scholarly journals Chromatin accessibility landscapes of immune cells in rheumatoid arthritis nominate monocytes in disease pathogenesis

BMC Biology ◽  
2021 ◽  
Vol 19 (1) ◽  
Author(s):  
Dandan Zong ◽  
Beibei Huang ◽  
Young Li ◽  
Yichen Lu ◽  
Nan Xiang ◽  
...  

Abstract Background Rheumatoid arthritis (RA) is a chronic, systemic autoimmune disease that involves a variety of cell types. However, how the epigenetic dysregulations of peripheral immune cells contribute to the pathogenesis of RA still remains largely unclear. Results Here, we analysed the genome-wide active DNA regulatory elements of four major immune cells, namely monocytes, B cells, CD4+ T cells and CD8+ T cells, in peripheral blood of RA patients, osteoarthritis (OA) patients and healthy donors using Assay of Transposase Accessible Chromatin with sequencing (ATAC-seq). We found a strong RA-associated chromatin dysregulation signature in monocytes, but no other examined cell types. Moreover, we found that serum C-reactive protein (CRP) can induce the RA-associated chromatin dysregulation in monocytes via in vitro experiments. And the extent of this dysregulation was regulated through the transcription factor FRA2. Conclusions Together, our study revealed a CRP-induced pathogenic chromatin dysregulation signature in monocytes from RA patients and predicted the responsible signalling pathway as potential therapeutic targets for the disease.

2017 ◽  
Vol 92 (3) ◽  
Author(s):  
Georgia Skardasi ◽  
Annie Y. Chen ◽  
Tomasz I. Michalak

ABSTRACTAccumulated evidence indicates that immune cells can support the replication of hepatitis C virus (HCV) in infected patients and in culture. However, there is a scarcity of data on the degree to which individual immune cell types support HCV propagation and on characteristics of virus assembly. We investigated the ability of authentic, patient-derived HCV to infectin vitrotwo closely related but functionally distinct immune cell types, CD4+and CD8+T lymphocytes, and assessed the properties of the virus produced by these cells. The HCV replication system in intermittently mitogen-stimulated T cells was adapted to infect primary human CD4+or CD8+T lymphocytes. HCV replicated in both cell types although at significantly higher levels in CD4+than in CD8+T cells. Thus, the HCV RNA replicative (negative) strand was detected in CD4+and CD8+cells at estimated mean levels ± standard errors of the means of 6.7 × 102± 3.8 × 102and 1.2 × 102± 0.8 × 102copies/μg RNA, respectively (P< 0.0001). Intracellular HCV NS5a and/or core proteins were identified in 0.9% of CD4+and in 1.2% of CD8+T cells. Double staining for NS5a and T cell type-specific markers confirmed that transcriptionally competent virus replicated in both cell types. Furthermore, an HCV-specific protease inhibitor, telaprevir, inhibited infection in both CD4+and CD8+cells. The emergence of unique HCV variants and the release of HCV RNA-reactive particles with biophysical properties different from those of virions in plasma inocula suggested that distinct viral particles were assembled, and therefore, they may contribute to the pool of circulating virus in infected patients.IMPORTANCEAlthough the liver is the main site of HCV replication, infection of the immune system is an intrinsic characteristic of this virus independent of whether infection is symptomatic or clinically silent. Many fundamental aspects of HCV lymphotropism remain uncertain, including the degree to which different immune cells support infection and contribute to virus diversity. We show that authentic, patient-derived HCV productively replicatesin vitroin two closely related but functionally distinct types of T lymphocytes, CD4+and CD8+cells. The display of viral proteins and unique variants, the production of virions with biophysical properties distinct from those in plasma serving as inocula, and inhibition of replication by an antiviral agent led us to ascertain that both T cell subtypes supported virus propagation. Infection of CD4+and CD8+T cells, which are central to adaptive antiviral immune responses, can directly affect HCV clearance, favor virus persistence, and decisively influence the development and progression of hepatitis C.


2022 ◽  
Vol 23 (2) ◽  
pp. 905
Author(s):  
Sunhee Jang ◽  
Eui-Jong Kwon ◽  
Jennifer Jooha Lee

Rheumatoid arthritis (RA) is a chronic, systemic autoimmune disease associated with synovial tissue proliferation, pannus formation, cartilage destruction, and systemic complications. Currently, advanced understandings of the pathologic mechanisms of autoreactive CD4+ T cells, B cells, macrophages, inflammatory cytokines, chemokines, and autoantibodies that cause RA have been achieved, despite the fact that much remains to be elucidated. This review provides an updated pathogenesis of RA which will unveil novel therapeutic targets.


1994 ◽  
Vol 14 (3) ◽  
pp. 2159-2169 ◽  
Author(s):  
P A Garrity ◽  
D Chen ◽  
E V Rothenberg ◽  
B J Wold

Interleukin-2 (IL-2) transcription is developmentally restricted to T cells and physiologically dependent on specific stimuli such as antigen recognition. Prior studies have shown that this stringent two-tiered regulation is mediated through a transcriptional promoter/enhancer DNA segment which is composed of diverse recognition elements. Factors binding to some of these elements are present constitutively in many cell types, while others are signal dependent, T cell specific, or both. This raises several questions about the molecular mechanism by which IL-2 expression is regulated. Is the developmental commitment of T cells reflected molecularly by stable interaction between available factors and the IL-2 enhancer prior to signal-dependent induction? At which level, factor binding to DNA or factor activity once bound, are individual regulatory elements within the native enhancer regulated? By what mechanism is developmental and physiological specificity enforced, given the participation of many relatively nonspecific elements? To answer these questions, we have used in vivo footprinting to determine and compare patterns of protein-DNA interactions at the native IL-2 locus in cell environments, including EL4 T-lymphoma cells and 32D clone 5 premast cells, which express differing subsets of IL-2 DNA-binding factors. We also used the immunosuppressant cyclosporin A as a pharmacological agent to further dissect the roles played by cyclosporin A-sensitive factors in the assembly and maintenance of protein-DNA complexes. Occupancy of all site types was observed exclusively in T cells and then only upon excitation of signal transduction pathways. This was true even though partially overlapping subsets of IL-2-binding activities were shown to be present in 32D clone 5 premast cells. This observation was especially striking in 32D cells because, upon signal stimulation, they mobilized a substantial set of IL-2 DNA-binding activities, as measured by in vitro assays using nuclear extracts. We conclude that binding activities of all classes fail to stably occupy their cognate sites in IL-2, except following activation of T cells, and that specificity of IL-2 transcription is enforced at the level of chromosomal occupancy, which appears to be an all-or-nothing phenomenon.


2020 ◽  
Vol 11 (1) ◽  
Author(s):  
Qian Liu ◽  
Lisa C. Zaba ◽  
Ansuman T. Satpathy ◽  
Michelle Longmire ◽  
Wen Zhang ◽  
...  

AbstractSystemic sclerosis (SSc) is a disease at the intersection of autoimmunity and fibrosis. However, the epigenetic regulation and the contributions of diverse cell types to SSc remain unclear. Here we survey, using ATAC-seq, the active DNA regulatory elements of eight types of primary cells in normal skin from healthy controls, as well as clinically affected and unaffected skin from SSc patients. We find that accessible DNA elements in skin-resident dendritic cells (DCs) exhibit the highest enrichment of SSc-associated single-nucleotide polymorphisms (SNPs) and predict the degrees of skin fibrosis in patients. DCs also have the greatest disease-associated changes in chromatin accessibility and the strongest alteration of cell–cell interactions in SSc lesions. Lastly, data from an independent cohort of patients with SSc confirm a significant increase of DCs in lesioned skin. Thus, the DCs epigenome links inherited susceptibility and clinically apparent fibrosis in SSc skin, and can be an important driver of SSc pathogenesis.


1994 ◽  
Vol 14 (3) ◽  
pp. 2159-2169
Author(s):  
P A Garrity ◽  
D Chen ◽  
E V Rothenberg ◽  
B J Wold

Interleukin-2 (IL-2) transcription is developmentally restricted to T cells and physiologically dependent on specific stimuli such as antigen recognition. Prior studies have shown that this stringent two-tiered regulation is mediated through a transcriptional promoter/enhancer DNA segment which is composed of diverse recognition elements. Factors binding to some of these elements are present constitutively in many cell types, while others are signal dependent, T cell specific, or both. This raises several questions about the molecular mechanism by which IL-2 expression is regulated. Is the developmental commitment of T cells reflected molecularly by stable interaction between available factors and the IL-2 enhancer prior to signal-dependent induction? At which level, factor binding to DNA or factor activity once bound, are individual regulatory elements within the native enhancer regulated? By what mechanism is developmental and physiological specificity enforced, given the participation of many relatively nonspecific elements? To answer these questions, we have used in vivo footprinting to determine and compare patterns of protein-DNA interactions at the native IL-2 locus in cell environments, including EL4 T-lymphoma cells and 32D clone 5 premast cells, which express differing subsets of IL-2 DNA-binding factors. We also used the immunosuppressant cyclosporin A as a pharmacological agent to further dissect the roles played by cyclosporin A-sensitive factors in the assembly and maintenance of protein-DNA complexes. Occupancy of all site types was observed exclusively in T cells and then only upon excitation of signal transduction pathways. This was true even though partially overlapping subsets of IL-2-binding activities were shown to be present in 32D clone 5 premast cells. This observation was especially striking in 32D cells because, upon signal stimulation, they mobilized a substantial set of IL-2 DNA-binding activities, as measured by in vitro assays using nuclear extracts. We conclude that binding activities of all classes fail to stably occupy their cognate sites in IL-2, except following activation of T cells, and that specificity of IL-2 transcription is enforced at the level of chromosomal occupancy, which appears to be an all-or-nothing phenomenon.


2017 ◽  
Vol 63 (3) ◽  
pp. 255-265
Author(s):  
N.M. Todosenko ◽  
O.G. Khaziakhmatova ◽  
K.A. Yurova ◽  
I.P. Malinina ◽  
L.S. Litvinova

The effect of different concentrations of the glucocorticoid (GC) methylprednisolone (MP) on CD4+CD95+HLA-DR+ T-cells and their ability to produce proinflammatory mediators in cultures of TCR-stimulated CD3+CD45RO+ T-lymphocytes in the in vitro system was investigated. T cells were obtained from healthy donors and patients with rheumatoid arthritis (RA).Under conditions of TCR-activation, MP increased the number of CD4+HLA-DR+CD95+ cells in CD3+CD45RO+ cultures obtained from RA patients and did not change their content in the control group. In general, MP decreased production of proinflammatory factors (IFN-, IL-2, IL-17, IL-21 and TNF-) by TCR-activated CD3+CD45RO+ cells from healthy donors and RA, consistent with the overall immunosuppressive mechanism of GC action. The correlation between CD4+CD45RO+HLA-DR+CD95+ T-cell contents and parameters reflecting production of proinflammatory mediators (IL-17, IL-21 and TNF-) in RA patients indicates maintenance of the pro-inflammatory potential of this T-cell population exposed to GC action. We suggest that relative resistance of CD4+CD45RO+CD95+HLA-DR+ T-cells of RA patients to the suppressor effect of GC leads to maintenance and even enhancement in the functional capacities of autoreactive cells in the pathogenesis of RA.


2020 ◽  
Author(s):  
Asa Thibodeau ◽  
Shubham Khetan ◽  
Alper Eroglu ◽  
Ryan Tewhey ◽  
Michael L. Stitzel ◽  
...  

AbstractCis-Regulatory elements (cis-REs) include promoters, enhancers, and insulators that regulate gene expression programs via binding of transcription factors. ATAC-seq technology effectively identifies active cis-REs in a given cell type (including from single cells) by mapping accessible chromatin at base-pair resolution. However, these maps are not immediately useful for inferring specific functions of cis-REs. For this purpose, we developed a deep learning framework (CoRE-ATAC) with novel data encoders that integrate DNA sequence (reference or personal genotypes) with ATAC-seq cut sites and read pileups. CoRE-ATAC was trained on 4 cell types (n=6 samples/replicates) and accurately predicted known cis-RE functions from 7 cell types (n=40 samples) that were not used in model training (mean average precision=0.80). CoRE-ATAC enhancer predictions from 19 human islet samples coincided with genetically modulated gain/loss of enhancer activity, which was confirmed by massively parallel reporter assays (MPRAs). Finally, CoRE-ATAC effectively inferred cis-RE function from aggregate single nucleus ATAC-seq (snATAC) data from human blood-derived immune cells that overlapped with known functional annotations in sorted immune cells, which established the efficacy of these models to study cis-RE functions of rare cells without the need for cell sorting. ATAC-seq maps from primary human cells reveal individual- and cell-specific variation in cis-RE activity. CoRE-ATAC increases the functional resolution of these maps, a critical step for studying regulatory disruptions behind diseases.Author SummaryNon-coding DNA sequences serve different functional roles to regulate gene expression. For these sequences to be active, they must be accessible for proteins and other factors to bind in order to carry out a specific regulatory function. Even so, mutations within these sequences or other regulatory events may modulate their activity or regulatory function. It is therefore critical that we identify these non-coding sequences and their specific regulatory function to fully understand how specific genes are regulated. Current sequencing technologies allow us to identify accessible sequences via chromatin accessibility maps from low cell numbers, enabling the study of clinical samples. However, determining the functional role associated with these sequences remains a challenge. Towards this goal, we harnessed the power of deep learning to unravel the intricacies of chromatin accessibility maps to infer their associated gene regulatory functions. We demonstrate that our method, CoRE-ATAC, can infer regulatory functions in diverse cell types, captures activity differences modulated by genetic mutations, and can be applied to accessibility maps of single cell clusters to infer regulatory functions of rare cell populations. These inferences will further our understanding of how genes are regulated and enable the study of these mechanisms as they relate to disease.


2021 ◽  
Vol 14 (1) ◽  
Author(s):  
Kerry E. Poppenberg ◽  
Vincent M. Tutino ◽  
Evan Tarbell ◽  
James N. Jarvis

Abstract Background Genetic variants in the human leukocyte antigen (HLA) locus contribute to the risk for developing scleroderma/systemic sclerosis (SSc). However, there are other replicated loci that also contribute to genetic risk for SSc, and it is unknown whether genetic risk in these non-HLA loci acts primarily on the vasculature, immune system, fibroblasts, or other relevant cell types. We used the Cistrome database to investigate the epigenetic landscapes surrounding 11 replicated SSc associated loci to determine whether SNPs in these loci may affect regulatory elements and whether they are likely to impact a specific cell type. Methods We mapped 11 replicated SNPs to haplotypes and sought to determine whether there was significant enrichment for H3K27ac and H3K4me1 marks, epigenetic signatures of enhancer function, on these haplotypes. We queried pathologically relevant cell types: B cells, endothelial cells, fibroblasts, monocytes, and T cells. We then identified the topologically associated domains (TADs) that encompass the SSc risk haplotypes in primary T cells to identify the full range of genes that may be influenced by SSc causal SNPs. We used gene ontology analyses of the genes within the TADs to gain insight into immunologic functions that might be affected by SSc causal SNPs. Results The SSc-associated haplotypes were enriched (p value < 0.01) for H3K4me1/H3K27ac marks in monocytes. Enrichment of one of the two histone marks was found in B cells, fibroblasts, and T cells. No enrichment was identified in endothelial cells. Ontological analyses of genes within the TADs encompassing the risk haplotypes showed enrichment for regulation of transcription, protein binding, activation of T lymphocytes, and proliferation of immune cells. Conclusions The 11 non-HLA SSc risk haplotypes queried are highly enriched for H3K4me1/H3K27ac-marked regulatory elements in a broad range of immune cells and fibroblasts. Furthermore, in immune cells, the risk haplotypes belong to larger chromatin structures encompassing genes that regulate a wide array of immune processes associated with SSc pathogenesis. Though importance of the vasculature in the pathobiology of SSc is widely accepted, we were unable to find evidence for genetic influences on endothelial cell function in these regions.


2015 ◽  
Vol 1 (2) ◽  
pp. 122-128
Author(s):  
Syuichi Koarada ◽  
Yuri Sadanaga ◽  
Natsumi Nagao ◽  
Satoko Tashiro ◽  
Rie Suematsu ◽  
...  

2020 ◽  
Vol 79 (Suppl 1) ◽  
pp. 1341.3-1342
Author(s):  
A. Alshevskaya ◽  
J. Lopatnikova ◽  
J. Zhukova ◽  
F. Kireev ◽  
O. Chumasova ◽  
...  

Background:Previous studies of co-expression profile of receptors to tumor necrosis factor alpha (TNF) in rheumatoid arthritis (RA) have revealed a number of indicators associated with diseases activity with 93% sensitivity and 90% specificity. However, the ratio of receptors to cytokines remains poorly understood. However, the question of therapy effect and its effectiveness in various alteration of cytokine receptors balance remains under investigated.Objectives:To evaluate the dynamics of co-expression and quantitative expression of type 1 and 2 receptors for TNF in the subpopulations of CD3+CD8+ cells associated with changes in disease severity before and after effective basic therapy.Methods:Subanalysis of patients with high disease activity level successfully treated with methotrexate and oral glucocorticoids (n = 9) was performed. As a control group, we used data from 43 healthy donors, comparable by sex and age distribution. Subpopulations of cytotoxic T cells were studied, which were included in the final diagnostic models for differentiating different degrees of severity of RA: naive T cells and memory T cells. The dynamics of changes in the indicators of receptors number and proportion of cells expressing the corresponding receptor were compared.Results:For naïve cytotoxic T cells, the main revealed feature was the relative stability of the number of expressed receptors (both TNFR1 and TNFR2), regardless of the therapy, while this number did not significantly differ from healthy ones for TNFR1 and was significantly lower for TNFR2 (p <0.05 for all three fractions). At the same time, in terms of cell percentage, on the contrary, the therapy led to a change in total proportion of TNFR1 + cells closer to healthy donors indicators, and the proportion of TNFR2 + cells in the opposite direction.For cytotoxic T memory cells, it was demonstrated that after successful treatment a significant increase in the number of type 1 receptors was observed, with a decrease in TNFR1+ cells proportion, while these indicators were close to the values of healthy donors. At the same time, healthy donors were characterized by a significantly higher expression of type 2 receptors in terms of cell density of receptors. It is noteworthy that with successful therapy, a slight increase in the number of TNFR2 was observed with a sharp decrease in the proportion of TNFR2+ cells (p = 0.043).Conclusion:The balance of TNF receptor expression on cells actively involved in immunopathological processes affects both the density distribution of receptors on cells and co-expression in a subpopulation. Effective treatment of RA leads to equalization of the expression profile either by the percentage of cells or by the number of receptors, approaching the indicators of healthy donors, but not simultaneously.Disclosure of Interests:None declared


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