The molecular basis of immune regulation in autoimmunity

2018 ◽  
Vol 132 (1) ◽  
pp. 43-67 ◽  
Author(s):  
Shu-Han Yang ◽  
Cai-yue Gao ◽  
Liang Li ◽  
Christopher Chang ◽  
Patrick S.C. Leung ◽  
...  

Autoimmune diseases can be triggered and modulated by various molecular and cellular characteristics. The mechanisms of autoimmunity and the pathogenesis of autoimmune diseases have been investigated for several decades. It is well accepted that autoimmunity is caused by dysregulated/dysfunctional immune susceptible genes and environmental factors. There are multiple physiological mechanisms that regulate and control self-reactivity, but which can also lead to tolerance breakdown when in defect. The majority of autoreactive T or B cells are eliminated during the development of central tolerance by negative selection. Regulatory cells such as Tregs (regulatory T) and MSCs (mesenchymal stem cells), and molecules such as CTLA-4 (cytotoxic T-lymphocyte associated antigen 4) and IL (interleukin) 10 (IL-10), help to eliminate autoreactive cells that escaped to the periphery in order to prevent development of autoimmunity. Knowledge of the molecular basis of immune regulation is needed to further our understanding of the underlying mechanisms of loss of tolerance in autoimmune diseases and pave the way for the development of more effective, specific, and safer therapeutic interventions.

2017 ◽  
Vol 63 (12) ◽  
pp. 1090-1099
Author(s):  
Patrícia Lima Falcão ◽  
Tarcisio Passos Ribeiro de Campos

Summary Previous studies have demonstrated the expression of the CD25 marker on the surface of naturally occurring T cells (Tregs) of mice, which have a self-reactive cellular profile. Recently, expression of other markers that aid in the identification of these cells has been detected in lymphocyte subtypes of individuals suffering of autoimmune and idiopathic diseases, including: CD25, CTLA-4 (cytotoxic T-lymphocyte antigen 4), HLA-DR (human leukocyte antigen) and Interleukin 10 (IL-10), opening new perspectives for a better understanding of an association between such receptors present on the cell surface and the prognosis of autoimmune diseases. The role of these molecules has already been described in the literature for the modulation of the inflammatory response in infectious and parasitic diseases. Thus, the function, phenotype and frequency of expression of the a-chain receptor of IL-2 (CD25) and IL-10 in lymphocyte subtypes were investigated. Murine models have been used to demonstrate a possible correlation between the expression of the CD25 marker (on the surface of CD4 lymphocytes) and the control of self-tolerance mechanisms. These studies provided support for the presentation of a review of the role of cells expressing IL-2, IL-10, HLA-DR and CTLA-4 receptors in the monitoring of immunosuppression in diseases classified as autoimmune, providing perspectives for understanding peripheral regulation mechanisms and the pathophysiology of these diseases in humans. In addition, a therapeutic approach based on the manipulation of the phenotype of these cells and ways of scintigraphically monitoring the manifestations of these diseases by labeling their receptors is discussed as a perspective. In this paper, we have included the description of experiments in ex vivo regulation of IL-10 and synthesis of thio-sugars and poly-sugars to produce radiopharmaceuticals for monitoring inflammation. These experiments may yield benefits for the treatment and prognosis of autoimmune diseases.


2021 ◽  
Vol 80 (Suppl 1) ◽  
pp. 1416.2-1416
Author(s):  
G. Sandri ◽  
L. Belletti ◽  
M. Cavedoni ◽  
C. Galluzzo ◽  
S. Bruni ◽  
...  

Background:Rare diseases are all those diseases that present, in the European Union, a prevalence of less than 5 cases per 10,000 people. The number of rare diseases is estimated at roughly 7,000 but there are also longstanding medical conditions that elude diagnosis and could be identified as rare.Objectives:Demonstrate the importance of international research in orphan diseases.Methods:We report a case of 44 y/o female patient who arrived to our observation in 2006. Short stature, early puberty, ligament laxity, BMI <17. From the age of 29: recurrent diarrhea, pain in the spine, osteolytic lesions in spine and endosteal thickening in long bones, muscle contractures, strength deficit, muscular hypotrophy and hypotonia, cardiac conduction and blood pressure disorders, demyelinating MS-lesions, hyperprolactinaemia, slow wound healing, sicca syndrome, osteoporosis. No familiarity for bone lesions. In 2007 her first son (21y/o) began to complain pain at limbs. The young man presented the same bone lesions as the mother and shortening of the PR, prolactinoma, recurrent diarrhea, short stature, early puberty. Over the years numerous pathologies have been first hypothesized and then excluded: multiple sclerosis, bone metastases, Paget’s disease, celiac disease, McCune Albright, Camurati-Engelmann syndrome, mitochondrial disease. No conclusive diagnosis despite the thousands of kilometers traveled, the numerous experts heard and the countless examinations carried out by the patients.Results:In September 2009, the patients had been investigated at the NIH (Washington D.C.) during the “Undiagnosed Diseases Program” but without results until 2013 when the patients were informed of the detection of an ATP6V1H gene mutation never described before in humans. The gene encodes a vacuolar ATPase, a multimeric enzyme that plays several roles: is involved in endocytosis, intracellular trafficking, and protein degradation and energy production, appears to be a risk factor in the development of dyslipidemias and type II diabetes, has a bone resorption function. Also in the patient’s father were founded the same mutation and asymptomatic bone lesions. In 2016 and 2017 studies have reported mouse models of osteoporosis that were generated by knocking out the ATP6V1H gene.Conclusion:from this case it is possible to understand the difficulty of diagnosing a rare disease, the need of an international collaboration in research. From these studies it can be deduced moreover that the ATP6V1H gene could be an important target for therapeutic interventions aimed at preventing bone resorption and treating osteoporosis; evidence to support exploration of MMP9 and MMP13 as therapeutic targets for patients with ATP6V1H deficiency.This mutation seems to affect only one family, but it is possible that the penetrance of the disease-causing mutation is variable. In literature is reported an enhanced expression of MMP-9 in a variety of autoimmune diseases and neurological pathologies (2) therefore the mutation can be at the basis of other much more common pathologies.References:[1]Zhang Y, Huang H, Zhao G, Yokoyama T, Vega H, Huang Y, Sood R, Bishop K, Maduro V, Accardi J, Toro C, Boerkoel CF, Lyons K, Gahl WA, Duan X, Malicdan MC, Lin S. ATP6V1H Deficiency Impairs Bone Development through Activation of MMP9 and MMP13. PLoS Genet. 2017 Feb 3;13(2):e1006481. doi: 10.1371/journal.pgen.1006481.[2]Ram M, Sherer Y, Shoenfeld Y. Matrix metalloproteinase-9 and autoimmune diseases. J Clin Immunol. 2006 Jul;26(4):299-307. doi: 10.1007/s10875-006-9022-6.Disclosure of Interests:Gilda Sandri: None declared, Lorenza Belletti: None declared, Michele Cavedoni: None declared, Claudio Galluzzo: None declared, stefano bruni Consultant of: Genzyme, Employee of: Genzyme, Maria Teresa Mascia: None declared


2004 ◽  
Vol 199 (9) ◽  
pp. 1285-1291 ◽  
Author(s):  
Martin A. Kriegel ◽  
Tobias Lohmann ◽  
Christoph Gabler ◽  
Norbert Blank ◽  
Joachim R. Kalden ◽  
...  

In autoimmune polyglandular syndromes (APS), several organ-specific autoimmune diseases are clustered. Although APS type I is caused by loss of central tolerance, the etiology of APS type II (APS-II) is currently unknown. However, in several murine models, depletion of CD4+ CD25+ regulatory T cells (Tregs) causes a syndrome resembling human APS-II with multiple endocrinopathies. Therefore, we hypothesized that loss of active suppression in the periphery could be a hallmark of this syndrome. Tregs from peripheral blood of APS-II, control patients with single autoimmune endocrinopathies, and normal healthy donors showed no differences in quantity (except for patients with isolated autoimmune diseases), in functionally important surface markers, or in apoptosis induced by growth factor withdrawal. Strikingly, APS-II Tregs were defective in their suppressive capacity. The defect was persistent and not due to responder cell resistance. These data provide novel insights into the pathogenesis of APS-II and possibly human autoimmunity in general.


2007 ◽  
Vol 37 (8) ◽  
pp. 1127-1136 ◽  
Author(s):  
S. Thunberg ◽  
M. Akdis ◽  
C. A. Akdis ◽  
R. Grönneberg ◽  
V. Malmström ◽  
...  

Cancers ◽  
2020 ◽  
Vol 12 (11) ◽  
pp. 3456 ◽  
Author(s):  
Lorenzo Pilla ◽  
Andrea Alberti ◽  
Pierluigi Di Mauro ◽  
Maria Gemelli ◽  
Viola Cogliati ◽  
...  

Advances in the genomic, molecular and immunological make-up of melanoma allowed the development of novel targeted therapy and of immunotherapy, leading to changes in the paradigm of therapeutic interventions and improvement of patients’ overall survival. Nevertheless, the mechanisms regulating either the responsiveness or the resistance of melanoma patients to therapies are still mostly unknown. The development of either the combinations or of the sequential treatment of different agents has been investigated but without a strongly molecularly motivated rationale. The need for robust biomarkers to predict patients’ responsiveness to defined therapies and for their stratification is still unmet. Progress in immunological assays and genomic techniques as long as improvement in designing and performing studies monitoring the expression of these markers along with the evolution of the disease allowed to identify candidate biomarkers. However, none of them achieved a definitive role in predicting patients’ clinical outcomes. Along this line, the cross-talk of melanoma cells with tumor microenvironment plays an important role in the evolution of the disease and needs to be considered in light of the role of predictive biomarkers. The overview of the relationship between the molecular basis of melanoma and targeted therapies is provided in this review, highlighting the benefit for clinical responses and the limitations. Moreover, the role of different candidate biomarkers is described together with the technical approaches for their identification. The provided evidence shows that progress has been achieved in understanding the molecular basis of melanoma and in designing advanced therapeutic strategies. Nevertheless, the molecular determinants of melanoma and their role as biomarkers predicting patients’ responsiveness to therapies warrant further investigation with the vision of developing more effective precision medicine.


2020 ◽  
Vol 3 (1) ◽  
Author(s):  
Asiel A. Benitez ◽  
Sara Khalil-Agüero ◽  
Anjali Nandakumar ◽  
Namita T. Gupta ◽  
Wen Zhang ◽  
...  

AbstractThe endogenous anti-tumor responses are limited in part by the absence of tumor-reactive T cells, an inevitable consequence of thymic central tolerance mechanisms ensuring prevention of autoimmunity. Here we show that tumor rejection induced by immune checkpoint blockade is significantly enhanced in Aire-deficient mice, the epitome of central tolerance breakdown. The observed synergy in tumor rejection extended to different tumor models, was accompanied by increased numbers of activated T cells expressing high levels of Gzma, Gzmb, Perforin, Cxcr3, and increased intratumoural levels of Cxcl9 and Cxcl10 compared to wild-type mice. Consistent with Aire’s central role in T cell repertoire selection, single cell TCR sequencing unveiled expansion of several clones with high tumor reactivity. The data suggest that breakdown in central tolerance synergizes with immune checkpoint blockade in enhancing anti-tumor immunity and may serve as a model to unmask novel anti-tumor therapies including anti-tumor TCRs, normally purged during central tolerance.


Circulation ◽  
2018 ◽  
Vol 138 (18) ◽  
pp. 2021-2035 ◽  
Author(s):  
Kohsuke Shirakawa ◽  
Jin Endo ◽  
Masaharu Kataoka ◽  
Yoshinori Katsumata ◽  
Naohiro Yoshida ◽  
...  

2002 ◽  
Vol 195 (3) ◽  
pp. 353-358 ◽  
Author(s):  
Xavier Saulquin ◽  
Emmanuel Scotet ◽  
Lydie Trautmann ◽  
Marie-Alix Peyrat ◽  
Franck Halary ◽  
...  

Recent data indicate that some cytotoxic T cells (CTLs) recognize so-called cryptic epitopes, encoded by nonprimary open reading frame (ORF) sequences or other nonclassical expression pathways. We describe here a novel mechanism leading to generation of a cryptic CTL epitope. We isolated from the synovial fluid of a patient suffering from a Reiter's syndrome an autoreactive T cell clone that recognized cellular IL-10 in the HLA-B*2705 context. The minimal IL-10 sequence corresponding to nucleotides 379–408 was shown to activate this clone, upon cotransfection into COS cells with the DNA encoding HLA-B*2705, but the synthetic peptide deduced from this sequence did not stimulate the clone. Using a site-directed mutagenesis approach, we found that this clone recognized a transframe epitope generated by an internal +1 frameshifting in the IL-10 sequence and so derived partly from ORF1, partly from ORF2. We defined that +1 frameshifting was induced by a specific heptamer sequence. These observations illustrate the variety of mechanisms leading to generation of cryptic epitopes and suggest that frameshifting in normal cellular genes may be more common than expected.


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