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1.
Life Sci ; 240: 117078, 2020 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-31759041

RESUMO

AIM: The cross regulation between neuroendocrine system, particularly Hypothalamus-Pituitary-Thyroid (HPT) axis and immune system during embryonic/early neonatal developmental stages shapes the functional attribute of immune response throughout the life. Thus, disruption of immune system was anticipated on exposure to thyroid disrupting pesticides (TDPs) mancozeb (MCZ) and fipronil (FPN) during critical windows of early postnatal days (PND) development. MAIN METHODS: Mice were exposed to MCZ and FPN as individual (0.5% LD 50 each) and as mixtures (0.25% and 0.5% LD 50 each) from PND 31 (initiation phase of immune response) till PND 60 (Maturation phase). Thyroxine (T4) supplementation was given from PND 51 to PND 60. Assessment was done at PND 61 as well as at PND 91 (adults). KEY FINDINGS: Plasma level of thyroid hormones (T3 and T4) was reduced but pituitary hormone (TSH) increased till adulthood on exposure to mixture pesticides but not on individual exposure. Mixture pesticides also increased body weight gain and reduced survival rate in adults. Exposure of individual pesticides exert immunotoxicity but more pronounced immune suppression was observed in mixture pesticides exposed group as reflected in reduced relative weight and cellularity in spleen and thymus, reduced in vitro mitogenic (Con A/LPS) response of splenocytes and thymocytes (reduced proliferative index and increased apoptotic/necrotic death). T4 supplementation ameliorated thyroid disruptive and immunotoxic effect of pesticides. SIGNIFICANCE: The additive/synergistic toxicity as well as hypothyroidism induced by mixture pesticides has produced pronounced immune suppression that reflected till adulthood. Supplementation of T4 prevented thyroid axis disruption mediated immunosuppression.


Assuntos
Disruptores Endócrinos/toxicidade , Fungicidas Industriais/toxicidade , Sistema Imunitário/efeitos dos fármacos , Inseticidas/toxicidade , Maneb/toxicidade , Praguicidas/antagonistas & inibidores , Praguicidas/toxicidade , Pirazóis/toxicidade , Tiroxina/metabolismo , Tiroxina/uso terapêutico , Zineb/toxicidade , Animais , Peso Corporal , Feminino , Masculino , Camundongos , Tamanho do Órgão/efeitos dos fármacos , Baço/citologia , Baço/efeitos dos fármacos , Baço/imunologia , Análise de Sobrevida , Timo/citologia , Timo/efeitos dos fármacos , Timo/imunologia
2.
Immunity ; 51(5): 930-948.e6, 2019 11 19.
Artigo em Inglês | MEDLINE | ID: mdl-31604687

RESUMO

Generation of the first T lymphocytes in the human embryo involves the emergence, migration, and thymus seeding of lymphoid progenitors together with concomitant thymus organogenesis, which is the initial step to establish the entire adaptive immune system. However, the cellular and molecular programs regulating this process remain unclear. We constructed a single-cell transcriptional landscape of human early T lymphopoiesis by using cells from multiple hemogenic and hematopoietic sites spanning embryonic and fetal stages. Among heterogenous early thymic progenitors, one subtype shared common features with a subset of lymphoid progenitors in fetal liver that are known as thymus-seeding progenitors. Unbiased bioinformatics analysis identified a distinct type of pre-thymic lymphoid progenitors in the aorta-gonad-mesonephros (AGM) region. In parallel, we investigated thymic epithelial cell development and potential cell-cell interactions during thymus organogenesis. Together, our data provide insights into human early T lymphopoiesis that prospectively direct T lymphocyte regeneration, which might lead to development of clinical applications.


Assuntos
Diferenciação Celular/genética , Linfopoese/genética , Organogênese/genética , Células Precursoras de Linfócitos T/citologia , Células Precursoras de Linfócitos T/metabolismo , Timo/embriologia , Biomarcadores , Diferenciação Celular/imunologia , Embrião de Mamíferos , Desenvolvimento Embrionário/genética , Perfilação da Expressão Gênica , Células-Tronco Hematopoéticas/citologia , Células-Tronco Hematopoéticas/metabolismo , Humanos , Imunofenotipagem , Linfopoese/imunologia , Detecção de Sinal Psicológico , Linfócitos T/imunologia , Linfócitos T/metabolismo , Timo/imunologia , Timo/metabolismo , Transcriptoma
3.
Nervenarzt ; 90(10): 1055-1066, 2019 Oct.
Artigo em Alemão | MEDLINE | ID: mdl-31538208

RESUMO

Myasthenia gravis (MG) is an autoimmune disorder caused by antibodies against acetylcholine receptors (AChR) or other structural proteins of the neuromuscular junction. This diminishes cholinergic transmission, thus leading to exercise-induced fatigue and sometimes manifest muscle weakness, including the bulbar and ocular musculature. Whereas ocular MG is as a rule initially symptomatically treated with acetylcholine esterase inhibitors, generalized MG requires long-term immunosuppression. The thymus plays a particular role in the pathophysiology of AChR antibody-positive MG, which can also manifest as a paraneoplastic disorder in the context of a thymoma. This article reviews the basic and advanced treatment options of the different disease subtypes including plasma exchange and immunoglobulins for treatment in a myasthenic crisis. Recently, clinical approval of eculizumab, a complement inhibitor, enriched the pharmacological armamentarium for AChR antibody-positive MG patients not appropriately responding to immunosuppression alone.


Assuntos
Miastenia Gravis , Anticorpos Monoclonais Humanizados/uso terapêutico , Humanos , Imunoglobulinas/uso terapêutico , Imunossupressão , Miastenia Gravis/imunologia , Miastenia Gravis/terapia , Troca Plasmática , Timo/imunologia , Timo/patologia
4.
Mol Immunol ; 114: 600-611, 2019 10.
Artigo em Inglês | MEDLINE | ID: mdl-31539668

RESUMO

In this work, we demonstrate that adhesion between medullary thymic epithelial cells (mTECs) and thymocytes is controlled by miRNAs. Adhesion between mTECs and developing thymocytes is essential for triggering negative selection (NS) of autoreactive thymocytes that occurs in the thymus. Immune recognition is mediated by the MHC / TCR receptor, whereas adhesion molecules hold cell-cell interaction stability. Indeed, these processes must be finely controlled, if it is not, it may lead to aggressive autoimmunity. Conversely, the precise molecular genetic control of mTEC-thymocyte adhesion is largely unclear. Here, we asked whether miRNAs would be controlling this process through the posttranscriptional regulation of mRNAs that encode adhesion molecules. For this, we used small interfering RNA to knockdown (KD) Dicer mRNA in vitro in a murine mTEC line. A functional assay with fresh murine thymocytes co-cultured with mTECs showed that single-positive (SP) CD4 and CD8 thymocyte adhesion was increased after Dicer KD and most adherent subtype was CD8 SP cells. Analysis of broad mTEC transcriptional expression showed that Dicer KD led to the modulation of 114 miRNAs and 422 mRNAs, including those encoding cell adhesion or extracellular matrix proteins, such as Lgals9, Lgals3pb, Tnc and Cd47. Analysis of miRNA-mRNA networks followed by miRNA mimic transfection showed that these mRNAs are under the control of miR-181b-5p and miR-30b*, which may ultimately control mTEC-thymocyte adhesion. The expression of CD80 surface marker in mTECs was increased after Dicer KD following thymocyte adhesion. This indicates the existence of new mechanisms in mTECs that involve the synergistic action of thymocyte adhesion and regulatory miRNAs.


Assuntos
Adesão Celular/imunologia , Células Epiteliais/imunologia , MicroRNAs/imunologia , Timócitos/imunologia , Timo/imunologia , Animais , Antígeno B7-1/imunologia , Biomarcadores/sangue , Diferenciação Celular/imunologia , Feminino , Regulação da Expressão Gênica/imunologia , Ativação Linfocitária/imunologia , Camundongos , Camundongos Endogâmicos C57BL , Receptores de Antígenos de Linfócitos T/imunologia , Tolerância a Antígenos Próprios/imunologia , Fatores de Transcrição/imunologia
5.
Immunogenetics ; 71(8-9): 513-518, 2019 09.
Artigo em Inglês | MEDLINE | ID: mdl-31418051

RESUMO

Demonstration that immature CD4 + 8+ thymocytes contain T cell precursors that are subjected to positive and negative selection was the major step towards understanding how the adaptive immune system acquires the ability to distinguish foreign or abnormal (mutated or infected) self-cells from normal (healthy) cells. In the present review, the roles of TCR, CD4, CD8, and MHC molecules in intrathymic selection and some of the crucial experiments that contributed to the solution of the great immunological puzzle of self/nonself discrimination are described in an historical perspective. Recently, these experiments were highlighted by the immunological community by awarding the 2016 Novartis Prize for Immunology to Philippa Marrack, John Kappler, and Harald von Boehmer.


Assuntos
Células Apresentadoras de Antígenos/imunologia , Doenças Autoimunes/imunologia , Sistema Imunitário/imunologia , Tolerância a Antígenos Próprios , Subpopulações de Linfócitos T/imunologia , Timo/imunologia , Animais , Humanos , Complexo Principal de Histocompatibilidade/imunologia , Receptores de Antígenos de Linfócitos T alfa-beta/imunologia , Timo/citologia
6.
Nat Immunol ; 20(9): 1244-1255, 2019 09.
Artigo em Inglês | MEDLINE | ID: mdl-31431722

RESUMO

Mucosal-associated invariant T cells (MAIT cells) recognize the microbial metabolite 5-(2-oxopropylideneamino)-6-D-ribitylaminouracil (5-OP-RU) presented by the MHC class Ib molecule, MR1. MAIT cells acquire effector functions during thymic development, but the mechanisms involved are unclear. Here we used single-cell RNA-sequencing to characterize the developmental path of 5-OP-RU-specific thymocytes. In addition to the known MAIT1 and MAIT17 effector subsets selected on bone-marrow-derived hematopoietic cells, we identified 5-OP-RU-specific thymocytes that were selected on thymic epithelial cells and differentiated into CD44- naive T cells. MAIT cell positive selection required signaling through the adapter, SAP, that controlled the expression of the transcription factor, ZBTB16. Pseudotemporal ordering of single cells revealed transcriptional trajectories of 5-OP-RU-specific thymocytes selected on either thymic epithelial cells or hematopoietic cells. The resulting model illustrates T cell lineage decisions.


Assuntos
Linhagem da Célula/imunologia , Células T Invariáveis Associadas à Mucosa/citologia , Células T Invariáveis Associadas à Mucosa/imunologia , Ribitol/análogos & derivados , Timócitos/citologia , Timócitos/imunologia , Uracila/análogos & derivados , Animais , Sequência de Bases , Diferenciação Celular/genética , Diferenciação Celular/imunologia , Antígenos de Histocompatibilidade Classe I/metabolismo , Receptores de Hialuronatos/metabolismo , Ativação Linfocitária/imunologia , Camundongos , Camundongos Knockout , Antígenos de Histocompatibilidade Menor/metabolismo , Proteína com Dedos de Zinco da Leucemia Promielocítica/biossíntese , Receptores de Antígenos de Linfócitos T alfa-beta/imunologia , Ribitol/imunologia , Análise de Sequência de RNA , Família de Moléculas de Sinalização da Ativação Linfocitária/metabolismo , Timo/citologia , Timo/imunologia , Uracila/imunologia
7.
Immunology ; 158(2): 121-135, 2019 10.
Artigo em Inglês | MEDLINE | ID: mdl-31322727

RESUMO

The Autoimmune Regulator (Aire) protein coordinates the negative selection of developing thymocytes by inducing the expression of hundreds of tissue-specific antigens within the thymic medulla, which is also a primary site of the expression of the immune checkpoint HLA-G molecule. Considering the immunomodulatory properties of Aire and HLA-G, and considering that the role of the constitutive thymus expression of HLA-G has not been elucidated, we studied the effect of AIRE cDNA transfection on HLA-G expression in 4D6 thymic cells and in the HLA-G-positive JEG-3 choriocarcinoma cells. Aire promoted the transactivation of HLA-G gene by increasing the overall transcription, inducing the transcription of at least G1 and G2/G4 isoforms, and incrementing the occurrence and distribution of intracellular HLA-G protein solely in 4D6 thymic cells. Luciferase-based assays and chromatin immunoprecipitation experiments performed in 4D6 cells revealed that Aire targeted at least two regions within the 5'-untranslated regulatory region (5'-URR) extending 1·4 kb from the first ATG initiation codon. The interaction occurs independently of three putative Aire-binding sites. These results indicate that the Aire-induced upregulation of HLA-G in thymic cells is likely to act through the interaction of Aire with specific HLA-G 5'-URR DNA-binding factors. Such a multimeric transcriptional complex might operate in the thymus during the process of promiscuous gene expression.


Assuntos
Células Epiteliais/imunologia , Antígenos HLA-G/genética , Fatores de Transcrição/genética , Ativação Transcricional/imunologia , Regiões 5' não Traduzidas , Autoimunidade/genética , Sítios de Ligação , Linhagem Celular Tumoral , Células Epiteliais/citologia , Genes Reporter , Antígenos HLA-G/imunologia , Humanos , Luciferases/genética , Luciferases/metabolismo , Plasmídeos/química , Plasmídeos/metabolismo , Ligação Proteica , Transdução de Sinais , Timo/citologia , Timo/imunologia , Fatores de Transcrição/imunologia , Transfecção
8.
Nat Commun ; 10(1): 3031, 2019 07 10.
Artigo em Inglês | MEDLINE | ID: mdl-31292453

RESUMO

Maternal immune dysregulation seems to affect fetal or postnatal immune development. Preeclampsia is a pregnancy-associated disorder with an immune basis and is linked to atopic disorders in offspring. Here we show reduction of fetal thymic size, altered thymic architecture and reduced fetal thymic regulatory T (Treg) cell output in preeclamptic pregnancies, which persists up to 4 years of age in human offspring. In germ-free mice, fetal thymic CD4+ T cell and Treg cell development are compromised, but rescued by maternal supplementation with the intestinal bacterial metabolite short chain fatty acid (SCFA) acetate, which induces upregulation of the autoimmune regulator (AIRE), known to contribute to Treg cell generation. In our human cohorts, low maternal serum acetate is associated with subsequent preeclampsia, and correlates with serum acetate in the fetus. These findings suggest a potential role of acetate in the pathogenesis of preeclampsia and immune development in offspring.


Assuntos
Acetatos/sangue , Feto/imunologia , Pré-Eclâmpsia/imunologia , Efeitos Tardios da Exposição Pré-Natal/imunologia , Linfócitos T Reguladores/imunologia , Acetatos/administração & dosagem , Acetatos/imunologia , Acetatos/metabolismo , Adulto , Animais , Animais Recém-Nascidos , Estudos de Casos e Controles , Desenvolvimento Infantil , Pré-Escolar , Suplementos Nutricionais , Feminino , Feto/citologia , Feto/diagnóstico por imagem , Microbioma Gastrointestinal/imunologia , Vida Livre de Germes/imunologia , Humanos , Tolerância Imunológica/imunologia , Lactente , Recém-Nascido , Estudos Longitudinais , Troca Materno-Fetal/imunologia , Camundongos , Tamanho do Órgão/imunologia , Pré-Eclâmpsia/sangue , Pré-Eclâmpsia/diagnóstico , Gravidez , Efeitos Tardios da Exposição Pré-Natal/patologia , Efeitos Tardios da Exposição Pré-Natal/prevenção & controle , Estudos Prospectivos , Timo/citologia , Timo/diagnóstico por imagem , Timo/crescimento & desenvolvimento , Timo/imunologia , Fatores de Transcrição/imunologia , Fatores de Transcrição/metabolismo , Ultrassonografia Pré-Natal , Adulto Jovem
9.
Scand J Immunol ; 90(5): e12806, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31276223

RESUMO

The Standard model of T cell recognition asserts that T cell receptor (TCR) specificities are positively and negatively selected during ontogeny in the thymus and that peripheral T cell repertoire has mild self-major histocompatibility complex (MHC) reactivity, known as MHC restriction of foreign antigen. Thus, the TCR must bind both a restrictive molecule (MHC allele) and a peptide reclining in its groove (pMHC ligand) in order to transmit signal into a T cell. The Standard and Cohn's Tritope models suggest contradictory roles for complementarity-determining regions (CDRs) of the TCRs. Here, I discuss both concepts and propose a different solution to ontogenetic mechanism for TCR-MHC-conserved interaction. I suggest that double (CD4+ CD8+ )-positive (DP) developing thymocytes compete with their αßTCRs for binding to self-pMHC on cortical thymic epithelial cells (cTECs) that present a selected set of tissue-restricted antigens. The competition between DPs involves TCR editing and secondary rearrangements, similar to germinal-centre B cell somatic hypermutation. These processes would generate cells with higher TCR affinity for self-pMHC, facilitating sufficiently long binding to cTECs to become thymic T regulatory cells (tTregs). Furthermore, CD4+ Foxp3+ tTregs can be generated by mTECs via Aire-dependent and Aire-independent pathways, and additionally on thymic bone marrow-derived APCs including thymic Aire-expressing B cells. Thymic Tregs differ from the induced peripheral Tregs, which comprise the negative feedback loop to restrain immune responses. The implication of thymocytes' competition for the highest binding to self-pMHC is the co-evolution of species-specific αßTCR V regions with MHC alleles.


Assuntos
Regiões Determinantes de Complementaridade/imunologia , Complexo Principal de Histocompatibilidade/imunologia , Receptores de Antígenos de Linfócitos T alfa-beta/imunologia , Linfócitos T Reguladores/imunologia , Humanos , Ativação Linfocitária/imunologia , Especificidade do Receptor de Antígeno de Linfócitos T/imunologia , Timo/imunologia , Fatores de Transcrição/metabolismo
10.
J Immunol Res ; 2019: 8785263, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31281853

RESUMO

Regulatory T cells (Tregs) play a critical role in controlling autoreactive T cells, and quantitative and/or qualitative deficiencies in Tregs are associated with autoimmune diseases, including type 1 diabetes (T1D), in both humans and mice. Both the incidence of T1D and percentages of peripheral Tregs in NOD mice vary considerably between animal facilities. In our animal facility, the incidence of T1D in NOD mice is high at 90-100% and the percentages of peripheral CD4+Foxp3+ cells in ~9-10-week-old female NOD mice are decreased compared to control (B6) mice shortly before high glucose is first detected (~12 weeks). These data suggest that there is an imbalance between Tregs and potentially pathogenic effector T cells at this age that could have significant impact on disease progression to overt diabetes. The goal of the current study was to investigate mechanisms that play a role in peripheral Treg : T effector cell balance in NOD mice, including differences in persistence/survival, peripheral homeostatic proliferation, and thymic production and output of CD4+ T cells. We found no differences in persistence/survival or homeostatic proliferation of either Tregs or effector T cells between NOD and B6 mice. Furthermore, although the percentages and absolute numbers of CD4+Foxp3+ cells in thymus were not decreased in NOD compared to B6 mice, the percentage of CD4+ recent thymic emigrants (RTE) that were Foxp3+ was significantly lower in 9-week-old NOD mice. Interestingly, the thymic output of CD4+Foxp3+ cells was not lower in NOD mice, whereas the thymic output of CD4+Foxp3- cells was significantly higher in NOD mice at that age compared to B6 mice. These data suggest that the higher thymic output of CD4+Foxp3- T cells contributes, at least in part, to the lower percentages of peripheral CD4+Foxp3+ Tregs in NOD mice and an imbalance between Tregs and T effector cells that may contribute to the development of full-blown diabetes.


Assuntos
Linfócitos T CD4-Positivos/imunologia , Linfócitos T Reguladores/imunologia , Timo/imunologia , Animais , Biomarcadores , Linfócitos T CD4-Positivos/metabolismo , Movimento Celular , Diabetes Mellitus Tipo 1/imunologia , Diabetes Mellitus Tipo 1/metabolismo , Feminino , Imunomodulação , Imunofenotipagem , Contagem de Linfócitos , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Endogâmicos NOD , Camundongos Transgênicos , Especificidade da Espécie , Linfócitos T Reguladores/metabolismo , Timo/metabolismo
11.
Vet Immunol Immunopathol ; 212: 15-22, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-31213247

RESUMO

Marek's disease virus (MDV), an α-herpesvirus targeting avian species, causes fatal Marek's disease (MD) in chickens. The host interferon (IFN) responses play a key role in resisting viral infection. However, host IFN responses following MDV infection in the chicken central immune organs (thymus and bursa of Fabricius), which contain numerous MDV target cells, is poorly understood. In this study, we performed animal experiments in specific pathogen-free chickens infected with two virulent MDV strains (BS/15 and Md5) or without infection as negative controls. Specifically, the type I IFN (IFN-α and IFN-ß) transcriptional and proteomic expression levels at 7, 10, 14, 17, and 21 days post infection (dpi) were detected and analyzed. Our results indicated that the mRNA and protein expression levels of IFN-α and IFN-ß in the thymus and bursa of Fabricius were mainly downregulated in cytolytic infection (such as 10 dpi) and reactivation (such as 17 dpi) stages, but not the latent (such as 14 dpi) stage of MDV infection, which was determined by comprehensively analyzing the MDV viral load and immune organ damage caused by MDV infection. These data suggest that MDV could inhibit the expression of host type I IFNs, which may be involved in the MDV-induced host immunosuppression and contribute to the immune escape of MDV from host immunity. Furthermore, we found that the downregulated expression of the host type I IFNs induced by BS/15 and Md5 infection was significantly different, which we speculated may be related to the diverse virulence and pathogenicity of MDV strains. In conclusion, our study demonstrated that MDV mostly inhibited the expression of type I IFNs in infected hosts, which may be associated to its pathogenesis.


Assuntos
Interferon Tipo I/imunologia , Doença de Marek/imunologia , Doenças das Aves Domésticas/imunologia , Animais , Bolsa de Fabricius/imunologia , Galinhas , Expressão Gênica , Herpesvirus Galináceo 2 , Interferon Tipo I/genética , Interferon-alfa/genética , Interferon-alfa/imunologia , Interferon beta/genética , Interferon beta/imunologia , Doenças das Aves Domésticas/virologia , Proteômica , RNA Mensageiro/genética , Organismos Livres de Patógenos Específicos , Timo/imunologia , Carga Viral , Virulência
12.
Scand J Immunol ; 90(4): e12797, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31166602

RESUMO

Distinctive "two signal" paths in immunology, taken by researchers with different academic backgrounds, seem to have both contained facets of the truth. Having been influenced by education at a medical school where Almroth Wright's early contributions were not forgotten, the author's "path less followed" led to views that began to gain recognition late in the twentieth century when the intimate relationship between innate and acquired immunity became more apparent.


Assuntos
Modelos Imunológicos , Agregação de Receptores , Linfócitos T/fisiologia , Timo/imunologia , Imunidade Adaptativa , Animais , Autoantígenos/imunologia , Autoimunidade , Consenso , Quadruplex G , Humanos , Imunidade Inata , Ativação Linfocitária , Tolerância a Antígenos Próprios
13.
Lupus ; 28(8): 1007-1012, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-31166866

RESUMO

We have previously reported that IL-23 receptor deficiency in MRL.lpr mice ameliorates lupus by altering the balance of pro- and anti-inflammatory cytokines in secondary lymphoid organs. As IL-23 may also impact thymic selection, we evaluated the effect of IL-23 on thymic T cell development in lupus-prone mice. We generated IL-23p19-deficient MRL.lpr mice and harvested their thymus at 8 weeks of age. We found that the late stage double negative DN4 population was increased in IL-23p19-/- MRL.lpr mice when compared to IL-23p19+/+ MRL.lpr mice. Despite this, mature thymocytes (CD24-TCRß+) were decreased by more than 50% in the IL-23p19-deficient mice versus wild-type controls. This was associated with a decrease in the generation of CD8+ T cells, possibly through downregulation of the IL-7 receptor. CD8+ T cells were not only fewer in numbers but also had decreased expression of the migration-related receptors CD44 and CD62L in the thymus and spleens of IL-23p19-deficient versus wild-type mice. We propose that IL-23 promotes the development of lupus-like autoimmunity not only through T cell polarization and cytokine production in the peripheral lymphoid organs but also by influencing T cell thymic development.


Assuntos
Linfócitos T CD8-Positivos/imunologia , Subunidade p19 da Interleucina-23/genética , Lúpus Eritematoso Sistêmico/imunologia , Timo/imunologia , Animais , Autoanticorpos/imunologia , Linfócitos B/imunologia , Regulação para Baixo , Lúpus Eritematoso Sistêmico/fisiopatologia , Ativação Linfocitária , Camundongos , Camundongos Endogâmicos MRL lpr , Camundongos Knockout , Baço/imunologia , Timo/citologia
14.
Int J Mol Sci ; 20(11)2019 May 30.
Artigo em Inglês | MEDLINE | ID: mdl-31151139

RESUMO

Here, we investigate the role of RelB in the regulation of genes which were identified to be induced in an aryl hydrocarbon receptor (AhR)-dependent manner and critically involved in regulation of immune responses. We analyzed the expression of genes of the AhR gene battery, cytokines, and immune regulatory enzymes in bone marrow-derived macrophages (BMM) and thymus of B6 wildtype (wt) mice and RelB knockout (RelB-/-) mice after treatment with various AhR ligands. The 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD)-induced expression of indoleamine 2,3-dioxygenase 1 (IDO1) and IDO2 was significantly repressed in thymus of RelB-/- mice but not in BMM derived from RelB-/- mice. Interestingly, the induced and basal expression of the cytokines interleukin (IL)-17A, IL-22, and CCL20 required the functional expression of RelB. The RelB-dependent expression of CCL20 was induced by the AhR ligands TCDD and 6-formylindolo[3,2-b]carbazole (FICZ), whereas indole-3-carbinol (I3C) suppressed CCL20 in lipopolysaccharide (LPS)-activated wt BMM. The LPS-induced expression of IL-6 and IL-10 was enhanced by TCDD and FICZ, whereas I3C significantly suppressed these cytokines in BMM. The exposure to FICZ led to higher increases of IL-17A and IL-22 mRNA compared to the effect of TCDD or I3C in thymus of wt mice. On the other hand, TCDD was the strongest inducer of CYP1A1, AhR Repressor (AhRR), and IDO2. In summary, these findings provide evidence for the important role of RelB in the transcriptional regulation of cytokines and enzymes induced by AhR ligands.


Assuntos
Receptores de Hidrocarboneto Arílico/metabolismo , Fator de Transcrição RelB/metabolismo , Animais , Citocinas/genética , Citocinas/metabolismo , Expressão Gênica , Regulação da Expressão Gênica , Imunomodulação/genética , Ligantes , Macrófagos/metabolismo , Masculino , Camundongos , Camundongos Knockout , Ligação Proteica , Receptores de Hidrocarboneto Arílico/genética , Timo/imunologia , Timo/metabolismo , Fator de Transcrição RelB/genética
15.
Nat Commun ; 10(1): 2603, 2019 06 13.
Artigo em Inglês | MEDLINE | ID: mdl-31197149

RESUMO

During thymic negative selection, autoreactive thymocytes carrying T cell receptor (TCR) with overtly strong affinity to self-MHC/self-peptide are removed by Bim-dependent apoptosis, but how Bim is specifically regulated to link TCR activation and apoptosis induction is unclear. Here we identify a murine T cell-specific genomic enhancer EBAB (Bub1-Acoxl-Bim), whose deletion leads to accumulation of thymocytes expressing high affinity TCRs. Consistently, EBAB knockout mice have defective negative selection and fail to delete autoreactive thymocytes in various settings, with this defect accompanied by reduced Bim expression and apoptosis induction. By contrast, EBAB is dispensable for maintaining peripheral T cell homeostasis via Bim-dependent pathways. Our data thus implicate EBAB as an important, developmental stage-specific regulator of Bim expression and apoptosis induction to enforce thymic negative selection and suppress autoimmunity. Our study unravels a part of genomic enhancer codes that underlie complex and context-dependent gene regulation in TCR signaling.


Assuntos
Autoimunidade/genética , Proteína 11 Semelhante a Bcl-2/genética , Elementos Facilitadores Genéticos/imunologia , Receptores de Antígenos de Linfócitos T/metabolismo , Timócitos/fisiologia , Animais , Apoptose/genética , Apoptose/imunologia , Autoimunidade/imunologia , Proteína 11 Semelhante a Bcl-2/metabolismo , Sistemas CRISPR-Cas/genética , Elementos Facilitadores Genéticos/genética , Feminino , Regulação da Expressão Gênica/imunologia , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Modelos Animais , Receptores de Antígenos de Linfócitos T/imunologia , Transdução de Sinais/genética , Transdução de Sinais/imunologia , Timo/citologia , Timo/imunologia
16.
Transl Res ; 210: 43-56, 2019 08.
Artigo em Inglês | MEDLINE | ID: mdl-31082370

RESUMO

Cytokine release syndrome (CRS) is a serious and potentially life-threatening complication that can be associated with biological drug products. In vitro assays or in vivo tests using nonhuman primates may fail to predict CRS due to species differences and the complexity of immune system. Therefore, model species that have human-specific immune components may improve the ability to identify CRS and enhance product safety. In this study we used bone marrow-liver-thymus (BLT) humanized mice to test muromonab (OKT3), an anti-CD3 antibody with a black box warning for CRS. Initially, we completed pilot and dose escalation studies with muromonab and showed that when the dose was increased sufficiently, BLT-humanized mice experienced serious adverse outcomes including moribundity. Full studies compared muromonab treatment with adalimumab, saline, and a group pretreated with methylprednisolone prior to muromonab. We evaluated immune cell activation using flow cytometry and cytokine expression using a custom 10-plex cytokine assay to assess levels of human TNF-α, IFN-γ, IL-2, IL-6, IL-8, IL-10, IL-13, IL-17A, IL12/23p40, and GM-CSF. Muromonab treated mice had significant increases in all cytokines tested with T-cell depletion and T-cell activation noted. Adalimumab (active) and saline (inactive) control groups did not demonstrate cytokine expression changes or alterations in T-cell numbers or activation. Further, pretreatment with methylprednisolone blunted or abrogated cytokine increases. This study demonstrates that BLT-humanized mice are capable of experiencing CRS, and could be used to screen biologics for this adverse event to enhance patient safety.


Assuntos
Medula Óssea/imunologia , Citocinas/metabolismo , Fígado/imunologia , Timo/imunologia , Animais , Células da Medula Óssea/citologia , Células da Medula Óssea/efeitos dos fármacos , Relação Dose-Resposta a Droga , Humanos , Fígado/citologia , Ativação Linfocitária/efeitos dos fármacos , Contagem de Linfócitos , Camundongos , Muromonab-CD3/farmacologia , Baço/citologia , Síndrome , Linfócitos T/efeitos dos fármacos
17.
Mol Immunol ; 111: 87-94, 2019 07.
Artigo em Inglês | MEDLINE | ID: mdl-31048099

RESUMO

Reticuloendotheliosis virus (REV), an avian retrovirus is able to infect a variety of birds and can cause immunosuppression. The aim of this study was to investigate the relationship of thymic lymphocytes apoptosis, proliferation and T cell subtype with immunosuppression. In this study, a hundred and twenty one-day old SPF chickens were randomly divided into control groups (group C) and a REV infection groups (group I). The chickens of group I received intraperitoneal injections of REV with 104.62/0.1 ml TCID50. On day 14, 21, 28 and 35 post-inoculation, the chickens of C group and I group were sacrificed by cardiac puncture blood collection, and the thymic lymphocytes was sterile collected. The proliferation ability of lymphocytes was tested by Cell Counting Kit-8. Flow cytometry was performed to detect apoptosis, cell cycle stage and the change in T cell subtype. The RNA genome copy numbers of REV virus were detected using real-time PCR. Real-time PCR and western blotting were performed to analyze the expression of CyclinD1 and Bcl-2. Our results showed that REV genome copy number steadily declined, the proliferation potential of thymic lymphocytes was inhibited, lymphocytes apoptosed, the ratio of CD4+/CD8+ decreased and the expression of CyclinD1 and Bcl-2 were firstly inhibited, then rapidly recovered. Thus, immunosuppression lead by REV is closely related to the change of T cell subtype, apoptosis, and proliferation of thymic lymphocytes.


Assuntos
Apoptose/imunologia , Proliferação de Células/fisiologia , Galinhas/imunologia , Vírus da Reticuloendoteliose/imunologia , Infecções por Retroviridae/imunologia , Subpopulações de Linfócitos T/imunologia , Timo/imunologia , Animais , Linfócitos T CD4-Positivos/imunologia , Linfócitos T CD8-Positivos/imunologia , Ciclo Celular/imunologia , Galinhas/virologia , Ciclina D1/imunologia , Dosagem de Genes/imunologia , Genoma Viral/imunologia , Imunossupressão/métodos , Doenças das Aves Domésticas/imunologia , Doenças das Aves Domésticas/virologia , Proteínas Proto-Oncogênicas c-bcl-2/imunologia , Infecções por Retroviridae/virologia , Subpopulações de Linfócitos T/virologia , Timo/virologia
18.
Biomed Pharmacother ; 115: 108909, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-31071508

RESUMO

Ginsenoside metabolite compound-K (C-K), which is an active metabolite of ginsenoside in vivo, can produce anti-inflammatory affects by activating glucocorticoid receptors (GRs) to inhibit the expression of ß-arrestin2. Studies have shown that C-K can inhibit the function of immune cells including macrophage polarization and phagocytosis. However, the mechanism by which C-K regulates macrophage polarization is currently unclear. Toll-like receptors (TLRs) are the pattern recognition receptors on the membrane of immune cells, with TLR4 being especially important in polarization of macrophages. The Gαi-mediated activation of nuclear factor-κB (NF-κB) by TLR4 promotes inflammation and phagocytosis in macrophages by increasing the proportion of type I phenotypic macrophages (M1). Whether C-K inhibits the signal transduction of TLR4-Gαi-NF-κB and how that effects macrophage polarization regulation in murine models of RA is not reported. The coupling of G proteins with receptors is regulated by ß-arrestin2, but it has been unclear whether C-K modulates the TLR4 interaction with G proteins by inhibiting the expression of ß-arrestin2. To explore these questions, the collagen-induced arthritis (CIA) mouse model was employed, and mice were treated with C-K (112 mg/kg/day). The results depict that C-K treatment inhibits macrophage phagocytosis and reduces the proportion of M1. C-K decreases the overexpressed ß-arrestin2, Gαi, TLR4 and NF-κB in macrophages of CIA mice, while increasing the expression of Gαs. Furthermore, C-K promotes TLR4-Gαs coupling and inhibits TLR4-Gαi coupling through ß-arrestin2 regulation in macrophages, leading to a decrease in the proportion of M1 to M2 macrophages and improved outcomes in CIA mice.


Assuntos
Artrite Experimental/tratamento farmacológico , Ginsenosídeos/uso terapêutico , Macrófagos Peritoneais/efeitos dos fármacos , beta-Arrestina 2/antagonistas & inibidores , Animais , Artrite Experimental/imunologia , Artrite Experimental/patologia , Células Cultivadas , Citocinas/sangue , Articulações do Pé/efeitos dos fármacos , Articulações do Pé/imunologia , Articulações do Pé/patologia , Macrófagos Peritoneais/imunologia , Camundongos Endogâmicos DBA , Fagocitose/efeitos dos fármacos , Baço/efeitos dos fármacos , Baço/imunologia , Timo/efeitos dos fármacos , Timo/imunologia , beta-Arrestina 2/genética
19.
Arch Immunol Ther Exp (Warsz) ; 67(4): 263-270, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31087106

RESUMO

Matured in the thymus, γδT cells can modulate the development of allergy in humans. The main γδT cell subsets have been described as interleukin (IL)-17A or interferon (IFN)-γ producers, but these cells can also produce other modulatory cytokines, such as IL-4 and IL-10. Here, we aimed to evaluate whether IgG can modulate the profile of cytokine production by γδT cells during their maturation in the thymus and after its migration to peripheral tissues. Thymic tissues were obtained from 12 infants, and peripheral blood mononuclear cells (PBMCs) were obtained from adults (both groups without an atopic background). IgG was purified from atopic and non-atopic volunteers. Thymocytes and PBMCs were cultured with purified atopic or non-atopic IgG, and intracellular cytokine production and phenotype were assessed. Mock and IVIg conditions were used as controls. IgG from non-atopic individuals induced IFN-γ and IL-10 production by thymic γδT cells, and no effect was observed on peripheral γδT cells. IL-17 production was inhibited by non-atopic IgG on thymic γδT cells and augmented by atopic IgG on peripheral γδT cells. Modulated thymic γδT cells did not produce IFN-γ and IL-10 simultaneously. We additionally evaluated the phenotype of intrathymic γδT cells and observed that IgG from all groups could induce CD25 expression and could not influence the CD28 expression of these cells. This report describes evidence revealing that IgG may influence the production of IFN-γ and IL-10 by intrathymic γδT cells depending on the donor atopic state. This observation is unprecedented and needs to be considered in further studies in the IgG immunotherapy field.


Assuntos
Células Sanguíneas/imunologia , Hipersensibilidade Imediata/imunologia , Imunoglobulina G/metabolismo , Linfócitos T/imunologia , Timo/imunologia , Adulto , Diferenciação Celular , Células Cultivadas , Feminino , Humanos , Imunoglobulinas Intravenosas/farmacologia , Recém-Nascido , Interferon gama/metabolismo , Interleucina-10/metabolismo , Interleucina-17/metabolismo , Ativação Linfocitária , Masculino , Receptores de Antígenos de Linfócitos T gama-delta/metabolismo
20.
Nat Commun ; 10(1): 2244, 2019 05 21.
Artigo em Inglês | MEDLINE | ID: mdl-31113942

RESUMO

Before they are used in the clinical setting, the effectiveness of artificially produced human-derived tissue-engineered medical products should be verified in an immunodeficient animal model, such as severe combined immunodeficient mice. However, small animal models are not sufficient to evaluate large-sized products for human use. Thus, an immunodeficient large animal model is necessary in order to properly evaluate the clinical efficacy of human-derived tissue-engineered products, such as artificial grafts. Here we report the development of an immunodeficient pig model, the operational immunodeficient pig (OIDP), by surgically removing the thymus and spleen, and creating a controlled immunosuppressive protocol using a combination of drugs commonly used in the clinical setting. We find that this model allows the long-term accommodation of artificial human vascular grafts. The development of the OIDP is an essential step towards a comprehensive and clinically relevant evaluation of human cell regeneration strategies at the preclinical stage.


Assuntos
Órgãos Bioartificiais , Prótese Vascular , Hospedeiro Imunocomprometido , Modelos Animais , Engenharia Tecidual , Animais , Implante de Prótese Vascular/métodos , Linhagem Celular , Fibroblastos , Humanos , Masculino , Impressão Tridimensional , Baço/imunologia , Baço/cirurgia , Suínos , Porco Miniatura/imunologia , Porco Miniatura/cirurgia , Timo/imunologia , Timo/cirurgia , Fatores de Tempo
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