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1.
Nat Commun ; 11(1): 6238, 2020 12 07.
Artigo em Inglês | MEDLINE | ID: mdl-33288744

RESUMO

Most T lymphocytes leave the thymus as naïve cells with limited functionality. However, unique populations of innate-like T cells differentiate into functionally distinct effector subsets during their development in the thymus. Here, we profiled >10,000 differentiating thymic invariant natural killer T (iNKT) cells using single-cell RNA sequencing to produce a comprehensive transcriptional landscape that highlights their maturation, function, and fate decisions at homeostasis. Our results reveal transcriptional profiles that are broadly shared between iNKT and mucosal-associated invariant T (MAIT) cells, illustrating a common core developmental program. We further unmask a mutual requirement for Hivep3, a zinc finger transcription factor and adapter protein. Hivep3 is expressed in early precursors and regulates the post-selection proliferative burst, differentiation and functions of iNKT cells. Altogether, our results highlight the common requirements for the development of innate-like T cells with a focus on how Hivep3 impacts the maturation of these lymphocytes.


Assuntos
Diferenciação Celular/imunologia , Imunidade Inata/imunologia , Células T Matadoras Naturais/imunologia , Análise de Célula Única/métodos , Linfócitos T/imunologia , Timo/imunologia , Animais , Diferenciação Celular/genética , Células Cultivadas , Proteínas de Ligação a DNA/genética , Proteínas de Ligação a DNA/imunologia , Proteínas de Ligação a DNA/metabolismo , Perfilação da Expressão Gênica/métodos , Imunidade Inata/genética , Camundongos Endogâmicos C57BL , Camundongos Knockout , Células T Invariáveis Associadas à Mucosa/citologia , Células T Invariáveis Associadas à Mucosa/imunologia , Células T Invariáveis Associadas à Mucosa/metabolismo , Células T Matadoras Naturais/citologia , Células T Matadoras Naturais/metabolismo , Análise de Sequência de RNA/métodos , Linfócitos T/citologia , Linfócitos T/metabolismo , Timócitos/citologia , Timócitos/imunologia , Timócitos/metabolismo , Timo/citologia , Timo/metabolismo
2.
Nat Commun ; 11(1): 6264, 2020 12 08.
Artigo em Inglês | MEDLINE | ID: mdl-33293517

RESUMO

The molecular and cellular mechanisms mediating thymic central tolerance and prevention of autoimmunity are not fully understood. Here we show that B7-CD28 co-stimulation and B7 expression by specific antigen-presenting cell (APC) types are required for clonal deletion and for regulatory T (Treg) cell generation from endogenous tissue-restricted antigen (TRA)-specific thymocytes. While B7-CD28 interaction is required for both clonal deletion and Treg induction, these two processes differ in their CD28 signaling requirements and in their dependence on B7-expressing dendritic cells, B cells, and thymic epithelial cells. Meanwhile, defective thymic clonal deletion due to altered B7-CD28 signaling results in the accumulation of mature, peripheral TRA-specific T cells capable of mediating destructive autoimmunity. Our findings thus reveal a function of B7-CD28 co-stimulation in shaping the T cell repertoire and limiting autoimmunity through both thymic clonal deletion and Treg cell generation.


Assuntos
Antígeno B7-1/metabolismo , Antígenos CD28/metabolismo , Tolerância Central , Deleção Clonal , Linfócitos T Reguladores/imunologia , Timo/imunologia , Animais , Células Apresentadoras de Antígenos/metabolismo , Autoimunidade/fisiologia , Antígenos CD28/genética , Diferenciação Celular/imunologia , Encefalomielite Autoimune Experimental/imunologia , Citometria de Fluxo , Técnicas de Introdução de Genes , Camundongos , Camundongos Knockout , Receptores de Antígenos de Linfócitos T alfa-beta/genética , Receptores de Antígenos de Linfócitos T alfa-beta/metabolismo , Transdução de Sinais/imunologia , Linfócitos T Reguladores/metabolismo , Timócitos/fisiologia , Timo/citologia , Timo/metabolismo
3.
Nat Commun ; 11(1): 6372, 2020 12 11.
Artigo em Inglês | MEDLINE | ID: mdl-33311516

RESUMO

The thymus is a primary lymphoid organ, essential for T cell maturation and selection. There has been long-standing interest in processes underpinning thymus generation and the potential to manipulate it clinically, because alterations of thymus development or function can result in severe immunodeficiency and autoimmunity. Here, we identify epithelial-mesenchymal hybrid cells, capable of long-term expansion in vitro, and able to reconstitute an anatomic phenocopy of the native thymus, when combined with thymic interstitial cells and a natural decellularised extracellular matrix (ECM) obtained by whole thymus perfusion. This anatomical human thymus reconstruction is functional, as judged by its capacity to support mature T cell development in vivo after transplantation into humanised immunodeficient mice. These findings establish a basis for dissecting the cellular and molecular crosstalk between stroma, ECM and thymocytes, and offer practical prospects for treating congenital and acquired immunological diseases.


Assuntos
Células Estromais , Timo/imunologia , Animais , Autoimunidade , Diferenciação Celular , Células Epiteliais/imunologia , Matriz Extracelular , Feminino , Humanos , Masculino , Camundongos , Camundongos Nus , Ratos , Regeneração , Timócitos , Timo/patologia , Timo/transplante , Tecidos Suporte
4.
Nat Commun ; 11(1): 6169, 2020 12 02.
Artigo em Inglês | MEDLINE | ID: mdl-33268794

RESUMO

A repertoire of T cells with diverse antigen receptors is selected in the thymus. However, detailed mechanisms underlying this thymic positive selection are not clear. Here we show that the CCR4-NOT complex limits expression of specific genes through deadenylation of mRNA poly(A) tails, enabling positive selection. Specifically, the CCR4-NOT complex is up-regulated in thymocytes before initiation of positive selection, where in turn, it inhibits up-regulation of pro-apoptotic Bbc3 and Dab2ip. Elimination of the CCR4-NOT complex permits up-regulation of Bbc3 during a later stage of positive selection, inducing thymocyte apoptosis. In addition, CCR4-NOT elimination up-regulates Dab2ip at an early stage of positive selection. Thus, CCR4-NOT might control thymocyte survival during two-distinct stages of positive selection by suppressing expression levels of pro-apoptotic molecules. Taken together, we propose a link between CCR4-NOT-mediated mRNA decay and T cell selection in the thymus.


Assuntos
Apoptose/genética , Exorribonucleases/genética , Proteínas Repressoras/genética , Timócitos/imunologia , Timo/imunologia , Animais , Apoptose/imunologia , Proteínas Reguladoras de Apoptose/genética , Proteínas Reguladoras de Apoptose/imunologia , Diferenciação Celular , Linhagem da Célula/genética , Linhagem da Célula/imunologia , Exorribonucleases/imunologia , Regulação da Expressão Gênica no Desenvolvimento , Camundongos , Poli A/genética , Poli A/imunologia , Estabilidade de RNA , RNA Mensageiro/genética , RNA Mensageiro/imunologia , Proteínas Repressoras/imunologia , Transdução de Sinais , Timócitos/citologia , Timo/citologia , Timo/crescimento & desenvolvimento , Proteínas Supressoras de Tumor/genética , Proteínas Supressoras de Tumor/imunologia , Proteínas Ativadoras de ras GTPase/genética , Proteínas Ativadoras de ras GTPase/imunologia
5.
PLoS One ; 15(10): e0241375, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33119684

RESUMO

Humanized mouse models are used extensively in research involving human pathogens and diseases. However, most of these models require preconditioning. Radio-active sources have been used routinely for this purpose but safety issues have motivated researchers to transition to chemical or X-ray based preconditioning. In this study, we directly compare 350 kV X-ray and Cs-137 low-dose precondition of NOG mice before human stem cell transplantation. Based on flow cytometry data, we found that engraftment of human cells into the mouse bone marrow was similar between radiation sources. Likewise, human engraftment in the peripheral blood was comparable between Cs-137 and three different X-ray doses with equal chimerization kinetics. In primary lymphoid organs such as the thymus and lymph nodes, and spleen, liver and lung, human-to-mouse chimerization was also comparable between irradiation sources. Development of different CD4 and CD8 T cells as well as these cells' maturation stages, i.e. from naïve to effector and memory subsets were generally analogous. Based on our results, we conclude that there are no discernable differences between the two sources in the low-dose spectrum investigated. However, while we encourage the transition to X-ray-based sources, we recommend all research groups to consider technical specifications and dose-finding studies.


Assuntos
Radioisótopos de Césio , Imunidade/efeitos da radiação , Raios X , Animais , Transplante de Medula Óssea , Feminino , Humanos , Cinética , Linfonodos/imunologia , Camundongos , Fenótipo , Timo/imunologia
6.
Ecotoxicol Environ Saf ; 206: 111413, 2020 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-33022443

RESUMO

Ammonia (NH3) gas is an atmospheric pollutant, produced from different sources. In poultry houses NH3 is produced from the biological process of liter, manure, and protein composition. It has been well documented that NH3 adversely effects the health of chickens. However, the underlying mechanism of NH3 toxicity on chicken thymus is still unknown. Thymus is an important immune organ, which play a critical role in eliciting protective immune responses to ensure healing process and elimination of harmful stimuli. The results showed that NH3 exposure reduced antioxidant activities and induced oxidative stress in thymus tissues. Histological observation showed normal morphology of chicken thymus in control group. In contrast, increased number of nuclear debris, vacuoles, and cristae break were seen in NH3 affected chickens. Ultrastructural analysis indicated mitochondrial breakdown, disappearance, vacuoles, and chromatin condensation in NH3 treated groups. The mRNA and protein expression of apoptosis related genes were significantly enhanced in the chicken thymus of NH3 affected chickens compared to control group. Moreover, Terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL) assay results suggested that NH3 exposure increased positive stained nuclei in the chicken thymus. Meanwhile, NH3 exposure reduced the number of CD8+ T-lymphocytes, decreased the adenosine triphosphate (ATPase) activities. The mRNA and protein expression of autophagy, energy metabolism, and mitochondrial dynamics proteins were altered by NH3 exposure. In summary, these results showed that NH3 induced oxidative stress, apoptosis and autophagic cell death (ACD), which could be the possible causes of immune damage and structural impairment in chicken thymus.


Assuntos
Poluentes Atmosféricos/toxicidade , Amônia/toxicidade , Apoptose/efeitos dos fármacos , Galinhas/metabolismo , Metabolismo Energético/efeitos dos fármacos , Proteínas Mitocondriais/metabolismo , Estresse Oxidativo/efeitos dos fármacos , Timo/efeitos dos fármacos , Animais , Antioxidantes/metabolismo , Autofagia/efeitos dos fármacos , Marcação In Situ das Extremidades Cortadas , Dinâmica Mitocondrial/efeitos dos fármacos , Proteínas Mitocondriais/genética , Timo/imunologia , Timo/metabolismo , Timo/patologia
7.
Nat Med ; 26(11): 1776-1787, 2020 11.
Artigo em Inglês | MEDLINE | ID: mdl-32868878

RESUMO

An effective strategy to cure HIV will likely require a potent and sustained antiviral T cell response. Here we explored the utility of chimeric antigen receptor (CAR) T cells, expressing the CD4 ectodomain to confer specificity for the HIV envelope, to mitigate HIV-induced pathogenesis in bone marrow, liver, thymus (BLT) humanized mice. CAR T cells expressing the 4-1BB/CD3-ζ endodomain were insufficient to prevent viral rebound and CD4+ T cell loss after the discontinuation of antiretroviral therapy. Through iterative improvements to the CAR T cell product, we developed Dual-CAR T cells that simultaneously expressed both 4-1BB/CD3-ζ and CD28/CD3-ζ endodomains. Dual-CAR T cells exhibited expansion kinetics that exceeded 4-1BB-, CD28- and third-generation costimulated CAR T cells, elicited effector functions equivalent to CD28-costimulated CAR T cells and prevented HIV-induced CD4+ T cell loss despite persistent viremia. Moreover, when Dual-CAR T cells were protected from HIV infection through expression of the C34-CXCR4 fusion inhibitor, these cells significantly reduced acute-phase viremia, as well as accelerated HIV suppression in the presence of antiretroviral therapy and reduced tissue viral burden. Collectively, these studies demonstrate the enhanced therapeutic potency of a novel Dual-CAR T cell product with the potential to effectively treat HIV infection.


Assuntos
Antígenos CD4/imunologia , Infecções por HIV/terapia , Imunoterapia Adotiva , Receptores de Antígenos Quiméricos/imunologia , Animais , Anticorpos Monoclonais Humanizados/imunologia , Anticorpos Monoclonais Humanizados/farmacologia , Medula Óssea/imunologia , Medula Óssea/virologia , Complexo CD3/antagonistas & inibidores , Antígenos CD4/administração & dosagem , Regulação da Expressão Gênica/imunologia , Proteína gp41 do Envelope de HIV/antagonistas & inibidores , Proteína gp41 do Envelope de HIV/imunologia , Infecções por HIV/imunologia , Infecções por HIV/patologia , Infecções por HIV/virologia , HIV-1/imunologia , HIV-1/patogenicidade , Humanos , Fígado/imunologia , Fígado/virologia , Camundongos , Fragmentos de Peptídeos/antagonistas & inibidores , Fragmentos de Peptídeos/imunologia , Domínios Proteicos/imunologia , Receptores CXCR4/antagonistas & inibidores , Receptores CXCR4/imunologia , Receptores de Antígenos Quiméricos/administração & dosagem , Linfócitos T/imunologia , Timo/imunologia , Timo/virologia , Membro 9 da Superfamília de Receptores de Fatores de Necrose Tumoral/antagonistas & inibidores
8.
Nat Commun ; 11(1): 4367, 2020 08 31.
Artigo em Inglês | MEDLINE | ID: mdl-32868763

RESUMO

Invariant natural killer T (iNKT), mucosal-associated invariant T (MAIT), and γδ T cells are innate T cells that acquire memory phenotype in the thymus and share similar biological characteristics. However, how their effector differentiation is developmentally regulated is still unclear. Here, we identify analogous effector subsets of these three innate T cell types in the thymus that share transcriptional profiles. Using single-cell RNA sequencing, we show that iNKT, MAIT and γδ T cells mature via shared, branched differentiation rather than linear maturation or TCR-mediated instruction. Simultaneous TCR clonotyping analysis reveals that thymic maturation of all three types is accompanied by clonal selection and expansion. Analyses of mice deficient of TBET, GATA3 or RORγt and additional in vivo experiments corroborate the predicted differentiation paths, while human innate T cells from liver samples display similar features. Collectively, our data indicate that innate T cells share effector differentiation processes in the thymus.


Assuntos
Diferenciação Celular , Imunidade Inata , Linfócitos T/metabolismo , Timo/imunologia , Animais , Células Cultivadas , Seleção Clonal Mediada por Antígeno , Humanos , Fígado/citologia , Fígado/imunologia , Ativação Linfocitária , Camundongos , Células T Invariáveis Associadas à Mucosa/metabolismo , Células T Matadoras Naturais/metabolismo , Análise de Sequência de RNA , Análise de Célula Única , Células Th17/metabolismo , Timo/citologia
9.
Proc Natl Acad Sci U S A ; 117(36): 22367-22377, 2020 09 08.
Artigo em Inglês | MEDLINE | ID: mdl-32848068

RESUMO

The γδ T cells reside predominantly at barrier sites and play essential roles in immune protection against infection and cancer. Despite recent advances in the development of γδ T cell immunotherapy, our understanding of the basic biology of these cells, including how their numbers are regulated in vivo, remains poor. This is particularly true for tissue-resident γδ T cells. We have identified the ß2 family of integrins as regulators of γδ T cells. ß2-integrin-deficient mice displayed a striking increase in numbers of IL-17-producing Vγ6Vδ1+ γδ T cells in the lungs, uterus, and circulation. Thymic development of this population was normal. However, single-cell RNA sequencing revealed the enrichment of genes associated with T cell survival and proliferation specifically in ß2-integrin-deficient IL-17+ cells compared to their wild-type counterparts. Indeed, ß2-integrin-deficient Vγ6+ cells from the lungs showed reduced apoptosis ex vivo, suggesting that increased survival contributes to the accumulation of these cells in ß2-integrin-deficient tissues. Furthermore, our data revealed an unexpected role for ß2 integrins in promoting the thymic development of the IFNγ-producing CD27+ Vγ4+ γδ T cell subset. Together, our data reveal that ß2 integrins are important regulators of γδ T cell homeostasis, inhibiting the survival of IL-17-producing Vγ6Vδ1+ cells and promoting the thymic development of the IFNγ-producing Vγ4+ subset. Our study introduces unprecedented mechanisms of control for γδ T cell subsets.


Assuntos
Antígenos CD18 , Linfócitos Intraepiteliais , Timo , Animais , Antígenos CD18/genética , Antígenos CD18/imunologia , Antígenos CD18/metabolismo , Homeostase/imunologia , Interleucina-17/genética , Interleucina-17/imunologia , Interleucina-17/metabolismo , Linfócitos Intraepiteliais/imunologia , Linfócitos Intraepiteliais/metabolismo , Linfócitos Intraepiteliais/fisiologia , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Timo/crescimento & desenvolvimento , Timo/imunologia , Timo/metabolismo
10.
Science ; 369(6503)2020 Jul 31.
Artigo em Inglês | MEDLINE | ID: mdl-32732394

RESUMO

The lymphoid system is intimately involved in immunological processes. The small lymphocyte that circulates through blood into lymphoid tissues, then through the lymph and back to the blood through the thoracic duct, is able to initiate immune responses after appropriate stimulation by antigen. However, the lymphocytes found in the thymus are deficient in this ability despite the fact that the thymus plays a central role in lymphocyte production and in ensuring the normal development of immunological faculty. During embryogenesis, lymphocytes are present in the thymus before they can be identified in the circulation and in other lymphoid tissues. They become "educated" in the thymus to recognize a great diversity of peptide antigens bound to the body's own marker antigen, the major histocompatibility complex, but they are purged if they strongly react against their own self-components. Lymphocytes differentiate to become various T cell subsets and then exit through the bloodstream to populate certain areas of the lymphoid system as peripheral T lymphocytes with distinct markers and immune functions.


Assuntos
Imunoterapia , Subpopulações de Linfócitos T/imunologia , Timo/imunologia , Animais , Linfócitos B/imunologia , Diferenciação Celular , Rejeição de Enxerto/imunologia , Sobrevivência de Enxerto/imunologia , Humanos , Linfoma/imunologia , Linfoma/terapia , Camundongos , Neoplasias Cutâneas/imunologia , Neoplasias Cutâneas/terapia , Transplante de Pele , Subpopulações de Linfócitos T/citologia , Timo/citologia
11.
PLoS One ; 15(7): e0235476, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32609751

RESUMO

To explore the molecular mechanism of the effect of Bacillus cereus PAS38 on the immunity of broilers, sixty 7-day-old broilers were divided into two groups with three replicates. The control group was fed with basal diet, and the treatment group was fed with basal diet containing Bacillus cereus PAS38 1×106 CFU/g. Thymus and bursa of fabricius were taken from two groups of broilers at the age of 42 days, total RNA was extracted, differential gene library was constructed by SSH technology, and immune-related differential genes were screened. Then, we used siRNA to interfere with the expression of some differential genes in the original generation lymphocytes of broiler blood to detect the change of cytokines mRNA expression level. A total of 42 immune-related differentially expressed genes were screened, including 22 up-regulated genes and 20 down-regulated genes. When 7 differentially up-regulated genes associated with enhanced immune function were interfered with in lymphocytes, some immune-promoting cytokines were down-regulated. These results showed that Bacillus cereus PAS38 might up-regulate the expression of JCHAIN, PRDX1, CD3E, CDK6 and other genes in immune organs of broilers, thereby affecting the development of immune organs, the expression of various cytokines and the transduction of immune signals, improving the immune capacity of broilers.


Assuntos
Bacillus cereus/imunologia , Bolsa de Fabricius , Galinhas , Interações entre Hospedeiro e Microrganismos/imunologia , Probióticos/farmacologia , Timo , Animais , Bolsa de Fabricius/efeitos dos fármacos , Bolsa de Fabricius/imunologia , Galinhas/imunologia , Galinhas/microbiologia , Citocinas/genética , Citocinas/imunologia , Técnicas de Hibridização Subtrativa/métodos , Timo/efeitos dos fármacos , Timo/imunologia
12.
Nat Commun ; 11(1): 3734, 2020 07 24.
Artigo em Inglês | MEDLINE | ID: mdl-32709894

RESUMO

Medullary thymic epithelial cells (mTEC) contribute to the development of T cell tolerance by expressing and presenting tissue-restricted antigens (TRA), so that developing T cells can assess the self-reactivity of their antigen receptors prior to leaving the thymus. mTEC are a heterogeneous population of cells that differentially express TRA. Whether mTEC subsets induce distinct autoreactive T cell fates remains unclear. Here, we establish bacterial artificial chromosome (BAC)-transgenic mouse lines with biased mTEClo or mTEChi expression of model antigens. The transgenic lines support negative selection of antigen-specific thymocytes depending on antigen dose. However, model antigen expression predominantly by mTEClo supports TCRαß+ CD8αα intraepithelial lymphocyte development; meanwhile, mTEChi-restricted expression preferentially induces Treg differentiation of antigen-specific cells in these models to impact control of infectious agents and tumor growth. In summary, our data suggest that mTEC subsets may have a function in directing distinct mechanisms of T cell tolerance.


Assuntos
Antígenos/imunologia , Diferenciação Celular/imunologia , Células Epiteliais/imunologia , Linfócitos T/imunologia , Timo/imunologia , Animais , Células Apresentadoras de Antígenos/imunologia , Antígenos/metabolismo , Infecções Bacterianas , Medula Óssea , Linhagem Celular Tumoral , Feminino , Tolerância Imunológica , Linfonodos , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Camundongos Transgênicos , Linfócitos T/metabolismo , Timócitos/imunologia , Fatores de Transcrição/genética
13.
Sci Rep ; 10(1): 9957, 2020 06 19.
Artigo em Inglês | MEDLINE | ID: mdl-32561775

RESUMO

Severe immunodeficient mice are widely used to examine human and animal cells behaviour in vivo. However, mice are short-lived and small in size; while large animals require specific large-scale equipment. Rabbits are also commonly employed as experimental models and are larger than mice or rats, easy to handle, and suitable for long-term observational and pre-clinical studies. Herein, we sought to develop and maintain stable strains of rabbits with X-linked severe combined immunodeficiency (X-SCID) via the CRISPR/Cas9 system targeting Il2rg. Consequently, X-SCID rabbits presented immunodeficient phenotypes including the loss of T and B cells and hypoplasia of the thymus. Further, these rabbits exhibited a higher success rate with engraftments upon allogeneic transplantation of skin tissue than did wild type controls. X-SCID rabbits could be stably maintained for a minimum of four generations. These results indicate that X-SCID rabbits are effective animals for use in a non-rodent model of severe immunodeficiency.


Assuntos
Sistemas CRISPR-Cas/genética , Repetições Palindrômicas Curtas Agrupadas e Regularmente Espaçadas/genética , Doenças por Imunodeficiência Combinada Ligada ao Cromossomo X/genética , Animais , Linfócitos B/imunologia , Sistemas CRISPR-Cas/imunologia , Repetições Palindrômicas Curtas Agrupadas e Regularmente Espaçadas/imunologia , Feminino , Técnicas de Inativação de Genes/métodos , Subunidade gama Comum de Receptores de Interleucina/genética , Subunidade gama Comum de Receptores de Interleucina/imunologia , Coelhos , Pele/imunologia , Linfócitos T/imunologia , Timo/imunologia , Doenças por Imunodeficiência Combinada Ligada ao Cromossomo X/imunologia
14.
Sci Rep ; 10(1): 10057, 2020 06 22.
Artigo em Inglês | MEDLINE | ID: mdl-32572110

RESUMO

Perinatally HIV-infected patients face the consequences of both chronic infection effects per se and long-term combination antiretroviral therapy (cART) on immunosenescence. Aims of our study were to evaluate which factors independently contribute to immunosenescence in HIV-infected young adults with a very different HIV infection duration (perinatally HIV-infected young individuals -pHIVy- and age-matched non perinatally HIV-infected youths -npHIVy), after durable  efficient cART. We considered low thymic and bone marrow output, respectively evaluated by quantifying T-cell receptor excision circles (TRECs), K-deleting recombination excision circles (KRECs), and shorter telomeres lenght (TL) as surrogate biomarkers of immunosenescence. Twenty-one pHIVy and 19 npHIVy (with a mean HIV duration of 3-8 years) were included; mean age was 27 years for both groups. Immunosenescence biomarkers were comparable between pHIVy and npHIVy (despite longer HIV-infection, higher frequency of AIDS events, past cART-free periods and concomitant chronic viral infections in pHIVy). At the multivariate analysis, CD4+ was the only variable independently associated with TRECs and TL. Our data suggest that a good level of thymic activity can compensate the deleterious effects of past periods without cART, if HIV replication is suppressed for a sufficient time.


Assuntos
Terapia Antirretroviral de Alta Atividade/métodos , Linfócitos T CD4-Positivos/metabolismo , Infecções por HIV/tratamento farmacológico , Efeitos Tardios da Exposição Pré-Natal/virologia , Medula Óssea/imunologia , Estudos Transversais , Feminino , Infecções por HIV/imunologia , Humanos , Imunossenescência , Masculino , Gravidez , Efeitos Tardios da Exposição Pré-Natal/imunologia , Receptores de Antígenos de Linfócitos T/metabolismo , Encurtamento do Telômero , Timo/imunologia , Replicação Viral , Adulto Jovem
15.
Proc Natl Acad Sci U S A ; 117(25): 14342-14353, 2020 06 23.
Artigo em Inglês | MEDLINE | ID: mdl-32513716

RESUMO

Immature T cells undergo a process of positive selection in the thymus when their new T cell receptor (TCR) engages and signals in response to self-peptides. As the T cell matures, a slew of negative regulatory molecules, including the inhibitory surface glycoprotein CD5, are up-regulated in proportion to the strength of the self-peptide signal. Together these regulators dampen TCR-proximal signaling and help avoid any subsequent peripheral activation of T cells by self-peptides. Paradoxically, antigen-specific T cells initially expressing more CD5 (CD5hi) have been found to better persist as effector/memory cells after a peripheral challenge. The molecular mechanisms underlying such a duality in CD5 function is not clear. We found that CD5 alters the basal activity of the NF-κB signaling in resting peripheral T cells. When CD5 was conditionally ablated, T cells were unable to maintain higher expression of the cytoplasmic NF-κB inhibitor IκBα. Consistent with this, resting CD5hi T cells expressed more of the NF-κB p65 protein than CD5lo cells, without significant increases in transcript levels, in the absence of TCR signals. This posttranslationally stabilized cellular NF-κB depot potentially confers a survival advantage to CD5hi T cells over CD5lo ones. Taken together, these data suggest a two-step model whereby the strength of self-peptide-induced TCR signal lead to the up-regulation of CD5, which subsequently maintains a proportional reserve of NF-κB in peripheral T cells poised for responding to agonistic antigen-driven T cell activation.


Assuntos
Antígenos CD5/metabolismo , Regulação da Expressão Gênica no Desenvolvimento/imunologia , Inibidor de NF-kappaB alfa/metabolismo , Proteína Tirosina Fosfatase não Receptora Tipo 6/metabolismo , Linfócitos T/imunologia , Transferência Adotiva , Animais , Apresentação do Antígeno/imunologia , Antígenos CD5/genética , Linhagem Celular Tumoral , Separação Celular , Sobrevivência Celular/imunologia , Feminino , Citometria de Fluxo , Lipopolissacarídeos/imunologia , Ativação Linfocitária , Camundongos , Camundongos Knockout , Modelos Animais , Cultura Primária de Células , Receptores de Antígenos de Linfócitos T alfa-beta/genética , Receptores de Antígenos de Linfócitos T alfa-beta/metabolismo , Transdução de Sinais/imunologia , Linfócitos T/metabolismo , Linfócitos T/transplante , Timo/citologia , Timo/crescimento & desenvolvimento , Timo/imunologia , Fator de Transcrição RelA/metabolismo , Regulação para Cima
16.
Ecotoxicol Environ Saf ; 200: 110715, 2020 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-32450432

RESUMO

Copper (Cu) is a necessary trace mineral due to its biological activity. Excessive Cu can induce inflammatory response in humans and animals, but the underlying mechanism is still unknown. Here, 240 broilers were used to study the effects of excessive Cu on oxidative stress and NF-κB-mediated inflammatory responses in immune organs. Chickens were fed with diet containing different concentrations of Cu (11, 110, 220, and 330 mg of Cu/kg dry matter). The experiment lasted for 49 days. Spleen, thymus, and bursa of Fabricius (BF) on day 49 were collected for histopathological observation and assessment of oxidative stress status. Additionally, the mRNA and protein levels of NF-κB and inflammatory cytokines were also analyzed. The results indicated that excess Cu could increase the number and area of splenic corpuscle as well as the ratio of cortex and medulla in thymus and BF. Furthermore, excessive Cu intake could decrease activities of superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GSH-Px); but increase contents of malondialdehyde (MDA), TNF-α, IL-1, IL-1ß; up-regulate mRNA levels of TNF-α, IFN-γ, IL-1, IL-1ß, IL-2, iNOS, COX-2, NF-κB and protein levels of TNF-α, IFN-γ, NF-κB, p-NF-κB in immune organs. In conclusion, excessive Cu could cause pathologic changes and induce oxidative stress with triggered NF-κB pathway, and might further regulate the inflammatory response in immune organs of chicken.


Assuntos
Galinhas/imunologia , Cobre/toxicidade , NF-kappa B/metabolismo , Estresse Oxidativo/efeitos dos fármacos , Animais , Bolsa de Fabricius/enzimologia , Bolsa de Fabricius/imunologia , Bolsa de Fabricius/metabolismo , Bolsa de Fabricius/patologia , Catalase/metabolismo , Galinhas/genética , Galinhas/metabolismo , Citocinas/genética , Citocinas/metabolismo , Glutationa Peroxidase/metabolismo , Inflamação/genética , Inflamação/metabolismo , Malondialdeído/metabolismo , NF-kappa B/genética , Baço/enzimologia , Baço/imunologia , Baço/metabolismo , Baço/patologia , Superóxido Dismutase/metabolismo , Timo/enzimologia , Timo/imunologia , Timo/metabolismo , Timo/patologia
17.
Nat Commun ; 11(1): 2198, 2020 05 04.
Artigo em Inglês | MEDLINE | ID: mdl-32366944

RESUMO

The thymus supports multiple αß T cell lineages that are functionally distinct, but mechanisms that control this multifaceted development are poorly understood. Here we examine medullary thymic epithelial cell (mTEC) heterogeneity and its influence on CD1d-restricted iNKT cells. We find three distinct mTEClow subsets distinguished by surface, intracellular and secreted molecules, and identify LTßR as a cell-autonomous controller of their development. Importantly, this mTEC heterogeneity enables the thymus to differentially control iNKT sublineages possessing distinct effector properties. mTEC expression of LTßR is essential for the development thymic tuft cells which regulate NKT2 via IL-25, while LTßR controls CD104+CCL21+ mTEClow that are capable of IL-15-transpresentation for regulating NKT1 and NKT17. Finally, mTECs regulate both iNKT-mediated activation of thymic dendritic cells, and iNKT availability in extrathymic sites. In conclusion, mTEC specialization controls intrathymic iNKT cell development and function, and determines iNKT pool size in peripheral tissues.


Assuntos
Diferenciação Celular/imunologia , Células Epiteliais/imunologia , Células T Matadoras Naturais/imunologia , Timócitos/imunologia , Timo/imunologia , Animais , Antígenos CD1d/genética , Antígenos CD1d/imunologia , Antígenos CD1d/metabolismo , Diferenciação Celular/genética , Linhagem da Célula/genética , Linhagem da Célula/imunologia , Proliferação de Células/genética , Células Dendríticas/imunologia , Células Dendríticas/metabolismo , Células Epiteliais/citologia , Células Epiteliais/metabolismo , Regulação da Expressão Gênica/imunologia , Ativação Linfocitária/imunologia , Receptor beta de Linfotoxina/genética , Receptor beta de Linfotoxina/imunologia , Receptor beta de Linfotoxina/metabolismo , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BL , Camundongos Knockout , Células T Matadoras Naturais/citologia , Células T Matadoras Naturais/metabolismo , Transdução de Sinais/genética , Transdução de Sinais/imunologia , Linfócitos T/citologia , Linfócitos T/imunologia , Linfócitos T/metabolismo , Timócitos/citologia , Timócitos/metabolismo , Timo/citologia , Timo/metabolismo
18.
Sci Rep ; 10(1): 8218, 2020 05 19.
Artigo em Inglês | MEDLINE | ID: mdl-32427927

RESUMO

Natural killer T (NKT) cells rapidly respond to antigenic stimulation with cytokine production and direct cytotoxicity. These innate-like characteristics arise from their differentiation into mature effector cells during thymic development. A subset of mature NKT cells remain thymic resident, but their activation and function remain poorly understood. We examined the roles of CD28 and CTLA-4 in driving the activation of thymic resident NKT cells. In contrast to studies with peripheral NKT cells, the proliferation of thymic NKT cells was significantly impaired when CD28 engagement was blocked, but unaffected by CTLA-4 activation or blockade. Within NKT subsets, however, stage 3 NKT cells, marked by higher NK1.1 expression, were significantly more sensitive to the loss of CD28 signals compared to NK1.1- stage 2 NKT cells. In good agreement, CD28 blockade suppressed NKT cell cytokine secretion, lowering the ratio of IFN-γ:IL-4 production by NK1.1+ NKT cells. Intriguingly, the activation-dependent upregulation of the master transcription factor PLZF did not require CD28-costimulation in either of the thymic NKT subsets, underlining a dichotomy between requirements for early activation vs subsequent proliferation and effector function by these cells. Collectively, our studies demonstrate the ability of CD28 co-stimulation to fine tune subset-specific responses by thymic resident NKT cells and contextually shape the milieu in this primary lymphoid organ.


Assuntos
Antígenos CD28/imunologia , Células T Matadoras Naturais/imunologia , Timo/imunologia , Animais , Proliferação de Células , Depleção Linfocítica , Camundongos , Camundongos Endogâmicos C57BL , Subpopulações de Linfócitos T
19.
Nat Commun ; 11(1): 2361, 2020 05 12.
Artigo em Inglês | MEDLINE | ID: mdl-32398640

RESUMO

The development of thymic regulatory T cells (Treg) is mediated by Aire-regulated self-antigen presentation on medullary thymic epithelial cells (mTECs) and dendritic cells (DCs), but the cooperation between these cells is still poorly understood. Here we show that signaling through Toll-like receptors (TLR) expressed on mTECs regulates the production of specific chemokines and other genes associated with post-Aire mTEC development. Using single-cell RNA-sequencing, we identify a new thymic CD14+Sirpα+ population of monocyte-derived dendritic cells (CD14+moDC) that are enriched in the thymic medulla and effectively acquire mTEC-derived antigens in response to the above chemokines. Consistently, the cellularity of CD14+moDC is diminished in mice with MyD88-deficient TECs, in which the frequency and functionality of thymic CD25+Foxp3+ Tregs are decreased, leading to aggravated mouse experimental colitis. Thus, our findings describe a TLR-dependent function of mTECs for the recruitment of CD14+moDC, the generation of Tregs, and thereby the establishment of central tolerance.


Assuntos
Colite/imunologia , Células Dendríticas/imunologia , Células Epiteliais/imunologia , Linfócitos T Reguladores/imunologia , Timo/imunologia , Transferência Adotiva , Animais , Apresentação do Antígeno , Autoantígenos/imunologia , Separação Celular , Quimiocinas/imunologia , Quimiocinas/metabolismo , Modelos Animais de Doenças , Células Epiteliais/metabolismo , Citometria de Fluxo , Receptores de Lipopolissacarídeos/metabolismo , Camundongos , Receptores Imunológicos/metabolismo , Tolerância a Antígenos Próprios , Análise de Sequência de RNA , Transdução de Sinais/imunologia , Análise de Célula Única , Linfócitos T Reguladores/transplante , Timo/citologia , Receptores Toll-Like/metabolismo , Regulação para Cima
20.
Gen Comp Endocrinol ; 294: 113497, 2020 08 01.
Artigo em Inglês | MEDLINE | ID: mdl-32360542

RESUMO

In birds, exposure to exogenous testosterone during embryonic development can suppress measures of immune function; however, it is unclear whether these effects are due to direct or indirect action via aromatization. Estradiol (E2) is synthesized from testosterone by the enzyme aromatase, and this conversion is a necessary step in many signaling pathways that are ostensibly testosterone-dependent. Many lines of evidence in mammals indicate that E2 can affect immune function. We tested the hypothesis that some of the immunomodulatory effects observed in response to in ovo testosterone exposure in birds are mediated by conversion to E2 by aromatase, by using fadrozole to inhibit aromatization of endogenous testosterone during a crucial period of embryonic immune system development in domestic chickens (Gallus gallus). We then measured total IgY antibody count, response to PHA challenge, mass of thymus and bursa of Fabricius, and plasma testosterone post-hatch on days 3 and 18. Because testosterone has a reputation for immunosuppression, we predicted that if modulation of an immune measure by testosterone is dependent on aromatization, then inhibition of estrogen production by fadrozole treatment would lead to elevated measures of that parameter. Conversely, if testosterone inhibits an immune measure directly, then fadrozole treatment would likely not alter that parameter. Fadrozole treatment reduced circulating E2 in female embryos, but had no effect on males or on testosterone in either sex. Fadrozole-treated chicks had decreased day 3 plasma IgY antibody titers and a strong trend towards increased day 18 thymic mass. Furthermore, fadrozole treatment generated a positive relationship between testosterone and thymic mass in males, and tended to increase day 18 IgY levels for a given bursal mass in females. There was no effect on PHA response, bursal mass, or plasma testosterone at either age post-hatch. The alteration of several indicators of immune function in fadrozole-treated chicks implicates aromatization as a relevant pathway through which developmental exposure to testosterone can affect immunity in birds.


Assuntos
Inibidores da Aromatase/farmacologia , Aromatase/metabolismo , Galinhas/imunologia , Imunidade/efeitos dos fármacos , Animais , Animais Recém-Nascidos , Bolsa de Fabricius/efeitos dos fármacos , Bolsa de Fabricius/imunologia , Galinhas/sangue , Galinhas/crescimento & desenvolvimento , Estradiol/sangue , Fadrozol/farmacologia , Feminino , Imunoglobulinas/sangue , Masculino , Tamanho do Órgão/efeitos dos fármacos , Fito-Hemaglutininas/farmacologia , Reprodutibilidade dos Testes , Testosterona/sangue , Timo/efeitos dos fármacos , Timo/imunologia
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