scholarly journals The Kynurenine Pathway—New Linkage between Innate and Adaptive Immunity in Autoimmune Endocrinopathies

2021 ◽  
Vol 22 (18) ◽  
pp. 9879
Author(s):  
Anna Krupa ◽  
Irina Kowalska

The kynurenine pathway (KP) is highly regulated in the immune system, where it promotes immunosuppression in response to infection or inflammation. Indoleamine 2,3-dioxygenase 1 (IDO1), the main enzyme of KP, has a broad spectrum of activity on immune cells regulation, controlling the balance between stimulation and suppression of the immune system at sites of local inflammation, relevant to a wide range of autoimmune and inflammatory diseases. Various autoimmune diseases, among them endocrinopathies, have been identified to date, but despite significant progress in their diagnosis and treatment, they are still associated with significant complications, morbidity, and mortality. The precise cellular and molecular mechanisms leading to the onset and development of autoimmune disease remain poorly clarified so far. In breaking of tolerance, the cells of the innate immunity provide a decisive microenvironment that regulates immune cells’ differentiation, leading to activation of adaptive immunity. The current review provided a comprehensive presentation of the known role of IDO1 and KP activation in the regulation of the innate and adaptive arms of the immune system. Significant attention has been paid to the immunoregulatory role of IDO1 in the most prevalent, organ-specific autoimmune endocrinopathies—type 1 diabetes mellitus (T1DM) and autoimmune thyroiditis.

2020 ◽  
Vol 22 (3) ◽  
pp. 449-458
Author(s):  
E. D. Merkushova ◽  
E. M. Khasanova ◽  
L. V. Gankovskaya

Psoriasis is a chronic auto-inflammatory, genetically determined dermatosis, being multifactorial by origin, characterized by hyperproliferation of epidermis, affected keratinocyte differentiation and inflammatory reaction in dermis. The disease is characterized by a tendency to spread over the area of lesion, and involvement of articular tissue in the pathological process, which significantly affects the living standards of patients and causes their disability. There are many provoking factors that contribute to occurrence of psoriasis, or progression of existing psoriatic process in individuals with a genetic predisposition. These factors include adverse climatic conditions, skin trauma, exposure to ultraviolet light, burns, infections, etc.This review describes the role of innate immunity in pathogenesis of psoriasis, and describes in detail the mechanisms involved into induction of inflammation of PAMPs and DAMPs. In psoriasis, positively charged catelicidin is considered one of the most important DAMPs, which can form a complex with negatively charged cell polyanions-LL-37/auto-RNA and LL-37/auto-DNA. The interaction of PAMP/DAMP ligands with specific PRR receptors leads to signal activation of effector components of immune system, i.e., assembly of inflammasome complex, caspase activation, synthesis of inflammatory cytokines and processing of their immature forms. The review focuses on the role of TLRs under the conditions of physiological norm, which recognize danger signals and provide protection from pathogens and their timely elimination, and in development of pathological process. Activation of TLRs induces the production of pro-inflammatory cytokines, interferons and antimicrobial peptides, chemokines that support the development of psoriatic inflammation.In addition to TLRs, the mechanisms of involvement of inflammasomes in the development of psoriasis, which provides processing of mature forms of IL-1β and IL-18, are described in detail. Mature forms of these cytokines mediate the development of inflammation in psoriatic focus. In addition, processing of these cytokines by caspases using the positive feedback mechanism provides an additional signal to activate transcriptional activity of their genes and contributes to perpetuated inflammation.The review presents data confirming participation of inflammasomes in the pathogenesis of psoriasis. Much attention is paid to description of pharmacological inhibitors of inflammasomes, which in the future may be the drugs of choice for treatment of inflammatory diseases. The study of molecular mechanisms of the innate immune system will reveal new approaches to prognosis and development of targeted therapy for psoriasis.


2021 ◽  
Vol 61 (1) ◽  
pp. 541-563 ◽  
Author(s):  
Martine J. Smit ◽  
Géraldine Schlecht-Louf ◽  
Maria Neves ◽  
Jelle van den Bor ◽  
Petronila Penela ◽  
...  

Elevated expression of the chemokine receptors CXCR4 and ACKR3 and of their cognate ligand CXCL12 is detected in a wide range of tumors and the tumor microenvironment (TME). Yet, the molecular mechanisms by which the CXCL12/CXCR4/ACKR3 axis contributes to the pathogenesis are complex and not fully understood. To dissect the role of this axis in cancer, we discuss its ability to impinge on canonical and less conventional signaling networks in different cancer cell types; its bidirectional crosstalk, notably with receptor tyrosine kinase (RTK) and other factors present in the TME; and the infiltration of immune cells that supporttumor progression. We discuss current and emerging avenues that target the CXCL12/CXCR4/ACKR3 axis. Coordinately targeting both RTKs and CXCR4/ACKR3 and/or CXCL12 is an attractive approach to consider in multitargeted cancer therapies. In addition, inhibiting infiltrating immune cells or reactivating the immune system along with modulating the CXCL12/CXCR4/ACKR3 axis in the TME has therapeutic promise.


2021 ◽  
Vol 22 (23) ◽  
pp. 12739
Author(s):  
Sofía Frigerio ◽  
Dalia A. Lartey ◽  
Geert R. D’Haens ◽  
Joep Grootjans

Patients with inflammatory bowel disease (IBD) have increased incidence of colorectal cancer (CRC). IBD-associated cancer follows a well-characterized sequence of intestinal epithelial changes, in which genetic mutations and molecular aberrations play a key role. IBD-associated cancer develops against a background of chronic inflammation and pro-inflammatory immune cells, and their products contribute to cancer development and progression. In recent years, the effect of the immunosuppressive microenvironment in cancer development and progression has gained more attention, mainly because of the unprecedented anti-tumor effects of immune checkpoint inhibitors in selected groups of patients. Even though IBD-associated cancer develops in the background of chronic inflammation which is associated with activation of endogenous anti-inflammatory or suppressive mechanisms, the potential role of an immunosuppressive microenvironment in these cancers is largely unknown. In this review, we outline the role of the immune system in promoting cancer development in chronic inflammatory diseases such as IBD, with a specific focus on the anti-inflammatory mechanisms and suppressive immune cells that may play a role in IBD-associated tumorigenesis.


2015 ◽  
Vol 212 (6) ◽  
pp. 845-853 ◽  
Author(s):  
Katrina Blazek ◽  
Hayley L. Eames ◽  
Miriam Weiss ◽  
Adam J. Byrne ◽  
Dany Perocheau ◽  
...  

The most studied biological role of type III interferons (IFNs) has so far been their antiviral activity, but their role in autoimmune and inflammatory diseases remains largely unexplored. Here, we show that treatment with IFN-λ2/IL-28A completely halts and reverses the development of collagen-induced arthritis (CIA) and discover cellular and molecular mechanisms of IL-28A antiinflammatory function. We demonstrate that treatment with IL-28A dramatically reduces numbers of proinflammatory IL-17–producing Th17 and γδ T cells in the joints and inguinal lymph nodes, without affecting T cell proliferative responses or levels of anticollagen antibodies. IL-28A exerts its antiinflammatory effect by restricting recruitment of IL-1b–expressing neutrophils, which are important for amplification of inflammation. We identify neutrophils as cells expressing high levels of IFN-λ receptor 1 (IFNLR1)–IL-28 receptor α (IL28RA) and targeted by IL-28A. Our data highlight neutrophils as contributors to the pathogenesis of autoimmune arthritis and present IFN-λs or agonists of IFNLR1–IL28RA as putative new therapeutics for neutrophil-driven inflammation.


Author(s):  
Hui Sun ◽  
Gang Xu ◽  
Pingsong Li ◽  
Yumei Li ◽  
Bingwei Sun

Purinergic signaling is that nucleotides (especially ATP) and adenosine are utilized as transmitter molecules, which play an important role in the immune system. In the extracellular ventricle, ATP plays a significant role of pro-inflammatory molecules mainly through activating P2 receptors, while adenosine plays the role of anti-inflammatory molecules mainly through activating P1 receptors. As we know,neutrophils are the most abundant immune cells in our circulation and have become an essential part of coordinating a series of complex events during inflammatory diseases. However, due to the destruction of inflammatory substances from neutrophils, the activation of neutrophils is fine-tuned, and purinergic signaling is associated with this process. As a matter of fact, altering the balance between P2 and P1 signals is of great importance for neutrophils to exert immune activities properly. Here, we review the role of purinergic signaling in regulatory function of neutrophils during inflammatory disease, and then discuss the potential contribution of targeted purinergic signals in the treatment of the neutrophil during inflammatory diseases.


2015 ◽  
Vol 2015 ◽  
pp. 1-14 ◽  
Author(s):  
N. Muñoz-Durango ◽  
A. Vecchiola ◽  
L. M. Gonzalez-Gomez ◽  
F. Simon ◽  
C. A. Riedel ◽  
...  

The mineralocorticoid receptor (MR) is a ligand dependent transcription factor. MR has been traditionally associated with the control of water and electrolyte homeostasis in order to keep blood pressure through aldosterone activation. However, there is growing evidence indicating that MR expression is not restricted to vascular and renal tissues, as it can be also expressed by cells of the immune system, where it responds to stimulation or antagonism, controlling immune cell function. On the other hand, aldosterone also has been associated with proinflammatory immune effects, such as the release of proinflammatory cytokines, generating oxidative stress and inducing fibrosis. The inflammatory participation of MR and aldosterone in the cardiovascular disease suggests an association with alterations in the immune system. Hypertensive patients show higher levels of proinflammatory mediators that can be modulated by MR antagonism. Although these proinflammatory properties have been observed in other autoimmune and chronic inflammatory diseases, the cellular and molecular mechanisms that mediate these effects remain unknown. Here we review and discuss the scientific work aimed at determining the immunological role of MR and aldosterone in humans, as well as animal models.


2019 ◽  
Vol 8 (11) ◽  
pp. 1837 ◽  
Author(s):  
Drago

: Gut microbiota regulates the host's immune system. Microorganisms and their compounds can co-exist peacefully with the immune system and coordinate its function and regulation. Some microbial clusters may be harmful and others helpful in the respective negative or positive balance of the immune network. These insights have revealed important mechanisms for understanding and treating autoimmune and inflammatory diseases. This Editorial aims to clarify the role of specific genus of gut microbiota, such as Prevotella, in influencing the pathogenesis of Rheumatoid Arthritis (RA).


2021 ◽  
Vol 7 (8) ◽  
pp. eabc2331 ◽  
Author(s):  
Jose M. Ayuso ◽  
Shujah Rehman ◽  
Maria Virumbrales-Munoz ◽  
Patrick H. McMinn ◽  
Peter Geiger ◽  
...  

Solid tumors generate a suppressive environment that imposes an overwhelming burden on the immune system. Nutrient depletion, waste product accumulation, hypoxia, and pH acidification severely compromise the capacity of effector immune cells such as T and natural killer (NK) cells to destroy cancer cells. However, the specific molecular mechanisms driving immune suppression, as well as the capacity of immune cells to adapt to the suppressive environment, are not completely understood. Thus, here, we used an in vitro microfluidic tumor-on-a-chip platform to evaluate how NK cells respond to the tumor-induced suppressive environment. The results demonstrated that the suppressive environment created by the tumor gradually eroded NK cell cytotoxic capacity, leading to compromised NK cell surveillance and tumor tolerance. Further, NK cell exhaustion persisted for an extended period of time after removing NK cells from the microfluidic platform. Last, the addition of checkpoint inhibitors and immunomodulatory agents alleviated NK cell exhaustion.


2009 ◽  
Vol 2009 ◽  
pp. 1-19 ◽  
Author(s):  
GongXin Yu

Chimpanzees and humans are closely related but differ in many deadly human diseases and other characteristics in physiology, anatomy, and pathology. In spite of decades of extensive research, crucial questions about the molecular mechanisms behind the differences are yet to be understood. Here I reportExonVar, a novel computational pipeline forExon-based human-chimpanzee comparativeVariant analysis. The objective is to comparatively analyze mutations specifically those that caused the frameshift and nonsense mutations and to assess their scale and potential impacts on human-chimpanzee divergence. Genomewide analysis of human and chimpanzee exons withExonVaridentified a number of species-specific, exon-disrupting mutations in chimpanzees but much fewer in humans. Many were found on genes involved in important biological processes such as T cell lineage development, the pathogenesis of inflammatory diseases, and antigen induced cell death. A “less-is-more” model was previously established to illustrate the role of the gene inactivation and disruptions during human evolution. Here this analysis suggested a different model where the chimpanzee-specific exon-disrupting mutations may act as additional evolutionary force that drove the human-chimpanzee divergence. Finally, the analysis revealed a number of sequencing errors in the chimpanzee and human genome sequences and further illustrated that they could be corrected without resequencing.


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