OBJECTIVE: Current data suggests that Bacille Calmette-Guerin (BCG) vaccination contributes to nonspecific enhancement of resistance to various infections. Thus, BCG vaccination induces both specific immunity against mycobacteria and non-specific \"trained immunity\" against various pathogens. To understand the fundamental mechanisms of \"trained\" immunity, studies of transcriptome changes occurring during BCG vaccination in innate immunity cells, as well as in their precursors, are necessary. Furthermore, this data possesses important significance for practical applications associated with the development of recombinant BCG strains aimed to enhance innate immunity against diverse infectious agents.
METHODS: We performed RNA sequencing of innate immune cells derived from murine bone marrow and spleen three days after subcutaneous BCG vaccination. Using fluorescence-activated cell sorting we obtained three cell populations for each mouse from both control and BCG vaccinated groups: bone marrow monocytes and neutrophils and splenic NK-cells. Then double-indexed cDNA libraries for Illumina sequencing from the collected samples were prepared, the resulting cDNA library mix was subjected to NovaSeq 6000 sequencing. This paper describes the collection of 24 RNA sequencing samples comprising 4 sets of immune cell populations obtained from subcutaneously BCG-vaccinated and control mice.

Bacille-Calmette-Guérin (BCG) is the only approved vaccine against Mycobacterium tuberculosis (MTB), offering protection not only against tuberculosis (TB) but also non-related infections. \'Trained immunity\' of innate immune cells is considered one of the mechanisms of this broad protection derived through BCG. Here, we investigated the effect of BCG on Natural Killer (NK) cells, a key innate immune cell type, and their subsequent responses to mycobacterial and HIV antigens. We found that BCG-induced KLRG1+ NK cells exhibit significantly higher production of IFNγ, compared to KLRG1- cells, indicating their memory-like responses upon exposure to these antigens (p < 0.05). These findings may be important in regions of high burden of HIV and TB where BCG is routinely administered.

Tuberculosis (TB) caused 1.5 million deaths in 2020, making it the leading infectious killer after COVID-19. Bacille Calmette-Guerin (BCG) is the only licensed vaccine against TB but has sub-optimal efficacy against pulmonary TB and reduced effectiveness in regions close to the equator with high burden. Efforts to find novel vaccines are hampered due to the need for large-scale, prolonged, and costly clinical trials. Controlled human infection models (CHIMs) for TB may be used to accelerate vaccine development by ensuring only the most promising vaccine candidates are selected for phase 3 trials, but it is not currently possible to give participants Mycobacterium tuberculosis as a challenge agent. This study aims to replicate and refine an established BCG CHIM at the Liverpool School of Tropical Medicine. Participants will receive an intradermal injection with licensed BCG vaccine (Statens Serum Institut strain). In phase A, participants will undergo punch biopsy two weeks after administration, paired with minimally invasive methods of skin sampling (skin swab, microbiopsy, skin scrape). BCG detection by classical culture and molecular methods will be compared between these techniques and gold standard punch biopsy. Techniques meeting our pre-defined sensitivity and specificity criteria will be applied in Phase B to longitudinally assess intradermal BCG growth two, seven and fourteen days after administration. We will also measure compartmental immune responses in skin, blood and respiratory mucosa in Phase B. This feasibility study will transfer and refine an existing and safe model of BCG controlled human infection. Longitudinal BCG quantification has the potential to increase model sensitivity to detect vaccine and therapeutic responses. If successful, we aim to transfer the model to Malawi in future studies, a setting with endemic TB disease, to accelerate development of vaccines and therapeutics relevant for underserved populations who stand to benefit the most. Registration: ISRCTN: ISRCTN94098600 and ClinicalTrials.gov: NCT05820594.

Trained Immunity is defined as a biological process normally induced by exogenous or endogenous insults that triggers epigenetic and metabolic reprogramming events associated with long-term adaptation of innate immune cells. This trained phenotype confers enhanced responsiveness to subsequent triggers, resulting in an innate immune \"memory\" effect. Trained Immunity, in the past decade, has revealed important benefits for host defense and homeostasis, but can also induce potentially harmful outcomes associated with chronic inflammatory disorders or autoimmune diseases. Interestingly, evidence suggest that the \"trainers\" prompting trained immunity are frequently glycans structures. In fact, the exposure of different types of glycans at the surface of pathogens is a key driver of the training phenotype, leading to the reprogramming of innate immune cells through the recognition of those glycan-triggers by a variety of glycan-binding proteins (GBPs) expressed by the immune cells. β-glucan or mannose-enriched structures in Candida albicans are some of the examples that highlight the potential of glycans in trained immunity, both in homeostasis and in disease. In this review, we will discuss the relevance of glycans exposed by pathogens in establishing key immunological hubs with glycan-recognizing receptors expressed in immune cells, highlighting how this glycan-GBP network can impact trained immunity. Finally, we discuss the power of glycans and GBPs as potential targets in trained immunity, envisioning potential therapeutic applications.

While more than four decades have elapsed since intravesical Bacillus Calmette-Guérin (BCG) was first used to manage non-muscle invasive bladder cancer (NMIBC), its precise mechanism of anti-tumor action remains incompletely understood. Besides the classic theory that BCG induces local (within the bladder) innate and adaptive immunity through interaction with multiple immune cells, three new concepts have emerged in the past few years that help explain the variable response to BCG therapy between patients. First, BCG has been found to directly interact and become internalized within cancer cells, inducing them to act as antigen-presenting cells (APCs) for T-cells while releasing multiple cytokines. Second, BCG has a direct cytotoxic effect on cancer cells by inducing apoptosis through caspase-dependent pathways, causing cell cycle arrest, releasing proteases from mitochondria, and inducing reactive oxygen species-mediated cell injury. Third, BCG can increase the expression of programmed death ligand 1 (PD-L1) on both cancer and infiltrating inflammatory cells to impair the cell-mediated immune response. Current data has shown that high-grade recurrence after BCG therapy is related to CD8+ T-cell anergy or \'exhaustion\'. High-field cancerization and subsequently higher neoantigen presentation to T-cells are also associated with this anergy. This may explain why BCG therapy stops working after a certain time in many patients. This review summarizes the detailed immunologic reactions associated with BCG therapy and the role of immune cell subsets in this process. Moreover, this improved mechanistic understanding suggests new strategies for enhancing the anti-tumor efficacy of BCG for future clinical benefit.

Bacillus Calmette-Guérin (BCG) immunotherapy has been a cornerstone treatment for non-muscle-invasive bladder cancer for decades and still faces challenges, such as severe immune adverse reactions, which reduce its use as a first-line treatment. This review examines BCG therapy\'s history, mechanisms, and current status, highlighting how nanotechnology and bioengineering are revitalizing its application. We discuss novel nanocarrier systems aimed at enhancing BCG\'s efficacy while mitigating specific side effects. These approaches promise improved tumor targeting, better drug loading, and an enhanced stimulation of anti-tumor immune responses. Key strategies involve using materials such as liposomes, polymers, and magnetic particles to encapsulate BCG or functional BCG cell wall components. Additionally, co-delivering BCG with chemotherapeutics enhances drug targeting and tumor-killing effects while reducing drug toxicity, with some studies even achieving synergistic effects. While most studies remain experimental, this research direction offers hope for overcoming BCG\'s limitations and advancing bladder cancer immunotherapy. Further elucidation of BCG\'s mechanisms and rigorous safety evaluations of new delivery systems will be crucial for translating these innovations into clinical practice.

Skin scar formation following Bacille Calmette-Guérin (BCG) or smallpox (Vaccinia) vaccination is an established marker of successful vaccination and \'vaccine take\'. Potent pathogen-specific (tuberculosis; smallpox) and pathogen-agnostic (protection from diseases unrelated to the intentionally targeted pathogen) effects of BCG and smallpox vaccines hold significant translational potential. Yet despite their use for centuries, how scar formation occurs and how local skin-based events relate to systemic effects that allow these two vaccines to deliver powerful health promoting effects has not yet been determined. We review here what is known about the events occurring in the skin and place this knowledge in the context of the overall impact of these two vaccines on human health with a particular focus on maternal-child health.

Trained immunity is a long-lasting change in the responsiveness of innate immune cells, leading to a stronger response upon an unrelated secondary challenge. Epigenetic, transcriptional, and metabolic reprogramming contribute to the development of trained immunity. By investigating the impact of gene variants on trained immunity responses after Bacillus Calmette-Guérin (BCG) vaccination, we identified a strong association between polymorphisms in the RORA gene and BCG-induced trained immunity in PBMCs isolated from healthy human donors. RORα, encoded by the RORA gene in humans, is a nuclear receptor and a transcription factor, regulating genes involved in circadian rhythm, inflammation, cholesterol, and lipid metabolism. We found that natural RORα agonists in the circulation negatively correlate with the strength of trained immunity responses after BCG vaccination. Moreover, pharmacological inhibition of RORα in human PBMCs led to higher cytokine production capacity and boosted trained immunity induction by BCG. Blocking RORα activity also resulted in morphological changes and increased ROS and lactate production of BCG-trained cells. Blocking lactate dehydrogenase A (LDHA) and glycolysis with sodium oxamate reduced the cytokine production capacity of cells trained with a combination of BCG and the RORα agonist. In conclusion, this study highlights the potential role of RORα in trained immunity, and its impact on human vaccination and diseases should be further investigated.

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

UNASSIGNED: To reduce the risk of disease recurrence and progression of intermediate and high-risk Non-Muscle Invasive Bladder Cancers (NMIBCs), intravesical adjuvant treatment with Bacillus Calmette-Guerin (BCG) represents the standard of care, although up to 50% of patients will eventually recur and up to 20% of them will progress to Muscle Invasive Bladder Cancer (MIBC). Radical Cystectomy (RC) is the treatment of choice in this setting; however, this represents a major and morbid surgery, thus meaning that not all NMIBCs patient could undergo or may refuse this procedure or may refuse. The search for effective bladder sparing strategies in NMIBCs BCG-unresponsive patients is a hot topic in the urologic field.
UNASSIGNED: We aimed to review the most important bladder-preserving strategies for BCG unresponsive disease, from those used in the past, even though rarely used nowadays (intravesical chemotherapy with single agents), to current available therapies (e.g. intravesical instillation with Gemcitabine-Docetaxel), and to future upcoming treatments (Oportuzumab Monatox).
UNASSIGNED: At present, bladder-preserving treatments in BCG-unresponsive patients are represented by the use of intravesical instillations, systemic immunotherapies, both with good short-term and modest mid-term efficacy, and numerous clinical trials ongoing, with encouraging initial results, in which patients could be recruited.