RESUMO
PD-1 blockade unleashes potent antitumor activity in CD8+ T cells but can also promote immunosuppressive T regulatory (Treg) cells, which may worsen the response to immunotherapy. Tumor-Treg inhibition is a promising strategy to improve the efficacy of checkpoint blockade immunotherapy; however, our understanding of the mechanisms supporting tumor-Tregs during PD-1 immunotherapy is incomplete. Here, we show that PD-1 blockade increases tumor-Tregs in mouse models of melanoma and metastatic melanoma patients. Mechanistically, Treg accumulation is not caused by Treg-intrinsic inhibition of PD-1 signaling but depends on an indirect effect of activated CD8+ T cells. CD8+ T cells produce IL-2 and colocalize with Tregs in mouse and human melanomas. IL-2 upregulates the anti-apoptotic protein ICOS on tumor-Tregs, promoting their accumulation. Inhibition of ICOS signaling before PD-1 immunotherapy improves control over immunogenic melanoma. Thus, interrupting the intratumor CD8+ T cell:Treg crosstalk represents a strategy to enhance the therapeutic efficacy of PD-1 immunotherapy.
Assuntos
Linfócitos T CD8-Positivos , Inibidores de Checkpoint Imunológico , Imunoterapia , Proteína Coestimuladora de Linfócitos T Induzíveis , Interleucina-2 , Melanoma , Receptor de Morte Celular Programada 1 , Linfócitos T Reguladores , Animais , Linfócitos T CD8-Positivos/imunologia , Linfócitos T Reguladores/imunologia , Humanos , Camundongos , Receptor de Morte Celular Programada 1/antagonistas & inibidores , Receptor de Morte Celular Programada 1/imunologia , Receptor de Morte Celular Programada 1/metabolismo , Melanoma/imunologia , Melanoma/terapia , Melanoma/tratamento farmacológico , Proteína Coestimuladora de Linfócitos T Induzíveis/metabolismo , Imunoterapia/métodos , Inibidores de Checkpoint Imunológico/farmacologia , Inibidores de Checkpoint Imunológico/uso terapêutico , Interleucina-2/imunologia , Camundongos Endogâmicos C57BL , Transdução de Sinais , Melanoma Experimental/imunologia , Melanoma Experimental/terapia , Linhagem Celular TumoralRESUMO
Interleukin 22 (IL-22) has a non-redundant role in immune defence of the intestinal barrier1-3. T cells, but not innate lymphoid cells, have an indispensable role in sustaining the IL-22 signalling that is required for the protection of colonic crypts against invasion during infection by the enteropathogen Citrobacter rodentium4 (Cr). However, the intestinal epithelial cell (IEC) subsets targeted by T cell-derived IL-22, and how T cell-derived IL-22 sustains activation in IECs, remain undefined. Here we identify a subset of absorptive IECs in the mid-distal colon that are specifically targeted by Cr and are differentially responsive to IL-22 signalling. Major histocompatibility complex class II (MHCII) expression by these colonocytes was required to elicit sustained IL-22 signalling from Cr-specific T cells, which was required to restrain Cr invasion. Our findings explain the basis for the regionalization of the host response to Cr and demonstrate that epithelial cells must elicit MHCII-dependent help from IL-22-producing T cells to orchestrate immune protection in the intestine.
Assuntos
Citrobacter rodentium , Colo , Células Epiteliais , Mucosa Intestinal , Linfócitos T , Animais , Feminino , Masculino , Camundongos , Citrobacter rodentium/imunologia , Colo/citologia , Colo/imunologia , Colo/microbiologia , Infecções por Enterobacteriaceae/imunologia , Infecções por Enterobacteriaceae/microbiologia , Células Epiteliais/imunologia , Células Epiteliais/microbiologia , Células Epiteliais/metabolismo , Antígenos de Histocompatibilidade Classe II/imunologia , Antígenos de Histocompatibilidade Classe II/metabolismo , Interleucina 22/imunologia , Interleucina 22/metabolismo , Mucosa Intestinal/imunologia , Mucosa Intestinal/microbiologia , Mucosa Intestinal/citologia , Camundongos Endogâmicos C3H , Camundongos Endogâmicos C57BL , Transdução de Sinais/imunologia , Linfócitos T/imunologia , Linfócitos T/metabolismoRESUMO
Immune tolerance is maintained in lymphoid organs (LOs). Despite the presence of complex immune cell networks in non-LOs, it is unknown whether self-tolerance is maintained in these tissues. We developed a technique to restrict genetic recombination to regulatory T cells (Tregs) only in skin. Selective depletion of skin Tregs resulted in T cell-mediated inflammation of hair follicles (HFs). Suppression did not rely on CTLA-4, but instead on high-affinity interleukin-2 (IL-2) receptor expression by skin Tregs, functioning exclusively in a cell-extrinsic manner. In a novel model of HF stem cell (HFSC)-driven autoimmunity, we reveal that skin Tregs immunologically protect the HFSC niche. Finally, we used spatial transcriptomics to identify aberrant IL-2 signaling at stromal-HF interfaces in a rare form of human alopecia characterized by HFSC destruction and alopecia areata. Collectively, these results reveal the fundamental biology of Tregs in skin uncoupled from the systemic pool and elucidate a mechanism of self-tolerance.
Assuntos
Privilégio Imunológico , Linfócitos T Reguladores , Humanos , Folículo Piloso , Interleucina-2 , Nicho de Células-TroncoRESUMO
Maintenance of immune homeostasis to the intestinal mictrobiota is dependent on a population of effector regulatory T (eTreg) cells that develop from microbiota-reactive induced (i)Treg cells. A cardinal feature of eTreg cells is their production of IL-10, which plays a non-redundant role in immune tolerance of commensal microbes. Here, we identify an unexpected role for IL-2-induced Stat3 signaling to program iTreg cells for eTreg cell differentiation and Il10 transcriptional competency. IL-2 proved to be both necessary and sufficient for eTreg cell development - contingent on Stat3 output of the IL-2 receptor coordinate with IL-2 signaling during early Treg cell commitment. Induction of iTreg cell programming in absence of IL-2-induced Stat3 signaling resulted in impaired eTreg cell differentiation and a failure to produce IL-10. An IL-2 mutein with reduced affinity for the IL-2Rγ (γ c ) chain was found to have blunted IL-2R Stat3 output, resulting in a deficiency of Il10 transcriptional programming that could not be fully rescued by Stat3 signaling subsequent to an initial window of iTreg cell differentiation. These findings expose a heretofore unappreciated role of IL-2 signaling that acts early to program subsequent production of IL-10 by developing eTreg cells, with broad implications for IL-2-based therapeutic interventions in immune-mediated diseases.
RESUMO
Intestinal colonization by antigenically foreign microbes necessitates expanded peripheral immune tolerance. Here we show commensal microbiota prime expansion of CD4 T cells unified by the Kruppel-like factor 2 (KLF2) transcriptional regulator and an essential role for KLF2+ CD4 cells in averting microbiota-driven intestinal inflammation. CD4 cells with commensal specificity in secondary lymphoid organs and intestinal tissues are enriched for KLF2 expression, and distinct from FOXP3+ regulatory T cells or other differentiation lineages. Mice with conditional KLF2 deficiency in T cells develop spontaneous rectal prolapse and intestinal inflammation, phenotypes overturned by eliminating microbiota or reconstituting with donor KLF2+ cells. Activated KLF2+ cells selectively produce IL-10, and eliminating IL-10 overrides their suppressive function in vitro and protection against intestinal inflammation in vivo. Together with reduced KLF2+ CD4 cell accumulation in Crohn's disease, a necessity for the KLF2+ subpopulation of T regulatory type 1 (Tr1) cells in sustaining commensal tolerance is demonstrated.
Assuntos
Linfócitos T CD4-Positivos , Microbiota , Camundongos , Animais , Interleucina-10/metabolismo , Linfócitos T Reguladores , Fatores de Transcrição/metabolismo , Inflamação/metabolismo , Fatores de Transcrição Kruppel-Like/metabolismoRESUMO
Although the activator protein-1 (AP-1) factor Batf is required for Th17 cell development, its mechanisms of action to underpin the Th17 program are incompletely understood. Here, we find that Batf ensures Th17 cell identity in part by restricting alternative gene programs through its actions to restrain IL-2 expression and IL-2-induced Stat5 activation. This, in turn, limits Stat5-dependent recruitment of Ets1-Runx1 factors to Th1- and Treg-cell-specific gene loci. Thus, in addition to pioneering regulatory elements in Th17-specific loci, Batf acts indirectly to inhibit the assembly of a Stat5-Ets1-Runx1 complex that enhances the transcription of Th1- and Treg-cell-specific genes. These findings unveil an important role for Stat5-Ets1-Runx1 interactions in transcriptional networks that define alternate T cell fates and indicate that Batf plays an indispensable role in both inducing and maintaining the Th17 program through its actions to regulate the competing actions of Stat5-assembled enhanceosomes that promote Th1- and Treg-cell developmental programs.
Assuntos
Interleucina-2 , Células Th17 , Diferenciação Celular , Interleucina-2/metabolismo , Fator de Transcrição STAT5/genética , Fator de Transcrição STAT5/metabolismo , Linfócitos T Reguladores/metabolismo , Fator de Transcrição AP-1/metabolismo , Fatores de Transcrição de Zíper de Leucina Básica/metabolismo , Subunidade alfa 2 de Fator de Ligação ao Core/metabolismo , Proteína Proto-Oncogênica c-ets-1/metabolismoRESUMO
The cytokine interleukin-23 (IL-23) is critical for development and maintenance of autoimmune inflammation in nonlymphoid tissues; however, the mechanism through which IL-23 supports tissue-specific immunity remains unclear. In mice, we found that circulating memory T cells were dispensable for anamnestic protection from Candida albicans skin infection, and tissue-resident memory (TRM) cell-mediated protection from C. albicans reinfection required IL-23. Administration of anti-IL-23 receptor antibody to mice after resolution of primary C. albicans infection resulted in loss of CD69+ CD103+ tissue-resident memory T helper 17 (TRM17) cells from skin, and clinical anti-IL-23 therapy depleted TRM17 cells from skin of patients with psoriasis. IL-23 receptor blockade impaired TRM17 cell proliferation but did not affect apoptosis susceptibility or tissue egress. IL-23 produced by CD301b+ myeloid cells was required for TRM17 maintenance in skin after C. albicans infection, and CD301b+ cells were necessary for TRM17 expansion during the development of imiquimod dermatitis. This study demonstrates that locally produced IL-23 promotes in situ proliferation of cutaneous TRM17 cells to support their longevity and function and provides mechanistic insight into the durable efficacy of IL-23 blockade in the treatment of psoriasis.
Assuntos
Interleucina-23 , Psoríase , Camundongos , Animais , Memória Imunológica , Interleucina-17 , Candida albicans/fisiologia , Proliferação de CélulasRESUMO
Interleukin (IL)-22 is central to immune defense at barrier sites. We examined the contributions of innate lymphoid cell (ILC) and T cell-derived IL-22 during Citrobacter rodentium (C.r) infection using mice that both report Il22 expression and allow lineage-specific deletion. ILC-derived IL-22 activated STAT3 in C.r-colonized surface intestinal epithelial cells (IECs) but only temporally restrained bacterial growth. T cell-derived IL-22 induced a more robust and extensive activation of STAT3 in IECs, including IECs lining colonic crypts, and T cell-specific deficiency of IL-22 led to pathogen invasion of the crypts and increased mortality. This reflected a requirement for T cell-derived IL-22 for the expression of a host-protective transcriptomic program that included AMPs, neutrophil-recruiting chemokines, and mucin-related molecules, and it restricted IFNγ-induced proinflammatory genes. Our findings demonstrate spatiotemporal differences in the production and action of IL-22 by ILCs and T cells during infection and reveal an indispensable role for IL-22-producing T cells in the protection of the intestinal crypts.
Assuntos
Citrobacter rodentium , Infecções por Enterobacteriaceae , Animais , Antibacterianos , Imunidade Inata , Interleucinas/metabolismo , Mucosa Intestinal , Linfócitos/metabolismo , Camundongos , Camundongos Endogâmicos C57BL , Linfócitos T/metabolismo , Interleucina 22RESUMO
Here, we show that the capacity to manufacture IL-2 identifies constituents of the expanded CD8 T cell effector pool that display stem-like features, preferentially survive, rapidly attain memory traits, resist exhaustion, and control chronic viral challenges. The cell-intrinsic synthesis of IL-2 by CD8 T cells attenuates the ability to receive IL-2-dependent STAT5 signals, thereby limiting terminal effector formation, endowing the IL-2-producing effector subset with superior protective powers. In contrast, the non-IL-2-producing effector cells respond to IL-2 signals and gain effector traits at the expense of memory formation. Despite having distinct properties during the effector phase, IL-2-producing and nonproducing CD8 T cells appear to converge transcriptionally as memory matures to form populations with equal recall abilities. Therefore, the potential to produce IL-2 during the effector, but not memory stage, is a consequential feature that dictates the protective capabilities of the response.
Assuntos
Linfócitos T CD8-Positivos/imunologia , Interleucina-2/biossíntese , Fator de Transcrição STAT5/imunologia , Animais , Interleucina-2/imunologia , Camundongos , Camundongos Congênicos , Camundongos Transgênicos , Transdução de Sinais/imunologiaRESUMO
Bile acids are lipid-emulsifying metabolites synthesized in hepatocytes and maintained in vivo through enterohepatic circulation between the liver and small intestine1. As detergents, bile acids can cause toxicity and inflammation in enterohepatic tissues2. Nuclear receptors maintain bile acid homeostasis in hepatocytes and enterocytes3, but it is unclear how mucosal immune cells tolerate high concentrations of bile acids in the small intestine lamina propria (siLP). CD4+ T effector (Teff) cells upregulate expression of the xenobiotic transporter MDR1 (encoded by Abcb1a) in the siLP to prevent bile acid toxicity and suppress Crohn's disease-like small bowel inflammation4. Here we identify the nuclear xenobiotic receptor CAR (encoded by Nr1i3) as a regulator of MDR1 expression in T cells that can safeguard against bile acid toxicity and inflammation in the mouse small intestine. Activation of CAR induced large-scale transcriptional reprogramming in Teff cells that infiltrated the siLP, but not the colon. CAR induced the expression of not only detoxifying enzymes and transporters in siLP Teff cells, as in hepatocytes, but also the key anti-inflammatory cytokine IL-10. Accordingly, CAR deficiency in T cells exacerbated bile acid-driven ileitis in T cell-reconstituted Rag1-/- or Rag2-/- mice, whereas pharmacological activation of CAR suppressed it. These data suggest that CAR acts locally in T cells that infiltrate the small intestine to detoxify bile acids and resolve inflammation. Activation of this program offers an unexpected strategy to treat small bowel Crohn's disease and defines lymphocyte sub-specialization in the small intestine.
Assuntos
Ácidos e Sais Biliares/metabolismo , Regulação da Expressão Gênica , Intestino Delgado/metabolismo , Receptores Citoplasmáticos e Nucleares/metabolismo , Linfócitos T/metabolismo , Membro 1 da Subfamília B de Cassetes de Ligação de ATP/biossíntese , Membro 1 da Subfamília B de Cassetes de Ligação de ATP/genética , Membro 1 da Subfamília B de Cassetes de Ligação de ATP/metabolismo , Animais , Linfócitos T CD4-Positivos/metabolismo , Receptor Constitutivo de Androstano , Doença de Crohn/metabolismo , Feminino , Ileíte/metabolismo , Inflamação/metabolismo , Interleucina-10/biossíntese , Interleucina-10/genética , Intestino Delgado/citologia , CamundongosRESUMO
BACKGROUND: IgA nephropathy is thought to be an autoimmune disease wherein galactose-deficient IgA1 (Gd-IgA1) is recognized by IgG autoantibodies, resulting in formation and renal accumulation of nephritogenic immune complexes. Although this hypothesis is supported by recent findings that, in renal immunodeposits of IgA nephropathy patients, IgG is enriched for Gd-IgA1-specific autoantibodies, experimental proof is still lacking. METHODS: IgG isolated from sera of IgA nephropathy patients or produced as a recombinant IgG (rIgG) was mixed with human Gd-IgA1 to form immune complexes. IgG from healthy individuals served as a control. Nude and SCID mice were injected with human IgG and Gd-IgA1, in immune complexes or individually, and their presence in kidneys was ascertained by immunofluorescence. Pathologic changes in the glomeruli were evaluated by quantitative morphometry and exploratory transcriptomic profiling was performed by RNA-Seq. RESULTS: Immunodeficient mice injected with Gd-IgA1 mixed with IgG autoantibodies from patients with IgA nephropathy, but not Gd-IgA1 mixed with IgG from healthy individuals, displayed IgA, IgG, and mouse complement C3 glomerular deposits and mesangioproliferative glomerular injury with hematuria and proteinuria. Un-complexed Gd-IgA1 or IgG did not induce pathological changes. Moreover, Gd-IgA1-rIgG immune complexes injected into immunodeficient mice induced histopathological changes characteristic of human disease. Exploratory transcriptome profiling of mouse kidney tissues indicated that these immune complexes altered gene expression of multiple pathways, in concordance with the changes observed in kidney biopsies of patients with IgA nephropathy. CONCLUSIONS: This study provides the first in vivo evidence for a pathogenic role of IgG autoantibodies specific for Gd-IgA1 in the pathogenesis of IgA nephropathy.
Assuntos
Autoanticorpos/imunologia , Glomerulonefrite por IGA/imunologia , Imunoglobulina G/imunologia , Animais , Complexo Antígeno-Anticorpo/administração & dosagem , Complexo Antígeno-Anticorpo/imunologia , Autoanticorpos/sangue , Modelos Animais de Doenças , Glomerulonefrite por IGA/sangue , Glomerulonefrite por IGA/patologia , Humanos , Imunoglobulina A/imunologia , Glomérulos Renais/imunologia , Glomérulos Renais/patologia , CamundongosRESUMO
The nonimmune roles of Tregs have been described in various tissues, including the BM. In this study, we comprehensively phenotyped marrow Tregs, elucidating their key features and tissue-specific functions. We show that marrow Tregs are migratory and home back to the marrow. For trafficking, marrow Tregs use S1P gradients, and disruption of this axis allows for specific targeting of the marrow Treg pool. Following Treg depletion, the function and phenotype of both mesenchymal stromal cells (MSCs) and hematopoietic stem cells (HSCs) was impaired. Transplantation also revealed that a Treg-depleted niche has a reduced capacity to support hematopoiesis. Finally, we found that marrow Tregs are high producers of IL-10 and that Treg-secreted IL-10 has direct effects on MSC function. This is the first report to our knowledge revealing that Treg-secreted IL-10 is necessary for stromal cell maintenance, and our work outlines an alternative mechanism by which this cytokine regulates hematopoiesis.
Assuntos
Células da Medula Óssea/fisiologia , Hematopoese , Células-Tronco Hematopoéticas/fisiologia , Interleucina-10/metabolismo , Células-Tronco Mesenquimais/fisiologia , Células Estromais/fisiologia , Linfócitos T Reguladores/imunologia , Animais , Células da Medula Óssea/citologia , Células da Medula Óssea/imunologia , Comunicação Celular , Proliferação de Células , Células Cultivadas , Técnicas de Cocultura , Feminino , Células-Tronco Hematopoéticas/citologia , Células-Tronco Hematopoéticas/imunologia , Masculino , Células-Tronco Mesenquimais/citologia , Células-Tronco Mesenquimais/imunologia , Camundongos , Camundongos Endogâmicos C57BL , Células Estromais/citologia , Células Estromais/imunologiaRESUMO
Acting in concert with TGF-ß, interleukin-6 (IL-6) signaling induces T helper 17 (TH17) cell development by programming TH17-related genes via signal transducers and activators of transcription 3 (STAT3). A role for IL-6 signaling beyond the inductive phase of TH17 cell development has not been defined because IL-23 signaling downstream of TH17 cell induction also activates STAT3 and is thought responsible for TH17 cell maintenance. Here, we find that IL-6 signaling is required for both induction and maintenance of mouse TH17 cells; IL-6Rα-deficient TH17 cells rapidly lost their TH17 phenotype and did not cause disease in two models of colitis. Cotransfer of wild-type TH17 cells with IL-6Rα-deficient TH17 cells induced colitis but was unable to rescue phenotype loss of the latter. High IL-6 expression in the colon promoted classic, or cis, rather than transreceptor signaling that was required for maintenance of TH17 cells. Thus, ongoing classic IL-6 signaling underpins the TH17 program and is required for TH17 cell maintenance and function.
Assuntos
Colite/imunologia , Interleucina-6/imunologia , Receptores de Interleucina-6/imunologia , Células Th17/imunologia , Animais , Colite/genética , Colo/imunologia , Feminino , Masculino , Camundongos Endogâmicos C57BL , Camundongos Knockout , Transdução de Sinais , Transcrição GênicaRESUMO
Appropriate balance of T helper 17 (Th17) and regulatory T (Treg) cells maintains immune tolerance and host defense. Disruption of Th17-Treg cell balance is implicated in a number of immune-mediated diseases, many of which display dysregulation of the insulin-like growth factor (IGF) system. Here, we show that, among effector T cell subsets, Th17 and Treg cells selectively expressed multiple components of the IGF system. Signaling through IGF receptor (IGF1R) activated the protein kinase B-mammalian target of rapamycin (AKT-mTOR) pathway, increased aerobic glycolysis, favored Th17 cell differentiation over that of Treg cells, and promoted a heightened pro-inflammatory gene expression signature. Group 3 innate lymphoid cells (ILC3s), but not ILC1s or ILC2s, were similarly responsive to IGF signaling. Mice with deficiency of IGF1R targeted to T cells failed to fully develop disease in the experimental autoimmune encephalomyelitis (EAE) model of multiple sclerosis. Thus, the IGF system represents a previously unappreciated pathway by which type 3 immunity is modulated and immune-mediated pathogenesis controlled.
Assuntos
Autoimunidade , Encefalomielite Autoimune Experimental/imunologia , Proteínas Proto-Oncogênicas c-akt/imunologia , Receptor IGF Tipo 1/imunologia , Linfócitos T Reguladores/imunologia , Serina-Treonina Quinases TOR/imunologia , Células Th17/imunologia , Animais , Comunicação Celular , Diferenciação Celular , Linhagem da Célula/genética , Linhagem da Célula/imunologia , Encefalomielite Autoimune Experimental/induzido quimicamente , Encefalomielite Autoimune Experimental/genética , Encefalomielite Autoimune Experimental/patologia , Feminino , Regulação da Expressão Gênica , Tolerância Imunológica , Imunidade Inata , Ativação Linfocitária , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , Glicoproteína Mielina-Oligodendrócito/administração & dosagem , Fragmentos de Peptídeos/administração & dosagem , Proteínas Proto-Oncogênicas c-akt/genética , Receptor IGF Tipo 1/genética , Transdução de Sinais , Linfócitos T Reguladores/patologia , Serina-Treonina Quinases TOR/genética , Células Th17/patologiaRESUMO
Glutamate dysregulation occurs in multiple sclerosis (MS), but whether excitotoxic mechanisms in mature oligodendrocytes contribute to demyelination and axonal injury is unexplored. Although current treatments modulate the immune system, long-term disability ensues, highlighting the need for neuroprotection. Glutamate is elevated before T2-visible white matter lesions appear in MS. We previously reported that myelin-reactive T cells provoke microglia to release glutamate from the system xc - transporter promoting myelin degradation in experimental autoimmune encephalomyelitis (EAE). Here, we explore the target for glutamate in mature oligodendrocytes. Most glutamate-stimulated calcium influx into oligodendrocyte somas is AMPA receptor (AMPAR)-mediated, and genetic deletion of AMPAR subunit GluA4 decreased intracellular calcium responses. Inducible deletion of GluA4 on mature oligodendrocytes attenuated EAE and loss of myelinated axons was selectively reduced compared to unmyelinated axons. These data link AMPAR signaling in mature oligodendrocytes to the pathophysiology of myelinated axons, demonstrating glutamate regulation as a potential neuroprotective strategy in MS.
Assuntos
Axônios/metabolismo , Encefalomielite Autoimune Experimental/patologia , Bainha de Mielina/metabolismo , Oligodendroglia/metabolismo , Receptores de AMPA/metabolismo , Animais , Axônios/patologia , Sinalização do Cálcio , Encefalomielite Autoimune Experimental/metabolismo , Feminino , Ácido Glutâmico , Integrases/metabolismo , Masculino , Camundongos Endogâmicos C57BL , Bainha de Mielina/patologia , Oligodendroglia/patologia , Subunidades ProteicasRESUMO
Late-onset sepsis (LOS) is thought to result from systemic spread of commensal microbes from the intestines of premature infants. Clinical use of probiotics for LOS prophylaxis has varied owing to limited efficacy, reflecting an incomplete understanding of relationships between development of the intestinal microbiome, neonatal dysbiosis and LOS. Using a model of LOS, we found that components of the developing microbiome were both necessary and sufficient to prevent LOS. Maternal antibiotic exposure that eradicated or enriched transmission of Lactobacillus murinus exacerbated and prevented disease, respectively. Prophylactic administration of some, but not all Lactobacillus spp. was protective, as was administration of Escherichia coli. Intestinal oxygen level was a major driver of colonization dynamics, albeit via mechanisms distinct from those in adults. These results establish a link between neonatal dysbiosis and LOS, and provide a basis for rational selection of probiotics that modulate primary succession of the microbiome to prevent disease.
Assuntos
Disbiose/tratamento farmacológico , Microbioma Gastrointestinal/efeitos dos fármacos , Sepse/tratamento farmacológico , Idade de Início , Animais , Animais Recém-Nascidos , Modelos Animais de Doenças , Disbiose/microbiologia , Disbiose/prevenção & controle , Humanos , Recém-Nascido Prematuro , Camundongos , Probióticos/uso terapêutico , Substâncias Protetoras/uso terapêutico , Sepse/microbiologia , Sepse/prevenção & controleRESUMO
The basic leucine zipper transcription factor activating transcription factor-like (Batf) contributes to transcriptional programming of multiple effector T cells and is required for T helper 17 (Th17) and T follicular helper (Tfh) cell development. Here, we examine mechanisms by which Batf initiates gene transcription in developing effector CD4 T cells. We find that, in addition to its pioneering function, Batf controls developmentally regulated recruitment of the architectural factor Ctcf to promote chromatin looping that is associated with lineage-specific gene transcription. The chromatin-organizing actions of Batf are largely dependent on Ets1, which appears to be indispensable for the Batf-dependent recruitment of Ctcf. Moreover, most of the Batf-dependent sites to which Ctcf is recruited lie outside of activating protein-1-interferon regulatory factor (Ap-1-Irf) composite elements (AICEs), indicating that direct involvement of Batf-Irf complexes is not required. These results identify a cooperative role for Batf, Ets1, and Ctcf in chromatin reorganization that underpins the transcriptional programming of effector T cells.
Assuntos
Fatores de Transcrição de Zíper de Leucina Básica/metabolismo , Fator de Ligação a CCCTC/metabolismo , Linfócitos T CD4-Positivos/metabolismo , Cromatina/metabolismo , Proteína Proto-Oncogênica c-ets-1/metabolismo , Animais , Montagem e Desmontagem da Cromatina , Genoma , Humanos , Fatores Reguladores de Interferon/metabolismo , Interleucinas/metabolismo , Ativação Linfocitária/imunologia , Camundongos Endogâmicos C57BL , Ligação Proteica , Regulação para Cima/genéticaRESUMO
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.
Assuntos
Infecções por Klebsiella/imunologia , Células Th17/imunologia , Animais , Linfócitos T CD4-Positivos/citologia , Linfócitos T CD4-Positivos/imunologia , Linfócitos T CD4-Positivos/metabolismo , Toxina Diftérica/farmacologia , Modelos Animais de Doenças , Feminino , Memória Imunológica , Interleucina-17/genética , Interleucina-17/metabolismo , Infecções por Klebsiella/patologia , Klebsiella pneumoniae/imunologia , Klebsiella pneumoniae/patogenicidade , Pulmão/efeitos dos fármacos , Pulmão/metabolismo , Pulmão/microbiologia , Camundongos , Camundongos Endogâmicos C57BL , Células Th17/citologia , Células Th17/metabolismoRESUMO
In response to infection, naïve CD4+ T cells differentiate into two subpopulations: T follicular helper (TFH) cells, which support B cell antibody production, and non-TFH cells, which enhance innate immune cell functions. Interleukin-2 (IL-2), the major cytokine produced by naïve T cells, plays an important role in the developmental divergence of these populations. However, the relationship between IL-2 production and fate determination remains unclear. Using reporter mice, we found that differential production of IL-2 by naïve CD4+ T cells defined precursors fated for different immune functions. IL-2 producers, which were fated to become TFH cells, delivered IL-2 to nonproducers destined to become non-TFH cells. Because IL-2 production was limited to cells receiving the strongest T cell receptor (TCR) signals, a direct link between TCR-signal strength, IL-2 production, and T cell fate determination has been established.