Bacterial immunotherapy for cancer induces CD4-dependent tumor-specific immunity through tumor-intrinsic interferon-γ signaling

Deconvoluting the interplay of innate and adaptive immunity in BCG-induced nonspecific and TB-specific host resistance

BCG is the oldest vaccine in continuous use. While current intradermal vaccination regimens confer limited protection outside the context of pediatric extrapulmonary tuberculosis (TB), promising new data indicate that when administered mucosally or intravenously at a higher dose, BCG can induce sterilizing immunity against pulmonary TB in nonhuman primates. BCG is also known to promote nonspecific host resistance against a variety of unrelated infections and is a standard immunotherapy for bladder cancer, suggesting that this innate immune function may contribute to its protective role against TB. Here, we propose that both the mycobacterial-specific and off-target effects of BCG depend on the interplay of adaptive and innate cells and the cytokines they produce, and that the elucidation of this interaction should be a major strategy in the development of more effective BCG-based vaccines and immunotherapies.

BCG therapy in bladder cancer and its tumor microenvironment interactions

SUMMARYBacillus Calmette-Guérin (BCG) has been the standard treatment for non-muscle-invasive bladder cancer for over 30 years. Despite its proven efficacy, challenges persist, including unclear mechanisms of action, resistance in 30%-50% of patients, and significant side effects. This review presents an updated and balanced discussion of the antitumor mechanisms of BCG, focusing on its direct effects on bladder cancer and its interactions with various cell types within the bladder tumor microenvironment. Notably, recent research on the interactions between BCG and the bladder microbiome is also incorporated. We further summarize and analyze the latest preclinical and clinical studies regarding both intrinsic and adaptive resistance to BCG in bladder cancer. Based on the current understanding of BCG's therapeutic principles and resistance mechanisms, we systematically explore strategies to improve BCG-based tumor immunotherapy. These include the development of recombinant BCG, combination therapy with different drugs, optimization of therapeutic regimens and management, and the exploration of new approaches by targeting changes in the bladder microbiota and its metabolites. These measures aim to effectively address the BCG resistance in bladder cancer, reduce its toxicity, and ultimately enhance the clinical anti-tumor efficacy. Bacterial therapy, represented by genetically engineered oncolytic bacteria, has gradually emerged in the field of cancer treatment in recent years. As the only bacterial drug successfully approved for oncology use, BCG has provided decades of clinical experience. By consolidating lessons from BCG's successes and limitations, we hope to provide valuable insights for the development and application of bacterial therapies in cancer treatment.

Targeting clonal mutations with synthetic microbes

Recently concluded, large-scale cancer genomics studies involving multiregion sequencing of primary tumors and paired metastases appear to indicate that many or most cancer patients have one or more "clonal" mutations in their tumors. Clonal mutations are those that are present in all of a patient's cancer cells. Clonally mutated proteins can potentially be targeted by inhibitors or E3 ligase small molecule glues, but developing new small molecule drugs for each patient is not feasible currently. Certain companies are using immunotherapies to target clonal mutations. I have devised another approach for exploiting clonal mutations, which I call "Oncolytic Vector Efficient Replication Contingent on Omnipresent Mutation Engagement" (OVERCOME). The ideal version of OVERCOME would likely employ a bioengineered facultative intracellular bacterium. The bacterium would initially be attenuated, but (transiently) reverse its attenuation upon clonal mutation detection.

Thermosensitive hydrogel delivery of BCG lysates and tumor antigens: A novel strategy for melanoma immunoprevention and therapeutics

Melanoma, recognized as one of the most aggressive forms of skin cancer, continues to show a steady rise in global incidence. While Bacillus Calmette-Guérin (BCG) has been identified as a potential intralesional therapy for melanoma, its therapeutic efficacy remains suboptimal. This study introduces a novel thermosensitive hydrogel formulated with BCG lysates and either OVA peptide or tumor cell lysates (PPP-BCG-OVA/TL). The hydrogel demonstrated the ability to elicit a robust systemic tumor antigen-specific T cell response and significantly enhanced the infiltration of CD45+ leukocytes, macrophages, CD8+ T cells, and natural killer (NK) cells into the tumor microenvironment. As a result, vaccination with PPP-BCG-OVA/TL hydrogel effectively inhibited tumor growth and extended survival in mouse models of subcutaneous melanoma in both preventive and therapeutic contexts. These findings highlight the potential to markedly improve the therapeutic efficacy of BCG lysates through the addition of tumor antigens and the use of a hydrogel-based delivery platform.

BCG's role in strengthening immune responses: Implications for tuberculosis and comorbid diseases

The BCG vaccine represents a significant milestone in the prevention of tuberculosis (TB), particularly in children. Researchers have been developing recombinant BCG (rBCG) variants that can trigger lasting memory responses, thereby enhancing protection against TB in adults. The breakdown of immune surveillance is a key link between TB and other communicable and non-communicable diseases. Notably, TB is more prevalent among people with comorbidities such as HIV, diabetes, cancer, influenza, COVID-19, and autoimmune disorders. rBCG formulations have the potential to address both TB and HIV co-pandemics. TB increases the risk of lung cancer and immunosuppression caused by cancer can reactivate latent TB infections. Moreover, BCG's efficacy extends to bladder cancer treatment and blood glucose regulation in patients with diabetes and TB. Additionally, BCG provides cross-protection against unrelated pathogens, emphasizing the importance of BCG-induced trained immunity in COVID-19 and other respiratory diseases. Furthermore, BCG reduced the severity of pulmonary TB-induced influenza virus infections. Recent studies have proposed innovations in BCG delivery, revaccination, and attenuation techniques. Disease-centered research has highlighted the immunomodulatory effects of BCG on TB, HIV, cancer, diabetes, COVID-19, and autoimmune diseases. The complex relationship between TB and comorbidities requires a nuanced re-evaluation to understand the shared attributes regulated by BCG. This review assessed the interconnected relationships influenced by BCG administration in TB and related disorders, recommending the expanded use of rBCG in healthcare. Collaboration among vaccine research stakeholders is vital to enhance BCG's efficacy against global health challenges.

Targeted Initiation of Trained Immunity in Tumor-Associated Macrophages with Membrane-Camouflaged Bacillus Calmette-Guérin for Lung Carcinoma Immunotherapy

Inducing trained immunity in macrophages is an increasingly promising strategy for preventing cancer development. However, it has not been investigated whether trained immunity in tumor-associated macrophages (TAMs) can be initiated for antitumor applications. Here, we provide a practical strategy that utilizes the macrophage membrane (M) to camouflage Bacillus Calmette-Guérin (M@BCG), endowing it with the capability to selectively target tumors and efficiently induce trained immunity for TAMs. Using a mouse model of Lewis lung carcinoma, we show that the introduction of macrophage membrane increases BCG's accumulation in orthotopic lung cancer tissues compared with naked BCG. The superior tumor-targeting ability can augment BCG-mediated trained immunity in TAMs, leading to a robust activation of immune responses. Furthermore, macrophage depletion and adoptive transfer of BCG-trained TAM experiments demonstrate that the antitumor activity of M@BCG is dependent on the trained immunity of TAMs. More importantly, intravenous administration of M@BCG can synergistically reinforce the antitumor activity of immune checkpoint blockade without causing systemic toxicity. Taken together, our study demonstrates the successful initiation of trained immunity in TAMs using M@BCG, which exhibits prominent antitumor performance through immune activation.

Bacterial live therapeutics for human diseases

The genomic revolution has fueled rapid progress in synthetic and systems biology, opening up new possibilities for using live biotherapeutic products (LBP) to treat, attenuate or prevent human diseases. Among LBP, bacteria-based therapies are particularly promising due to their ability to colonize diverse human tissues, modulate the immune system and secrete or deliver complex biological products. These bacterial LBP include engineered pathogenic species designed to target specific diseases, and microbiota species that promote microbial balance and immune system homeostasis, either through local administration or the gut-body axes. This review focuses on recent advancements in preclinical and clinical trials of bacteria-based LBP, highlighting both on-site and long-reaching strategies.

Tumor-specific antibodies elicited by engineered bacteria promote bladder cancer immunotherapy

The intratumoral microbiome has recently emerged as a new hallmark of cancer, with implications for response or resistance to therapy. While bacteria can either promote or inhibit cancer growth, intratumoral bacteria can also be engineered using synthetic biology to remodel the tumor microenvironment. Here, we engineered the probiotic bacterium E. coli Nissle 1917 (EcN) to express the human chemokine CXCL13, a critical component of germinal center (GC) formation. The GC reaction is a fundamental aspect of adaptive immunity by which antibody affinity develops in secondary lymphoid organs for defense against pathogens. Using orthotopic models of bladder cancer, engineered CXCL13-expressing EcN colonized bladder tumors and elicited GC responses in bladder tumor-draining lymph nodes after intravesical delivery. Furthermore, when combined with PD-1 blockade, engineered EcN amplified the antitumor antibody response and promoted long-term survival and protective immunity upon tumor rechallenge. Thus, we demonstrate that synthetically engineered CXCL13-expressing EcN can enhance the efficacy of PD-1 checkpoint blockade immunotherapy by amplifying tumor-specific humoral immunity.

Atypical B Cells Promote Cancer Progression and Poor Response to Bacillus Calmette-Guérin in Non-Muscle Invasive Bladder Cancer

Poor response to Bacillus Calmette-Guérin (BCG) immunotherapy remains a major barrier in the management of patients with non-muscle invasive bladder cancer (NMIBC). Multiple factors are associated with poor outcomes, including biological aging and female sex. More recently, it has emerged that a B-cell-infiltrated pretreatment immune microenvironment of NMIBC tumors can influence the response to intravesically administered BCG. The mechanisms underlying the roles of B cells in NMIBC are poorly understood. Here, we show that B-cell-dominant tertiary lymphoid structures (TLSs), a hallmark feature of the chronic mucosal immune response, are abundant and located close to the epithelial compartment in pretreatment tumors from BCG non-responders. Digital spatial proteomic profiling of whole tumor sections from male and female patients with NMIBC who underwent treatment with intravesical BCG, revealed higher expression of immune exhaustion-associated proteins within the tumor-adjacent TLSs in both responders and non-responders. Chronic local inflammation, induced by the N-butyl-N-(4-hydroxybutyl) nitrosamine carcinogen, led to TLS formation with recruitment and differentiation of the immunosuppressive atypical B-cell (ABC) subset within the bladder microenvironment, predominantly in aging female mice compared to their male counterparts. Depletion of ABCs simultaneous to BCG treatment delayed cancer progression in female mice. Our findings provide evidence indicating a role for ABCs in BCG response and will inform future development of therapies targeting the B-cell-exhaustion axis.

Bacterial nanotechnology as a paradigm in targeted cancer therapeutic delivery and immunotherapy

Cancer, a multifaceted and diverse ailment, presents formidable obstacles to traditional treatment modalities. Nanotechnology presents novel prospects for surmounting these challenges through its capacity to facilitate meticulous and regulated administration of therapeutic agents to malignant cells while concurrently modulating the immune system to combat neoplasms. Bacteria and their derivatives have emerged as highly versatile and multifunctional platforms for cancer nanotherapy within the realm of nanomaterials. This comprehensive review delves into the multifaceted and groundbreaking implementations of bacterial nanotechnology within cancer therapy. This review encompasses four primary facets: the utilization of bacteria as living conveyors of medicinal substances, the employment of bacterial components as agents that stimulate the immune system, the deployment of bacterial vectors as tools for delivering genetic material, and the development of bacteria-derived nano-drugs as intelligent nano-medications. Furthermore, we elucidate the merits and modalities of operation pertaining to these bacterial nano-systems, along with their capacity to synergize with other cutting-edge nanotechnologies, such as CRISPR-Cas systems. Additionally, we offer insightful viewpoints regarding the forthcoming trajectories and prospects within this expanding domain. It is our deduction that bacterial nanotechnology embodies a propitious and innovative paradigm in the realm of cancer therapy, which has the potential to provide numerous advantages and synergistic effects in enhancing the outcomes and quality of life for individuals afflicted with cancer.

The clinical significance and anti-tumor role of PRKG1 in bladder cancer

Introduction

cGMP-dependent protein kinase 1 (PRKG1) has shown to be associated with some tumorigenesis, while the role of PRKG1 in bladder cancer is unclear.

Methods

To investigate the biological and clinical significance of PRKG1 in bladder cancer, we detected the expression of PRKG1 and explored the function of PRKG1 in bladder cancer cells. The PRKG1 transcripts data was downloaded from The Cancer Genome Atlas (TCGA) database, and immunohistochemistry staining was conducted on formalin-fixed paraffin-embedded (FFPE) sample tissues. Relationship between clinical characteristics of patients and expression of PRKG1 was analyzed in FFPE samples, TCGA database, and GSE19423 dataset. PRKG1 was over-expressed, and cell proliferation, migration, invasion, apoptosis, and spheroidizing ability were then detected. Chemosensitivity to cisplatin was detected with cell viability, and half-maximal drug inhibitory concentration (IC50) was calculated. In addition, the relation between PRKG1 expression and the infiltration level of tumor immune cells in tumor microenvironment were analyzed.

Results

The results showed expression of PRKG1 was lower in bladder cancer, compared with normal tissues both at protein and transcript levels. Lower PRKG1 expression was related to higher tumor grade, T stage, and muscle invasion, also predicted worse overall survival and recurrence free survival in patients treated with Bacillus Calmette-Guerin (BCG) intravesical immunotherapy. Analysis of tumor immune cells infiltration showed lower PRKG1 was associated with non-inflamed tumor microenvironment.

Conclusion

The present study firstly identified the anti-tumor role and tumor immune regulatory role of PRKG1, also found loss of PRKG1 could be used as a prognosis factor. The present study provided a potential biomarker and therapy target to bladder cancer.

Harnessing microbial antigens as cancer antigens: a promising avenue for cancer immunotherapy

Immunotherapy has revolutionized cancer treatment by leveraging the immune system's innate capabilities to combat malignancies. Despite the promise of tumor antigens in stimulating anti-tumor immune responses, their clinical utility is hampered by limitations in eliciting robust and durable immune reactions, exacerbated by tumor heterogeneity and immune evasion mechanisms. Recent insights into the immunogenic properties of host homologous microbial antigens have sparked interest in their potential for augmenting anti-tumor immunity while minimizing off-target effects. This review explores the therapeutic potential of microbial antigen peptides in tumor immunotherapy, beginning with an overview of tumor antigens and their challenges in clinical translation. We further explore the intricate relationship between microorganisms and tumor development, elucidating the concept of molecular mimicry and its implications for immune recognition of tumor-associated antigens. Finally, we discuss methodologies for identifying and characterizing microbial antigen peptides, highlighting their immunogenicity and prospects for therapeutic application.

Trained immunity inducers in cancer immunotherapy

While most of the cancer immunotherapy strategies engage adaptive immunity, especially tumor-associated T cells, the small fraction of responding patients and types of cancers amenable, and the possibility of severe adverse effects limit its usage. More effective and general interventions are urgently needed. Recently, a de facto innate immune memory, termed 'trained immunity', has become a new research focal point, and promises to be a powerful tool for achieving long-term therapeutic benefits against cancers. Trained immunity-inducing agents such as BCG and fungal glucan have been shown to be able to avert the suppressive tumor microenvironment (TME), enhance T cell responses, and eventually lead to tumor regression. Here, we review the current understating of trained immunity induction and highlight the critical roles of emergency granulopoiesis, interferon γ and tissue-specific induction. Preclinical and clinical studies that have exploited trained immunity inducers for cancer immunotherapy are summarized, and repurposed trained immunity inducers from other fields are proposed. We also outline the challenges and opportunities for trained immunity in future cancer immunotherapies. We envisage that more effective cancer vaccines will combine the induction of trained immunity with T cell therapies.

In Situ Synthesis of an Immune-Checkpoint Blocker from Engineered Bacteria Elicits a Potent Antitumor Response

Immune-checkpoint blockade (ICB) reinvigorates T cells from exhaustion and potentiates T-cell responses to tumors. However, most patients do not respond to ICB therapy, and only a limited response can be achieved in a "cold" tumor with few infiltrated lymphocytes. Synthetic biology can be used to engineer bacteria as controllable bioreactors to synthesize biotherapeutics in situ. We engineered attenuated Salmonella VNP20009 with synthetic gene circuits to produce PD-1 and Tim-3 scFv to block immunosuppressive receptors on exhausted T cells to reinvigorate their antitumor response. Secreted PD-1 and Tim-3 scFv bound PD-1+ Tim-3+ T cells through their targeting receptors in vitro and potentiated the T-cell secretion of IFN-γ. Engineered bacteria colonized the hypoxic core of the tumor and synthesized PD-1 and Tim-3 scFv in situ, reviving CD4+ T cells and CD8+ T cells to execute an antitumor response. The bacteria also triggered a strong innate immune response, which stimulated the expansion of IFN-γ+ CD4+ T cells within the tumors to induce direct and indirect antitumor immunity.

Microbial cancer immunotherapy reprograms hematopoietic stem cells to enhance anti-tumor immunity

Mycobacterium bovis BCG is the vaccine against tuberculosis and an immunotherapy for bladder cancer. When administered intravenously, BCG reprograms bone marrow hematopoietic stem and progenitor cells (HSPCs), leading to heterologous protection against infections. Whether HSPC-reprogramming contributes to the anti-tumor effects of BCG administered into the bladder is unknown. We demonstrate that BCG administered in the bladder in both mice and humans reprograms HSPCs to amplify myelopoiesis and functionally enhance myeloid cell antigen presentation pathways. Reconstitution of naive mice with HSPCs from bladder BCG-treated mice enhances anti-tumor immunity and tumor control, increases intratumor dendritic cell infiltration, reprograms pro-tumorigenic neutrophils, and synergizes with checkpoint blockade. We conclude that bladder BCG acts systemically, reprogramming HSPC-encoded innate immunity, highlighting the broad potential of modulating HSPC phenotypes to improve tumor immunity.

Bacillus Calmette-Guérin immunotherapy induces an efficient antitumor response to control murine melanoma depending on MyD88 signaling

Bacillus Calmette-Guérin (BCG) is the first line treatment for bladder cancer and it is also proposed for melanoma immunotherapy. BCG modulates the tumor microenvironment (TME) inducing an antitumor effective response, but the immune mechanisms involved still poorly understood. The immune profile of B16-F10 murine melanoma cells was assessed by infecting these cells with BCG or stimulating them with agonists for different innate immune pathways such as TLRs, inflammasome, cGAS-STING and type I IFN. B16-F10 did not respond to any of those stimuli, except for type I IFN agonists, contrasting with bone marrow-derived macrophages (BMDMs) that showed high production of proinflammatory cytokines. Additionally, we confirmed that BCG is able to infect B16-F10, which in turn can activate macrophages and spleen cells from mice in co-culture experiments. Furthermore, we established a subcutaneous B16-F10 melanoma model for intratumoral BCG treatment and compared wild type mice to TLR2-/-, TLR3-/-, TLR4-/-, TLR7-/-, TLR3/7/9-/-, caspase 1-/-, caspase 11-/-, IL-1R-/-, cGAS-/-, STING-/-, IFNAR-/-, MyD88-/-deficient animals. These results in vivo demonstrate that MyD88 signaling is important for BCG immunotherapy to control melanoma in mice. Also, BCG fails to induce cytokine production in the co-culture experiments using B16-F10 and BMDMs or spleen cells derived from MyD88-/- compared to wild-type (WT) animals. Immunotherapy with BCG was not able to induce the recruitment of inflammatory cells in the TME from MyD88-/- mice, impairing tumor control and IFN-γ production by T cells. In conclusion, MyD88 impacts on both innate and adaptive responses to BCG leading to an efficient antitumor response against melanoma.

Therapeutic bacteria and viruses to combat cancer: double-edged sword in cancer therapy: new insights for future

Cancer, ranked as the second leading cause of mortality worldwide, leads to the death of approximately seven million people annually, establishing itself as one of the most significant health challenges globally. The discovery and identification of new anti-cancer drugs that kill or inactivate cancer cells without harming normal and healthy cells and reduce adverse effects on the immune system is a potential challenge in medicine and a fundamental goal in Many studies. Therapeutic bacteria and viruses have become a dual-faceted instrument in cancer therapy. They provide a promising avenue for cancer treatment, but at the same time, they also create significant obstacles and complications that contribute to cancer growth and development. This review article explores the role of bacteria and viruses in cancer treatment, examining their potential benefits and drawbacks. By amalgamating established knowledge and perspectives, this review offers an in-depth examination of the present research landscape within this domain and identifies avenues for future investigation.

Breaking Barriers: Modulation of Tumor Microenvironment to Enhance Bacillus Calmette-Guérin Immunotherapy of Bladder Cancer

The clinical management of bladder cancer continues to present significant challenges. Bacillus Calmette-Guérin (BCG) immunotherapy remains the gold standard of treatment for non-muscle invasive bladder cancer (NMIBC), but many patients develop recurrence and progression to muscle-invasive disease (MIBC), which is resistant to BCG. This review focuses on the immune mechanisms mobilized by BCG in bladder cancer tumor microenvironments (TME), mechanisms of BCG resistance, the dual role of the BCG-triggered NFkB/TNFα/PGE2 axis in the regulation of anti-tumor and tumor-promoting aspects of inflammation, and emerging strategies to modulate their balance. A better understanding of BCG resistance will help develop new treatments and predictive biomarkers, paving the way for improved clinical outcomes in bladder cancer patients.

Identification of Lung Adenocarcinoma Subtypes Based on MHC-II Gene Expression Profile and Immunological Analysis

INTRODUCTION

Major histocompatibility complex class II molecule (MHC-II) is pivotal in anti-tumor immunity, and targeting MHC-II in tumors may help improve patient survival. But function of MHC-II in the immunotherapy and prognosis of lung adenocarcinoma (LUAD) patients has not been thoroughly studied and reported.

METHODS

We selected LUAD-related MHC-II genes from public databases based on previous literature reports. We identified different subtypes according to expression differences of these genes in different LUAD samples through cluster analysis. We used R package to conduct a series of analyses on different subtypes, exploring their survival differences, gene expression differences, pathway enrichment differences, and differences in immune characteristics and immune therapy. Finally, we screened potential drugs from the cMAP database.

RESULTS

We identified two MHC-II-related LUAD subtypes. Our analyses presented that patients with cluster2 subtype showed better prognosis, higher immune scores, higher levels of immune cell infiltration and immune function activation. In addition, patients with this subtype had higher immunophenoscore, lower TIDE scores, and DEPTH scores. We also identified 10 small molecule drugs, such as lenalidomide, VX-745, and tyrphostin-AG-1295.

CONCLUSION

Overall, MHC-II is not only a potential biomarker for accurately distinguishing LUAD subtypes but also a predictive factor for their survival. Our study offers novel insights into understanding of impact of MHC-II in LUAD and offers a new perspective for improving the accurate classification of LUAD patients and enhancing drug treatment.

Intratumor injection of BCG Ag85A high-affinity peptides enhanced anti-tumor efficacy in PPD-positive melanoma

As one of the scheduled immunization vaccines worldwide, virtually all individuals have been vaccinated with BCG vaccine. In order to verify the hypothesis that delivering BCG high-affinity peptides to tumor areas could activate the existing BCG memory T cells to attack tumor, we firstly predicted the HLA-A*0201 high-affinity peptides of BCG Ag85A protein (KLIANNTRV, GLPVEYLQV), and then, A375 melanoma cells and HLA-A*0201 PBMCs (from PPD-positive adults) were added to co-incubated with the predicted peptides in vitro. We found that the predicted BCG high-affinity peptides could be directly loaded onto the surface of tumor cells, enhancing the tumor-killing efficacy of PBMCs from PPD-positive volunteer. Then, we constructed PPD-positive mice model bearing B16F10 subcutaneous tumors and found that intratumor injection of BCG Ag85A high-affinity peptides (SGGANSPAL, YHPQQFVYAGAMSGLLD) enhanced the anti-tumor efficacy in PPD-positive melanoma mice. Along with the better anti-tumor efficacy, the expression of PDL1 on tumor cell surface was also increased, and stronger antitumor effects occurred when further combined with anti-PD1 antibody. For microenvironment analysis, the proportion of effector memory T cells was increased and the better treatment efficacy may be attributed to the elevated effector memory CD4 + T cells within the tumor. In conclusion, using the existing immune response of BCG vaccine by delivering high-affinity peptides of BCG to tumor area is a safe and promising therapy for cancer.

A paclitaxel-hyaluronan conjugate (ONCOFID-P-B™) in patients with BCG-unresponsive carcinoma in situ of the bladder: a dynamic assessment of the tumor microenvironment

BACKGROUND

The intravesical instillation of the paclitaxel-hyaluronan conjugate ONCOFID-P-B™ in patients with bacillus Calmette-Guérin (BCG)-unresponsive bladder carcinoma in situ (CIS; NCT04798703 phase I study), induced 75 and 40% of complete response (CR) after 12 weeks of intensive phase and 12 months of maintenance phase, respectively. The aim of this study was to provide a detailed description of the tumor microenvironment (TME) of ONCOFID-P-B™-treated BCG-unresponsive bladder CIS patients enrolled in the NCT04798703 phase I study, in order to identify predictive biomarkers of response.

METHODS

The composition and spatial interactions of tumor-infiltrating immune cells and the expression of the most relevant hyaluronic acid (HA) receptors on cancer cells, were analyzed in biopsies from the 20 patients enrolled in the NCT04798703 phase I study collected before starting ONCOFID-P-B™ therapy (baseline), and after the intensive and the maintenance phases. Clinical data were correlated with cell densities, cell distribution and cell interactions. Associations between immune populations or HA receptors expression and outcome were analyzed using univariate Cox regression and log-rank analysis.

RESULTS

In baseline biopsies, patients achieving CR after the intensive phase had a lower density of intra-tumoral CD8+ cytotoxic T lymphocytes (CTL), but also fewer interactions between CTL and macrophages or T-regulatory cells, as compared to non-responders (NR). NR expressed higher levels of the HA receptors CD44v6, ICAM-1 and RHAMM. The intra-tumoral macrophage density was positively correlated with the expression of the pro-metastatic and aggressive variant CD44v6, and the combined score of intra-tumoral macrophage density and CD44v6 expression had an AUC of 0.85 (95% CI 0.68-1.00) for patient response prediction.

CONCLUSIONS

The clinical response to ONCOFID-P-B™ in bladder CIS likely relies on several components of the TME, and the combined evaluation of intra-tumoral macrophages density and CD44v6 expression is a potentially new predictive biomarker for patient response. Overall, our data allow to advance a potential rationale for combinatorial treatments targeting the immune infiltrate such as immune checkpoint inhibitors, to make bladder CIS more responsive to ONCOFID-P-B™ treatment.

BCG as an Innovative Option for HCC Treatment: Repurposing and Mechanistic Insights

This study investigates Bacillus Calmette-Guérin (BCG) as a potential treatment for hepatocellular carcinoma (HCC), a condition often associated with unfavorable treatment outcomes. Exploiting BCG's recognized immune-boosting properties, preclinical trials are conducted using HCC mice, with a single subcutaneous dose of BCG administered post-tumor formation. Results indicate that BCG treatment effectively diminishes tumor burden and extends survival in both male and female HCC mice. Positive influences on hepatic fibrosis and metabolism are observed, leading to a reduction in lipid levels. Spatial analysis underscores BCG's tumor-specific effects, inducing the enrichment of metabolic pathways and inhibiting various cancer-related pathways. Furthermore, BCG promotes immune cell infiltration, including CD4+, CD8+ T cells, and M1 macrophages, in both v-akt murine thymoma viral oncogene homolog 1(AKT)/neutoblastoma RAS viral oncogene homolog (RAS) and β-catenin positive HCC models. Interestingly, blocking T cells, trained immunity, and Interferon-γ (IFN-γ) function reverses BCG's anti-HCC effects. In conclusion, BCG emerges as a promising treatment option for HCC, characterized by a favorable safety profile and efficacy in inhibiting fibrosis, improving metabolism, and engaging both trained immunity and T cells in therapeutic mechanisms.

Complex associations between cancer progression and immune gene expression reveals early influence of transmissible cancer on Tasmanian devils

The world's largest extant carnivorous marsupial, the Tasmanian devil, is challenged by Devil Facial Tumor Disease (DFTD), a fatal, clonally transmitted cancer. In two decades, DFTD has spread across 95% of the species distributional range. A previous study has shown that factors such as season, geographic location, and infection with DFTD can impact the expression of immune genes in Tasmanian devils. To date, no study has investigated within-individual immune gene expression changes prior to and throughout the course of DFTD infection. To explore possible changes in immune response, we investigated four locations across Tasmania that differed in DFTD exposure history, ranging between 2 and >30 years. Our study demonstrated considerable complexity in the immune responses to DFTD. The same factors (sex, age, season, location and DFTD infection) affected immune gene expression both across and within devils, although seasonal and location specific variations were diminished in DFTD affected devils. We also found that expression of both adaptive and innate immune genes starts to alter early in DFTD infection and continues to change as DFTD progresses. A novel finding was that the lower expression of immune genes MHC-II, NKG2D and CD8 may predict susceptibility to earlier DFTD infection. A case study of a single devil with regressed tumor showed opposite/contrasting immune gene expression patterns compared to the general trends observed across devils with DFTD infection. Our study highlights the complexity of DFTD's interactions with the host immune system and the need for long-term studies to fully understand how DFTD alters the evolutionary trajectory of devil immunity.

In situ immunomodulation of tumors with biosynthetic bacteria promote anti-tumor immunity

Immune checkpoint blockade (ICB) therapy potently revives T cell's response to cancer. However, patients suffered with tumors that had inadequate infiltrated immune cells only receive limited therapeutic benefits from ICB therapy. Synthetic biology promotes the alternative strategy of harnessing tumor-targeting bacteria to synthesize therapeutics to modulate immunity in situ. Herein, we engineered attenuated Salmonella typhimurium VNP20009 with gene circuits to synthetize granulocyte-macrophage colony-stimulating factor (GM-CSF) and interleukin 7 (IL-7) within tumors, which recruited dendritic cells (DCs) and enhanced T cell priming to elicit anti-tumor response. The bacteria-produced GM-CSF stimulated the maturation of bone marrow-derived dendritic cells (BMDCs), while IL-7 promoted the proliferation of spleen isolated T cells and inhibited cytotoxicity T cell apoptosis in vitro. Virtually, engineered VNP20009 prefer to colonize in tumors, and inhibited tumor growth by enhancing DCs and T cell infiltration. Moreover, the tumor-toxic GZMB+ CD8+ T cell and IFN-γ+ CD8+ T cell populations conspicuously increased with the treatment of engineered bacteria. The combination of GM-CSF-IL-7-VNP20009 with PD-1 antibody synergistically stunted the tumor progress and stasis.

A Novel Protozoa Parasite-Derived Protein Adjuvant Is Effective in Immunization with Cancer Cells to Activate the Cancer-Specific Protective Immunity and Inhibit the Cancer Growth in a Murine Model of Colorectal Cancer

Cancer-specific CD8+ cytotoxic T cells play important roles in preventing cancer growth, and IFN-γ, in addition to IL-12 and type I interferon, is critical for activating CD8+ cytotoxic T cells. We recently identified the capability of the amino-terminus region of dense granule protein 6 (GRA6Nt) of Toxoplasma gondii, an intracellular protozoan parasite, to activate IFN-γ production of microglia, a tissue-resident macrophage population. Therefore, in the present study, we examined whether recombinant GRA6Nt protein (rGRA6Nt) functions as an effective adjuvant to potently activate cancer-specific protective immunity using a murine model of MC38 colorectal cancer (CRC). When mice were immunized with non-replicable (either treated with mitomycin C or irradiated by X-ray) MC38 CRC cells in combination with rGRA6Nt adjuvant and received a challenge implantation of replication-capable MC38 tumor cells, those mice markedly inhibited the growth of the implanted tumors in association with a two-fold increase in CD8+ T cell density within the tumors. In addition, CD8+ T cells of the immunized mice secreted significantly increased amounts of granzyme B, a key mediator of the cytotoxic activity of CD8+ T cells, and IFN-γ in response to MC38 CRC cells in vitro when compared to the T cells from unimmunized mice. Notably, the protective effects of the immunization were specific to MC38 CRC cells, as the immunized mice did not exhibit a significantly inhibited growth of EL4 lymphoma tumors. These results indicate that rGRA6Nt is a novel and effective protein adjuvant when used in immunizations with non-replicable cancer cells to potently activate the protective immunity specifically against the cancer cells employed in the immunization.

Muropeptides and muropeptide transporters impact on host immune response

In bacteria, the cell envelope is the key element surrounding and protecting the bacterial content from mechanical or osmotic damages. It allows the selective interchanges of solutes, ions, cellular debris, and drugs between the cellular compartments and the external environment, thanks to the presence of transmembrane proteins called transporters. The major component of the cell envelope is the peptidoglycan, consisting of long linear glycan strands cross-linked by short peptide stems. During cell growth or under stress conditions, peptidoglycan fragments, the muropeptides, are released by bacteria and recognized by the host Pattern Recognition Receptor, promoting the activation of their innate defense mechanisms. The review sums up the salient aspects of microbiota-host interaction with a focus on the NOD-dependent immune response to bacterial peptidoglycan and on the accountability of muropeptide transporters in the crosstalk with the host and in antibiotic resistance. Furthermore, it retraces the discoveries and applications of microorganisms-derived components such as vaccines or vaccine adjuvants.

Non-mutational neoantigens in disease

The ability of mammals to mount adaptive immune responses culminating with the establishment of immunological memory is predicated on the ability of the mature T cell repertoire to recognize antigenic peptides presented by syngeneic MHC class I and II molecules. Although it is widely believed that mature T cells are highly skewed towards the recognition of antigenic peptides originating from genetically diverse (for example, foreign or mutated) protein-coding regions, preclinical and clinical data rather demonstrate that novel antigenic determinants efficiently recognized by mature T cells can emerge from a variety of non-mutational mechanisms. In this Review, we describe various mechanisms that underlie the formation of bona fide non-mutational neoantigens, such as epitope mimicry, upregulation of cryptic epitopes, usage of non-canonical initiation codons, alternative RNA splicing, and defective ribosomal RNA processing, as well as both enzymatic and non-enzymatic post-translational protein modifications. Moreover, we discuss the implications of the immune recognition of non-mutational neoantigens for human disease.

Salmonella immunotherapy engineered with highly efficient tumor antigen coating establishes antigen-specific CD8+ T cell immunity and increases in antitumor efficacy with type I interferon combination therapy

Bacteria-based cancer therapy employs various strategies to combat tumors, one of which is delivering tumor-associated antigen (TAA) to generate specific immunity. Here, we utilized a poly-arginine extended HPV E7 antigen (9RE7) for attachment on Salmonella SL7207 outer membrane to synthesize the bacterial vaccine Salmonella-9RE7 (Sal-9RE7), which yielded a significant improvement in the amount of antigen presentation compared to the previous lysine-extended antigen coating strategy. In TC-1 tumor mouse models, Sal-9RE7 monotherapy decreased tumor growth by inducing E7 antigen-specific immunity. In addition, pairing Sal-9RE7 with adjuvant Albumin-IFNβ (Alb-IFNβ), a protein cytokine fusion, the combination significantly increased the antitumor efficacy and enhanced immunogenicity in the tumor microenvironment (TME). Our study made a significant contribution to personalized bacterial immunotherapy via TAA delivery and demonstrated the advantage of combination therapy.

Trained immunity: Target for prophylaxis and therapy

Trained immunity is a de facto memory for innate immune responses, leading to long-term functional reprogramming of innate immune cells. In physiological conditions, trained immunity leads to adaptive states that enhance resistance against pathogens and contributes to immunosurveillance. Dysregulated trained immunity can however lead either to defective innate immune responses in severe infections or cancer or to inflammatory and autoimmune diseases if trained immunity is inappropriately activated. Here, we review the immunological and molecular mechanisms that mediate trained immunity induction and propose that trained immunity represents an important target for prophylactic and therapeutic approaches in human diseases. On the one hand, we argue that novel approaches that induce trained immunity may enhance vaccine efficacy. On the other hand, induction of trained immunity in cancer, and inhibition of exaggerated induction of trained immunity in inflammatory disorders, are viable targets amenable for new therapeutic approaches.

From mucosal infection to successful cancer immunotherapy

The clinical management of advanced malignancies of the upper and lower urinary tract has been revolutionized with the advent of immune checkpoint blockers (ICBs). ICBs reinstate or bolster pre-existing immune responses while creating new T cell specificities. Immunogenic cancers, which tend to benefit more from immunotherapy than cold tumours, harbour tumour-specific neoantigens, often associated with a high tumour mutational burden, as well as CD8+ T cell infiltrates and ectopic lymphoid structures. The identification of beneficial non-self tumour antigens and natural adjuvants is the focus of current investigation. Moreover, growing evidence suggests that urinary or intestinal commensals, BCG and uropathogenic Escherichia coli influence long-term responses in patients with kidney or bladder cancer treated with ICBs. Bacteria infecting urothelium could be a prominent target for T follicular helper cells and B cells, linking innate and cognate CD8+ memory responses. In the urinary tract, commensal flora differ between healthy and tumoural mucosae. Although antibiotics can affect the prognosis of urinary tract malignancies, bacteria can have a major influence on cancer immunosurveillance. Beyond their role as biomarkers, immune responses against uropathogenic commensals could be harnessed for the design of future immunoadjuvants that can be advantageously combined with ICBs.

Anoikis-associated signatures predict prognosis and immune response in bladder cancer

Objective: Anoikis is a type of programmed cell death that occurs in normal epithelial and endothelial cells. However, the specific role of anoikis regulators (ANRs) in bladder cancer (BLCA) remains unknown. Therefore, the objective of this study was to find subgroups that could identify different levels of anoikis resistance in BLCA and construct an anoikis scoring system to assess prognosis. Method: By obtaining ANRs from public datasets, subgroups of BLCA with varying degrees of anoikis resistance were identified, and risk was determined. Result: ANRs affects the occurrence and prognosis of BLCA and can be predicted by establishing risk models. Conclusion: The anoikis scoring system and anoikis-associated risk profiles may help develop more effective and personalized treatment strategies for BLCA patients.

Immune mechanisms and molecular therapeutic strategies to enhance immunotherapy in non-muscle invasive bladder cancer: Invited review for special issue "Seminar: Treatment Advances and Molecular Biology Insights in Urothelial Carcinoma"

Intravesical immunotherapy with Bacillus Calmette-Guérin (BCG) has been the standard of care for patients with high-risk non non-muscle invasive bladder cancer (NMIBC) for over four decades. Despite its success as a cancer immunotherapy, disease recurrence and progression remain common. Current efforts are focused on developing effective and well-tolerated alternatives to BCG and salvage bladder preservation therapies after BCG has failed. The focus of this review is to synthesize our current understanding of the molecular biology and tumor immune microenvironment of NMIBC to provide rationale for existing and emerging therapeutic targets. We highlight recent and ongoing clinical trials and define the current treatment landscape, challenges, and future directions of salvage treatment. Combination regimens that are rationally designed will be needed to make meaningful therapeutic advancements. Investigations into the molecular underpinnings of NMIBC are leading to the emergence of predictive molecular biomarkers that provide greater insight into the clinical heterogeneity of NMIBC and enable us to identify drivers of treatment resistance and new therapeutic targets.

STING Protein-Based In Situ Vaccine Synergizes CD4+ T, CD8+ T, and NK Cells for Tumor Eradication

Stimulator of interferon genes (STING) signaling is a promising target in cancer immunotherapy, with many ongoing clinical studies in combination with immune checkpoint blockade (ICB). Existing STING-based therapies largely focus on activating CD8+ T cell or NK cell-mediated cytotoxicity, while the role of CD4+ T cells in STING signaling has yet to be extensively studied in vivo. Here, a distinct CD4-mediated, protein-based combination therapy of STING and ICB as an in situ vaccine, is reported. The treatment eliminates subcutaneous MC38 and YUMM1.7 tumors in 70-100% of mice and protected all cured mice against rechallenge. Mechanistic studies reveal a robust TH 1 polarization and suppression of Treg of CD4+ T cells, followed by an effective collaboration of CD4+ T, CD8+ T, and NK cells to eliminate tumors. Finally, the potential to overcome host STING deficiency by significantly decreasing MC38 tumor burden in STING KO mice is demonstrated, addressing the translational challenge for the 19% of human population with loss-of-function STING variants.

Bacteria-based immunotherapy for cancer: a systematic review of preclinical studies

Immunotherapy has been emerging as a powerful strategy for cancer management. Recently, accumulating evidence has demonstrated that bacteria-based immunotherapy including naive bacteria, bacterial components, and bacterial derivatives, can modulate immune response via various cellular and molecular pathways. The key mechanisms of bacterial antitumor immunity include inducing immune cells to kill tumor cells directly or reverse the immunosuppressive microenvironment. Currently, bacterial antigens synthesized as vaccine candidates by bioengineering technology are novel antitumor immunotherapy. Especially the combination therapy of bacterial vaccine with conventional therapies may further achieve enhanced therapeutic benefits against cancers. However, the clinical translation of bacteria-based immunotherapy is limited for biosafety concerns and non-uniform production standards. In this review, we aim to summarize immunotherapy strategies based on advanced bacterial therapeutics and discuss their potential for cancer management, we will also propose approaches for optimizing bacteria-based immunotherapy for facilitating clinical translation.

Effects of Bacillus Calmette-Guérin on immunometabolism, microbiome and liver diseases⋆

Metabolic diseases have overtaken infectious diseases as the most serious public health issue and economic burden in most countries. Moreover, metabolic diseases increase the risk of having infectious diseases. The treatment of metabolic disease may require a long-term strategy of taking multiple medications, which can be costly and have side effects. Attempts to expand the therapeutic use of vaccination to prevent or treat metabolic diseases have attracted significant interest. A growing body of evidence indicates that Bacillus Calmette-Guérin (BCG) offers protection against non-infectious diseases. The non-specific effects of BCG occur likely due to the induction of trained immunity. In this regard, understanding how BCG influences the development of chronic metabolic health including liver diseases would be important. This review focuses on research on BCG, the constellation of disorders associated with metabolic health issues including liver diseases and diabetes as well as how BCG affects the gut microbiome, immunity, and metabolism.

Microbial peptides activate tumour-infiltrating lymphocytes in glioblastoma

Microbial organisms have key roles in numerous physiological processes in the human body and have recently been shown to modify the response to immune checkpoint inhibitors1,2. Here we aim to address the role of microbial organisms and their potential role in immune reactivity against glioblastoma. We demonstrate that HLA molecules of both glioblastoma tissues and tumour cell lines present bacteria-specific peptides. This finding prompted us to examine whether tumour-infiltrating lymphocytes (TILs) recognize tumour-derived bacterial peptides. Bacterial peptides eluted from HLA class II molecules are recognized by TILs, albeit very weakly. Using an unbiased antigen discovery approach to probe the specificity of a TIL CD4+ T cell clone, we show that it recognizes a broad spectrum of peptides from pathogenic bacteria, commensal gut microbiota and also glioblastoma-related tumour antigens. These peptides were also strongly stimulatory for bulk TILs and peripheral blood memory cells, which then respond to tumour-derived target peptides. Our data hint at how bacterial pathogens and bacterial gut microbiota can be involved in specific immune recognition of tumour antigens. The unbiased identification of microbial target antigens for TILs holds promise for future personalized tumour vaccination approaches.

Drug-induced interstitial pneumonia after intravesical Bacillus Calmette-Guerin administration for bladder cancer with scleroderma

Introduction

Intravesical Bacillus Calmette-Guerin administration is the standard therapy for high-risk nonmuscle invasive bladder cancer and is usually well tolerated. However, some patients experience severe, potentially fatal, complications including interstitial pneumonitis.

Case presentation

A 72-year-old female with scleroderma was diagnosed with bladder carcinoma in situ. She developed severe interstitial pneumonitis with the first administration of intravesical Bacillus Calmette-Guerin after the cessation of immunosuppressive agents. Six days after the first administration, she experienced dyspnea at rest, and computed tomography revealed scattered frosted shadows in the upper lung. The following day, she required intubation. We suspected drug-induced interstitial pneumonia and started steroid pulse therapy for 3 days, resulting in a complete response. No exacerbation of scleroderma symptoms or recurrence of cancer was observed 9 months after Bacillus Calmette-Guerin therapy.

Conclusion

For patients receiving intravesical Bacillus Calmette-Guerin therapy, close observation of the respiratory condition is necessary for early therapeutic intervention.

Case Report: Step-by-step procedures for total intracorporeal laparoscopic kidney autotransplantation in a patient with distal high-risk upper tract urothelial carcinoma

A 47-year-old man presented to the emergency department with right abdominal pain and a new onset of painless haematuria two weeks earlier. Urine cytology test results suggested urothelial carcinoma. Computed tomography urography (CTU) showed a filling defect in the lower right ureter with right hydronephrosis. Lymphadenopathy and any signs of metastatic disease were absent on CTU. Cystoscopy appeared normal. Creatinine level was also normal before surgery. After the treatment options were discussed, the patient chose to undergo 3D total intracorporeal laparoscopic kidney autotransplantation, bladder cuff excision, and segmental resection of the proximal two-thirds of the ureter based on the membrane anatomy concept. After more than one year of follow-up, the patient was in good health and showed no signs of haematuria. Surveillance cystoscopy and CTU examination showed no evidence of disease recurrence. Therefore, it is reasonable to assume that kidney-sparing surgery may be considered for carefully selected patients with high-grade upper tract urothelial carcinoma.

Maintaining a 'fit' immune system: the role of vaccines

INTRODUCTION

Conventionally, vaccines are thought to induce a specific immune response directed against a target pathogen. Long recognized but poorly understood nonspecific benefits of vaccination, such as reduced susceptibility to unrelated diseases or cancer, are now being investigated and may be due in part to "trained immunity'.

AREAS COVERED

We discuss 'trained immunity' and whether vaccine-induced 'trained immunity' could be leveraged to prevent morbidity due to a broader range of causes.

EXPERT OPINION

The prevention of infection i.e. maintaining homeostasis by preventing the primary infection and resulting secondary illnesses, is the pivotal strategy used to direct vaccine design and may have long-term, positive impacts on health at all ages. In the future, we anticipate that vaccine design will change to not only prevent the target infection (or related infections) but to generate positive modifications to the immune response that could prevent a wider range of infections and potentially reduce the impact of immunological changes associated with aging. Despite changing demographics, adult vaccination has not always been prioritized. However, the SARS-CoV-2 pandemic has demonstrated that adult vaccination can flourish given the right circumstances, demonstrating that harnessing the potential benefits of life-course vaccination is achievable for all.

[Molecular mechanisms of impaired antigenic presentation as a cause of tumor escape from immune surveillance]

The review summarizes data on the features of antigen presentation in tumor cells. The molecular mechanisms of the antitumor immune response are considered with an emphasis on the ability of tumor cells to avoid the action of immune surveillance. The features of expression of MHC molecules depending on treatment regimens are provided. Ways to improve existing and create new treatment regimens aimed at elimination of tumor cells because of antitumor immune response are discussed.

Tumor-targeting albumin nanoparticles as an efficacious drug delivery system and potential diagnostic tool in non-muscle-invasive bladder cancer therapy

Current intravesical chemotherapy for non-muscle invasive bladder cancer (NMIBC) has limited efficacy due to loss of the instilled agent from urine voiding and the agent's lack of specificity for the tumors. We developed a nanocarrier (txCD47-HNP, ∼100 nm) based on human serum albumin conjugated with a peptide that targets the cluster of differentiation 47 receptor overexpressed on bladder cancer (BC) cells. The IC₅₀ of gemcitabine elaidate (GEM) loaded in the txCD47-HNP was almost an order of magnitude lower than that of free GEM. In a mouse orthotopic BC model, GEM loaded in txCD47-HNP effectively reduced the tumor burden. Tumor cells in BC patients' urine can also be targeted by fluorescence-labeled txCD47-HNP resulting in >83 % of the cells exhibiting fluorescence. Thus, txCD47-HNP can potentially be a theranostic agent in NMIBC management by serving as a targeted drug delivery vehicle as well as an alternative to urine cytology.

AIM2 inflammasome activation benefits the therapeutic effect of BCG in bladder carcinoma

A large proportion of bladder cancer (BLCA) patients suffer from malignant progression to life-threatening muscle-invasive bladder cancer (MIBC). Inflammation is a critical event in cancer development, but little is known about the role of inflammation in BLCA. In this study, the expression of the innate immune sensor AIM2 is much lower in high-grade BLCA and positively correlates with the survival rates of the BLCA patients. A novel AIM2 overexpressed BLCA model is proposed to investigate the impact of AIM2 on BLCA development. Mice inoculated with AIM2-overexpressed cells show tumor growth delay and prolonged survival compared to the control group. Meanwhile, CD11b⁺ cells significantly infiltrate AIM2-overexpressed tumors, and AIM2-overexpression in 5637 cells enhanced the inflammasome activation. In addition, oligodeoxynucleotide (ODN) TTAGGG (A151), an AIM2 inflammasome inhibitor, could abolish the elevation of AIM2-induced cleavage of inflammatory cytokines and pyroptosis. Orthotopic BLCA by AIM2-overexpressed cells exhibits a better response to Bacillus Calmette-Guérin (BCG) immunotherapy. Overall, AIM2 inflammasome activation can inhibit the BLCA tumorigenesis and enhance the therapeutic effect of BCG in BLCA. This study provides new insights into the anti-tumor effect of AIM2 inflammasome activation in BLCA and the immunotherapeutic strategy of BLCA development.

Remodeling the bladder tumor immune microenvironment by mycobacterial species with changes in their cell envelope composition

Intravesical BCG instillation after bladder tumor resection is the standard treatment for non-muscle invasive bladder cancer; however, it is not always effective and frequently has undesirable side effects. Therefore, new strategies that improve the clinical management of patients are urgently needed. This study aimed to comprehensively evaluate the bladder tumor immune microenvironment profile after intravesical treatment with a panel of mycobacteria with variation in their cell envelope composition and its impact on survival using an orthotopic murine model to identify more effective and safer therapeutic strategies. tumor-bearing mice were intravesically treated with a panel of BCG and M. brumae cultured under different conditions. Untreated tumor-bearing mice and healthy mice were also included as controls. After mycobacterial treatments, the infiltrating immune cell populations in the bladder were analysed by flow cytometry. We provide evidence that mycobacterial treatment triggered a strong immune infiltration into the bladder, with BCG inducing higher global absolute infiltration than M. brumae. The induced global immune microenvironment was strikingly different between the two mycobacterial species, affecting both innate and adaptive immunity. Compared with M. brumae, BCG treated mice exhibited a more robust infiltration of CD4⁺ and CD8⁺ T-cells skewed toward an effector memory phenotype, with higher frequencies of NKT cells, neutrophils/gMDSCs and monocytes, especially the inflammatory subset, and higher CD4⁺ T_EM/CD4⁺ T_reg and CD8⁺ T_EM/CD4⁺ T_reg ratios. Conversely, M. brumae treatment triggered higher proportions of total activated immune cells and activated CD4⁺ and CD8⁺ T_EM cells and lower ratios of CD4⁺ T_EM cells/CD4⁺ T_regs, CD8⁺ T_EM cells/CD4⁺ T_regs and inflammatory/reparative monocytes. Notably, the mycobacterial cell envelope composition in M. brumae had a strong impact on the immune microenvironment, shaping the B and myeloid cell compartment and T-cell maturation profile and thus improving survival. Overall, we demonstrate that the bladder immune microenvironment induced by mycobacterial treatment is species specific and shaped by mycobacterial cell envelope composition. Therefore, the global bladder immune microenvironment can be remodelled, improving the quality of infiltrating immune cells, the balance between inflammatory and regulatory/suppressive responses and increasing survival.

Immune activation is essential for the antitumor activity of EZH2 inhibition in urothelial carcinoma

The long-term survival of patients with advanced urothelial carcinoma (UCa) is limited because of innate resistance to treatment. We identified elevated expression of the histone methyltransferase EZH2 as a hallmark of aggressive UCa and hypothesized that EZH2 inhibition, via a small-molecule catalytic inhibitor, might have antitumor effects in UCa. Here, in a carcinogen-induced mouse bladder cancer model, a reduction in tumor progression and an increase in immune infiltration upon EZH2 inhibition were observed. Treatment of mice with EZH2i causes an increase in MHC class II expression in the urothelium and can activate infiltrating T cells. Unexpectedly, we found that the lack of an intact adaptive immune system completely abolishes the antitumor effects induced by EZH2 catalytic inhibition. These findings show that immune evasion is the only important determinant for the efficacy of EZH2 catalytic inhibition treatment in a UCa model.

BCG-Induced Tumor Immunity Requires Tumor-Intrinsic CIITA Independent of MHC-II

For decades, BCG immunotherapy has been the standard of care for non-muscle-invasive bladder cancer. Despite this clinical experience, the mechanism by which BCG stimulates tumor-eliminating immunity is unclear, and there is still a need for more accurate prediction of clinical outcomes in advance of treatment initiation. We have shown that BCG stimulates tumor-specific T-cell immunity that requires tumor cell expression of the IFNγ receptor (IFNGR); however, the downstream components of IFNGR signaling responsible for responsiveness to BCG are unknown. Here, we demonstrate that the IFNγ-driven, tumor cell intrinsic expression of the class II transactivator CIITA is required for activation of a tumor-specific CD4 T-cell response and BCG-induced tumor immunity. Despite the established role for CIITA in controlling MHC-II antigen presentation machinery, the requirement for CIITA is independent of MHC-II and associated genes. Rather, we find that CIITA is required for a broader tumor-intrinsic transcriptional program linked to critical pathways of tumor immunity via mechanisms that remain to be determined. Tumor cell intrinsic expression of CIITA is not required for a response to immunotherapy targeting programmed cell death protein 1 (PD-1), suggesting that different modalities of immunotherapy for bladder cancer could be employed based on tumor-intrinsic characteristics.

Modified immunoscore improves the prediction of progression-free survival in patients with non-muscle-invasive bladder cancer: A digital pathology study

Tumour-infiltrating lymphocytes (TIL), known to be of prognostic value in various solid tumours, have been in the focus of research in the last years. TIL are often quantified via IMMUNOSCORE ® (IS), a scoring system based on TIL cell densities. Recent studies were able to replicate these findings for muscle-invasive bladder cancer (MIBC), however data regarding non-muscle-invasive bladder cancer (NMIBC) are scarce. This study aimed to evaluate the value of a modified Immunoscore (mIS) as a predictive marker for NMIBC prognosis using tissue-micro-arrays (TMAs). We analysed two TMAs containing 316 samples from 158 patients with NMIBC, stained for CD3, CD8, CD45RO and FOXP3. Stained TIL were captured by digital pathology, cumulated, averaged, and reported as density (stained cells per mm²). The mIS was then constructed based on density of all four immune-cell types. Clinical, pathological and follow-up data were collected retrospectively. Univariable and multivariable cox regression analysis was performed to assess the potential value of mIS as a predictor for progression free survival (PFS) and recurrence-free-survival (RFS). Patients within "European Organisation for Research and Treatment of Cancer" (EORTC) risk groups were further substratified in high mIS and low mIS subgroups. Finally log-rank test was used to compare the different survival curves. The median age in our cohort was 68 years (Interquartile Range (IQR): 60 - 76), and 117 (74%) patients were male. A total of 26 patients (16.5%) were classified as EORTC low risk, 45 (28.5%) as intermediate risk and 87 (55.1%) as high risk. Patients in the EORTC high risk group with low mIS showed a shorter PFS in comparison to high mIS (HR 2.9, CI 0.79 - 11.0, p=0.082). In contrast, no predictive potential regarding PFS was observed in intermediate or low risk groups. Furthermore, mIS was not able to predict RFS in any EORTC risk group. mIS could be utilized to predict prognosis more accurately in high-risk patients with NMIBC by identifying those with higher or lower risk of progression. Therefore, mIS could be used to allocate these highrisk patients to more streamlined follow-up or more aggressive treatment strategies.

Role of interferon-gamma (IFN-γ) and IFN-γ receptor 1/2 (IFNγR1/2) in regulation of immunity, infection, and cancer development: IFN-γ-dependent or independent pathway

IFN-γ, a soluble cytokine being produced by T lymphocytes, macrophages, mucosal epithelial cells, or natural killer cells, is able to bind to the IFN-γ receptor (IFNγR) and in turn activate the Janus kinase (JAK)-signal transducer and transcription protein (STAT) pathway and induce expression of IFN-γ-stimulated genes. IFN-γ is critical for innate and adaptive immunity and aberrant IFN-γ expression and functions have been associated with different human diseases. However, the IFN-γ/IFNγR signaling could be a double-edged sword in cancer development because the tissue microenvironments could determine its anti- or pro-tumorigenic activities. The IFNγR protein consists of two IFNγR1 and IFNγR2 chains, subunits of which play different roles under certain conditions. This review assessed IFNγR polymorphisms, expression and functions in development and progression of various human diseases in an IFN-γ-dependent or independent manner. This review also discussed tumor microenvironment, microbial infection, and vital molecules in the IFN-γ upstream signaling that might regulate IFNγR expression, drug resistance, and druggable strategy, to provide evidence for further application of IFNγR.

Recent advances in biological membrane-based nanomaterials for cancer therapy

Nanomaterials have shown significant advantages in cancer theranostics, owing to their enhanced permeability and retention effect in tumors and multi-function integration capability. Biological membranes, which are collected from various cells and their secreted membrane structures, can further be applied to establish membrane-based nanomaterials with perfect biocompatibility, tumor-targeting capacity, immune-stimulatory activity and adjustable versatility for cancer therapy. In this review, according to their source, membranes are divided into four groups: (1) cell membranes; (2) secretory membranes; (3) engineered membranes; and (4) hybrid membranes. First, cell membranes can be extracted from natural cells of the body, tumor tissue cells, and bacteria. Furthermore, secretory membranes mainly refer to exosome, apoptotic body and bacterial outer membrane vesicle, and membranes with specific protein/peptide expression or therapeutic inclusions are obtained from engineered cells. Finally, a hybrid membrane will be constituted by two or more of the abovementioned membranes. These membranes can form drug-carrying nanoparticles themselves or coat multi-functional nanoparticles, further realizing efficient cancer therapy. We summarize the application of various biological membrane-based nanomaterials in cancer therapy and point out their advantages as well as the places that need to be further improved, providing systematic knowledge of this field and a strategy for further optimization.

Novel intravesical bacterial immunotherapy induces rejection of BCG-unresponsive established bladder tumors

Background

Intravesical BCG is the gold-standard therapy for non-muscle invasive bladder cancer (NMIBC); however, it still fails in a significant proportion of patients, so improved treatment options are urgently needed.

Methods

Here, we compared BCG antitumoral efficacy with another live attenuated mycobacteria, MTBVAC, in an orthotopic mouse model of bladder cancer (BC). We aimed to identify both bacterial and host immunological factors to understand the antitumoral mechanisms behind effective bacterial immunotherapy for BC.

Results

We found that the expression of the BCG-absent proteins ESAT6/CFP10 by MTBVAC was determinant in mediating bladder colonization by the bacteria, which correlated with augmented antitumoral efficacy. We further analyzed the mechanism of action of bacterial immunotherapy and found that it critically relied on the adaptive cytotoxic response. MTBVAC enhanced both tumor antigen-specific CD4⁺ and CD8⁺ T-cell responses, in a process dependent on stimulation of type 1 conventional dendritic cells. Importantly, improved intravesical bacterial immunotherapy using MBTVAC induced eradication of fully established bladder tumors, both as a monotherapy and specially in combination with the immune checkpoint inhibitor antiprogrammed cell death ligand 1 (anti PD-L1).

Conclusion

These results contribute to the understanding of the mechanisms behind successful bacterial immunotherapy against BC and characterize a novel therapeutic approach for BCG-unresponsive NMIBC cases.

BCG in Bladder Cancer Immunotherapy

BCG is a live attenuated strain of Mycobacterium bovis that is primarily used as a vaccine against tuberculosis. In the past four decades, BCG has also been used for the treatment of non-muscle invasive bladder cancer (NMIBC). In patients with NMIBC, BCG reduces the risk of tumor recurrence and decreases the likelihood of progression to more invasive disease. Despite the long-term clinical experience with BCG, its mechanism of action is still being elucidated. Data from animal models and from human studies suggests that BCG activates both the innate and adaptive arms of the immune system eventually leading to tumor destruction. Herein, we review the current data regarding the mechanism of BCG and summarize the evidence for its clinical efficacy and recommended indications and clinical practice.