ILC2s regulate adaptive Th2 cell functions via PD-L1 checkpoint control

Group 2 innate lymphoid cells (ILC2s) are important effector cells driving the initiation of type 2 immune responses leading to adaptive T helper 2 (Th2) immunity. Here we show that ILC2s dynamically express the checkpoint inhibitor molecule PD-L1 during type 2 pulmonary responses. Surprisingly, PD-L1:PD-1 interaction between ILC2s and CD4+ T cells did not inhibit the T cell response, but PD-L1–expressing ILC2s stimulated increased expression of GATA3 and production of IL-13 by Th2 cells both in vitro and in vivo. Conditional deletion of PD-L1 on ILC2s impaired early Th2 polarization and cytokine production, leading to delayed worm expulsion during infection with the gastrointestinal helminth Nippostrongylus brasiliensis. Our results identify a novel PD-L1–controlled mechanism for type 2 polarization, with ILC2s mediating an innate checkpoint to control adaptive T helper responses, which has important implications for the treatment of type 2 inflammation.

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IL-9–mediated survival of type 2 innate lymphoid cells promotes damage control in helminth-induced lung inflammation

Journal of Experimental Medicine ◽

10.1084/jem.20130071 ◽

2013 ◽

Vol 210 (13) ◽

pp. 2951-2965 ◽

Cited By ~ 239

Author(s):

Jan-Eric Turner ◽

Peter J. Morrison ◽

Christoph Wilhelm ◽

Mark Wilson ◽

Helena Ahlfors ◽

...

Keyword(s):

Lung Inflammation ◽

Damage Control ◽

Recovery Phase ◽

Innate Lymphoid Cells ◽

Lymphoid Cells ◽

Th2 Cells ◽

Nippostrongylus Brasiliensis

IL-9 fate reporter mice established type 2 innate lymphoid cells (ILC2s) as major producers of this cytokine in vivo. Here we focus on the role of IL-9 and ILC2s during the lung stage of infection with Nippostrongylus brasiliensis, which results in substantial tissue damage. IL-9 receptor (IL-9R)–deficient mice displayed reduced numbers of ILC2s in the lung after infection, resulting in impaired IL-5, IL-13, and amphiregulin levels, despite undiminished numbers of Th2 cells. As a consequence, the restoration of tissue integrity and lung function was strongly impaired in the absence of IL-9 signaling. ILC2s, in contrast to Th2 cells, expressed high levels of the IL-9R, and IL-9 signaling was crucial for the survival of activated ILC2s in vitro. Furthermore, ILC2s in the lungs of infected mice required the IL-9R to up-regulate the antiapoptotic protein BCL-3 in vivo. This highlights a unique role for IL-9 as an autocrine amplifier of ILC2 function, promoting tissue repair in the recovery phase after helminth-induced lung inflammation.

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Cc Chemokine Receptor (Ccr)3/Eotaxin Is Followed by Ccr4/Monocyte-Derived Chemokine in Mediating Pulmonary T Helper Lymphocyte Type 2 Recruitment after Serial Antigen Challenge in Vivo

Journal of Experimental Medicine ◽

10.1084/jem.191.2.265 ◽

2000 ◽

Vol 191 (2) ◽

pp. 265-274 ◽

Cited By ~ 230

Author(s):

Clare M. Lloyd ◽

Tracy Delaney ◽

Trang Nguyen ◽

Jane Tian ◽

Carlos Martinez-A ◽

...

Keyword(s):

Chemokine Receptor ◽

Progressive Increase ◽

Allergic Airway Disease ◽

Antigen Challenge ◽

Th2 Cells ◽

T Helper ◽

Cc Chemokine

Isolated peripheral blood CD4 cells from allergic individuals express CC chemokine receptor (CCR)3 and CCR4 after expansion in vitro. In addition, human T helper type 2 (Th2) cells polarized in vitro selectively express CCR3 and CCR4 at certain stages of activation/differentiation and respond preferentially to the ligands eotaxin and monocyte-derived chemokine (MDC). However, controversy arises when the in vivo significance of this distinct expression is discussed. To address the functional role of CCR3/eotaxin and CCR4/MDC during the in vivo recruitment of Th2 cells, we have transferred effector Th cells into naive mice to induce allergic airway disease. Tracking of these cells after repeated antigen challenge has established that both CCR3/eotaxin and CCR4/MDC axes contribute to the recruitment of Th2 cells to the lung, demonstrating the in vivo relevance of the expression of these receptors on Th2 cells. We have shown that involvement of the CCR3/eotaxin pathway is confined to early stages of the response in vivo, whereas repeated antigen stimulation results in the predominant use of the CCR4/MDC pathway. We propose that effector Th2 cells respond to both CCR3/eotaxin and CCR4/MDC pathways initially, but that a progressive increase in CCR4-positive cells results in the predominance of the CCR4/MDC axis in the long-term recruitment of Th2 cells in vivo.

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Acetylcholine production by group 2 innate lymphoid cells promotes mucosal immunity to helminths

Science Immunology ◽

10.1126/sciimmunol.abd0359 ◽

2021 ◽

Vol 6 (57) ◽

pp. eabd0359

Author(s):

Luke B. Roberts ◽

Corinna Schnoeller ◽

Rita Berkachy ◽

Matthew Darby ◽

Jamie Pillaye ◽

...

Keyword(s):

Innate Lymphoid Cells ◽

Lymphoid Cells ◽

Mucosal Barrier ◽

Nippostrongylus Brasiliensis ◽

Interleukin 33 ◽

Group 2 ◽

Maximal Induction

Innate lymphoid cells (ILCs) are critical mediators of immunological and physiological responses at mucosal barrier sites. Whereas neurotransmitters can stimulate ILCs, the synthesis of small-molecule neurotransmitters by these cells has only recently been appreciated. Group 2 ILCs (ILC2s) are shown here to synthesize and release acetylcholine (ACh) during parasitic nematode infection. The cholinergic phenotype of pulmonary ILC2s was associated with their activation state, could be induced by in vivo exposure to extracts of Alternaria alternata or the alarmin cytokines interleukin-33 (IL-33) and IL-25, and was augmented by IL-2 in vitro. Genetic disruption of ACh synthesis by murine ILC2s resulted in increased parasite burdens, lower numbers of ILC2s, and reduced lung and gut barrier responses to Nippostrongylus brasiliensis infection. These data demonstrate a functional role for ILC2-derived ACh in the expansion of ILC2s for maximal induction of type 2 immunity.

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The Absence of Interleukin 1 Receptor–Related T1/St2 Does Not Affect T Helper Cell Type 2 Development and Its Effector Function

Journal of Experimental Medicine ◽

10.1084/jem.190.10.1541 ◽

1999 ◽

Vol 190 (10) ◽

pp. 1541-1548 ◽

Cited By ~ 147

Author(s):

Katsuaki Hoshino ◽

Shin-ichiro Kashiwamura ◽

Kozo Kuribayashi ◽

Taku Kodama ◽

Tohru Tsujimura ◽

...

Keyword(s):

Mast Cells ◽

Cell Function ◽

Interleukin 1 ◽

Orphan Receptor ◽

Th2 Cells ◽

Nippostrongylus Brasiliensis ◽

T Helper ◽

Th2 Responses ◽

And Function

T1/ST2, an orphan receptor with homology with the interleukin (IL)-1 receptor family, is expressed constitutively and stably on the surface of T helper type 2 (Th2) cells, but not on Th1 cells. T1/ST2 is also expressed on mast cells, which are critical for Th2-mediated effector responses. To evaluate whether T1/ST2 is required for Th2 responses and mast cell function, we have generated T1/ST2-deficient (T1/ST2−/−) mice and examined the roles of T1/ST2. Naive CD4+ T cells isolated from T1/ST2−/− mice developed to Th2 cells in response to IL-4 in vitro. T1/ST2−/− mice showed normal Th2 responses after infection with the helminthic parasite Nippostrongylus brasiliensis as well as in the mouse model of allergen-induced airway inflammation. In addition, differentiation and function of bone marrow–derived cultured mast cells were unaffected. These findings demonstrate that T1/ST2 does not play an essential role in development and function of Th2 cells and mast cells.

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Extract of Nippostrongylus brasiliensisStimulates Polyclonal Type-2 Immunoglobulin Response by Inducing De Novo Class Switch

Infection and Immunity ◽

10.1128/iai.68.9.4913-4922.2000 ◽

2000 ◽

Vol 68 (9) ◽

pp. 4913-4922 ◽

Cited By ~ 14

Author(s):

Humphrey N. Ehigiator ◽

Andrew W. Stadnyk ◽

Timothy D. G. Lee

Keyword(s):

B Cells ◽

De Novo ◽

Immunoglobulin E ◽

T Cell Response ◽

In Vitro Cultures ◽

Interleukin 4 ◽

Nippostrongylus Brasiliensis ◽

Class Switch

ABSTRACT Infection with the nematode parasite Nippostrongylus brasiliensis induces a pronounced type-2 T-cell response that is associated with marked polyclonal immunoglobulin E (IgE) and IgG1 production in mice. To examine the differential roles of the infection and products produced by nematodes, we investigated a soluble extract of N. brasiliensis for the ability to mediate this type-2 response. We found that the extract induced a marked increase in IgE and IgG1 levels, similar to that induced by the infection. The extract did not affect the level of IgG2a in serum, showing that the effect was specific to IgE and IgG1 (type-2-associated immunoglobulin) rather than inducing a nonspecific increase in all immunoglobulin isotypes. This response was also associated with increased interleukin-4 production in vitro. These results confirm that the extract, like infection, is a strong inducer of polyclonal type-2 responses and a reliable model for investigating the regulation of nematode-induced responses. The extract induced the production of IgG1 when added to in vitro cultures of lipopolysaccharide-stimulated B cells. This provides evidence for the induction of class switch. It did not induce upregulation of IgG1 in naive (unstimulated) B cells or expand B cells in in vitro cultures. Analysis of DNA from the spleens of mice treated with the extract by digestion-circularization PCR demonstrated a marked increase in the occurrence of γ1 switch region gene recombination in the cells in vivo. These results provide strong evidence that soluble worm products are able to mediate the marked polyclonal γ1/ɛ response and that infection is not required to mediate this response. Furthermore, these data provide evidence that the soluble nematode extract induces this effect by causing de novo class switch of B cells and not by an expansion of IgG1 B cells or an increase in antibody production by IgG1 plasma cells.

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n-3 Fatty acids inhibit transcription of human IL-13: implications for development of T helper type 2 immune responses

British Journal Of Nutrition ◽

10.1017/s0007114512002917 ◽

2012 ◽

Vol 109 (6) ◽

pp. 990-1000 ◽

Cited By ~ 8

Author(s):

Emily MacLean ◽

Norman Madsen ◽

Harissios Vliagoftis ◽

Catherine Field ◽

Lisa Cameron

Keyword(s):

Fatty Acids ◽

Fatty Acid ◽

Allergic Disease ◽

Transcriptional Activation ◽

Control Diet ◽

Th2 Cells ◽

T Helper ◽

Helper Type

Fish oil supplementation during pregnancy has been associated with lower levels of cord blood IL-13, suggesting that the administration ofn-3 fatty acids may attenuate the development of allergic disease. The present study aimed to investigate the mechanism by whichn-3 fatty acid administration influences the production of IL-13. Pregnant BALB/c mice were fed nutritionally complete high-fat diets (15 %, w/w) with ann-3 fatty acid-enriched (DHA 1 %, w/w) or control diet (0 % DHA) immediately following delivery. Pups were exposed during suckling and weaned to the maternal diet for the remainder of the study. The production of IL-13, IL-4, IL-10 and interferon-γ from the splenocytes of ovalbumin (ova)-sensitised animals was assessed followingin vitroova stimulation or unstimulated conditions. Human T helper type 2 (Th2) cells were mitogen-stimulated in the presence or absence of DHA (10 μm) and assessed for IL-13 and IL-4 expression using intracellular flow cytometry. The influence on transcriptional activation was studied using a human IL-13 promoter reporter construct and electromobility shift assay. Ova-activated splenocytes from DHA-fed mice produced less IL-13 (57·2 (se21·7) pg/ml) and IL-4 (7·33 (se3·4) pg/ml) compared with cells from the animals fed the control diet (161·5 (se45·0),P< 0·05; 33·2 (se11·8),P< 0·05).In vitro, DHA inhibited the expression of IL-13 protein from human Th2 cells as well as transcriptional activation and binding of the transcription factors cyclic AMP response element binding and activating transcription factor 2 to the human IL-13 promoter. These data indicate the potential ofn-3 fatty acids to attenuate IL-13 expression, and suggest that they may subsequently reduce allergic sensitisation and the development of allergic disease.

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T Cell Receptor–Induced Calcineurin Activation Regulates T Helper Type 2 Cell Development by Modifying the Interleukin 4 Receptor Signaling Complex

Journal of Experimental Medicine ◽

10.1084/jem.191.11.1869 ◽

2000 ◽

Vol 191 (11) ◽

pp. 1869-1880 ◽

Cited By ~ 82

Author(s):

Masakatsu Yamashita ◽

Makoto Katsumata ◽

Makio Iwashima ◽

Motoko Kimura ◽

Chiori Shimizu ◽

...

Keyword(s):

Cell Receptor ◽

Cell Development ◽

Interleukin 4 ◽

Th2 Cells ◽

T Helper ◽

Signaling Complex ◽

Th2 Cell ◽

Interleukin 4 Receptor

The activation of downstream signaling pathways of both T cell receptor (TCR) and interleukin 4 receptor (IL-4R) is essential for T helper type 2 (Th2) cell development, which is central to understanding immune responses against helminthic parasites and in allergic and autoimmune diseases. However, little is known about how these two distinct signaling pathways cooperate with each other to induce Th2 cells. Here, we show that successful Th2 cell development depends on the effectiveness of TCR-induced activation of calcineurin. An inhibitor of calcineurin activation, FK506, inhibited the in vitro anti-TCR–induced Th2 cell generation in a dose-dependent manner. Furthermore, the development of Th2 cells was significantly impaired in naive T cells from dominant-negative calcineurin Aα transgenic mice, whereas that of Th1 cells was less affected. Efficient calcineurin activation in naive T cells upregulated Janus kinase (Jak)3 transcription and the amount of protein. The generation of Th2 cells induced in vitro by anti-TCR stimulation was inhibited significantly by the presence of Jak3 antisense oligonucleotides, suggesting that the Jak3 upregulation is an important event for the Th2 cell development. Interestingly, signal transducer and activator of transcription (STAT)5 became physically and functionally associated with the IL-4R in the anti-TCR–activated developing Th2 cells that received efficient calcineurin activation, and also in established cloned Th2 cells. In either cell population, the inhibition of STAT5 activation resulted in a diminished IL-4–induced proliferation. Moreover, our results suggest that IL-4–induced STAT5 activation is required for the expansion process of developing Th2 cells. Thus, Th2 cell development is controlled by TCR-mediated activation of the Ca2+/calcineurin pathway, at least in part, by modifying the functional structure of the IL-4R signaling complex.

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Pulmonary type-2 innate lymphoid cells in paediatric severe asthma: phenotype and response to steroids

European Respiratory Journal ◽

10.1183/13993003.01809-2018 ◽

2019 ◽

Vol 54 (2) ◽

pp. 1801809 ◽

Cited By ~ 11

Author(s):

Prasad Nagakumar ◽

Franz Puttur ◽

Lisa G. Gregory ◽

Laura Denney ◽

Louise Fleming ◽

...

Keyword(s):

Symptom Control ◽

Innate Lymphoid Cells ◽

Lymphoid Cells ◽

Th2 Cells ◽

Poor Control ◽

Inhaled Steroids ◽

Elevated Type

Children with severe therapy-resistant asthma (STRA) have poor control despite maximal treatment, while those with difficult asthma (DA) have poor control from failure to implement basic management, including adherence to therapy. Although recognised as clinically distinct, the airway molecular phenotype, including the role of innate lymphoid cells (ILCs) and their response to steroids in DA and STRA is unknown.Immunophenotyping of sputum and blood ILCs and T-cells from STRA, DA and non-asthmatic controls was undertaken. Leukocytes were analysed longitudinally pre- and post-intramuscular triamcinolone in children with STRA. Cultured ILCs were evaluated to assess steroid responsiveness in vitro.Airway eosinophils, type 2 T-helper (Th2) cells and ILC2s were significantly higher in STRA patients compared to DA and disease controls, while IL-17+ lymphoid cells were similar. ILC2s and Th2 cells were significantly reduced in vivo following intramuscular triamcinolone and in vitro with steroids. Furthermore, asthma attacks and symptoms reduced after systemic steroids despite persistence of steroid-resistant IL-17+ cells and eosinophils.Paediatric STRA and DA have distinct airway molecular phenotypes with STRA characterised by elevated type-2 cells. Systemic corticosteroids, but not maintenance inhaled steroids resulted in improved symptom control and exacerbations concomitant with a reduction in functional ILC2s despite persistently elevated IL-17+ lymphoid cells.

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MicroRNA regulation of type 2 innate lymphoid cell homeostasis and function in allergic inflammation

Journal of Experimental Medicine ◽

10.1084/jem.20170545 ◽

2017 ◽

Vol 214 (12) ◽

pp. 3627-3643 ◽

Cited By ~ 40

Author(s):

Priti B. Singh ◽

Heather H. Pua ◽

Hannah C. Happ ◽

Christoph Schneider ◽

Jakob von Moltke ◽

...

Keyword(s):

Target Genes ◽

Therapeutic Potential ◽

Allergic Inflammation ◽

Lymphoid Cells ◽

Th2 Cells ◽

Signaling Inhibitors ◽

Regulated Gene Expression ◽

And Function

MicroRNAs (miRNAs) exert powerful effects on immunity through coordinate regulation of multiple target genes in a wide variety of cells. Type 2 innate lymphoid cells (ILC2s) are tissue sentinel mediators of allergic inflammation. We established the physiological requirements for miRNAs in ILC2 homeostasis and immune function and compared the global miRNA repertoire of resting and activated ILC2s and T helper type 2 (TH2) cells. After exposure to the natural allergen papain, mice selectively lacking the miR-17∼92 cluster in ILC2s displayed reduced lung inflammation. Moreover, miR-17∼92–deficient ILC2s exhibited defective growth and cytokine expression in response to IL-33 and thymic stromal lymphopoietin in vitro. The miR-17∼92 cluster member miR-19a promoted IL-13 and IL-5 production and inhibited expression of several targets, including SOCS1 and A20, signaling inhibitors that limit IL-13 and IL-5 production. These findings establish miRNAs as important regulators of ILC2 biology, reveal overlapping but nonidentical miRNA-regulated gene expression networks in ILC2s and TH2 cells, and reinforce the therapeutic potential of targeting miR-19 to alleviate pathogenic allergic responses.

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