significantly less follicular phenotype and higher IL-10 production in naïve mice. c-Maf deficiency resulted in a significant reduction of CD9+ IL-10-producing Breg in the pancreas. Pancreatic ductal adenocarcinoma (PDAC) progression resulted in the accumulation of circulating B cells with the follicular phenotype and less IL-10 production in the pancreas. Notably, B cell c-Maf deficiency delayed PDAC tumor progression and resulted in proinflammatory B cells. Further, tumor volume reduction and increased effective T cells in the tumor-draining LN were observed in B cell c-Maf KO mice in the B16.F10 melanoma model. RNA-seq analysis of isolated B cells revealed that B cell c-Maf signaling modulates immunoglobulin-associated genes and tumor-specific Ab production. We furthermore demonstrated c-Maf-positive B cell subsets and an increase of IL-10-producing B cells after incubation with IL-4 and CD40L in the peripheral blood of patients with melanoma.

CONCLUSION

Our study highlights that B cell c-Maf signaling drives tumor progression through the modulation of Breg, inflammatory responses, and tumor-specific Ab responses.

Neoadjuvant vidutolimod and nivolumab in high-risk resectable melanoma: A prospective phase II trial

Intratumoral TLR9 agonists and anti-PD-1 produce clinical responses and broad immune activation. We conducted a single-arm study of neoadjuvant TLR9 agonist vidutolimod combined with anti-PD-1 nivolumab in high-risk resectable melanoma. In 31 evaluable patients, 55% major pathologic response (MPR) was observed, meeting primary endpoint. MPR was associated with necrosis, and melanophagocytosis with increased CD8+ tumor-infiltrating lymphocytes and plasmacytoid dendritic cells (pDCs) in the tumor microenvironment, and increased frequencies of Ki67+CD8+ T cells peripherally. MPRs had an enriched pre-treatment gene signature of myeloid cells, and response to therapy was associated with gene signatures of immune cells, pDCs, phagocytosis, and macrophage activation. MPRs gut microbiota were enriched for Gram-negative bacteria belonging to the Bacteroidaceae and Enterobacteriaceae families and the small subgroup of Gram-negative Firmicutes. Our findings support that combined vidutolimod and nivolumab stimulates a broad anti-tumor immune response and is associated with distinct baseline myeloid gene signature and gut microbiota. ClinicalTrials.gov identifier: NCT03618641.

Lactate dehydrogenase A is a diagnostic biomarker associated with immune infiltration, m6A modification and ferroptosis in endometrial cancer

Background

Lactate dehydrogenase A (LDHA) has been confirmed as a tumor promoter in various cancers, but its role in endometrial cancer remains unclear.

Methods

The Cancer Genome Atlas (TCGA), quantitative real-time polymerase chain reaction and the Human Protein Atlas were utilized to analyzed the LDHA expression in EC. The LDHA levels of patients with different clinical features were compared based on the TCGA cohort. The Genome Ontology, Kyoto Encyclopedia of Genes and Genomes, and Gene Set Enrichment Analysis of LDHA-related genes were conducted by R language. The influence of LDHA knockdown on cell proliferation, apoptosis, migration and invasion was detected by in vitro experiment. The relationship between LDHA expression and immune infiltration was explored by Tumor Immune Estimation Resource 2.0 and Gene Expression Profiling Interactive Analysis. The association of LDHA level with N6-methyladenosine (m6A) modification and ferroptosis was investigated based on the TCGA-UCEC and the GEO cohort.

Results

The LDHA was overexpressed in EC tissues and EC cell lines, and had high predictive accuracy for the EC diagnosis. The LDHA level was associated with age, histological type, histologic grade, and radiation therapy. LDHA-related genes participated in multiple biological functions and signaling pathways. LDHA downregulation significantly promoted cell apoptosis and inhibited the proliferation, migration, and invasion of EC cells. LDHA expression was connected to multiple tumor-infiltrating lymphocytes (TILs), m6A-related genes, and ferroptosis-related genes.

Conclusion

LDHA has the potential to work as an EC biomarker associated with TILs, m6A modification, and ferroptosis in EC.

The Dual Role of B Cells in the Tumor Microenvironment: Implications for Cancer Immunology and Therapy

The tumor microenvironment (TME) is a complex and heterogeneous tissue composed of various cell types, including tumor cells, stromal cells, and immune cells, as well as non-cellular elements. Given their pivotal role in humoral immunity, B cells have emerged as promising targets for anti-tumor therapies. The dual nature of B cells, exhibiting both tumor-suppressive and tumor-promoting functions, has garnered significant attention. Understanding the distinct effects of various B cell subsets on different tumors could pave the way for novel targeted tumor therapies. This review provides a comprehensive overview of the heterogeneous B cell subsets and their multifaceted roles in tumorigenesis, as well as the therapeutic potential of targeting B cells in cancer treatment. To develop more effective cancer immunotherapies, it is essential to decipher the heterogeneity of B cells and their roles in shaping the TME.

Notch1 blockade by a novel, selective anti-Notch1 neutralizing antibody improves immunotherapy efficacy in melanoma by promoting an inflamed TME

BACKGROUND

Immune checkpoint inhibitors (ICI) have dramatically improved the life expectancy of patients with metastatic melanoma. However, about half of the patient population still present resistance to these treatments. We have previously shown Notch1 contributes to a non-inflamed TME in melanoma that reduces the response to ICI. Here, we addressed the therapeutic effects of a novel anti-Notch1 neutralizing antibody we produced, alone and in combination with immune checkpoint inhibition in melanoma models.

METHODS

Anti-Notch1 was designed to interfere with ligand binding. Mice were immunized with a peptide encompassing EGF-like repeats 11-15 of human Notch1, the minimal required region that allows ligand binding and Notch1 activation. Positive clones were expanded and tested for neutralizing capabilities. Anti-Notch1-NIC was used to determine whether anti-Notch1 was able to reduce Notch1 cleavage; while anti-SNAP23 and BCAT2 were used as downstream Notch1 and Notch2 targets, respectively. K457 human melanoma cells and the YUMM2.1 and 1.7 syngeneic mouse melanoma cells were used. Cell death after anti-Notch1 treatment was determined by trypan blue staining and compared to the effects of the gamma-secretase inhibitor DBZ. 10 mg/kg anti-Notch1 was used for in vivo tumor growth of YUMM2.1 and 1.7 cells. Tumors were measured and processed for flow cytometry using antibodies against major immune cell populations.

RESULTS

Anti-Notch1 selectively inhibited Notch1 but not Notch2; caused significant melanoma cell death in vitro but did not affect normal melanocytes. In vivo, it delayed tumor growth without evident signs of gastro-intestinal toxicities; and importantly promoted an inflamed TME by increasing the cytotoxic CD8+ T cells while reducing the tolerogenic Tregs and MDSCs, resulting in enhanced efficacy of anti-PD-1.

CONCLUSIONS

Anti-Notch1 safely exerts anti-melanoma effects and improves immune checkpoint inhibitor efficacy. Thus, anti-Notch1 could represent a novel addition to the immunotherapy repertoire for melanoma.

Advancements in tumor-infiltrating lymphocytes: Historical insights, contemporary milestones, and future directions in oncology therapy

Tumor-infiltrating lymphocytes (TILs) are a subtype of immune cells that infiltrate and accumulate within tumors. Studies proved that TILs can be used as prognostic and predictive markers for cancer patients' responses to immunotherapy. This review explores the modern knowledge of TILs, the challenges and opportunities for utilizing TILs in cancer treatment, such as the rise of therapies under TIL circumstances, the identification of biomarkers for TIL activity, and methods used to isolate and expand TILs for therapeutic use. Ongoing clinical trials and promising results in different cancer types are highlighted, including melanoma, ovarian, and colorectal cancer. This also focuses on ongoing efforts to improve TIL-based therapies by identifying the specific subsets of TILs that are most effective in treating cancer and developing methods to increase the functionality and persistence of TILs in the tumor microenvironment. The article recapitulates the present state TILs therapy, ongoing research, and improvements to its potency.

Inhibition of the Rho/MRTF pathway improves the response of BRAF-resistant melanoma to PD1/PDL1 blockade

Metastatic cutaneous melanoma is a fatal skin cancer. Resistance to targeted and immune therapies limits the benefits of current treatments. Identifying and adding anti-resistance agents to current treatment protocols can potentially improve clinical responses. Myocardin-related transcription factor (MRTF) is a transcriptional coactivator whose activity is indirectly regulated by actin and the Rho family of GTPases. We previously demonstrated that development of BRAF inhibitor (BRAFi) resistance frequently activates the Rho/MRTF pathway in human and mouse BRAFV600E melanomas. In clinical trials, pretreatment with BRAFi reduces the benefit of immune therapies. We aimed to test the efficacy of concurrent treatment with our MRTF pathway inhibitor CCG-257081 and anti-PD1 in vivo and to examine its effects on the melanoma immune microenvironment. Because MRTF pathway activation upregulates the expression of immune checkpoint inhibitor genes/proteins, we asked whether CCG-257081 can improve the response to immune checkpoint blockade. CCG-257081 reduced the expression of PDL1 in BRAFi-resistant melanoma cells and decreased surface PDL1 levels on both BRAFi-sensitive and -resistant melanoma cells. Using our recently described murine vemurafenib-resistant melanoma model, we found that CCG-257081, in combination with anti-PD1 immune therapy, reduced tumor growth and increased survival. Moreover, anti-PD1/CCG-257081 co-treatment increased infiltration of CD8+ T cells and B cells into the tumor microenvironment and reduced tumor-associated macrophages. Here, we propose CCG-257081 as an anti-resistance and immune therapy-enhancing anti-melanoma agent.

CD4+ T cells in antitumor immunity

Advances in cancer immunotherapy have transformed cancer care and realized unprecedented responses in many patients. The growing arsenal of novel therapeutics - including immune checkpoint inhibition (ICI), adoptive T cell therapies (ACTs), and cancer vaccines - reflects the success of cancer immunotherapy. The therapeutic benefits of these treatment modalities are generally attributed to the enhanced quantity and quality of antitumor CD8+ T cell responses. Nevertheless, CD4+ T cells are now recognized to play key roles in both the priming and effector phases of the antitumor immune response. In addition to providing T cell help through co-stimulation and cytokine production, CD4+ T cells can also possess cytotoxicity either directly on MHC class II-expressing tumor cells or to other cells within the tumor microenvironment (TME). The presence of specific populations of CD4+ T cells, and their intrinsic plasticity, within the TME can represent an important determinant of clinical response to immune checkpoint inhibitors, vaccines, and chimeric antigen receptor (CAR) T cell therapies. Understanding how the antitumor functions of specific CD4+ T cell types are induced while limiting their protumorigenic attributes will enable more successful immunotherapies.

Computational immune synapse analysis reveals T-cell interactions in distinct tumor microenvironments

The tumor microenvironment (TME) and the cellular interactions within it can be critical to tumor progression and treatment response. Although technologies to generate multiplex images of the TME are advancing, the many ways in which TME imaging data can be mined to elucidate cellular interactions are only beginning to be realized. Here, we present a novel approach for multipronged computational immune synapse analysis (CISA) that reveals T-cell synaptic interactions from multiplex images. CISA enables automated discovery and quantification of immune synapse interactions based on the localization of proteins on cell membranes. We first demonstrate the ability of CISA to detect T-cell:APC (antigen presenting cell) synaptic interactions in two independent human melanoma imaging mass cytometry (IMC) tissue microarray datasets. We then verify CISA's applicability across data modalities with melanoma histocytometry whole slide images, revealing that T-cell:macrophage synapse formation correlates with T-cell proliferation. We next show the generality of CISA by extending it to breast cancer IMC images, finding that CISA quantifications of T-cell:B-cell synapses are predictive of improved patient survival. Our work demonstrates the biological and clinical significance of spatially resolving cell-cell synaptic interactions in the TME and provides a robust method to do so across imaging modalities and cancer types.

Oxidized Melanoma Antigens Promote Activation and Proliferation of Cytotoxic T-Cell Subpopulations

Increasing evidence suggests the role of reactive oxygen and nitrogen species (RONS) in regulating antitumor immune effects and immunosuppression. RONS modify biomolecules and induce oxidative post-translational modifications (oxPTM) on proteins that can alarm phagocytes. However, it is unclear if and how protein oxidation by technical means could be a strategy to foster antitumor immunity and therapy. To this end, cold gas plasma technology producing various RONS simultaneously to oxidize the two melanoma-associated antigens MART and PMEL is utilized. Cold plasma-oxidized MART (oxMART) and PMEL (oxPMEL) are heavily decorated with oxPTMs as determined by mass spectrometry. Immunization with oxidized MART or PMEL vaccines prior to challenge with viable melanoma cells correlated with significant changes in cytokine secretion and altered T-cell differentiation of tumor-infiltrated leukocytes (TILs). oxMART promoted the activity of cytotoxic central memory T-cells, while oxPMEL led to increased proliferation of cytotoxic effector T-cells. Similar T-cell results are observed after incubating splenocytes of tumor-bearing mice with B16F10 melanoma cells. This study, for the first time, provides evidence of the importance of oxidative modifications of two melanoma-associated antigens in eliciting anticancer immunity.

Tertiary lymphoid structures in anticancer immunity

Tertiary lymphoid structures (TLS) are transient ectopic lymphoid aggregates where adaptive antitumour cellular and humoral responses can be elaborated. Initially described in non-small cell lung cancer as functional immune lymphoid structures associated with better clinical outcome, TLS have also been found in many other carcinomas, as well as melanomas and sarcomas, and associated with improved response to immunotherapy. The manipulation of TLS as a therapeutic strategy is now coming of age owing to the likely role of TLS in the improved survival of patients with cancer receiving immune checkpoint inhibitor treatment. TLS have also garnered considerable interest as a predictive biomarker of the response to antitumour therapies, including immune checkpoint blockade and, possibly, chemotherapy. However, several important questions still remain regarding the definition of TLS in terms of both their cellular composition and functions. Here, we summarize the current views on the composition of TLS at different stages of their development. We also discuss the role of B cells and T cells associated with TLS and their dialogue in mounting antibody and cellular antitumour responses, as well as some of the various mechanisms that negatively regulate antitumour activity of TLS. The prognostic value of TLS to the clinical outcome of patients with cancer and the relationship between TLS and the response to therapy are then addressed. Finally, we present some preclinical evidence that favours the idea that manipulating the formation and function of TLS could lead to a potent next-generation cancer immunotherapy.

Tertiary lymphoid structures in diseases: immune mechanisms and therapeutic advances

Tertiary lymphoid structures (TLSs) are defined as lymphoid aggregates formed in non-hematopoietic organs under pathological conditions. Similar to secondary lymphoid organs (SLOs), the formation of TLSs relies on the interaction between lymphoid tissue inducer (LTi) cells and lymphoid tissue organizer (LTo) cells, involving multiple cytokines. Heterogeneity is a distinguishing feature of TLSs, which may lead to differences in their functions. Growing evidence suggests that TLSs are associated with various diseases, such as cancers, autoimmune diseases, transplant rejection, chronic inflammation, infection, and even ageing. However, the detailed mechanisms behind these clinical associations are not yet fully understood. The mechanisms by which TLS maturation and localization affect immune function are also unclear. Therefore, it is necessary to enhance the understanding of TLS development and function at the cellular and molecular level, which may allow us to utilize them to improve the immune microenvironment. In this review, we delve into the composition, formation mechanism, associations with diseases, and potential therapeutic applications of TLSs. Furthermore, we discuss the therapeutic implications of TLSs, such as their role as markers of therapeutic response and prognosis. Finally, we summarize various methods for detecting and targeting TLSs. Overall, we provide a comprehensive understanding of TLSs and aim to develop more effective therapeutic strategies.

Cryoablation and post-progression immune checkpoint inhibition in metastatic melanoma: a phase II trial

Image-guided percutaneous cryoablation is an established minimally invasive oncologic treatment. We hypothesized that cryoablation may modify the immune microenvironment through direct modulation of the tumor, thereby generating an anti-tumor response in tumors refractory to immune checkpoint inhibition (ICI). In this non-randomized phase II single-center study (NCT03290677), subjects with unresectable melanoma progressing on ICI underwent cryoablation of an enlarging metastasis, and ICI was continued for a minimum of two additional cycles. The primary endpoints were safety, feasibility and tumor response in non-ablated lesions. From May 2018 through July 2020, 17 patients were treated on study. The study met its primary endpoints with the combination strategy found to be safe and feasible with an objective response rate of 23.5% and disease control rate of 41% (4 partial response, 3 stable disease). Our data support further study of this synergistic therapeutic approach.

Morphological and Immunohistochemical Aspects with Prognostic Implications and Therapeutic Targets of Primary Sinonasal Mucosal Melanoma: A Retrospective Study

Sinonasal mucosal melanoma originates from melanocytes and it is a rare malignancy in the sinonasal tract. It is an aggressive melanocytic neoplasm with a very poor prognosis. The symptoms are nonspecific and the diagnosis is delayed, usually until the advanced stages of the disease. The current study performs a correlation between the histopathological aspects of sinonasal mucosal melanoma and different types of immune cells present in the microenvironment, with prognostic and therapeutic implications. The endpoint is to quantify the cellular immune microenvironment and correlate it with patient survival. This study presents nine cases of primary sinonasal mucosal melanomas diagnosed at the Emergency City Hospital Timisoara, Romania during a period of 15 years. The histopathological examination was performed in the Department of Pathology of the same hospital, using morphological hematoxylin-eosin staining. Additional immunohistochemical reactions were performed to confirm the diagnosis and evaluate the components of the tumor immune microenvironment. This study identifies eosinophils, macrophages, natural killer cells and plasma cells as favorable prognostic factors. Therefore, a CD8:CD4 ratio of more than 3 is correlated with a good response to PD-1 inhibitor therapy.

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.

A Bibliometric Analysis of Metabolic Reprogramming in the Tumor Microenvironment From 2003 to 2022

BACKGROUND

Despite considerable progress in cancer immunotherapy, it is not available for many patients. Resistance to immune checkpoint blockers arises from the intricate interactions between cancer and its microenvironment. Metabolic reprogramming in tumor and immune cells in the tumor microenvironment (TME) influences anti-tumor immune responses by remodeling the immune microenvironment. Metabolic reprogramming has emerged as an important hallmark of tumorigenesis. However, few studies have focused on the TME and metabolic reprogramming. Therefore, we aimed to explore the current research status and popular topics in TME-related metabolic reprogramming over a 20 years using a bibliometric approach.

METHODS

Studies focusing on metabolic reprogramming and TME were searched using the Web of Science Core Collection database. Bibliometric and visual analyses of the articles and reviews were performed using Bibliometrix, VOSviewer, and CiteSpace.

RESULTS

In total, 4726 articles published between 2003 and 2022 were selected. The number of publications and citations has increased annually. Cooperation network analysis indicated that the United States holds the foremost position in metabolic reprogramming and TME research with the highest volume of publications and citations, thus exerting the greatest influence. Among these institutions, Fudan University displayed the highest level of productivity. Frontiers in Immunology showed the highest degree of productivity in this field. Ho Ping-Chih made the most article contributions, and Pearce Edward J. was the most co-cited author. Four clusters were obtained after a cluster analysis of the authors' keywords: TME, metabolic reprogramming, immunometabolism, and immunity. Immunometabolism, glycolysis, immune cells, and tumor-associated macrophages are relatively recent keywords that have attracted increasing attention.

CONCLUSIONS

A comprehensive landscape of advancements in metabolic reprogramming and the TME was evaluated, which provided crucial information for scholars to further advance this promising field. Further research should explore new topics related to immunometabolism in the TME using a transdisciplinary approach.

Establishment of a CD8+ T cells-related prognostic risk model for acral melanoma based on single-cell and bulk RNA sequencing

BACKGROUND

CD8+ T cells have been recognized as crucial factors in the prognosis of melanoma. However, there is currently a lack of gene markers that accurately describe their characteristics and functions in acral melanoma (AM), which hinders the development of personalized medicine.

METHODS

Firstly, we explored the composition differences of immune cells in AM using single-cell RNA sequencing (scRNA-seq) data and comprehensively characterized the immune microenvironment of AM in terms of composition, developmental differentiation, function, and cell communication. Subsequently, we constructed and validated a prognostic risk scoring model based on differentially expressed genes (DEGs) of CD8+ T cells using the TCGA-SKCM cohort through Lasso-Cox method. Lastly, immunofluorescence staining was performed to validate the expression of four genes (ISG20, CCL4, LPAR6, DDIT3) in AM and healthy skin tissues as included in the prognostic model.

RESULTS

The scRNA-seq data revealed that memory CD8+ T cells accounted for the highest proportion in the immune microenvironment of AM, reaching 70.5%. Cell-cell communication analysis showed extensive communication relationships among effector CD8+ T cells. Subsequently, we constructed a prognostic scoring model based on DEGs derived from CD8+ T cell sources. Four CD8+ T cell-related genes were included in the construction and validation of the prognostic model. Additionally, immunofluorescence results demonstrated that ISG20 and CCL4 were downregulated, while LPAR6 and DDIT3 were upregulated in AM tissues compared to normal skin tissues.

CONCLUSION

Identifying biomarkers based on the expression levels of CD8+ T cell-related genes may be an effective approach for establishing prognostic models in AM patients. The independently prognostic risk evaluation model we constructed provides new insights and theoretical support for immunotherapy in AM.

The distribution and maturation of tertiary lymphoid structures can predict clinical outcomes of patients with gastric adenocarcinoma

Introduction

Tertiary lymphoid structures (TLSs) are analogues of secondary lymphoid organs that contain various immune cells. The spatial distribution, maturation and composition of TLSs have differential effects on prognosis, and the roles of TLSs in gastric adenocarcinoma (GA) have not been revealed.

Methods

Thus, we evaluated the prognostic value of TLSs in GA through analysis of bulk RNA sequencing(RNA-seq) data from public databases and validated our findings in tumour samples from the Fudan University Shanghai Cancer Center (FUSCC) cohort. The spatial distribution,maturation, and composition of TLSs in GA were analysed by reviewing H&E-stained sections and by multiplex immunofluorescence (mIF) staining.

Results

We found that TLSs, especially TLSs with germinal centres (GCs) and TLSs located in the invasive margin (IM), were correlated with prolonged overall survival (OS). Second, analysis of public RNA-seq data showed that high dendritic cell (DC) scores were a favourable prognostic factor in GA patients with high scores for both TLSs and GCs. In the FUSCC cohort, DC-LAMP+ DCs weresignificantly enriched in IM-TLSs with GCs, suggesting a potential correlation between the tumour immune activation milieu and the DC abundance. Third, compared to that in TLSs without GCs, the proportion of FOXP3+CD8+ Treg cells was significantly decreased in IM-TLSs with GCs, and the percentage of PD1+CD20+ B cells was significantly increased in TLSs with GCs.

Discussion

Our results demonstrate that the spatial arrangement and maturation of TLSs significantly affect prognosis and indicate that TLSs could be a new additional factor for histopathological evaluation.

Mature tertiary lymphoid structures: important contributors to anti-tumor immune efficacy

Tertiary lymphoid structures (TLS) represent the ectopic aggregations of immune cells arising during chronic inflammation or tumor progression. In cancer, TLS are often associated with beneficial clinical outcomes in patients undergoing immunotherapy, underscoring their prognostic and predictive significance. Mature TLS, characterized by germinal centers and areas of T-cell and B-cell aggregation, are considered primary locations for activating and maintaining both humoral and cellular anti-tumor immune effects. Despite their recognized importance, the mechanisms driving the formation of mature TLS in cancer and their influence on the immune response within tumors remain insufficiently understood. Therefore, this review aims to comprehensively explore the structural composition, development mechanisms, maturity impact factors, immunological function, and innovative therapeutic strategies of mature TLS within the tumor microenvironment. The research summarized herein offers novel insights and considerations for therapeutic approaches to promote TLS generation and maturation in patients with cancer, representing a promising avenue for future cancer therapies.

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.

Identification of potential hub genes and biological mechanism in rheumatoid arthritis and non-small cell lung cancer via integrated bioinformatics analysis

BACKGROUND

Although there is evidence of the association between RA and NSCLC, little is known about their interaction mechanisms. The aim of this study is to identify potential hub genes and biological mechanism in RA and NSCLC via integrated bioinformatics analysis.

METHODS

The gene expression datasets of RA and NSCLC were downloaded to discover and validate hub genes. After identifying DEGs, we performed enrichment analysis, PPI network construction and module analysis, selection and validation of hub genes. Moreover, we selected the hub gene PTPRC for expression and prognosis analysis, immune analysis, mutation and methylation analysis in NSCLC. Finally, we performed real-time PCR, colony formation assay, wound healing assay, transwell invasion assay, sphere formation assay and western blotting to validate the role of PTPRC in A549 cells.

RESULTS

We obtained 320 DEGs for subsequent analysis. Enrichment results showed that the DEGs were mainly involved in Th1, Th2 and Th17 cell differentiation. In addition, four hub genes, BIRC5, PTPRC, PLEK, and FYN, were identified after selection and validation. These hub genes were subsequently shown to be closely associated with immune cells and related pathways. In NSCLC, PTPRC was downregulated, positively correlated with immune infiltration and immune cells. Experiments showed that PTPRC could promote the proliferation, migration and invasion, and the ability to form spheroids of A549 cells. In addition, PTPRC could regulate the increased expression of CD45, β-catenin, c-Myc and LEF1 proteins.

CONCLUSIONS

This study explored the hub genes and related mechanisms of RA and NSCLC, demonstrated the central role of the inflammatory response and the adaptive immune system, and identified PTPRC as an immune-related biomarker and potential therapeutic target for RA and NSCLC patients. In addition, PTPRC can significantly promote the proliferation, migration and invasion of A549 cells, and its mechanism may be to promote the EMT process by regulating the Wnt signaling pathway and promote cell stemness, which in turn has a promoting effect on A549 cells.