70 results found
Jackson WD, Giacomassi C, Ward S, et al., 2023, TLR7 activation at epithelial barriers promotes emergency myelopoiesis and lung antiviral immunity, eLife, Vol: 12, ISSN: 2050-084X
Monocytes are heterogeneous innate effector leukocytes generated in the bone marrow and released into circulation in a CCR2-dependent manner. During infection or inflammation, myelopoiesis is modulated to rapidly meet the demand for more effector cells. Danger signals from peripheral tissues can influence this process. Herein we demonstrate that repetitive TLR7 stimulation via the epithelial barriers drove a potent emergency bone marrow monocyte response in mice. This process was unique to TLR7 activation and occurred independently of the canonical CCR2 and CX3CR1 axes or prototypical cytokines. The monocytes egressing the bone marrow had an immature Ly6C-high profile and differentiated into vascular Ly6C-low monocytes and tissue macrophages in multiple organs. They displayed a blunted cytokine response to further TLR7 stimulation and reduced lung viral load after RSV and influenza virus infection. These data provide insights into the emergency myelopoiesis likely to occur in response to the encounter of single-stranded RNA viruses at barrier sites.
Plum T, Binzberger R, Thiele R, et al., 2023, Mast cells link immune sensing to antigen-avoidance behaviour, Nature, Vol: 620, Pages: 634-642, ISSN: 0028-0836
The physiological functions of mast cells remain largely an enigma. In the context of barrier damage, mast cells are integrated in type 2 immunity and, together with immunoglobulin E (IgE), promote allergic diseases. Allergic symptoms may, however, facilitate expulsion of allergens, toxins and parasites and trigger future antigen avoidance1,2,3. Here, we show that antigen-specific avoidance behaviour in inbred mice4,5 is critically dependent on mast cells; hence, we identify the immunological sensor cell linking antigen recognition to avoidance behaviour. Avoidance prevented antigen-driven adaptive, innate and mucosal immune activation and inflammation in the stomach and small intestine. Avoidance was IgE dependent, promoted by Th2 cytokines in the immunization phase and by IgE in the execution phase. Mucosal mast cells lining the stomach and small intestine rapidly sensed antigen ingestion. We interrogated potential signalling routes between mast cells and the brain using mutant mice, pharmacological inhibition, neural activity recordings and vagotomy. Inhibition of leukotriene synthesis impaired avoidance, but overall no single pathway interruption completely abrogated avoidance, indicating complex regulation. Collectively, the stage for antigen avoidance is set when adaptive immunity equips mast cells with IgE as a telltale of past immune responses. On subsequent antigen ingestion, mast cells signal termination of antigen intake. Prevention of immunopathology-causing, continuous and futile responses against per se innocuous antigens or of repeated ingestion of toxins through mast-cell-mediated antigen-avoidance behaviour may be an important arm of immunity.
Thomson J, Harwoood C, Strid J, et al., 2023, Neoantigens from actinic keratosis are predicted to be more immunogenic than those from cutaneous squamous cell carcinoma - a strategy for immune escape?, British Society for Investigative Dermatology Annual Meeting (BSID), Publisher: OXFORD UNIV PRESS, Pages: E4-E5, ISSN: 0007-0963
Thomson J, Healy E, Strid J, et al., 2023, Homologous recombination deficiency scores in AK and cSCC are associated with tumor-immune phenotype, 1st International Societies for Investigative Dermatology Meeting, Publisher: ELSEVIER SCIENCE INC, Pages: S47-S47, ISSN: 0022-202X
Lim KHJ, Giampazolias E, Schulz O, et al., 2022, Loss of secreted gelsolin enhances response to anticancer therapies, Journal for ImmunoTherapy of Cancer, Vol: 10, ISSN: 2051-1426
Type 1 conventional dendritic cells (cDC1) play a critical role in priming anticancer cytotoxic CD8+ T cells. DNGR-1 (a.k.a. CLEC9A) is a cDC1 receptor that binds to F-actin exposed on necrotic cancer and normal cells. DNGR-1 signaling enhances cross-presentation of dead-cell associated antigens, including tumor antigens. We have recently shown that secreted gelsolin (sGSN), a plasma protein, competes with DNGR-1 for binding to dead cell-exposed F-actin and dampens anticancer immunity. Here, we investigated the effects of loss of sGSN on various anticancer therapies that are thought to induce cell death and provoke an immune response to cancer. We compared WT (wildtype) with Rag1-/- , Batf3-/- , Clec9agfp/gfp , sGsn-/- or sGsn-/- Clec9agfp/gfp mice implanted with transplantable tumor cell lines, including MCA-205 fibrosarcoma, 5555 BrafV600E melanoma and B16-F10 LifeAct (LA)-ovalbumin (OVA)-mCherry melanoma. Tumor-bearing mice were treated with (1) doxorubicin (intratumoral) chemotherapy for MCA-205, (2) BRAF-inhibitor PLX4720 (oral gavage) targeted therapy for 5555 BrafV600E, and (3) X-ray radiotherapy for B16 LA-OVA-mCherry. We confirmed that efficient tumor control following each therapy requires an immunocompetent host as efficacy was markedly reduced in Rag1-/- compared with WT mice. Notably, across all the therapeutic modalities, loss of sGSN significantly enhanced tumor control compared with treated WT controls. This was an on-target effect as mice deficient in both sGSN and DNGR-1 behaved no differently from WT mice following therapy. In sum, we find that mice deficient in sGsn display enhanced DNGR-1-dependent responsiveness to chemotherapy, targeted therapy and radiotherapy. Our findings are consistent with the notion some cancer therapies induce immunogenic cell death (ICD), which mobilizes anticancer T cells. Our results point to cDC1 and DNGR-1 as decoders of ICD and to sGSN as a negative regulator of such decoding, highlighting sGSN as a possible targe
Lim KHJ, Giampazolias E, Schulz O, et al., 2022, Targeting the secreted gelsolin-DNGR-1 dendritic cell axis to enhance anti-cancer therapies, Annual Meeting of the European-Society-for-Medical-Oncology (ESMO), Publisher: ELSEVIER, Pages: S557-S557, ISSN: 0923-7534
Serger E, Luengo-Gutierrez L, Chadwick JS, et al., 2022, The gut metabolite indole-3 propionate promotes nerve regeneration and repair, Nature, Vol: 607, Pages: 585-592, ISSN: 0028-0836
The regenerative potential of mammalian peripheral nervous system neurons after injury is critically limited by their slow axonal regenerative rate1. Regenerative ability is influenced by both injury-dependent and injury-independent mechanisms2. Among the latter, environmental factors such as exercise and environmental enrichment have been shown to affect signalling pathways that promote axonal regeneration3. Several of these pathways, including modifications in gene transcription and protein synthesis, mitochondrial metabolism and the release of neurotrophins, can be activated by intermittent fasting (IF)4,5. However, whether IF influences the axonal regenerative ability remains to be investigated. Here we show that IF promotes axonal regeneration after sciatic nerve crush in mice through an unexpected mechanism that relies on the gram-positive gut microbiome and an increase in the gut bacteria-derived metabolite indole-3-propionic acid (IPA) in the serum. IPA production by Clostridium sporogenes is required for efficient axonal regeneration, and delivery of IPA after sciatic injury significantly enhances axonal regeneration, accelerating the recovery of sensory function. Mechanistically, RNA sequencing analysis from sciatic dorsal root ganglia suggested a role for neutrophil chemotaxis in the IPA-dependent regenerative phenotype, which was confirmed by inhibition of neutrophil chemotaxis. Our results demonstrate the ability of a microbiome-derived metabolite, such as IPA, to facilitate regeneration and functional recovery of sensory axons through an immune-mediated mechanism.
Zhou L, Kong G, Palmisano I, et al., 2022, Reversible CD8 T cell-neuron cross-talk causes aging-dependent neuronal regenerative decline., Science, Vol: 376, Pages: 1-15, ISSN: 0036-8075
INTRODUCTIONAxonal regeneration and neurological functional recovery are extremely limited in the elderly. Consequently, injuries to the nervous system are typically followed by severe and long-term disability. Our understanding of the molecular mechanisms underlying aging-dependent regenerative failure is poor, hindering progress in the development of effective therapies for neurological repair. To facilitate the design of repair strategies, there is a pressing need to identify critical molecular and cellular mechanisms that cause regenerative failure in aging.RATIONALEAging causes a broad spectrum of modifications in cell signaling, including changes in metabolism, immunity, and overall tissue homeostasis, which play key roles in nervous system physiology and response to insults. Thus, we hypothesized that injuries to the aged nervous system would be followed by unique molecular and cellular modifications that would contribute to aging-dependent regenerative decline. To this end, molecular and cellular signatures associated with aging and injury to the nervous system were systematically investigated by performing RNA sequencing from dorsal root ganglia (DRG) in a well-established model of sciatic nerve injury in young versus aged mice. Insight into these mechanisms could allow the discovery of previously unrecognized molecular targets to counteract aging-dependent regenerative decline.RESULTSInitial analysis of RNA sequencing data identified that aging was mainly associated with a marked increase in T cell activation and signaling in DRG after sciatic nerve injury in mice. Subsequent experiments demonstrated that aging was associated with increased inflammatory cytokines including lymphotoxins in DRG both preceding and following sciatic nerve injury. Specifically, we found that lymphotoxin β was required for the phosphorylation of NF-κB that drives the expression of the chemokine CXCL13 in DRG sensory neurons. CXCL13 attracted CD8+ T cells that expresse
Thomsen I, Kunowska N, de Souza R, et al., 2021, RUNX1 regulates a transcription program that affects the dynamics of cell cycle entry of naive resting B cells, Journal of Immunology, Vol: 207, Pages: 2976-2991, ISSN: 0022-1767
RUNX1 is a transcription factor that plays key roles in hematopoietic development and in hematopoiesis and lymphopoiesis. In this article, we report that RUNX1 regulates a gene expression program in naive mouse B cells that affects the dynamics of cell cycle entry in response to stimulation of the BCR. Conditional knockout of Runx1 in mouse resting B cells resulted in accelerated entry into S-phase after BCR engagement. Our results indicate that Runx1 regulates the cyclin D2 (Ccnd2) gene, the immediate early genes Fosl2, Atf3, and Egr2, and the Notch pathway gene Rbpj in mouse B cells, reducing the rate at which transcription of these genes increases after BCR stimulation. RUNX1 interacts with the chromatin remodeler SNF-2-related CREB-binding protein activator protein (SRCAP), recruiting it to promoter and enhancer regions of the Ccnd2 gene. BCR-mediated activation triggers switching between binding of RUNX1 and its paralog RUNX3 and between SRCAP and the switch/SNF remodeling complex member BRG1. Binding of BRG1 is increased at the Ccnd2 and Rbpj promoters in the Runx1 knockout cells after BCR stimulation. We also find that RUNX1 exerts positive or negative effects on a number of genes that affect the activation response of mouse resting B cells. These include Cd22 and Bank1, which act as negative regulators of the BCR, and the IFN receptor subunit gene Ifnar1 The hyperresponsiveness of the Runx1 knockout B cells to BCR stimulation and its role in regulating genes that are associated with immune regulation suggest that RUNX1 could be involved in regulating B cell tolerance.
Schiavoni G, Munitz A, Strid J, 2021, Editorial: Emerging roles for type 2-associated cells and cytokines in cancer immunity, Frontiers in Immunology, Vol: 12, ISSN: 1664-3224
Jackson WD, Gulino A, Fossati-Jimack L, et al., 2021, C3 Drives Inflammatory Skin Carcinogenesis Independently of C5, JOURNAL OF INVESTIGATIVE DERMATOLOGY, Vol: 141, Pages: 404-+, ISSN: 0022-202X
Aguilera-Lizarraga J, Florens MV, Viola MF, et al., 2021, Local immune response to food antigens drives meal-induced abdominal pain, Nature, Vol: 590, Pages: 151-156, ISSN: 0028-0836
Up to 20% of people worldwide develop gastrointestinal symptoms following a meal1, leading to decreased quality of life, substantial morbidity and high medical costs. Although the interest of both the scientific and lay communities in this issue has increased markedly in recent years, with the worldwide introduction of gluten-free and other diets, the underlying mechanisms of food-induced abdominal complaints remain largely unknown. Here we show that a bacterial infection and bacterial toxins can trigger an immune response that leads to the production of dietary-antigen-specific IgE antibodies in mice, which are limited to the intestine. Following subsequent oral ingestion of the respective dietary antigen, an IgE- and mast-cell-dependent mechanism induced increased visceral pain. This aberrant pain signalling resulted from histamine receptor H1-mediated sensitization of visceral afferents. Moreover, injection of food antigens (gluten, wheat, soy and milk) into the rectosigmoid mucosa of patients with irritable bowel syndrome induced local oedema and mast cell activation. Our results identify and characterize a peripheral mechanism that underlies food-induced abdominal pain, thereby creating new possibilities for the treatment of irritable bowel syndrome and related abdominal pain disorders.
Giovanni SD, serger E, Chadwick J, et al., 2020, The intermittent fasting-dependent gut microbial metabolite indole-3 propionate promotes nerve regeneration and recovery after injury
<jats:title>Abstract</jats:title> <jats:p>The regenerative potential of mammalian peripheral nervous system (PNS) neurons after injury is critically limited by their slow axonal regenerative rate<jats:sup>1</jats:sup>. Since a delayed target re-innervation leads to irreversible loss of function of target organs<jats:sup>2</jats:sup>, accelerated axonal regeneration is required to enhance functional outcomes following injury. Regenerative ability is influenced by both injury-dependent and injury-independent mechanisms<jats:sup>3</jats:sup>. Among the latter, environmental factors such as exercise and environmental enrichment have been shown to affect signalling pathways that promote axonal regeneration<jats:sup>4</jats:sup>. Several of these pathways, including modifications in gene transcription and protein synthesis, mitochondrial metabolism and release of neurotrophins, can be activated by intermittent fasting (IF)<jats:sup>5,6</jats:sup>. IF has in turn been shown to increase synaptic plasticity<jats:sup>7,8</jats:sup> and neurogenesis<jats:sup>9</jats:sup>, partially sharing molecular mechanisms with axonal regeneration. However, whether IF influences the axonal regenerative ability remains to be investigated. Here we show that IF promotes axonal regeneration after sciatic nerve crush in the mouse via an unexpected mechanism that relies upon the gram + gut microbiome and an increase of the gut bacteria-derived metabolite indole-3-propionic acid (IPA) in the serum. IPA production by <jats:italic>Clostridium sporogenes</jats:italic> is required for efficient axonal regeneration, and delivery of IPA after sciatic injury significantly enhances axonal regeneration, accelerating recovery of sensory function. Mechanistically, RNA sequencing analysis from sciatic dorsal root ganglia suggested a role for neutrophil chemotaxis in the IPA-d
Strid K, Botto M, Jackson W, et al., 2020, C3 Drives Inflammatory Skin Carcinogenesis Independently of C5, Journal of Investigative Dermatology, ISSN: 0022-202X
Pereira B, De Maeyer RPH, Covre LP, et al., 2020, Sestrins induce natural killer function in senescent-like CD8(+) T cells, Nature Immunology, Vol: 21, Pages: 684-694, ISSN: 1529-2908
Aging is associated with remodeling of the immune system to enable the maintenance of life-long immunity. In the CD8+ T cell compartment, aging results in the expansion of highly differentiated cells that exhibit characteristics of cellular senescence. Here we found that CD27−CD28−CD8+ T cells lost the signaling activity of the T cell antigen receptor (TCR) and expressed a protein complex containing the agonistic natural killer (NK) receptor NKG2D and the NK adaptor molecule DAP12, which promoted cytotoxicity against cells that expressed NKG2D ligands. Immunoprecipitation and imaging cytometry indicated that the NKG2D–DAP12 complex was associated with sestrin 2. The genetic inhibition of sestrin 2 resulted in decreased expression of NKG2D and DAP12 and restored TCR signaling in senescent-like CD27−CD28−CD8+ T cells. Therefore, during aging, sestrins induce the reprogramming of non-proliferative senescent-like CD27−CD28−CD8+ T cells to acquire a broad-spectrum, innate-like killing activity.
Hayes MD, Ward S, Crawford G, et al., 2020, Inflammation-induced IgE promotes epithelial hyperplasia and tumour growth, eLife, Vol: 9, Pages: 1-24, ISSN: 2050-084X
IgE is the least abundant circulating antibody class but is constitutively present in healthy tissues bound to resident cells via its high-affinity receptor, FcεRI. The physiological role of endogenous IgE antibodies is unclear but it has been suggested that they provide host protection against a variety of noxious environmental substances and parasitic infections at epithelial barrier surfaces. Here we show, in mice, that skin inflammation enhances levels of IgE antibodies that have natural specificities and a repertoire, VDJ rearrangements and CDRH3 characteristics similar to those of IgE antibodies in healthy tissue. IgE-bearing basophils are recruited to inflamed skin via CXCL12 and thymic stromal lymphopoietin (TSLP)/IL-3-dependent upregulation of CXCR4. In the inflamed skin, IgE/FcεRI-signalling in basophils promotes epithelial cell growth and differentiation, partly through histamine engagement of H1R and H4R. Furthermore, this IgE response strongly drives tumour outgrowth of epithelial cells harbouring oncogenic mutation. These findings indicate that natural IgE antibodies support skin barrier defences, but that during chronic tissue inflammation this role may be subverted to promote tumour growth.
Hayes MD, Ward S, Crawford G, et al., 2019, Natural IgE promotes epithelial hyperplasia and inflammation-driven tumour growth
<jats:title>Abstract</jats:title><jats:p>IgE is the least abundant circulating antibody class but is constitutively present in healthy tissues bound to resident cells via its high-affinity receptor, FcεRI. The physiological role of endogenous IgE is unclear but it is suggested to provide host protection against a variety of noxious environmental substances and parasitic infections at epithelial barrier surfaces. Here we show that skin inflammation enhances levels of IgE with natural specificities and with a similar repertoire, VDJ rearrangements and CDRH3 characteristics as in healthy tissue. IgE-bearing basophils are recruited to inflamed skin via CXCL12 and TSLP/IL-3-dependent upregulation of CXCR4. In the inflamed skin, IgE/FcεRI-signalling in basophils promotes epithelial cell growth and differentiation, partly through histamine engagement of H<jats:sub>1</jats:sub>R and H<jats:sub>4</jats:sub>R. Furthermore, this natural IgE response strongly drives tumour outgrowth of epithelial cells harbouring oncogenic mutation. These findings indicate that natural IgE support skin barrier defences however during chronic tissue inflammation this may be subverted to promote tumour growth.</jats:p>
Ferrer IR, West HC, Henderson S, et al., 2019, A wave of monocytes is recruited to replenish the long-term Langerhans cell network after immune injury, Science Immunology, Vol: 4, Pages: 1-14, ISSN: 2470-9468
A dense population of embryo-derived Langerhans cells (eLCs) is maintained within the sealed epidermis without contribution from circulating cells. When this network is perturbed by transient exposure to ultraviolet light, short-term LCs are temporarily reconstituted from an initial wave of monocytes but thought to be superseded by more permanent repopulation with undefined LC precursors. However, the extent to which this process is relevant to immunopathological processes that damage LC population integrity is not known. Using a model of allogeneic hematopoietic stem cell transplantation, where alloreactive T cells directly target eLCs, we have asked whether and how the original LC network is ultimately restored. We find that donor monocytes, but not dendritic cells, are the precursors of long-term LCs in this context. Destruction of eLCs leads to recruitment of a wave of monocytes that engraft in the epidermis and undergo a sequential pathway of differentiation via transcriptionally distinct EpCAM+ precursors. Monocyte-derived LCs acquire the capacity of self-renewal, and proliferation in the epidermis matched that of steady-state eLCs. However, we identified a bottleneck in the differentiation and survival of epidermal monocytes, which, together with the slow rate of renewal of mature LCs, limits repair of the network. Furthermore, replenishment of the LC network leads to constitutive entry of cells into the epidermal compartment. Thus, immune injury triggers functional adaptation of mechanisms used to maintain tissue-resident macrophages at other sites, but this process is highly inefficient in the skin.
Crawford G, Hayes MD, Seoane RC, et al., 2018, Epithelial damage and tissue gamma delta T cells promote a unique tumor-protective IgE response, Nature Immunology, Vol: 19, Pages: 859-870, ISSN: 1529-2908
IgE is an ancient and conserved immunoglobulin isotype with potent immunological function. Nevertheless, the regulation of IgE responses remains an enigma, and evidence of a role for IgE in host defense is limited. Here we report that topical exposure to a common environmental DNA-damaging xenobiotic initiated stress surveillance by γδTCR+ intraepithelial lymphocytes that resulted in class switching to IgE in B cells and the accumulation of autoreactive IgE. High-throughput antibody sequencing revealed that γδ T cells shaped the IgE repertoire by supporting specific variable-diversity-joining (VDJ) rearrangements with unique characteristics of the complementarity-determining region CDRH3. This endogenous IgE response, via the IgE receptor FcεRI, provided protection against epithelial carcinogenesis, and expression of the gene encoding FcεRI in human squamous-cell carcinoma correlated with good disease prognosis. These data indicate a joint role for immunosurveillance by T cells and by B cells in epithelial tissues and suggest that IgE is part of the host defense against epithelial damage and tumor development.
Ling GS, Crawford G, Buang N, et al., 2018, C1q restrains autoimmunity and viral infection by regulating CD8+ T cell metabolism, Science, Vol: 360, Pages: 558-563, ISSN: 0036-8075
Deficiency of C1q, the initiator of the complement classical pathway, is associated with the development of systemic lupus erythematosus (SLE). Explaining this association in terms of abnormalities in the classical pathway alone remains problematic because C3 deficiency does not predispose to SLE. Here, using a mouse model of SLE, we demonstrate that C1q, but not C3, restrains the response to self-antigens by modulating the mitochondrial metabolism of CD8+ T cells, which can themselves propagate autoimmunity. C1q deficiency also triggers an exuberant effector CD8+ T cell response to chronic viral infection leading to lethal immunopathology. These data establish a link between C1q and CD8+ T cell metabolism and may explain how C1q protects against lupus, with implications for the role of viral infections in the perpetuation of autoimmunity.
Silva-Santos B, Strid J, 2018, Working in "NK Mode": Natural Killer Group 2 Member D and Natural Cytotoxicity Receptors in Stress-Surveillance by gamma delta T Cells, FRONTIERS IN IMMUNOLOGY, Vol: 9, ISSN: 1664-3224
Natural killer cell receptors (NKRs) are germline-encoded transmembrane proteins that regulate the activation and homeostasis of NK cells as well as other lymphocytes. For γδ T cells, NKRs play critical roles in discriminating stressed (transformed or infected) cells from their healthy counterparts, as proposed in the “lymphoid stress-surveillance” theory. Whereas the main physiologic role is seemingly fulfilled by natural killer group 2 member D, constitutively expressed by γδ T cells, enhancement of their therapeutic potential may rely on natural cytotoxicity receptors (NCRs), like NKp30 or NKp44, that can be induced selectively on human Vδ1+ T cells. Here, we review the contributions of NCRs, NKG2D, and their multiple ligands, to γδ T cell biology in mouse and human.
Duggan SP, Garry C, Behan FM, et al., 2018, siRNA library screening identifies a druggable immune-signature driving esophageal adenocarcinoma cell growth, Cellular and Molecular Gastroenterology and Hepatology, Vol: 5, Pages: 569-590, ISSN: 2352-345X
Background & Aims: Effective therapeutic approaches are urgently required to tackle the alarmingly poor survival outcomes in esophageal adenocarcinoma (EAC) patients. EAC originates from within the intestinal-type metaplasia, Barrett’s esophagus, a condition arising on a background of gastroesophageal reflux disease and associated inflammation.Methods:This study used a druggable genome small interfering RNA (siRNA) screening library of 6022 siRNAs in conjunction with bioinformatics platforms, genomic studies of EAC tissues, somatic variation data of EAC from The Cancer Genome Atlas data of EAC, and pathologic and functional studies to define novel EAC-associated, and targetable, immune factors.Results:By using a druggable genome library we defined genes that sustain EAC cell growth, which included an unexpected immunologic signature. Integrating Cancer Genome Atlas data with druggable siRNA targets showed a striking concordance and an EAC-specific gene amplification event associated with 7 druggable targets co-encoded at Chr6p21.1. Over-representation of immune pathway–associated genes supporting EAC cell growth included leukemia inhibitory factor, complement component 1, q subcomponent A chain (C1QA), and triggering receptor expressed on myeloid cells 2 (TREM2), which were validated further as targets sharing downstream signaling pathways through genomic and pathologic studies. Finally, targeting the triggering receptor expressed on myeloid cells 2-, C1q-, and leukemia inhibitory factor–activated signaling pathways (TYROBP–spleen tyrosine kinase and JAK-STAT3) with spleen tyrosine kinase and Janus-activated kinase inhibitor fostamatinib R788 triggered EAC cell death, growth arrest, and reduced tumor burden in NOD scid gamma mice.Conclusions:These data highlight a subset of genes co-identified through siRNA targeting and genomic studies of expression and somatic variation, specifically highlighting the contribution that immune-related fac
Gaya M, Barral P, Burbage M, et al., 2017, Initiation of antiviral B cell Immunity relies on innate signals from spatially positioned NKT cells, Cell, Vol: 172, Pages: 517-533.e20, ISSN: 0092-8674
B cells constitute an essential line of defense from pathogenic infections through the generation of class-switched antibody-secreting cells (ASCs) in germinal centers. Although this process is known to be regulated by follicular helper T (TfH) cells, the mechanism by which B cells initially seed germinal center reactions remains elusive. We found that NKT cells, a population of innate-like T lymphocytes, are critical for the induction of B cell immunity upon viral infection. The positioning of NKT cells at the interfollicular areas of lymph nodes facilitates both their direct priming by resident macrophages and the localized delivery of innate signals to antigen-experienced B cells. Indeed, NKT cells secrete an early wave of IL-4 and constitute up to 70% of the total IL-4-producing cells during the initial stages of infection. Importantly, the requirement of this innate immunity arm appears to be evolutionarily conserved because early NKT and IL-4 gene signatures also positively correlate with the levels of neutralizing antibodies in Zika-virus-infected macaques. In conclusion, our data support a model wherein a pre-TfH wave of IL-4 secreted by interfollicular NKT cells triggers the seeding of germinal center cells and serves as an innate link between viral infection and B cell immunity.
Silva-Santos B, Strid J, 2017, γδ T cells get adaptive, NATURE IMMUNOLOGY, Vol: 18, Pages: 370-372, ISSN: 1529-2908
Silva-Santos B, Strid J, 2017, γδ T cells get adaptive., Nature Immunology, Vol: 18, Pages: 370-372, ISSN: 1529-2916
Throughout ontogeny, the γδ TCR repertoire in human blood becomes less diverse and more focused, yet is private in nature, and specific adult γδ T cell subsets undergo substantial clonal expansion after challenge with cytomegalovirus.
Giacomassi C, Ling GS, Buang N, et al., 2016, Complement C3 Exacerbates TLR7-Mediated Skin Inflammation but Not Systemic Autoimmunity, Annual European Congress of Rheumatology (EULAR), Publisher: BMJ Publishing Group, Pages: 280-281, ISSN: 0003-4967
Giacomassi C, Buang N, Ling GS, et al., 2016, Complement C3 exacerbates imiquimod-induced skin inflammation and psoriasiform dermatitis, Journal of Investigative Dermatology, Vol: 137, Pages: 760-763, ISSN: 1523-1747
The complement system is pivotal in protection against pathogens, but also plays important roles in bridging innate and adaptive immune responses (Scott and Botto, 2015) and in modulating local and systemic inflammation (Markiewski and Lambris, 2007). Activation of complement occurs through three different pathways (classical, alternative and lectin), converges at C3 cleavage and culminates in the formation of the membrane attack complex. The anaphylotoxic fragments, C3a and C5a, generated during the proteolytic cascade, recruit immune cells that can promote the removal of debris and pathogens, but can also cause tissue damage (Markiewski and Lambris, 2007).
Hayes MD, Crawford G, Castro-Seoane R, et al., 2016, IgE strongly promotes inflammation-driven skin carcinogenesis, Annual Meeting of the European-Society-for-Dermatological-Research (ESDR), Publisher: Elsevier, Pages: S211-S211, ISSN: 0022-202X
Dalessandri T, Crawford G, Hayes M, et al., 2016, IL-13 from intraepithelial lymphocytes regulates tissue homeostasis and protects against carcinogenesis in the skin, Nature Communications, Vol: 7, Pages: 1-12, ISSN: 2041-1723
The skin is under constant renewal and exposure to environmental challenges. Howhomeostasis is maintained alongside protective mechanisms against damage is unclear.Among the basal epithelial cells (ECs) is a population of resident intraepithelial lymphocytes(IELs) that provide host-protective immune surveillance. Here we show that IELscross-communicate with ECs via the production of IL-13. Skin ECs are activated by IEL-derivedIL-13, enabling a canonical EC stress response. In the absence of IL-13, or canonical IEL, theskin has decreased ability to repair its barrier and increased susceptibility to cutaneouscarcinogenesis. IL-13 controls the rate of EC movement through the epidermis, which mightexplain the importance of IL-13 for epidermal integrity and its suppressive effect on skincarcinogenesis. These findings show that IL-13 acts as a molecular bridge between IELs andECs, and reveal a critical host-defensive role for type-2 immunity in regulating EC tissuehomeostasis and carcinogenesis.
Strid J, McLean WH, Irvine AD, 2016, Too Much, Too Little or Just Enough: A Goldilocks Effect for IL-13 and Skin Barrier Regulation?, Journal of Investigative Dermatology, Vol: 136, Pages: 561-564, ISSN: 1523-1747
The mechanistic relationship between IL-4/IL-13 and skin barrier function has been of interest since the filaggrin discovery and the subsequent in vitro demonstration that IL-4 and IL-13 downregulate filaggrin expression in cultured keratinocytes. Hönzke and colleagues explore these interactions further. The effects of IL-4/ll-13 may be context dependent, with differing roles in homeostasis and in disease.
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