Inflammasomes Are Influenced by Epigenetic and Autophagy Mechanisms in Colorectal Cancer Signaling.

Inflammasomes contribute to colorectal cancer signaling by primarily inducing inflammation in the surrounding tumor microenvironment. Its role in inflammation is receiving increasing attention, as inflammation has a protumor effect in addition to inducing tissue damage. The inflammasome's function is complex and controlled by several layers of regulation. Epigenetic processes impact the functioning or manifestation of genes that are involved in the control of inflammasomes or the subsequent signaling cascades. Researchers have intensively studied the significance of epigenetic mechanisms in regulation, as they encompass several potential therapeutic targets. The regulatory interactions between the inflammasome and autophagy are intricate, exhibiting both advantageous and harmful consequences. The regulatory aspects between the two entities also encompass several therapeutic targets. The relationship between the activation of the inflammasome, autophagy, and epigenetic alterations in CRC is complex and involves several interrelated pathways. This article provides a brief summary of the newest studies on how epigenetics and autophagy control the inflammasome, with a special focus on their role in colorectal cancer. Based on the latest findings, we also provide an overview of the latest therapeutic ideas for this complex network.

Colonic Tuft Cells: The Less-Recognized Therapeutic Targets in Inflammatory Bowel Disease and Colorectal Cancer.

Tuft cells are more than guardian chemosensory elements of the digestive tract. They produce a variety of immunological effector molecules in response to stimulation; moreover, they are essential for defense against protozoa and nematodes. Beyond the description of their characteristics, this review aims to elucidate the potential pathogenic and therapeutic roles of colonic tuft cells in inflammatory bowel disease and colorectal cancer, focusing on their primarily immunomodulatory action. Regarding inflammatory bowel disease, tuft cells are implicated in both maintaining the integrity of the intestinal epithelial barrier and in tissue repair and regeneration processes. In addition to maintaining intestinal homeostasis, they display complex immune-regulatory functions. During the development of colorectal cancer, tuft cells can promote the epithelial-to-mesenchymal transition, alter the gastrointestinal microenvironment, and modulate both the anti-tumor immune response and the tumor microenvironment. A wide variety of their biological functions can be targeted for anti-inflammatory or anti-tumor therapies; however, the adverse side effects of immunomodulatory actions must be strictly considered.

[Primary immunodeficiency and autoimmune diseases]. / Primer immunhiány és autoimmun betegségek.

Primary immunodeficiencies consist of a group of genetically heterogeneous immune disorders affecting distinct elements of the innate and adaptive immune system. Patients with primary immunodeficiency are more prone to develop not only recurrent infections, but non-infectious complications, like inflammatory or granulomatous conditions, lymphoproliferative and solid malignancies, autoinflammatory disorders, and a broad spectrum of autoimmune diseases. The concomitant appearance of primary immunodeficiency and autoimmunity appears to be rather paradoxical, therefore making the diagnosis of immunodeficiency patients with autoimmune complications challenging. Mutations of one or more genes playing a fundamental role in immunoregulation and/or immune tolerance network are thought to be responsible for primary immunodeficiencies. The diverse immunological abnomalities along with the compensatory and excessive sustained inflammatory response result in tissue damage and finally in manifestation of organ-, cell-specific or systemic autoimmune diseases. Several forms of primary immunodeficiency disorders are characterized by a variety of specific autoimmune phenomena. This overview addresses the spectrum of autoimmune diseases associated with primary immunodeficiencies, and explores the molecular and cellular mechanisms underlying abnormalities of the immune system. The case presented finally highlights that both the recognition of autoimmune diseases in association with immunodeficiencies and the diagnosis of immunodefiency in those phenotypes with predominant autoimmunity could be challenging. Orv Hetil. 2018; 159(23): 908-918.

[Tumorigenesis: interplay of pattern recognition receptors and autophagy]. / Tumorigenezis: a mintázatfelismerõ receptorok és az autofágia jelátviteli összefüggései.

According to recent data, the involvement of autophagy in tumor development is unquestionable. Nevertheless, cell-derived pathogen/danger-associated molecular pattern (PAMP/DAMP)-sensing Toll-like receptors (TLRs) are also able to contribute to tumorigenesis and immune escape of malignantly transformed cells. Besides immunocompetent cells, several types of tumors also exhibit TLRs. TLR- and autophagy-related signaling pathways, on the other hand, may evolve anti-tumor effects in a context dependent cell- and microenvironment-specific mode. Nowadays, the autophagy machinery has been considered as a crucial homeostatic process of eukaryotic cells, and as essential constituent of the immune system influencing antimicrobial and inflammation-related immune responses. Accumulating evidence indicates that TLRs and autophagy are interdependent in response to PAMPs and DAMPs, in addition there is a bi-directional controling cross-modulation between them. Regarding personalized medicine, theoretically, it is reasonable that manipulation of the TLR-autophagy regulatory loop might be adaptable for anti-cancer therapy.

[Tocilizumab treatment of HHV8-positive/HIV-negative, multricentric plasma cell type Castleman's disease]. / Sikeres tocilizumabkezelés HHV8-pozitív/ HIV-negatív Castleman-betegség plazmasejtes multicentrikus típusában.

This is a case presentation of a HHV8-positive multicentric Castleman's disease (MCD) of plasma cell type. The patient failed to respond to combined immunosuppressive therapy and monoclonal anti-CD20 therapy. Interestingly, administration of anti-IL-6R antibody stabilized the disease and resulted in clearance of HHV8 from the involved lymph nodes.

Republished: Importance of carcinoma-associated fibroblast-derived proteins in clinical oncology.

Carcinoma-associated fibroblast (CAF) as prominent cell type of the tumour microenvironment has complex interaction with both the cancer cells and other non-neoplastic surrounding cells. The CAF-derived regulators and extracellular matrix proteins can support cancer progression by providing a protective microenvironment for the cancer cells via reduction of chemotherapy sensitivity. On the other hand, these proteins may act as powerful prognostic markers as well as potential targets of anticancer therapy. In this review, we summarise the clinical importance of the major CAF-derived signals influencing tumour behaviour and determining the outcome of chemotherapy.

Preconditioning with intravenous colitic cell-free DNA prevents DSS-colitis by altering TLR9-associated gene expression profile.

BACKGROUND: Presence of cell-free-circulating DNA (fcDNA) sequences in sera of patients with inflammatory bowel diseases (IBD) is a well-established phenomenon. Potential roles of fcDNA in diagnosis, prognosis and therapy monitoring of chronic inflammatory colonic disorders have already been examined, albeit its actual biological function still remains unclear. AIMS AND METHODS: In the present experiment, we studied the immunobiological effects of isolated fcDNA of normal and inflammatory origin administered intravenously to mice prior to induction of dextran sulfate sodium (DSS)-colitis. In addition to evaluate the current disease and histological activity, changes of the gene expression profile in isolated lamina propria cells upon TLR9 ligation were assayed. RESULTS: A single intravenous dose of fcDNA pretreatment with colitic fcDNA exhibited beneficial response concerning the clinical and histological severity of DSS-colitis as compared to effects of normal fcDNA. Pretreatment with colitic fcDNA substantially altered the expression of several TLR9-related and inflammatory cytokine genes in a clinically favorable manner. CONCLUSIONS: During the process of acute colitis, the subsequent inflammatory environment presumably results in changes of fcDNA with the potential to facilitate the downregulation of inflammation and improvement of regeneration. Thus, preconditioning of mice with colitis-derived fcDNA via TLR9 signaling could exert a tissue-protective effect and influence beneficially the course of DSS-colitis. Elucidating mechanisms of immune response alterations by nucleic acids may provide further insight into the etiology of IBD and develop the basis of novel immunotherapies.

Sirtuins Affect Cancer Stem Cells via Epigenetic Regulation of Autophagy.

Sirtuins (SIRTs) are stress-responsive proteins that regulate several post-translational modifications, partly by acetylation, deacetylation, and affecting DNA methylation. As a result, they significantly regulate several cellular processes. In essence, they prolong lifespan and control the occurrence of spontaneous tumor growth. Members of the SIRT family have the ability to govern embryonic, hematopoietic, and other adult stem cells in certain tissues and cell types in distinct ways. Likewise, they can have both pro-tumor and anti-tumor effects on cancer stem cells, contingent upon the specific tissue from which they originate. The impact of autophagy on cancer stem cells, which varies depending on the specific circumstances, is a very intricate phenomenon that has significant significance for clinical and therapeutic purposes. SIRTs exert an impact on the autophagy process, whereas autophagy reciprocally affects the activity of certain SIRTs. The mechanism behind this connection in cancer stem cells remains poorly understood. This review presents the latest findings that position SIRTs at the point where cancer cells and autophagy interact. Our objective is to highlight the various roles of distinct SIRTs in cancer stem cell-related functions through autophagy. This would demonstrate their significance in the genesis and recurrence of cancer and offer a more precise understanding of their treatment possibilities in relation to autophagy.

Association of self-DNA mediated TLR9-related gene, DNA methyltransferase, and cytokeratin protein expression alterations in HT29-cells to DNA fragment length and methylation status.

To understand the biologic role of self-DNA bound to Toll-like Receptor 9 (TLR9), we assayed its effect on gene and methyltransferase expressions and cell differentiation in HT29 cells. HT29 cells were incubated separately with type-1 (normally methylated/nonfragmented), type-2 (normally methylated/fragmented), type-3 (hypermethylated/nonfragmented), or type-4 (hypermethylated/fragmented) self-DNAs. Expression levels of TLR9-signaling and proinflammatory cytokine-related genes were assayed by qRT-PCR. Methyltransferase activity and cell differentiation were examined by using DNA methyltransferase (DNMT1, -3A, -3B) and cytokeratin (CK) antibodies. Treatment with type-1 DNA resulted in significant increase in TLR9 expression. Type-2 treatment resulted in the overexpression of TLR9-related signaling molecules (MYD88A, TRAF6) and the IL8 gene. In the case of type-3 treatment, significant overexpression of NFkB, IRAK2, and IL8 as well as downregulation of TRAF6 was detected. Using type-4 DNA, TRAF6 and MYD88A gene expression was upregulated, while MYD88B, IRAK2, IL8, and TNFSF10 were all underexpressed. CK expression was significantly higher only after type-1 DNA treatment. DNMT3A expression could also be induced by type-1 DNA treatment. DNA structure may play a significant role in activation of the TLR9-dependent and even independent proinflammatory pathways. There may be a molecular link between TLR9 signaling and DNMT3A. The mode of self-DNA treatment may influence HT29 cell differentiation.

Cancer Stem Cell Relationship with Pro-Tumoral Inflammatory Microenvironment.

Inflammatory processes and cancer stem cells (CSCs) are increasingly recognized as factors in the development of tumors. Emerging evidence indicates that CSCs are associated with cancer properties such as metastasis, treatment resistance, and disease recurrence. However, the precise interaction between CSCs and the immune microenvironment remains unexplored. Although evasion of the immune system by CSCs has been extensively studied, new research demonstrates that CSCs can also control and even profit from the immune response. This review provides an overview of the reciprocal interplay between CSCs and tumor-infiltrating immune cells, collecting pertinent data about how CSCs stimulate leukocyte reprogramming, resulting in pro-tumor immune cells that promote metastasis, chemoresistance, tumorigenicity, and even a rise in the number of CSCs. Tumor-associated macrophages, neutrophils, Th17 and regulatory T cells, mesenchymal stem cells, and cancer-associated fibroblasts, as well as the signaling pathways involved in these pro-tumor activities, are among the immune cells studied. Although cytotoxic leukocytes have the potential to eliminate CSCs, immune evasion mechanisms in CSCs and their clinical implications are also known. We intended to compile experimental findings that provide direct evidence of interactions between CSCs and the immune system and CSCs and the inflammatory milieu. In addition, we aimed to summarize key concepts in order to comprehend the cross-talk between CSCs and the tumor microenvironment as a crucial process for the effective design of anti-CSC therapies.

Good's syndrome: brief overview of an enigmatic immune deficiency.

Good's syndrome, an infrequent adult-onset immunodeficiency is characterized by the triad of thymoma, hypogammaglobulinemia, and increased susceptibility to recurrent infections. The clinical presentation is highly variable, with a spectrum ranging from recurrent bacterial and opportunistic infections to concomitant autoimmune diseases and, sometimes malignant pathologies. Due to heterogeneous clinical phenotypes and the lack of adequate diagnostic criteria, its recognition is often challenging, even delaying it by years. It is one of the most unusual, less studied form of the immune deficiency syndromes with a still unknown pathophysiology. It was initially considered a thymoma-associated variant of primary antibody deficiencies with a reduced or absent number of mature B cells, but it later emerged that significant defects of T cell-mediated immune functions are the underlying cause of opportunistic infections. On the basis of current evidence, Good's syndrome is evaluated as a distinct acquired form of combined immunodeficiency states and classified as a phenocopy of primary immunodeficiency diseases. Epigenetic and acquired genetic factors can play an ultimate role in its evolution.

CAR-Based Therapy for Autoimmune Diseases: A Novel Powerful Option.

The pervasive application of chimeric antigen receptor (CAR)-based cellular therapies in the treatment of oncological diseases has long been recognized. However, CAR T cells can target and eliminate autoreactive cells in autoimmune and immune-mediated diseases. By doing so, they can contribute to an effective and relatively long-lasting remission. In turn, CAR Treg interventions may have a highly effective and durable immunomodulatory effect via a direct or bystander effect, which may have a positive impact on the course and prognosis of autoimmune diseases. CAR-based cellular techniques have a complex theoretical foundation and are difficult to implement in practice, but they have a remarkable capacity to suppress the destructive functions of the immune system. This article provides an overview of the numerous CAR-based therapeutic options developed for the treatment of immune-mediated and autoimmune diseases. We believe that well-designed, rigorously tested cellular therapies could provide a promising new personalized treatment strategy for a significant number of patients with immune-mediated disorders.

Autoimmunity and Carcinogenesis: Their Relationship under the Umbrella of Autophagy.

The immune system and autophagy share a functional relationship. Both innate and adaptive immune responses involve autophagy and, depending on the disease's origin and pathophysiology, it may have a detrimental or positive role on autoimmune disorders. As a "double-edged sword" in tumors, autophagy can either facilitate or impede tumor growth. The autophagy regulatory network that influences tumor progression and treatment resistance is dependent on cell and tissue types and tumor stages. The connection between autoimmunity and carcinogenesis has not been sufficiently explored in past studies. As a crucial mechanism between the two phenomena, autophagy may play a substantial role, though the specifics remain unclear. Several autophagy modifiers have demonstrated beneficial effects in models of autoimmune disease, emphasizing their therapeutic potential as treatments for autoimmune disorders. The function of autophagy in the tumor microenvironment and immune cells is the subject of intensive study. The objective of this review is to investigate the role of autophagy in the simultaneous genesis of autoimmunity and malignancy, shedding light on both sides of the issue. We believe our work will assist in the organization of current understanding in the field and promote additional research on this urgent and crucial topic.

[Good syndrome: a rare, unusual immunodeficiency condition]. / Good-szindróma: egy ritka, szokatlan immunhiányos állapot.

Good syndrome is an infrequent and unique clinical entity of associated thymoma and immunodeficiency, first described almost 70 years ago. It is characterized by increased susceptibility to recurrent invasive bacterial and opportunistic infections as well as autoimmune and malignant diseases with an omnious prognosis. The affected patients are mainly middle-aged persons. The most consistent immunological abnormalities are hypogammaglobulinemia and reduced/absent B cells. More recently it was classified as an acquired combined (T, B) immunodeficiency and labelled as a phenocopy. This complex immunocompromised condition can lead to heterogenous clinical phenotypes, making the diagnosis rather challenging. The thymoma is mainly benign, and an incidental finding. Since the thymus plays a critical role in the development of the immune system, the altered tissue structure and microenvironment in thymoma can both predispose to manifestation of immunodeficiency and autoimmunity. The etiopathogenesis of the disease is still unclear, but it is assumed that epigenetic and acquired genetic factors can be highly responsible for its evolvement. Currently there is no specific therapy for Good syndrome. In addition to thymectomy, control of infections, possibly secondary prevention, and regular immunoglobulin replacement are recommended. Orv Hetil. 2023; 164(22): 859-863.

[Characteristics of intestinal tuft cells and their role in the pathomechanism of inflammatory bowel disease and colorectal carcinoma]. / Az intestinalis bojtos sejtek sajátosságai és szerepük a gyulladásos bélbetegség és a colorectalis carcinoma patomechanizmusában.

Given their fundamental physiological importance, their involvement in the immune system, and their close association with the development of intestinal diseases, the interest in intestinal epithelial cells has increased significantly over the past fifteen years. Their close association with intestinal worm and protozoan infections - a significant 2016 discovery - has further stimulated research into uncommon chemosensitive tuft epithelial cells. Although their numbers are relatively low, tuft cells are now recognized as an essential sentinel of the gastrointestinal tract, as their taste receptors for succinate, sweet, and bitter continuously monitor intestinal contents. When stimulated, tuft cells release a number of effector molecules, including immunomodulatory molecules like interleukin 25, prostaglandins E2 and D2, cysteinyl leukotriene C4, acetylcholine, thymic stromal lymphopoietin, and beta-endorphins. Tuft cells have been shown to be crucial for immunity against nematodes and protozoa. The majority of tuft cell research has used the doublecortin-like (microtubule-linked) kinase 1 protein marker on mice; however, the expression of the enzyme cyclooxygenase-1 may help identify human intestinal tuft cells. Few studies have examined the association between tuft cells and intestinal diseases in humans. This article provides an update on intestinal epithelial tuft cells, including their physiology, immunological nodal function, and role in human diseases. We conclude by discussing the potential clinical therapeutic value of tuft cells. Orv Hetil. 2023; 164(44): 1727-1735.

Disagreements in the therapeutic use of mesenchymal stem cell-derived secretome.

In a recent article, the authors provide a detailed summary of the characteristics and biological functions of mesenchymal stem cells (MSCs), as well as a discussion on the potential mechanisms of action of MSC-based therapies. They describe the morphology, biogenesis, and current isolation techniques of exosomes, one of the most important fractions of the MSC-derived secretome. They also summarize the characteristics of MSC-derived exosomes and highlight their functions and therapeutic potential for tissue/organ regeneration and for kidney, liver, cardiovascular, neurological, and musculoskeletal diseases, as well as cutaneous wound healing. Despite the fact that MSCs are regarded as an important pillar of regenerative medicine, their regenerative potential has been demonstrated to be limited in a number of pathological conditions. The negative effects of MSC-based cell therapy have heightened interest in the therapeutic use of MSC-derived secretome. On the other hand, MSC-derived exosomes and microvesicles possess the potential to have a significant impact on disease development, including cancer. MSCs can interact with tumor cells and promote mutual exchange and induction of cellular markers by exchanging secretome. Furthermore, enzymes secreted into and activated within exosomes can result in tumor cells acquiring new properties. As a result, therapeutic applications of MSC-derived secretomes must be approached with extreme caution.

Mesenchymal Stem Cell-Derived Secretome: A Potential Therapeutic Option for Autoimmune and Immune-Mediated Inflammatory Diseases.

Immune-mediated inflammatory diseases (IMIDs) encompass several entities such as "classic" autoimmune disorders or immune-mediated diseases with autoinflammatory characteristics. Adult stem cells including mesenchymal stem cells (MSCs) are by far the most commonly used type in clinical practice. However, due to the possible side effects of MSC-based treatments, there is an increase in interest in the MSC-secretome (containing large extracellular vesicles, microvesicles, and exosomes) as an alternative therapeutic option in IMIDs. A wide spectrum of MSC-secretome-related biological activities has been proven thus far including anti-inflammatory, anti-apoptotic, and immunomodulatory properties. In comparison with MSCs, the secretome is less immunogenic but exerts similar biological actions, so it can be considered as an ideal cell-free therapeutic alternative. Additionally, since the composition of the MSC-secretome can be engineered, for a future perspective, it could also be viewed as part of a potential delivery system within nanomedicine, allowing us to specifically target dysfunctional cells or tissues. Although many encouraging results from pre-clinical studies have recently been obtained that strongly support the application of the MSC-secretome in IMIDs, human studies with MSC-secretome administration are still in their infancy. This article reviews the immunomodulatory effects of the MSC-secretome in IMIDs and provides insight into the interpretation of its beneficial biological actions.

Colitis and Colorectal Carcinogenesis: The Focus on Isolated Lymphoid Follicles.

Gut-associated lymphoid tissue is one of the most diverse and complex immune compartments in the human body. The subepithelial compartment of the gut consists of immune cells of innate and adaptive immunity, non-hematopoietic mesenchymal cells, and stem cells of different origins, and is organized into secondary (and even tertiary) lymphoid organs, such as Peyer's patches, cryptopatches, and isolated lymphoid follicles. The function of isolated lymphoid follicles is multifaceted; they play a role in the development and regeneration of the large intestine and the maintenance of (immune) homeostasis. Isolated lymphoid follicles are also extensively associated with the epithelium and its conventional and non-conventional immune cells; hence, they can also function as a starting point or maintainer of pathological processes such as inflammatory bowel diseases or colorectal carcinogenesis. These relationships can significantly affect both physiological and pathological processes of the intestines. We aim to provide an overview of the latest knowledge of isolated lymphoid follicles in colonic inflammation and colorectal carcinogenesis. Further studies of these lymphoid organs will likely lead to an extended understanding of how immune responses are initiated and controlled within the large intestine, along with the possibility of creating novel mucosal vaccinations and ways to treat inflammatory bowel disease or colorectal cancer.

Cell-Free DNA in the Pathogenesis and Therapy of Non-Infectious Inflammations and Tumors.

The basic function of the immune system is the protection of the host against infections, along with the preservation of the individual antigenic identity. The process of self-tolerance covers the discrimination between self and foreign antigens, including proteins, nucleic acids, and larger molecules. Consequently, a broken immunological self-tolerance results in the development of autoimmune or autoinflammatory disorders. Immunocompetent cells express pattern-recognition receptors on their cell membrane and cytoplasm. The majority of endogenous DNA is located intracellularly within nuclei and mitochondria. However, extracellular, cell-free DNA (cfDNA) can also be detected in a variety of diseases, such as autoimmune disorders and malignancies, which has sparked interest in using cfDNA as a possible biomarker. In recent years, the widespread use of liquid biopsies and the increasing demand for screening, as well as monitoring disease activity and therapy response, have enabled the revival of cfDNA research. The majority of studies have mainly focused on the function of cfDNA as a biomarker. However, research regarding the immunological consequences of cfDNA, such as its potential immunomodulatory or therapeutic benefits, is still in its infancy. This article discusses the involvement of various DNA-sensing receptors (e.g., absent in melanoma-2; Toll-like receptor 9; cyclic GMP-AMP synthase/activator of interferon genes) in identifying host cfDNA as a potent danger-associated molecular pattern. Furthermore, we aim to summarize the results of the experimental studies that we recently performed and highlight the immunomodulatory capacity of cfDNA, and thus, the potential for possible therapeutic consideration.

Survival of HT29 cancer cells is influenced by hepatocyte growth factor receptor inhibition through modulation of self-DNA-triggered TLR9-dependent autophagy response.

HGFR activation drives the malignant progression of colorectal cancer, and its inhibition displays anti-autophagic activity. The interrelated role of HGFR inhibition and TLR9/autophagy signaling in HT29 cancer cells subjected to modified self-DNA treatments has not been clarified. We analyzed this complex interplay with cell metabolism and proliferation measurements, TLR9, HGFR and autophagy inhibitory assays and WES Simple Western blot-based autophagy flux measurements, gene expression analyses, immunocytochemistry, and transmission electron microscopy. The overexpression of MyD88 and caspase-3 was associated with enhanced HT29 cell proliferation, suggesting that incubation with self-DNAs could suppress the apoptosis-induced compensatory cell proliferation. HGFR inhibition blocked the proliferation-reducing effect of genomic and hypermethylated, but not that of fragmented DNA. Lowest cell proliferation was achieved with the concomitant use of genomic DNA, HGFR inhibitor, and chloroquine, when the proliferation stimulating effect of STAT3 overexpression could be outweighed by the inhibitory effect of LC3B, indicating the putative involvement of HGFR-mTOR-ULK1 molecular cascade in HGFR inhibitor-mediated autophagy. The most intense cell proliferation was caused by the co-administration of hypermethylated DNA, TLR9 and HGFR inhibitors, when decreased expression of both canonical and non-canonical HGFR signaling pathways and autophagy-related genes was present. The observed ultrastructural changes also support the context-dependent role of HGFR inhibition and autophagy on cell survival and proliferation. Further investigation of the influence of the studied signaling pathways and cellular processes can provide a basis for novel, individualized anti-cancer therapies.