scholarly journals Modulation of Anti-Tumour Immune Responses by Probiotic Bacteria

Vaccines ◽  
2020 ◽  
Vol 8 (2) ◽  
pp. 329 ◽  
Author(s):  
Georgios Aindelis ◽  
Katerina Chlichlia
Keyword(s):  
Immune Responses ◽  
Intestinal Microbiota ◽  
Current Knowledge ◽  
Human Subjects ◽  
Bacterial Species ◽  
Probiotic Bacteria ◽  
Response To Treatment ◽  
Malignant Tumours ◽  
Cancer Immunotherapies

There is a growing amount of evidence to support the beneficial role of a balanced intestinal microbiota, or distinct members thereof, in the manifestation and progression of malignant tumours, not only in the gastrointestinal tract but also in distant tissues as well. Intriguingly, bacterial species have been demonstrated to be indispensable modulatory agents of widely-used immunotherapeutic or chemotherapeutic regiments. However, the exact contribution of commensal bacteria to immunity, as well as to neoplasia formation and response to treatment, has not been fully elucidated, and most of the current knowledge acquired from animal models has yet to be translated to human subjects. Here, recent advances in understanding the interaction of gut microbes with the immune system and the modulation of protective immune responses to cancer, either naturally or in the context of widely-used treatments, are reviewed, along with the implications of these observations for future therapeutic approaches. In this regard, bacterial species capable of facilitating optimal immune responses against cancer have been surveyed. According to the findings summarized here, we suggest that strategies incorporating probiotic bacteria and/or modulation of the intestinal microbiota can be used as immune adjuvants, aiming to optimize the efficacy of cancer immunotherapies and conventional anti-tumour treatments.

scholarly journals Discovery of novel community-relevant small proteins in a simplified human intestinal microbiome

Microbiome ◽  
2021 ◽  
Vol 9 (1) ◽  
Author(s):  
Hannes Petruschke ◽  
Christian Schori ◽  
Sebastian Canzler ◽  
Sarah Riesbeck ◽  
Anja Poehlein ◽  
...  
Keyword(s):  
Microbial Communities ◽  
Intestinal Microbiota ◽  
De Novo ◽  
Bacterial Species ◽  
Intestinal Microbiome ◽  
Single Strain ◽  
Small Proteins ◽  
Human Intestinal Microbiota ◽  
Wide Range

Abstract Background The intestinal microbiota plays a crucial role in protecting the host from pathogenic microbes, modulating immunity and regulating metabolic processes. We studied the simplified human intestinal microbiota (SIHUMIx) consisting of eight bacterial species with a particular focus on the discovery of novel small proteins with less than 100 amino acids (= sProteins), some of which may contribute to shape the simplified human intestinal microbiota. Although sProteins carry out a wide range of important functions, they are still often missed in genome annotations, and little is known about their structure and function in individual microbes and especially in microbial communities. Results We created a multi-species integrated proteogenomics search database (iPtgxDB) to enable a comprehensive identification of novel sProteins. Six of the eight SIHUMIx species, for which no complete genomes were available, were sequenced and de novo assembled. Several proteomics approaches including two earlier optimized sProtein enrichment strategies were applied to specifically increase the chances for novel sProtein discovery. The search of tandem mass spectrometry (MS/MS) data against the multi-species iPtgxDB enabled the identification of 31 novel sProteins, of which the expression of 30 was supported by metatranscriptomics data. Using synthetic peptides, we were able to validate the expression of 25 novel sProteins. The comparison of sProtein expression in each single strain versus a multi-species community cultivation showed that six of these sProteins were only identified in the SIHUMIx community indicating a potentially important role of sProteins in the organization of microbial communities. Two of these novel sProteins have a potential antimicrobial function. Metabolic modelling revealed that a third sProtein is located in a genomic region encoding several enzymes relevant for the community metabolism within SIHUMIx. Conclusions We outline an integrated experimental and bioinformatics workflow for the discovery of novel sProteins in a simplified intestinal model system that can be generically applied to other microbial communities. The further analysis of novel sProteins uniquely expressed in the SIHUMIx multi-species community is expected to enable new insights into the role of sProteins on the functionality of bacterial communities such as those of the human intestinal tract.

scholarly journals Intestinal Microbiota as an Alternative Therapeutic Target for Epilepsy

2016 ◽  
Vol 2016 ◽  
pp. 1-6 ◽  
Author(s):  
Jiaying Wu ◽  
Yuyu Zhang ◽  
Hongyu Yang ◽  
Yuefeng Rao ◽  
Jing Miao ◽  
...  
Keyword(s):  
Immune Responses ◽  
Intestinal Microbiota ◽  
Neurological Disorders ◽  
Digestive System ◽  
Hygiene Hypothesis ◽  
Host Susceptibility ◽  
Immune Disorders ◽  
The Central Nervous System ◽  
Symbiotic Microbiota

Epilepsy is one of the most widespread serious neurological disorders, and an aetiological explanation has not been fully identified. In recent decades, a growing body of evidence has highlighted the influential role of autoimmune mechanisms in the progression of epilepsy. The hygiene hypothesis draws people’s attention to the association between gut microbes and the onset of multiple immune disorders. It is also believed that, in addition to influencing digestive system function, symbiotic microbiota can bidirectionally and reversibly impact the programming of extraintestinal pathogenic immune responses during autoimmunity. Herein, we investigate the concept that the diversity of parasitifer sensitivity to commensal microbes and the specific constitution of the intestinal microbiota might impact host susceptibility to epilepsy through promotion of Th17 cell populations in the central nervous system (CNS).

scholarly journals Gut microbiome dysbiosis in anorexia nervosa

2021 ◽  
Vol 75 ◽  
pp. 283-291
Author(s):  
Agata Janczy ◽  
Magdalena Landowska ◽  
Zdzisław Kochan
Keyword(s):  
Anorexia Nervosa ◽  
Gut Microbiota ◽  
Body Mass ◽  
Intestinal Microbiota ◽  
Gut Microbiome ◽  
Dietary Habits ◽  
Eating Habits ◽  
Current Knowledge ◽  
Functional Gastrointestinal Disorders

Anorexia nervosa (AN) is described as an eating disorder, which is characterized by malnutrition, a fear of gaining body mass, and a disturbed self-body image. This disease is dependent on biological, psychological and socio-cultural factors. Among the various biological factors, the importance of intestinal microbiota has recently attracted much attention. Identification of the gut microbiota dysbiosis in patients with AN has opened new and promising research directions. Recent observations focus in particular on the association between intestinal microorganisms and the occurrence of functional gastrointestinal disorders associated with anorexia, anxiety and depression, as well as the regulation of eating habits. The composition of the gut microbiota differs between patients with AN and individuals with normal body mass. This is due to the incorrect diet of patients; on the other hand, there is growing interest in the role of intestinal microbiota in the pathogenesis of AN, its changes through re-nutrition practices, and in particular the modulation of intestinal microbiological composition by means of nutritional interventions or the use of preand probiotics as standard supplements therapy of eating disorders. There is a need for further research about the microbiome - intestine - brain axis. Furthermore, consequences of changes in dietary habits as part of AN treatment are also unknown. However, better knowledge about the relationship between the gut microbiome and the brain can help improve the treatment of this disorder. This review aims to present the current knowledge about the potential role of intestinal microbiota in the pathogenesis, course and treatment of AN.

scholarly journals The complex functions of microRNA-150 in allergy, autoimmunity and immune tolerance

2021 ◽  
Vol 5 (4) ◽  
pp. 195-221
Author(s):  
Katarzyna Nazimek ◽  
Keyword(s):  
Immune Responses ◽  
Immune Tolerance ◽  
Therapeutic Potential ◽  
Current Knowledge ◽  
Signaling Cascades ◽  
Cell Functions ◽  
Regulatory Circuits ◽  
Complex Functions ◽  
Genetic Level

<abstract> <p>At present, special efforts are being made to develop the strategies allowing for activation of long-lasting antigen-specific immune tolerance in therapy of allergic and autoimmune diseases. Some of these therapeutic approaches are aimed at modulating cell functions at genetic level by using miRNA-based and miRNA-targeting treatments. Simultaneously, the crucial role of extracellular vesicles as natural miRNA conveyors is highlighted for induction of antigen-specific immune tolerance, especially that they appear to be easily manipulatable for therapeutic applications. Among other immune-related miRNAs, miR-150 is getting special attention as it is differently expressed by immune cells at various stages of their maturation and differentiation. In addition, miR-150 is involved in different signaling cascades orchestrating humoral and cell-mediated mechanisms of both innate and adaptive immune responses. Therefore, miR-150 is considered a master regulator of immunity in mammals. Currently, physiological miR-150-dependent regulatory circuits and causes of their malfunctioning that underlie the pathogenesis of allergic and autoimmune disorders are being unraveled. Thus, present review summarizes the current knowledge of the role of miR-150 in the pathogenesis and complications of these diseases. Furthermore, the involvement of miR-150 in regulation of immune responses to allergens and self-antigens and in induction of antigen-specific immune tolerance is discussed with the special emphasis on the therapeutic potential of this miRNA.</p> </abstract>

scholarly journals Regulatory Immune Cells in Idiopathic Pulmonary Fibrosis: Friends or Foes?

2021 ◽  
Vol 12 ◽  
Author(s):  
Chiel van Geffen ◽  
Astrid Deißler ◽  
Markus Quante ◽  
Harald Renz ◽  
Dominik Hartl ◽  
...  
Keyword(s):  
Immune System ◽  
Idiopathic Pulmonary Fibrosis ◽  
Pulmonary Fibrosis ◽  
Immune Responses ◽  
Immune Cells ◽  
Current Knowledge ◽  
Suppressor Cells ◽  
Interstitial Lung Diseases ◽  
Stromal Stem Cells

The immune system is receiving increasing attention for interstitial lung diseases, as knowledge on its role in fibrosis development and response to therapies is expanding. Uncontrolled immune responses and unbalanced injury-inflammation-repair processes drive the initiation and progression of idiopathic pulmonary fibrosis. The regulatory immune system plays important roles in controlling pathogenic immune responses, regulating inflammation and modulating the transition of inflammation to fibrosis. This review aims to summarize and critically discuss the current knowledge on the potential role of regulatory immune cells, including mesenchymal stromal/stem cells, regulatory T cells, regulatory B cells, macrophages, dendritic cells and myeloid-derived suppressor cells in idiopathic pulmonary fibrosis. Furthermore, we review the emerging role of regulatory immune cells in anti-fibrotic therapy and lung transplantation. A comprehensive understanding of immune regulation could pave the way towards new therapeutic or preventive approaches in idiopathic pulmonary fibrosis.

scholarly journals The Role of Intestinal Microbiota in Acute Graft-versus-Host Disease

2015 ◽  
Vol 2015 ◽  
pp. 1-9 ◽  
Author(s):  
Yuanyuan Chen ◽  
Ye Zhao ◽  
Qiao Cheng ◽  
Depei Wu ◽  
Haiyan Liu
Keyword(s):  
Immune Responses ◽  
Intestinal Microbiota ◽  
Graft Versus Host Disease ◽  
Inflammatory Diseases ◽  
Hematopoietic Stem ◽  
Host Disease ◽  
Graft Versus Host ◽  
Host Immune Responses ◽  
Acute Graft

The mammalian intestinal microbiota is a complex ecosystem that plays an important role in host immune responses. Recent studies have demonstrated that alterations in intestinal microbiota composition are linked to multiple inflammatory diseases in humans, including acute graft-versus-host disease (aGVHD). aGVHD is one of the major obstacles in allogeneic hematopoietic stem cell transplantation (allo-HSCT), characterized by tissue damage in the gastrointestinal (GI) tract, liver, lung, and skin. Here, we review the current understanding of the role of intestinal microbiota in the control of immune responses during aGVHD. Additionally, the possibility of using probiotic strains for potential treatment or prevention of aGVHD will be discussed.

scholarly journals Phagocytosis: A Fundamental Process in Immunity

2017 ◽  
Vol 2017 ◽  
pp. 1-18 ◽  
Author(s):  
Carlos Rosales ◽  
Eileen Uribe-Querol
Keyword(s):  
Immune Responses ◽  
Host Response ◽  
Current Knowledge ◽  
General View ◽  
Cellular Mechanisms ◽  
Complex Process ◽  
Fundamental Process ◽  
Target Particle ◽  
Acquired Immune Responses

One hundred years have passed since the death of Élie Metchnikoff (1845–1916). He was the first to observe the uptake of particles by cells and realized the importance of this process for the host response to injury and infection. He also was a strong advocate of the role of phagocytosis in cellular immunity, and with this he gave us the basis for our modern understanding of inflammation and the innate and acquired immune responses. Phagocytosis is an elegant but complex process for the ingestion and elimination of pathogens, but it is also important for the elimination of apoptotic cells and hence fundamental for tissue homeostasis. Phagocytosis can be divided into four main steps: (i) recognition of the target particle, (ii) signaling to activate the internalization machinery, (iii) phagosome formation, and (iv) phagolysosome maturation. In recent years, the use of new tools of molecular biology and microscopy has provided new insights into the cellular mechanisms of phagocytosis. In this review, we present a general view of our current knowledge on phagocytosis. We emphasize novel molecular findings, particularly on phagosome formation and maturation, and discuss aspects that remain incompletely understood.

scholarly journals The Role of Autophagy in Tumor Immunology—Complex Mechanisms That May Be Explored Therapeutically

2020 ◽  
Vol 10 ◽  
Author(s):  
Alana Serrano Campelo de Souza ◽  
Letícia Boslooper Gonçalves ◽  
Ana Paula Lepique ◽  
Patrícia Savio de Araujo-Souza
Keyword(s):  
Immune Responses ◽  
Tumor Cells ◽  
Immune Escape ◽  
Nk Cell ◽  
Nutrient Deficiency ◽  
Potential Interaction ◽  
Migration And Invasion ◽  
Inhibitory Molecules ◽  
Cancer Immunotherapies

The tumor microenvironment (TME) is complex, and its composition and dynamics determine tumor fate. From tumor cells themselves, with their capacity for unlimited replication, migration, and invasion, to fibroblasts, endothelial cells, and immune cells, which can have pro and/or anti-tumor potential, interaction among these elements determines tumor progression. The understanding of molecular pathways involved in immune escape has permitted the development of cancer immunotherapies. Targeting molecules or biological processes that inhibit antitumor immune responses has allowed a significant improvement in cancer patient’s prognosis. Autophagy is a cellular process required to eliminate dysfunctional proteins and organelles, maintaining cellular homeostasis. Usually a process associated with protection against cancer, autophagy associated to cancer cells has been reported in response to hypoxia, nutrient deficiency, and oxidative stress, conditions frequently observed in the TME. Recent studies have shown a paradoxical association between autophagy and tumor immune responses. Tumor cell autophagy increases the expression of inhibitory molecules, such as PD-1 and CTLA-4, which block antitumor cytotoxic responses. Moreover, it can also directly affect antitumor immune responses by, for example, degrading NK cell-derived granzyme B and protecting tumor cells. Interestingly, the activation of autophagy on dendritic cells has the opposite effects, enhancing antigen presentation, triggering CD8+ T cells cytotoxic activity, and reducing tumor growth. Therefore, this review will focus on the most recent aspects of autophagy and tumor immune environment. We describe the dual role of autophagy in modulating tumor immune responses and discuss some aspects that must be considered to improve cancer treatment.

Dietary and Physiological Effects of Zinc on the Immune System

2021 ◽  
Vol 41 (1) ◽  
Author(s):  
Inga Wessels ◽  
Henrike Josephine Fischer ◽  
Lothar Rink
Keyword(s):  
Immune Responses ◽  
Immune Cells ◽  
Immune Cell ◽  
Current Knowledge ◽  
Annual Review ◽  
Publication Date ◽  
Biological Processes ◽  
And Function ◽  
Broad Overview

Evidence for the importance of zinc for all immune cells and for mounting an efficient and balanced immune response to various environmental stressors has been accumulating in recent years. This article describes the role of zinc in fundamental biological processes and summarizes our current knowledge of zinc's effect on hematopoiesis, including differentiation into immune cell subtypes. In addition, the important role of zinc during activation and function of immune cells is detailed and associated with the specific immune responses to bacteria, parasites, and viruses. The association of zinc with autoimmune reactions and cancers as diseases with increased or decreased immune responses is also discussed. This article provides a broad overview of the manifold roles that zinc, or its deficiency, plays in physiology and during various diseases. Consequently, we discuss why zinc supplementation should be considered, especially for people at risk of deficiency. Expected final online publication date for the Annual Review of Nutrition, Volume 41 is September 2021. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.

Parasite glycans and antibody-mediated immune responses inSchistosomainfection

Parasitology ◽  
2012 ◽  
Vol 139 (9) ◽  
pp. 1219-1230 ◽  
Author(s):  
ANGELA VAN DIEPEN ◽  
NIELS S. J. VAN DER VELDEN ◽  
CORNELIS H. SMIT ◽  
MONIEK H. J. MEEVISSEN ◽  
CORNELIS H. HOKKE
Keyword(s):  
Immune Responses ◽  
Current Knowledge ◽  
Expression Profiles ◽  
Antibody Responses ◽  
Infection Rates ◽  
Immune Intervention ◽  
Protective Mechanisms ◽  
Future Directions ◽  
Slow Development

SUMMARYSchistosome infections in humans are characterized by the development of chronic disease and high re-infection rates after treatment due to the slow development of immunity. It appears that anti-schistosome antibodies are at least partially mediating protective mechanisms. Efforts to develop a vaccine based on immunization with surface-exposed or secreted larval or worm proteins are ongoing. Schistosomes also express a large number of glycans as part of their glycoprotein and glycolipid repertoire, and antibody responses to those glycans are mounted by the infected host. This observation raises the question if glycans might also form novel vaccine targets for immune intervention in schistosomiasis. This review summarizes current knowledge of antibody responses and immunity in experimental and natural infections withSchistosoma, the expression profiles of schistosome glycans (the glycome), and antibody responses to individual antigenic glycan motifs. Future directions to study anti-glycan responses in schistosomiasis in more detail in order to address more precisely the possible role of glycans in antibody-mediated immunity are discussed.

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