InVivoMAb anti-mouse/human IL-7

Catalog #BE0048
Product Citations:
14
Clone:
M25
Reactivities:
Mouse, Human

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Product Details

The M25 monoclonal antibody reacts with mouse and human IL-7, a 20-28 kDa hematopoietic growth factor secreted by stromal cells in the bone marrow and thymus. IL-7 is also produced by keratinocytes, dendritic cells, hepatocytes, neurons, and epithelial cells. IL-7 binds to the IL-7 receptor, a heterodimer consisting of IL-7 receptor alpha and the common gamma chain receptor. Binding results in stimulation of differentiation of pluripotent hematopoietic stem cells into lymphoid progenitor cells and proliferation of all lymphoid cells. IL-7 is also important for proliferation of pre-B cells as well as T and NK cell survival, development and homeostasis. The M25 antibody is useful for neutralizing the bioactivity of IL-7 as well as administration of IL-7 cytokine. IL-7 administration as a complex with M25 prolongs IL-7 availability in vivo by decreasing specific and nonspecific consumption.

Specifications

Isotype Mouse IgG2b
Recommended Isotype Control(s) InVivoMAb mouse IgG2b isotype control, unknown specificity
Recommended Dilution Buffer InVivoPure pH 7.0 Dilution Buffer
Conjugation This product is unconjugated. Conjugation is available via our Antibody Conjugation Services.
Immunogen Recombinant human IL-7
Reported Applications in vivo IL-7 neutralization
in vivo IL-7 receptor stimulation (as a complex with IL-7)
Formulation PBS, pH 7.0
Contains no stabilizers or preservatives
Endotoxin <2EU/mg (<0.002EU/μg)
Determined by LAL gel clotting assay
Purity >95%
Determined by SDS-PAGE
Sterility 0.2 µm filtration
Production Purified from cell culture supernatant in an animal-free facility
Purification Protein G
RRID AB_1107711
Molecular Weight 150 kDa
Storage The antibody solution should be stored at the stock concentration at 4°C. Do not freeze.
in vivo IL-7 receptor stimulation (as a complex with IL-7)
Arbelaez, C. A., et al. (2015). "IL-7/IL-7 Receptor Signaling Differentially Affects Effector CD4+ T Cell Subsets Involved in Experimental Autoimmune Encephalomyelitis" J Immunol 195(5): 1974-1983. PubMed

IL-17-producing CD4(+) T (Th17) cells, along with IFN-gamma-expressing Th1 cells, represent two major pathogenic T cell subsets in experimental autoimmune encephalomyelitis (EAE), the animal model of multiple sclerosis (MS). The cytokines and transcription factors involved in the development and effector functions of Th1 and Th17 cells have been largely characterized. Among them, IL-23 is essential for the generation of stable and encephalitogenic Th17 cells and for the development of EAE. The IL-7/IL-7R signaling axis participates in cell survival, and perturbation of this pathway has been associated with enhanced susceptibility to MS. A link between IL-23-driven pathogenic T cells and IL-7/IL-7R signaling has previously been proposed, but has not been formally addressed. In the current study, we showed that Th17 cells from mice with EAE express high levels of IL-7Ralpha compared with Th1 cells. Using mice that constitutively express IL-7Ralpha on T cells, we determined that sustained IL-7R expression in IL-23R-deficient mice could not drive pathogenic T cells and the development of EAE. IL-7 inhibited the differentiation of Th17 cells, but promoted IFN-gamma and GM-CSF secretion in vitro. In vivo IL-7/anti-IL-7 mAb complexes selectively expanded and enhanced the proliferation of CXCR3-expressing Th1 cells, but did not impact Th17 cells and EAE development in wild-type and IL-23R-deficient mice. Importantly, high IL-7 expression was detected in the CNS during EAE and could drive the plasticity of Th17 cells to IFN-gamma-producing T cells. Together, these data address the contribution of IL-23/IL-23R and IL-7/IL-7R signaling in Th17 and Th1 cell dynamics during CNS autoimmunity.

in vivo IL-7 receptor stimulation (as a complex with IL-7)
Abt, M. C., et al. (2015). "Innate Immune Defenses Mediated by Two ILC Subsets Are Critical for Protection against Acute Clostridium difficile Infection" Cell Host Microbe 18(1): 27-37. PubMed

Infection with the opportunistic enteric pathogen Clostridium difficile is an increasingly common clinical complication that follows antibiotic treatment-induced gut microbiota perturbation. Innate lymphoid cells (ILCs) are early responders to enteric pathogens; however, their role during C. difficile infection is undefined. To identify immune pathways that mediate recovery from C. difficile infection, we challenged C57BL/6, Rag1(-/-) (which lack T and B cells), and Rag2(-/-)Il2rg(-/-) (Raggammac(-/-)) mice (which additionally lack ILCs) with C. difficile. In contrast to Rag1(-/-) mice, ILC-deficient Raggammac(-/-) mice rapidly succumbed to infection. Rag1(-/-) but not Raggammac(-/-) mice upregulate expression of ILC1- or ILC3-associated proteins following C. difficile infection. Protection against infection was restored by transferring ILCs into Raggammac(-/-) mice. While ILC3s made a minor contribution to resistance, loss of IFN-gamma or T-bet-expressing ILC1s in Rag1(-/-) mice increased susceptibility to C. difficile. These data demonstrate a critical role for ILC1s in defense against C. difficile.

in vivo IL-7 neutralization
Le Saout, C., et al. (2014). "Chronic exposure to type-I IFN under lymphopenic conditions alters CD4 T cell homeostasis" PLoS Pathog 10(3): e1003976. PubMed

HIV infection and the associated chronic immune activation alter T cell homeostasis leading to CD4 T cell depletion and CD8 T cell expansion. The mechanisms behind these outcomes are not totally defined and only partially explained by the direct cytopathic effect of the virus. In this manuscript, we addressed the impact of lymphopenia and chronic exposure to IFN-alpha on T cell homeostasis. In a lymphopenic murine model, this interaction led to decreased CD4 counts and CD8 T cell expansion in association with an increase in the Signal Transducer and Activator of Transcription 1 (STAT1) levels resulting in enhanced CD4 T cell responsiveness to IFN-alpha. Thus, in the setting of HIV infection, chronic stimulation of this pathway could be detrimental for CD4 T cell homeostasis.

in vivo IL-7 receptor stimulation (as a complex with IL-7)
McKinstry, K. K., et al. (2014). "Effector CD4 T-cell transition to memory requires late cognate interactions that induce autocrine IL-2" Nat Commun 5: 5377. PubMed

It is unclear how CD4 T-cell memory formation is regulated following pathogen challenge, and when critical mechanisms act to determine effector T-cell fate. Here, we report that following influenza infection most effectors require signals from major histocompatibility complex class II molecules and CD70 during a late window well after initial priming to become memory. During this timeframe, effector cells must produce IL-2 or be exposed to high levels of paracrine or exogenously added IL-2 to survive an otherwise rapid default contraction phase. Late IL-2 promotes survival through acute downregulation of apoptotic pathways in effector T cells and by permanently upregulating their IL-7 receptor expression, enabling IL-7 to sustain them as memory T cells. This new paradigm defines a late checkpoint during the effector phase at which cognate interactions direct CD4 T-cell memory generation.

in vivo IL-7 receptor stimulation (as a complex with IL-7)
Webster, K. E., et al. (2014). "IL-17-producing NKT cells depend exclusively on IL-7 for homeostasis and survival" Mucosal Immunol 7(5): 1058-1067. PubMed

Natural killer T (NKT) cells are innate-like T cells that rapidly recognize pathogens and produce cytokines that shape the ensuing immune response. IL-17-producing NKT cells are enriched in barrier tissues, such as the lung, skin, and peripheral lymph nodes, and the factors that maintain this population in the periphery have not been elucidated. Here we show that NKT17 cells deviate from other NKT cells in their survival requirements. In contrast to conventional NKT cells that are maintained by IL-15, RORgammat(+) NKT cells are IL-15 independent and instead rely completely on IL-7. IL-7 initiates a T-cell receptor-independent (TCR-independent) expansion of NKT17 cells, thus supporting their homeostasis. Without IL-7, survival is dramatically impaired, yet residual cells remain lineage committed with no downregulation of RORgammat evident. Their preferential response to IL-7 does not reflect enhanced signaling through STAT proteins, but instead is modulated via the PI3K/AKT/mTOR signaling pathway. The ability to compete for IL-7 is dependent on high-density IL-7 receptor expression, which would promote uptake of low levels of IL-7 produced in the non-lymphoid sites of lung and skin. This dependence on IL-7 is also reported for RORgammat(+) innate lymphoid cells and CD4(+) Th17 cells, and suggests common survival requirements for functionally similar cells.

in vivo IL-7 receptor stimulation (as a complex with IL-7)
Smolarchuk, C., et al. (2014). "T cells generated in the absence of a thoracic thymus fail to establish homeostasis" Eur J Immunol 44(8): 2263-2273. PubMed

Cervical thymus mimics the thoracic thymus in supporting T-cell development and exists in a subset of mice and humans. Importantly, it remains unknown whether the cervical thymus can generate T cells that are self-tolerant in the complete absence of signals from the thoracic thymus. Using a fetal liver reconstitution model in thoracic thymectomized RAG(-/-) mice, we found that T cells could be generated without contribution from the thoracic thymus. However, these mice had decreased T cells, increased proportions of effector memory T cells and Treg phenotype cells, increased serum IgG1/2b, and increased frequency of T cells expressing IFN-gamma, IL-17 or IL-10. Half of the mice that received a thoracic thymectomy and fetal liver cells, unlike sham surgery controls, developed substantial morbidity with age. Disease was associated with lymphopenia-driven activation rather than inherent defects in the cervical thymus, as both thoracic and cervical thymocytes could generate disease in lymphopenic recipients. Administration of the homeostatic cytokine IL-7 caused a rapid, transient increase in T-cell numbers and reduced the time to disease onset. Together the data suggests that the cervical thymus can function in the complete absence of the thoracic thymus; however, the T cells generated do not establish homeostasis.

in vivo IL-7 receptor stimulation (as a complex with IL-7)
Li, L., et al. (2013). "Differential response of regulatory and conventional CD4(+) lymphocytes to CD3 engagement: clues to a possible mechanism of anti-CD3 action?" J Immunol 191(7): 3694-3704. PubMed

Several clinical trials have shown anti-CD3 treatment to be a promising therapy for autoimmune diabetes, but its mechanism of action remains unclear. Foxp3(+) regulatory T cells (Tregs) are likely to be involved, but through unknown mechanistic pathways. We profiled the transcriptional consequences in CD4(+) Tregs and conventional T cells (Tconvs) in the first hours and days after anti-CD3 treatment of NOD mice. Anti-CD3 treatment led to a transient transcriptional response, terminating faster than most Ag-induced responses. Most transcripts were similarly induced in Tregs and Tconvs, but several were differential, in particular, those encoding the IL-7R and transcription factors Id2/3 and Gfi1, upregulated in Tregs but repressed in Tconvs. Because IL-7R was a plausible candidate for driving the homeostatic response of Tregs to anti-CD3, we tested its relevance by supplementation of anti-CD3 treatment with IL-7/anti-IL-7 complexes. Although ineffective alone, IL-7 significantly improved the rate of remission induced by anti-CD3. Four anti-human CD3 mAbs exhibited the same differential effect on IL-7R expression in human as in mouse cells, suggesting that the mechanism also underlies therapeutic effect in human cells, and perhaps a rationale for testing a combination of anti-CD3 and IL-7 for the treatment of recent-onset human type 1 diabetes. Thus, systems-level analysis of the response to anti-CD3 in the early phase of the treatment demonstrates different responses in Tregs and Tconvs, and provides new leads to a mechanistic understanding of its mechanism of action in reverting recent-onset diabetes.

in vivo IL-7 receptor stimulation (as a complex with IL-7)
Simonetta, F., et al. (2012). "Interleukin-7 influences FOXP3+CD4+ regulatory T cells peripheral homeostasis" PLoS One 7(5): e36596. PubMed

Mechanisms governing peripheral CD4+ FOXP3+ regulatory T cells (Treg) survival and homeostasis are multiple suggesting tight and complex regulation of regulatory T cells homeostasis. Some specific factors, such as TGF-beta, interleukin-2 (IL-2) and B7 costimulatory molecules have been identified as essentials for maintenance of the peripheral Treg compartment. Conversely, Treg dependency upon classical T cell homeostatic factors such as IL-7 is still unclear. In this work, we formally investigated the role of IL-7 in Treg homeostasis in vivo in murine models. We demonstrated that IL-7 availability regulated the size of peripheral Treg cell pool and thus paralleled the impact of IL-7 on conventional T cell pool. Moreover, we showed that IL-7 administration increased Treg cell numbers by inducing thymic-independent Treg peripheral expansion. Importantly the impact of IL-7 on Treg expansion was detected whether conventional T cells were present or absent as IL-7 directly participates to the peripheral expansion of Treg after adoptive transfer into lymphopenic hosts. Our results definitively identify IL-7 as a central factor contributing to Treg peripheral homeostasis, thus reassembling Treg to other T cell subsets in respect of their need for IL-7 for their peripheral maintenance.

    • Immunology and Microbiology
    • ,
    IL-10 Promotes CXCL13 Expression in Macrophages Following Foot-and-Mouth Disease Virus Infection.

    In International Journal of Molecular Sciences on 28 March 2023 by Guo, Z., Chen, F., et al.

    PubMed

    Foot-and-mouth disease (FMD) is one of the most contagious livestock diseases in the world, posing a constant global threat to the animal trade and national economies. The chemokine C-X-C motif chemokine ligand 13 (CXCL13), a biomarker for predicting disease progression in some diseases, was recently found to be increased in sera from mice infected with FMD virus (FMDV) and to be associated with the progression and severity of the disease. However, it has not yet been determined which cells are involved in producing CXCL13 and the signaling pathways controlling CXCL13 expression in these cells. In this study, the expression of CXCL13 was found in macrophages and T cells from mice infected with FMDV, and CXCL13 was produced in bone-marrow-derived macrophages (BMDMs) by activating the nuclear factor-kappaB (NF-κB) and JAK/STAT pathways following FMDV infection. Interestingly, CXCL13 concentration was decreased in sera from interleukin-10 knock out (IL-10-/-) mice or mice blocked IL-10/IL-10R signaling in vivo after FMDV infection. Furthermore, CXCL13 was also decreased in IL-10-/- BMDMs and BMDMs treated with anti-IL-10R antibody following FMDV infection in vitro. Lastly, it was demonstrated that IL-10 regulated CXCL13 expression via JAK/STAT rather than the NF-κB pathway. In conclusion, the study demonstrated for the first time that macrophages and T cells were the cellular sources of CXCL13 in mice infected with FMDV; CXCL13 was produced in BMDMs via NF-κB and JAK/STAT pathways; and IL-10 promoted CXCL13 expression in BMDMs via the JAK/STAT pathway.

    • Immunology and Microbiology
    • ,
    • Neuroscience
    • ,
    • In Vivo
    • ,
    • Mus musculus (House mouse)
    Small intestine and colon tissue-resident memory CD8+ T cells exhibit molecular heterogeneity and differential dependence on Eomes.

    In Immunity on 10 January 2023 by Lin, Y. H., Duong, H. G., et al.

    PubMed

    Tissue-resident memory CD8+ T (TRM) cells are a subset of memory T cells that play a critical role in limiting early pathogen spread and controlling infection. TRM cells exhibit differences across tissues, but their potential heterogeneity among distinct anatomic compartments within the small intestine and colon has not been well recognized. Here, by analyzing TRM cells from the lamina propria and epithelial compartments of the small intestine and colon, we showed that intestinal TRM cells exhibited distinctive patterns of cytokine and granzyme expression along with substantial transcriptional, epigenetic, and functional heterogeneity. The T-box transcription factor Eomes, which represses TRM cell formation in some tissues, exhibited unexpected context-specific regulatory roles in supporting the maintenance of established TRM cells in the small intestine, but not in the colon. Taken together, these data provide previously unappreciated insights into the heterogeneity and differential requirements for the formation vs. maintenance of intestinal TRM cells. Copyright © 2022 Elsevier Inc. All rights reserved.

    • FC/FACS
    • ,
    • Mus musculus (House mouse)
    • ,
    • Cell Biology
    • ,
    • Immunology and Microbiology
    IRF4 deficiency vulnerates B-cell progeny for leukemogenesis via somatically acquired Jak3 mutations conferring IL-7 hypersensitivity.

    In Cell Death and Differentiation on 1 November 2022 by Das Gupta, D., Paul, C., et al.

    PubMed

    The processes leading from disturbed B-cell development to adult B-cell progenitor acute lymphoblastic leukemia (BCP-ALL) remain poorly understood. Here, we describe Irf4-/- mice as prone to developing BCP-ALL with age. Irf4-/- preB-I cells exhibited impaired differentiation but enhanced proliferation in response to IL-7, along with reduced retention in the IL-7 providing bone marrow niche due to decreased CXCL12 responsiveness. Thus selected, preB-I cells acquired Jak3 mutations, probably following irregular AID activity, resulting in malignant transformation. We demonstrate heightened IL-7 sensitivity due to Jak3 mutants, devise a model to explain it, and describe structural and functional similarities to Jak2 mutations often occurring in human Ph-like ALL. Finally, targeting JAK signaling with Ruxolitinib in vivo prolonged survival of mice bearing established Irf4-/- leukemia. Intriguingly, organ infiltration including leukemic meningeosis was selectively reduced without affecting blood blast counts. In this work, we present spontaneous leukemogenesis following IRF4 deficiency with potential implications for high-risk BCP-ALL in adult humans. © 2022. The Author(s).

    Age-Associated Changes to Lymph Node Fibroblastic Reticular Cells.

    In Front Aging on 14 July 2022 by Kwok, T., Medovich, S. C., et al.

    PubMed

    The decreased proportion of antigen-inexperienced, naïve T cells is a hallmark of aging in both humans and mice, and contributes to reduced immune responses, particularly against novel and re-emerging pathogens. Naïve T cells depend on survival signals received during their circulation among the lymph nodes by direct contacts with stroma, in particular fibroblastic reticular cells. Macroscopic changes to the architecture of the lymph nodes have been described, but it is unclear how lymph node stroma are altered with age, and whether these changes contribute to reduced naïve T cell maintenance. Here, using 2-photon microscopy, we determined that the aged lymph node displayed increased fibrosis and correspondingly, that naïve T-cell motility was impaired in the aged lymph node, especially in proximity to fibrotic deposition. Functionally, adoptively transferred young naïve T-cells exhibited reduced homeostatic turnover in aged hosts, supporting the role of T cell-extrinsic mechanisms that regulate their survival. Further, we determined that early development of resident fibroblastic reticular cells was impaired, which may correlate to the declining levels of naïve T-cell homeostatic factors observed in aged lymph nodes. Thus, our study addresses the controversy as to whether aging impacts the composition lymph node stroma and supports a model in which impaired differentiation of lymph node fibroblasts and increased fibrosis inhibits the interactions necessary for naïve T cell homeostasis. Copyright © 2022 Kwok, Medovich, Silva-Junior, Brown, Haug, Barrios, Morris and Lancaster.

    • Immunology and Microbiology
    IRF4 deficiency vulnerates B cell progeny for leukemogenesis via somatically acquired i>Jak3/i> mutations conferring IL-7 hypersensitivity

    Preprint on BioRxiv : the Preprint Server for Biology on 18 February 2022 by Gupta, D. D., Paul, C., et al.

    PubMed

    The processes leading from disturbed B cell development to adult B cell progenitor acute lymphoblastic leukemia (BCP-ALL) are poorly understood. Here, we describe Irf4 −/− mice as prone to developing BCP-ALL with age. Irf4 −/− preB-I cells exhibited impaired differentiation but enhanced proliferation in response to IL-7, along with reduced retention in the IL-7 providing bone marrow niche due to decreased CXCL12 responsiveness. Thus selected, preB-I cells acquired Jak3 mutations, probably following irregular AID activity, resulting in malignant transformation. We demonstrate heightened IL-7 sensitivity due to Jak3 mutants, devise a model to explain it and describe structural and functional similarities to Jak2 mutations often occurring in human Ph-like ALL. Finally, targeting JAK signaling with Ruxolitinib in vivo prolonged survival of mice bearing established Irf4 −/− leukemia. Intriguingly, organ infiltration including leukemic meningeosis was selectively reduced without affecting blood blast counts. In this work, we present spontaneous leukemogenesis following IRF4 deficiency with potential implications for high-risk BCP-ALL in adult humans.

    ILC3s control splenic cDC homeostasis via lymphotoxin signaling.

    In The Journal of Experimental Medicine on 3 May 2021 by Vanderkerken, M., Baptista, A. P., et al.

    PubMed

    The spleen contains a myriad of conventional dendritic cell (cDC) subsets that protect against systemic pathogen dissemination by bridging antigen detection to the induction of adaptive immunity. How cDC subsets differentiate in the splenic environment is poorly understood. Here, we report that LTα1β2-expressing Rorgt+ ILC3s, together with B cells, control the splenic cDC niche size and the terminal differentiation of Sirpα+CD4+Esam+ cDC2s, independently of the microbiota and of bone marrow pre-cDC output. Whereas the size of the splenic cDC niche depended on lymphotoxin signaling only during a restricted time frame, the homeostasis of Sirpα+CD4+Esam+ cDC2s required continuous lymphotoxin input. This latter property made Sirpα+CD4+Esam+ cDC2s uniquely susceptible to pharmacological interventions with LTβR agonists and antagonists and to ILC reconstitution strategies. Together, our findings demonstrate that LTα1β2-expressing Rorgt+ ILC3s drive splenic cDC differentiation and highlight the critical role of ILC3s as perpetual regulators of lymphoid tissue homeostasis. © 2021 Vanderkerken et al.

    • FC/FACS
    • ,
    • Mus musculus (House mouse)
    IRF4 deficiency vulnerates B progeny for leukemogenesis via Jak3 mutations resembling Ph-like B-ALL in humans

    Preprint on Research Square on 9 March 2021 by Gupta, D. D., Paul, C., et al.

    PubMed

    How disturbances of B cell development provoke adult B acute lymphoblastic leukemia (B-ALL) remains poorly understood. Here we describe Irf4–/– mice as prone to developing B-ALL with age. Irf4–/– pro/preB cells exhibited impaired differentiative but enhanced proliferative potential in vitro and accumulated in spleens of healthy Irf4–/– mice, suggesting reduced adherence to the IL-7 providing bone marrow niche. Thus selected, pro/preB cells transformed acquiring proliferative IL-7 independency through Jak3 gain-of-function mutations. Targeting JAK signaling with Ruxolitinib in vivo prolonged survival of mice bearing established Irf4–/– leukemia. Intriguingly, organ infiltration including leukemic meningeosis was selectively reduced without affecting blood blast counts. As low IRF4 expression and JAK3 mutations also characterize a subpopulation of Ph-like B-ALL in adult humans, our results imply Irf4–/– mice as a suitable model for investigating preleukemic conditions in adults. Using this model, we identified an unexpected effect of Ruxolitinib treatment in B-ALL.

    • Immunology and Microbiology
    Effector TH17 Cells Give Rise to Long-Lived TRM Cells that Are Essential for an Immediate Response against Bacterial Infection.

    In Cell on 22 August 2019 by Amezcua Vesely, M. C., Pallis, P., et al.

    PubMed

    Adaptive immunity provides life-long protection by generating central and effector memory T cells and the most recently described tissue resident memory T (TRM) cells. However, the cellular origin of CD4 TRM cells and their contribution to host defense remain elusive. Using IL-17A tracking-fate mouse models, we found that a significant fraction of lung CD4 TRM cells derive from IL-17A-producing effector (TH17) cells following immunization with heat-killed Klebsiella pneumonia (Kp). These exTH17 TRM cells are maintained in the lung by IL-7, produced by lymphatic endothelial cells. During a memory response, neither antibodies, γδ T cells, nor circulatory T cells are sufficient for the rapid host defense required to eliminate Kp. Conversely, using parabiosis and depletion studies, we demonstrated that exTH17 TRM cells play an important role in bacterial clearance. Thus, we delineate the origin and function of airway CD4 TRM cells during bacterial infection, offering novel strategies for targeted vaccine design. Copyright © 2019 Elsevier Inc. All rights reserved.

    IL-7 treatment augments and prolongs sepsis-induced expansion of IL-10-producing B lymphocytes and myeloid-derived suppressor cells.

    In PLoS ONE on 22 February 2018 by Kulkarni, U., Herrmenau, C., et al.

    PubMed

    Immunological dysregulation in sepsis is associated with often lethal secondary infections. Loss of effector cells and an expansion of immunoregulatory cell populations both contribute to sepsis-induced immunosuppression. The extent and duration of this immunosuppression are unknown. Interleukin 7 (IL-7) is important for the maintenance of lymphocytes and can accelerate the reconstitution of effector lymphocytes in sepsis. How IL-7 influences immunosuppressive cell populations is unknown. We have used the mouse model of peritoneal contamination and infection (PCI) to investigate the expansion of immunoregulatory cells as long-term sequelae of sepsis with or without IL-7 treatment. We analysed the frequencies and numbers of regulatory T cells (Tregs), double negative T cells, IL-10 producing B cells and myeloid-derived suppressor cells (MDSCs) for 3.5 months after sepsis induction. Sepsis induced an increase in IL-10+ B cells, which was enhanced and prolonged by IL-7 treatment. An increased frequency of MDSCs in the spleen was still detectable 3.5 months after sepsis induction and this was more pronounced in IL-7-treated mice. MDSCs from septic mice were more potent at suppressing T cell proliferation than MDSCs from control mice. Our data reveal that sepsis induces a long lasting increase in IL-10+ B cells and MDSCs. Late-onset IL-7 treatment augments this increase, which should be relevant for clinical interventions.

    • Immunology and Microbiology
    • ,
    • Stem Cells and Developmental Biology
    • ,
    • Mus musculus (House mouse)
    Stimulation of hair follicle stem cell proliferation through an IL-1 dependent activation of γδT-cells.

    In eLife on 4 December 2017 by Lee, P., Gund, R., et al.

    PubMed

    The cutaneous wound-healing program is a product of a complex interplay among diverse cell types within the skin. One fundamental process that is mediated by these reciprocal interactions is the mobilization of local stem cell pools to promote tissue regeneration and repair. Using the ablation of epidermal caspase-8 as a model of wound healing in Mus musculus, we analyzed the signaling components responsible for epithelial stem cell proliferation. We found that IL-1α and IL-7 secreted from keratinocytes work in tandem to expand the activated population of resident epidermal γδT-cells. A downstream effect of activated γδT-cells is the preferential proliferation of hair follicle stem cells. By contrast, IL-1α-dependent stimulation of dermal fibroblasts optimally stimulates epidermal stem cell proliferation. These findings provide new mechanistic insights into the regulation and function of epidermal cell-immune cell interactions and into how components that are classically associated with inflammation can differentially influence distinct stem cell niches within a tissue.

    • Immunology and Microbiology
    • ,
    • Neuroscience
    PI3Kδ inhibition supports memory T cells with enhanced antitumor fitness

    Preprint on BioRxiv : the Preprint Server for Biology on 20 July 2017 by Bowers, J. S., Majchrzak, K., et al.

    PubMed

    h4>SUMMARY/h4> Phosphatidylinositol-3-kinase p110δ (PI3Kδ) inhibition by Idelalisib (CAL-101) in hematological malignancies directly induces apoptosis in cancer cells and disrupts immunological tolerance by depleting regulatory T cells (Tregs). Yet, little is known about the direct impact of PI3Kδ blockade on effector T cells from CAL-101 therapy. Herein, we demonstrate a direct effect of p110δ inactivation via CAL-101 on murine and human CD8 + T cells that promotes a strong undifferentiated memory phenotype (elevated CD62L/CCR7, CD127 and Tcf7). These CAL-101 T cells also persisted longer after transfer and exerted stronger antitumor immunity compared to traditionally expanded CD8 + T cells in two solid tumor models. Thus, this report describes a novel direct enhancement of CD8 + T cell memory by a p110δ inhibitor that leads to markedly improved tumor regression. This finding has significant implications to improve outcomes from next generation cancer immunotherapies. h4>Highlights/h4> In vitro blockade of PI3K p110δ with CAL-101 endows antitumor T cells with a stronger memory phenotype than those treated with AKTi The strong memory phenotype of CAL-101 treated cells translates into improved survival of mice bearing aggressive tumors after adoptive transfer of these T cells Human CAR engineered T cells treated with CAL-101 possess an enhanced memory phenotype and robust antitumor efficacy The antitumor efficacy of CAL-101 primed T cells is not mediated by high CD62L or CD127 expression, but is likely driven by their stem memory phenotype h4>eTOC Blurb/h4> Bowers et al report a novel function of PI3K blockade using the p110δ subunit inhibitor CAL-101 to induce memory and antitumor potency in CD8 + T cells. Ex vivo treatment of T cells with CAL-101 leads to improved antitumor control and subject survival in both murine transgenic T cell and human CAR T cell models.

    • Cancer Research
    • ,
    • Immunology and Microbiology
    Interdependent IL-7 and IFN-γ signalling in T-cell controls tumour eradication by combined α-CTLA-4+α-PD-1 therapy.

    In Nature Communications on 8 August 2016 by Shi, L. Z., Fu, T., et al.

    PubMed

    Combination therapy with α-CTLA-4 and α-PD-1 has shown significant clinical responses in different types of cancer. However, the underlying mechanisms remain elusive. Here, combining detailed analysis of human tumour samples with preclinical tumour models, we report that concomitant blockade of CTLA-4 and PD-1 improves anti-tumour immune responses and synergistically eradicates tumour. Mechanistically, combination therapy relies on the interdependence between IL-7 and IFN-γ signalling in T cells, as lack of either pathway abrogates the immune-boosting and therapeutic effects of combination therapy. Combination treatment increases IL-7Rα expression on tumour-infiltrating T cells in an IFN-γ/IFN-γR signalling-dependent manner, which may serve as a potential biomarker for clinical trials with immune checkpoint blockade. Our data suggest that combining immune checkpoint blockade with IL-7 signalling could be an effective modality to improve immunotherapeutic efficacy. Taken together, we conclude that combination therapy potently reverses immunosuppression and eradicates tumours via an intricate interplay between IFN-γ/IFN-γR and IL-7/IL-7R pathways.

    • Immunology and Microbiology
    Innate Immune Defenses Mediated by Two ILC Subsets Are Critical for Protection against Acute Clostridium difficile Infection.

    In Cell Host & Microbe on 8 July 2015 by Abt, M. C., Lewis, B. B., et al.

    PubMed

    Infection with the opportunistic enteric pathogen Clostridium difficile is an increasingly common clinical complication that follows antibiotic treatment-induced gut microbiota perturbation. Innate lymphoid cells (ILCs) are early responders to enteric pathogens; however, their role during C. difficile infection is undefined. To identify immune pathways that mediate recovery from C. difficile infection, we challenged C57BL/6, Rag1(-/-) (which lack T and B cells), and Rag2(-/-)Il2rg(-/-) (Ragγc(-/-)) mice (which additionally lack ILCs) with C. difficile. In contrast to Rag1(-/-) mice, ILC-deficient Ragγc(-/-) mice rapidly succumbed to infection. Rag1(-/-) but not Ragγc(-/-) mice upregulate expression of ILC1- or ILC3-associated proteins following C. difficile infection. Protection against infection was restored by transferring ILCs into Ragγc(-/-) mice. While ILC3s made a minor contribution to resistance, loss of IFN-γ or T-bet-expressing ILC1s in Rag1(-/-) mice increased susceptibility to C. difficile. These data demonstrate a critical role for ILC1s in defense against C. difficile. Copyright © 2015 Elsevier Inc. All rights reserved.

    • Endocrinology and Physiology
    • ,
    • Immunology and Microbiology
    • ,
    • Neuroscience
    Effector CD4 T-cell transition to memory requires late cognate interactions that induce autocrine IL-2.

    In Nature Communications on 5 November 2014 by McKinstry, K. K., Strutt, T. M., et al.

    PubMed

    It is unclear how CD4 T-cell memory formation is regulated following pathogen challenge, and when critical mechanisms act to determine effector T-cell fate. Here, we report that following influenza infection most effectors require signals from major histocompatibility complex class II molecules and CD70 during a late window well after initial priming to become memory. During this timeframe, effector cells must produce IL-2 or be exposed to high levels of paracrine or exogenously added IL-2 to survive an otherwise rapid default contraction phase. Late IL-2 promotes survival through acute downregulation of apoptotic pathways in effector T cells and by permanently upregulating their IL-7 receptor expression, enabling IL-7 to sustain them as memory T cells. This new paradigm defines a late checkpoint during the effector phase at which cognate interactions direct CD4 T-cell memory generation.

    • Immunology and Microbiology
    Chronic exposure to type-I IFN under lymphopenic conditions alters CD4 T cell homeostasis.

    In PLoS Pathogens on 1 March 2014 by Le Saout, C., Hasley, R. B., et al.

    PubMed

    HIV infection and the associated chronic immune activation alter T cell homeostasis leading to CD4 T cell depletion and CD8 T cell expansion. The mechanisms behind these outcomes are not totally defined and only partially explained by the direct cytopathic effect of the virus. In this manuscript, we addressed the impact of lymphopenia and chronic exposure to IFN-α on T cell homeostasis. In a lymphopenic murine model, this interaction led to decreased CD4 counts and CD8 T cell expansion in association with an increase in the Signal Transducer and Activator of Transcription 1 (STAT1) levels resulting in enhanced CD4 T cell responsiveness to IFN-α. Thus, in the setting of HIV infection, chronic stimulation of this pathway could be detrimental for CD4 T cell homeostasis.