scholarly journals Innate Lymphoid Cells in Response to Intracellular Pathogens: Protection Versus Immunopathology

Author(s):  
Anna A. Korchagina ◽  
Ekaterina Koroleva ◽  
Alexei V. Tumanov

Innate lymphoid cells (ILCs) are a heterogeneous group of cytokine-producing lymphocytes which are predominantly located at mucosal barrier surfaces, such as skin, lungs, and gastrointestinal tract. ILCs contribute to tissue homeostasis, regulate microbiota-derived signals, and protect against mucosal pathogens. ILCs are classified into five major groups by their developmental origin and distinct cytokine production. A recently emerged intriguing feature of ILCs is their ability to alter their phenotype and function in response to changing local environmental cues such as pathogen invasion. Once the pathogen crosses host barriers, ILCs quickly activate cytokine production to limit the spread of the pathogen. However, the dysregulated ILC responses can lead to tissue inflammation and damage. Furthermore, the interplay between ILCs and other immune cell types shapes the outcome of the immune response. Recent studies highlighted the important role of ILCs for host defense against intracellular pathogens. Here, we review recent advances in understanding the mechanisms controlling protective and pathogenic ILC responses to intracellular pathogens. This knowledge can help develop new ILC-targeted strategies to control infectious diseases and immunopathology.

2021 ◽  
Vol 12 ◽  
Author(s):  
Aidil Zaini ◽  
Thomas S. Fulford ◽  
Raelene J. Grumont ◽  
Jessica Runting ◽  
Grace Rodrigues ◽  
...  

Group 2 innate lymphoid cells (ILC2s) are emerging as important cellular regulators of homeostatic and disease-associated immune processes. The cytokine interleukin-33 (IL-33) promotes ILC2-dependent inflammation and immunity, with IL-33 having been shown to activate NF-κB in a wide variety of cell types. However, it is currently unclear which NF-κB members play an important role in IL-33-dependent ILC2 biology. Here, we identify the NF-κB family member c-Rel as a critical component of the IL-33-dependent activation of ILC2s. Although c-Rel is dispensable for ILC2 development, it is critical for ILC2 function in the lung, with c-Rel-deficient (c-Rel–/–) mice present a significantly reduced response to papain- and IL-33-induced lung inflammation. We also show that the absence of c-Rel reduces the IL-33-dependent expansion of ILC2 precursors and lower levels of IL-5 and IL-13 cytokine production by mature ILC2s in the lung. Together, these results identify the IL-33-c-Rel axis as a central control point of ILC2 activation and function.


2020 ◽  
pp. 2000018
Author(s):  
Yoshinari Nakatsuka ◽  
Ai Yaku ◽  
Tomohiro Handa ◽  
Alexis Vandenbon ◽  
Yuki Hikichi ◽  
...  

Regnase-1 is an RNase critical for posttranscriptional control of pulmonary immune homeostasis in mice by degrading immune-related mRNAs. However, little is known about the cell types Regnase-1 controls in the lung, and its relevance to human pulmonary diseases.Regnase-1-dependent changes in lung immune cell types were examined by a competitive bone marrow transfer mouse model, and group 2 innate lymphoid cells (ILC2s) were identified. Then the associations between Regnase-1 in ILC2s and human diseases were investigated by transcriptome analysis and a bleomycin-induced pulmonary fibrosis mouse model. The clinical significance of Regnase-1 in ILC2s was further assessed using patients-derived cells.Regnase-1-deficiency resulted in the spontaneous proliferation and activation of ILC2s in the lung. Intriguingly, genes associated with pulmonary fibrosis were highly upregulated in Regnase1-deficient ILC2s compared with wild-type, and supplementation of Regnase-1-deficient ILC2s augmented bleomycin-induced pulmonary fibrosis in mice. Regnase-1 suppresses mRNAs encoding transcription factors Gata3 and Egr1, which are potent to regulate fibrosis-associated genes. Clinically, Regnase-1 protein levels in ILC2 negatively correlated with the ILC2 population in bronchoalveolar lavage (BAL) fluid. Furthermore, idiopathic pulmonary fibrosis (IPF) patients with more than 1500 cells·mL−1 peripheral blood ILC2s exhibited poorer prognosis than patients with lower numbers, implying the contribution of Regnase-1 in ILC2s for the progression of IPF.Collectively, Regnase-1 was identified as a critical posttranscriptional regulator of the pro-fibrotic function of ILC2s both in mouse and human, suggesting that Regnase-1 may be a novel therapeutic target for IPF.


2021 ◽  
Author(s):  
Aidil Zaini ◽  
Thomas S. Fulford ◽  
Raelene J. Grumont ◽  
Jessica Runting ◽  
Grace Rodrigues ◽  
...  

AbstractGroup 2 innate lymphoid cells (ILC2s) are emerging as important cellular regulators of homeostatic and disease-associated immune processes. The cytokine interleukin-33 (IL-33) promotes ILC2-dependent inflammation and immunity, with IL-33 having been shown to activate NF-κB in a wide variety of cell types. However, it is currently unclear which NF-κB members play an important role in IL-33-dependent ILC2 biology. Here, we identify the NF-κB family member c-Rel as a critical component of the IL-33-dependent activation of ILC2s. Although c-Rel is dispensable for ILC2 development, it is critical for ILC2 function in the lung, with c-Rel-deficient (c-Rel–/–) mice resistant to papain- and IL-33-induced lung inflammation. We also show that the absence of c-Rel reduces the IL-33-dependent expansion of ILC2 precursors and lower levels of IL-5 and IL-13 cytokine production by mature ILC2s in the lung. Together, these results identify the IL-33-c-Rel axis as a central control point of ILC2 activation and function.


2019 ◽  
Vol 20 (6) ◽  
pp. 1377 ◽  
Author(s):  
Takashi Ebihara ◽  
Ichiro Taniuchi

Group 2 innate lymphoid cells (ILC2s) are tissue-resident cells and are a major source of innate TH2 cytokine secretion upon allergen exposure or parasitic-worm infection. Accumulating studies have revealed that transcription factors, including GATA-3, Bcl11b, Gfi1, RORα, and Ets-1, play a role in ILC2 differentiation. Recent reports have further revealed that the characteristics and functions of ILC2 are influenced by the physiological state of the tissues. Specifically, the type of inflammation strongly affects the ILC2 phenotype in tissues. Inhibitory ILC2s, memory-like ILC2s, and ex-ILC2s with ILC1 features acquire their characteristic properties following exposure to their specific inflammatory environment. We have recently reported a new ILC2 population, designated as exhausted-like ILC2s, which emerges after a severe allergic inflammation. Exhausted-like ILC2s are featured with low reactivity and high expression of inhibitory receptors. Therefore, for a more comprehensive understanding of ILC2 function and differentiation, we review the recent knowledge of transcriptional regulation of ILC2 differentiation and discuss the roles of the Runx transcription factor in controlling the emergence of exhausted-like ILC2s. The concept of exhausted-like ILC2s sheds a light on a new aspect of ILC2 biology in allergic diseases.


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 ◽  
...  

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.


Author(s):  
Lucas Vajko

Group 2 innate lymphoid cells (ILC2) are the majority of ILCs in murine lungs at steady state. ILC2s are the main producer of type-2-cytokines, IL-4, IL-5, IL-9, IL-13, and amphiregulin, playing key roles in lung tissue homeostasis, airway responses to pathogens and allergens, and in cancer-related defenses. ILC functions are regulated by cell surface receptors. NKR-P1B is an inhibitory receptor, which recognizes C-type lectin-related protein (Clr-b) as its ligand. NKR-P1B is expressed on subsets of natural killer cells, ILC2, ILC3, γδ T cells, macrophages and dendritic cells in a tissue-specific manner and regulates NK cell and ILC3 functions in the gut. Expression and function of NKR-P1B in the lung ILC populations is unexplored. Moreover, Clr-b, the ligand for NKR-P1B, is expressed in the bronchial epithelium, endothelial cells and in lung parenchyma, but its role in immune regulation in the lung is unknown. We hypothesize that ILC2s in the lung express NKR-P1B, and their function is regulated by the NKR-P1B:Clr-b recognition system. Using wild-type (WT) and NKR-P1B-deficient mice, we study the expression of NKR-P1B on lung ILC2, and the function of NKR-P1B:Clr-b recognition system in ILC2 development and function. We compare the phenotype, frequency, numbers and cytokine production by ILC2s upon stimulation between WT and NKR-P1B-deficient mice using antibody staining and flow cytometry analysis. This study will reveal the role of NKR-P1B as a model system for its human homolog, NKR-P1A, in the regulation of ILC development and function, advancing our understanding of how immune responses in the lung are regulated.


eLife ◽  
2019 ◽  
Vol 8 ◽  
Author(s):  
Prashant Rajbhandari ◽  
Douglas Arneson ◽  
Sydney K Hart ◽  
In Sook Ahn ◽  
Graciel Diamante ◽  
...  

Immune cells are vital constituents of the adipose microenvironment that influence both local and systemic lipid metabolism. Mice lacking IL10 have enhanced thermogenesis, but the roles of specific cell types in the metabolic response to IL10 remain to be defined. We demonstrate here that selective loss of IL10 receptor α in adipocytes recapitulates the beneficial effects of global IL10 deletion, and that local crosstalk between IL10-producing immune cells and adipocytes is a determinant of thermogenesis and systemic energy balance. Single Nuclei Adipocyte RNA-sequencing (SNAP-seq) of subcutaneous adipose tissue defined a metabolically-active mature adipocyte subtype characterized by robust expression of genes involved in thermogenesis whose transcriptome was selectively responsive to IL10Rα deletion. Furthermore, single-cell transcriptomic analysis of adipose stromal populations identified lymphocytes as a key source of IL10 production in response to thermogenic stimuli. These findings implicate adaptive immune cell-adipocyte communication in the maintenance of adipose subtype identity and function.


2013 ◽  
Vol 2013 ◽  
pp. 1-12
Author(s):  
Marisa Vulcano ◽  
María Gabriela Lombardi ◽  
María Elena Sales

Besides being the main neurotransmitter in the parasympathetic nervous system, acetylcholine (ACh) can act as a signaling molecule in nonneuronal tissues. For this reason, ACh and the enzymes that synthesize and degrade it (choline acetyltransferase and acetylcholinesterase) as well as muscarinic (mAChRs) and nicotinic receptors conform the non-neuronal cholinergic system (nNCS). It has been reported that nNCS regulates basal cellular functions including survival, proliferation, adhesion, and migration. Moreover, nNCS is broadly expressed in tumors and in different components of the immune system. In this review, we summarize the role of nNCS in tumors and in different immune cell types focusing on the expression and function of mAChRs in breast tumors and dendritic cells (DCs) and discussing the role of DCs in breast cancer.


2021 ◽  
Author(s):  
Kristi J Warren ◽  
Jill A Poole ◽  
Jenea M Sweeter ◽  
Jane M DeVasure ◽  
John D Dickinson ◽  
...  

Abstract Background: Respiratory viral infections are one of the leading causes of need for emergency care and hospitalizations in asthmatic individuals, and airway-secreted cytokines are released within hours of viral infection to initiate these exacerbations. IL-33, specifically, contributes to these allergic exacerbations by amplifying type 2 inflammation. We hypothesized that blocking IL-33 in RSV-induced exacerbation would significantly reduce allergic inflammation. Methods: Sensitized BALB/c mice were challenged with aerosolized ovalbumin (OVA) to establish allergic inflammation, followed by RSV-A2 infection to yield four treatment groups: Saline only (Saline), RSV-infected alone (RSV), OVA alone (OVA), and OVA-treated with RSV infection (OVA-RSV). Lung outcomes included lung mRNA and protein markers of allergic inflammation, histology for mucus cell metaplasia and lung immune cell influx by cytospin and flow cytometry. Results: While thymic stromal lymphopoietin (TSLP) and IL-33 were detected 6 hours after RSV infection in the OVA-RSV mice, IL-23 protein was uniquely upregulated in RSV-infected mice alone. OVA-RSV animals varied from RSV- or OVA-treated mice as they had increased lung eosinophils, neutrophils, group 2 innate lymphoid cells (ILC2) and group 3 innate lymphoid cells (ILC3) detectable as early as 6 hours after RSV infection. Neutralized IL-33 significantly reduced ILC2 and eosinophils, and the prototypical allergic proteins, IL-5, IL-13, CCL17 and CCL22 in OVA-RSV mice. Numbers of neutrophils and ILC3 were also reduced with anti-IL-33 treatment in both RSV and OVA-RSV treated animals as well. Conclusions: Taken together, our findings indicate a broad reduction in allergic-proinflammatory events mediated by IL-33 in RSV-induced asthma exacerbation.


Sign in / Sign up

Export Citation Format

Share Document