scholarly journals Cytokine-Mediated Regulation of Innate Lymphoid Cell Plasticity in Gut Mucosal Immunity

2020 ◽  
Vol 11 ◽  
Author(s):  
Carlo De Salvo ◽  
Kristine-Ann Buela ◽  
Theresa T. Pizarro
Keyword(s):  
Active Sites ◽  
Regulatory Elements ◽  
Lymphoid Cells ◽  
Innate Immune Responses ◽  
Cell Plasticity ◽  
Tissue Microenvironment ◽  
Commensal Flora ◽  
Mucosal Surfaces ◽  
Cytokine Milieu ◽  
Environmental Antigens

Mucosal barriers are active sites that encounter a bombardment of antigenic stimuli derived from both the commensal flora and a variety of pathogens, as well as from environmental insults. As such, the ability to mount appropriate innate immune responses is an important first line of defense that confers protection to the host. Central to innate immunity are innate lymphoid cells (ILCs), which were first described a decade ago, and represent a family of heterogeneous cells driven by specific transcription factors and exhibit distinct cytokine profiles that are shared with their CD4+ T-helper cell counterparts. ILCs are particularly enriched at mucosal surfaces, and the tissue microenvironment and cytokine milieu in which ILCs reside are critical factors that drive the behavior and overall function of these cells. In fact, ILCs situated at mucosal barriers must be able to temper their response to a constant exposure of environmental antigens, but also promptly react to pathogens or signals that are potentially harmful to the host. In this context, the ability of ILCs to readily transdifferentiate in response to their dynamic surroundings has become a vigorous area of research, and defining specific mechanism(s) of ILC plasticity is at the advent of discovery. This review will summarize what is currently known regarding the network of cytokines and regulatory elements that enable ILCs to readily transform, based on the range of diverse signals and signal gradients they encounter that lead to either protective or pathogenic function(s), with focus on the gut mucosal immune system.

scholarly journals Immunity and Tolerance Induced by Intestinal Mucosal Dendritic Cells

2016 ◽  
Vol 2016 ◽  
pp. 1-8 ◽  
Author(s):  
Julio Aliberti
Keyword(s):  
Dendritic Cells ◽  
Immune Responses ◽  
Food Allergies ◽  
Commensal Flora ◽  
Inflammatory Conditions ◽  
Mucosal Surfaces ◽  
Dendritic Cell Population ◽  
Proinflammatory Responses ◽  
Environmental Antigens

Dendritic cells present in the digestive tract are constantly exposed to environmental antigens, commensal flora, and invading pathogens. Under steady-state conditions, these cells have high tolerogenic potential, triggering differentiation of regulatory T cells to protect the host from unwanted proinflammatory immune responses to innocuous antigens or commensals. On the other hand, these cells must discriminate between commensal flora and invading pathogens and mount powerful immune response against pathogens. A potential result of unbalanced tolerogenic versus proinflammatory responses mediated by dendritic cells is associated with chronic inflammatory conditions, such as Crohn’s disease, ulcerative colitis, food allergies, and celiac disease. Herein, we review the dendritic cell population involved in mediating tolerance and immunity in mucosal surfaces, the progress in unveiling their development in vivo, and factors that can influence their functions.

scholarly journals Genetic variants associated with cross-disorder and disorder-specific risk for psychiatric disorders are enriched at epigenetically active sites in peripheral lymphoid cells

2021 ◽  
Author(s):  
Mary-Ellen Lynall ◽  
Blagoje Soskic ◽  
James Hayhurst ◽  
Jeremy Schwartzentruber ◽  
Daniel F. Levey ◽  
...  
Keyword(s):  
T Cells ◽  
Psychiatric Disorders ◽  
Active Sites ◽  
Immune Cell ◽  
Regulatory Elements ◽  
Multiple Organ ◽  
Lymphoid Cells ◽  
Risk Variants ◽  
Organ Systems ◽  
Specific Disorders

Multiple psychiatric disorders have been associated with abnormalities in both the innate and adaptive immune systems. The role of these abnormalities in pathogenesis, and whether they are driven by psychiatric risk variants, remains unclear. We tested for enrichment of GWAS variants associated with multiple psychiatric disorders (cross-disorder or trans-diagnostic risk), or 5 specific disorders (cis-diagnostic risk), in regulatory elements in immune cells. We used three independent epigenetic datasets representing multiple organ systems and immune cell subsets. Trans-diagnostic and cis-diagnostic risk variants (for schizophrenia and depression) were enriched at epigenetically active sites in brain tissues and in lymphoid cells (T, B and NK cells), especially stimulated CD4+ T cells. There was no evidence for enrichment of either trans-risk or cis-risk variants for schizophrenia or depression in myeloid cells. This suggests a model where stimuli (e.g. infection) activate T cells to unmask the effects of psychiatric risk variants, contributing to the pathogenesis of mental health disorders.

scholarly journals Gata3 drives development of RORγt+ group 3 innate lymphoid cells

2014 ◽  
Vol 211 (2) ◽  
pp. 199-208 ◽  
Author(s):  
Nicolas Serafini ◽  
Roel G.J. Klein Wolterink ◽  
Naoko Satoh-Takayama ◽  
Wei Xu ◽  
Christian A.J. Vosshenrich ◽  
...  
Keyword(s):  
T Cell ◽  
Fetal Liver ◽  
Innate Lymphoid Cells ◽  
Lymphoid Cells ◽  
T Cell Subsets ◽  
Mucosal Barrier ◽  
Hematopoietic Stem ◽  
Mucosal Surfaces ◽  
Gata3 Expression ◽  
Group 3

Group 3 innate lymphoid cells (ILC3) include IL-22–producing NKp46+ cells and IL-17A/IL-22–producing CD4+ lymphoid tissue inducerlike cells that express RORγt and are implicated in protective immunity at mucosal surfaces. Whereas the transcription factor Gata3 is essential for T cell and ILC2 development from hematopoietic stem cells (HSCs) and for IL-5 and IL-13 production by T cells and ILC2, the role for Gata3 in the generation or function of other ILC subsets is not known. We found that abundant GATA-3 protein is expressed in mucosa-associated ILC3 subsets with levels intermediate between mature B cells and ILC2. Chimeric mice generated with Gata3-deficient fetal liver hematopoietic precursors lack all intestinal RORγt+ ILC3 subsets, and these mice show defective production of IL-22 early after infection with the intestinal pathogen Citrobacter rodentium, leading to impaired survival. Further analyses demonstrated that ILC3 development requires cell-intrinsic Gata3 expression in fetal liver hematopoietic precursors. Our results demonstrate that Gata3 plays a generalized role in ILC lineage determination and is critical for the development of gut RORγt+ ILC3 subsets that maintain mucosal barrier homeostasis. These results further extend the paradigm of Gata3-dependent regulation of diversified innate ILC and adaptive T cell subsets.

scholarly journals Characterization of two atypical promoters and alternate mRNA processing in the mouse Thy-1.2 glycoprotein gene.

1986 ◽  
Vol 6 (8) ◽  
pp. 2923-2931 ◽  
Author(s):  
H A Ingraham ◽  
G A Evans
Keyword(s):  
Genomic Sequence ◽  
Regulatory Elements ◽  
Initiation Site ◽  
Lymphoid Cells ◽  
Gene Encoding ◽  
Specific Expression ◽  
Transcriptional Initiation ◽  
Glycoprotein Gene ◽  
Cell Type Specific Expression ◽  
Flanking Region

The promoter and 5' flanking region of the mouse Thy-1.2 glycoprotein gene were characterized by DNA sequencing, primer extension analysis, and deletion analysis. Transcriptional initiation sites were identified which corresponded to two separate exons upstream of the portion of the gene encoding the Thy-1.2 glycoprotein. We demonstrated that the mouse Thy-1.2 gene was transcribed from two atypical promoters separated by 260 base pairs in the genomic sequence. These promoters contained neither TATAAG nor GGPyCCAATCT homologous sequences but defined a conserved nonamer CTCCCTGCT at -48 from each initiation site. Two Thy-1.2 mRNA species of 1,835 and 1,939 nucleotides, differing in the 5' untranslated region of the mRNA, were thus transcribed from the single Thy-1.2 gene by mRNA splicing to the same downstream exon. Recombinant genomes in which the bacterial chloramphenicol acetyltransferase gene was expressed from either of the two Thy-1.2 promoters demonstrated that each promoter functioned independently and did not direct cell-specific expression in lymphoid cells. The 5' flanking region of the Thy-1.2 gene upstream of -68 could be eliminated without altering cell-type-specific expression. This suggests that regulatory elements responsible for tissue and developmental stage-specific expression of the Thy-1.2 gene are not present in the 5' flanking DNA but may reside downstream of the promoters.

Interferon and IL-27 antagonize the function of group 2 innate lymphoid cells and type 2 innate immune responses

2015 ◽  
Vol 17 (1) ◽  
pp. 76-86 ◽  
Author(s):  
Kazuyo Moro ◽  
Hiroki Kabata ◽  
Masanobu Tanabe ◽  
Satoshi Koga ◽  
Natsuki Takeno ◽  
...  
Keyword(s):  
Immune Responses ◽  
Innate Lymphoid Cells ◽  
Innate Immune ◽  
Lymphoid Cells ◽  
Innate Immune Responses ◽  
Group 2

scholarly journals Type 3 innate lymphoid cells maintain intestinal epithelial stem cells after tissue damage

2015 ◽  
Vol 212 (11) ◽  
pp. 1783-1791 ◽  
Author(s):  
Patricia Aparicio-Domingo ◽  
Monica Romera-Hernandez ◽  
Julien J. Karrich ◽  
Ferry Cornelissen ◽  
Natalie Papazian ◽  
...  
Keyword(s):  
Stem Cells ◽  
Tissue Damage ◽  
Innate Lymphoid Cells ◽  
Lymphoid Cells ◽  
Intestinal Damage ◽  
Intestinal Epithelial ◽  
Epithelial Stem Cells ◽  
Intestinal Tissue ◽  
Mucosal Surfaces ◽  
Type 3

Disruption of the intestinal epithelial barrier allows bacterial translocation and predisposes to destructive inflammation. To ensure proper barrier composition, crypt-residing stem cells continuously proliferate and replenish all intestinal epithelial cells within days. As a consequence of this high mitotic activity, mucosal surfaces are frequently targeted by anticancer therapies, leading to dose-limiting side effects. The cellular mechanisms that control tissue protection and mucosal healing in response to intestinal damage remain poorly understood. Type 3 innate lymphoid cells (ILC3s) are regulators of homeostasis and tissue responses to infection at mucosal surfaces. We now demonstrate that ILC3s are required for epithelial activation and proliferation in response to small intestinal tissue damage induced by the chemotherapeutic agent methotrexate. Multiple subsets of ILC3s are activated after intestinal tissue damage, and in the absence of ILC3s, epithelial activation is lost, correlating with increased pathology and severe damage to the intestinal crypts. Using ILC3-deficient Lgr5 reporter mice, we show that maintenance of intestinal stem cells after damage is severely impaired in the absence of ILC3s or the ILC3 signature cytokine IL-22. These data unveil a novel function of ILC3s in limiting tissue damage by preserving tissue-specific stem cells.

scholarly journals Multi-modal single cell analysis reveals brain immune landscape plasticity during aging and gut microbiota dysbiosis

2020 ◽  
Author(s):  
Samantha M. Golomb ◽  
Ian H. Guldner ◽  
Anqi Zhao ◽  
Qingfei Wang ◽  
Bhavana Palakurthi ◽  
...  
Keyword(s):  
Single Cell ◽  
Immune Cells ◽  
Immune Cell ◽  
Cell Types ◽  
Cell Plasticity ◽  
Tissue Microenvironment ◽  
Gut Dysbiosis ◽  
Resolution Single ◽  
The Brain ◽  
Gut Microbiota Dysbiosis

ABSTRACTThe brain contains a diverse array of immune cell types. The phenotypic and functional plasticity of brain immune cells collectively contribute to brain tissue homeostasis and disease progression. Immune cell plasticity is profoundly influenced by local tissue microenvironment cues and systemic factors. Yet, the transcriptional mechanism by which systemic stimuli, such as aging and gut microbiota dysbiosis, reshape brain immune cell plasticity and homeostasis has not been fully delineated. Using Cellular Indexing of Transcriptomes and Epitopes by sequencing (CITE-seq), we analyzed compositional and transcriptional changes of the brain immune landscape in response to aging and gut dysbiosis. We first examined the discordance between canonical surface marker-defined immune cell types (Cell-ID) and their transcriptome signatures, which suggested transcriptional plasticity among immune cells despite sharing the same cell surface markers. Specifically, inflammatory and patrolling Ly6C+ monocytes were shifted predominantly to a pro-inflammatory transcriptional program in the aged brain, while brain ILCs shifted toward an ILC2 transcriptional profile. Finally, aging led to an increase of ILC-like cells expressing a T memory stemness (Tscm) signature in the brain. Antibiotics (ABX)-induced gut dysbiosis reduced the frequency of ILCs exhibiting Tscm-like properties in the aged mice, but not in the young mice. Enabled by high-resolution single-cell molecular phenotyping, our study revealed that systemic changes due to aging and gut dysbiosis prime the brain environment for an increased propensity for neuroinflammation, which provided insights into gut dysbiosis in age-related neurological diseases.Manuscript SummaryGolomb et al. performed Cellular Indexing of Transcriptomes and Epitopes by sequencing (CITE-seq) on immune cells from the brains of young and aged mice with and without antibiotics-induced gut dysbiosis. High resolution, single cell immunophenotyping enabled the dissection of extensive transcriptional plasticity of canonically identified monocytes and innate lymphoid cells (ILCs) in the aged brain. Through differential gene expression and trajectory inference analyses, the authors revealed tissue microenvironment-dependent cellular responses influenced by aging and gut dysbiosis that may potentiate neuroinflammatory diseases.Graphical Abstract

scholarly journals T-bet fate mapping identifies a novel ILC1-ILC2 subset in vivo

2020 ◽  
Author(s):  
J-H Schroeder ◽  
N Garrido-Mesa ◽  
T Zabinski ◽  
AL Gallagher ◽  
L Campbell ◽  
...  
Keyword(s):  
Transcription Factors ◽  
Immune Responses ◽  
Critical Role ◽  
Innate Lymphoid Cells ◽  
Lymphoid Cells ◽  
Fate Mapping ◽  
Functional Roles ◽  
Mucosal Surfaces ◽  
Group 2

ABSTRACTInnate lymphoid cells (ILC) play a critical role in regulating immune responses at mucosal surfaces. Various subsets exist resembling T cell lineages defined by the expression of specific transcription factors. Thus, T-bet is expressed in ILC1 and Th1 cells. In order to further understand the functional roles of T-bet in ILC, we generated a fate-mapping mouse model that permanently marks cells and their progeny that are expressing, or have ever expressed T-bet. Here we have identified and characterised a novel ILC with characteristics of ILC1 and ILC2 that are “fate-mapped” for T-bet expression and arise early in neonatal life prior to establishment of a mature microbiome. These ILC1-ILC2 cells are critically dependent on T-bet and are able to express type 1 and type 2 cytokines at steady state, but not in the context of inflammation. These findings refine our understanding of ILC lineage regulation and stability and have important implications for the understanding of ILC biology at mucosal surfaces.SUMMARYInnate lymphoid cells (ILC) play a critical role in regulating immune responses at mucosal surfaces. Three distinct ILC groups have been described according to expression of subset defining transcription factors and other markers. In this study we characterize a novel ILC subset with characteristics of group 1 and group 2 ILC in vivo.

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