Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 11 de 11
Filtrar
Mais filtros










Base de dados
Intervalo de ano de publicação
1.
PLoS Pathog ; 17(10): e1009858, 2021 Oct 07.
Artigo em Inglês | MEDLINE | ID: mdl-34618873

RESUMO

Autoimmune diseases are often treated by glucocorticoids and immunosuppressive drugs that could increase the risk for infection, which in turn deteriorate disease and cause mortality. Low-dose IL-2 (Ld-IL2) therapy emerges as a new treatment for a wide range of autoimmune diseases. To examine its influence on infection, we retrospectively studied 665 patients with systemic lupus erythematosus (SLE) including about one third receiving Ld-IL2 therapy, where Ld-IL2 therapy was found beneficial in reducing the incidence of infections. In line with this clinical observation, Ld-IL2 treatment accelerated viral clearance in mice infected with influenza A virus or lymphocytic choriomeningitis virus (LCMV). Noticeably, despite enhancing anti-viral immunity in LCMV infection, Ld-IL2 treatment exacerbated CD8+ T cell-mediated immunopathology. In summary, Ld-IL2 therapy reduced the risk of infections in SLE patients and enhanced the control of viral infection, but caution should be taken to avoid the potential risk of CD8+ T cell-mediated immunopathology in severe infections.

2.
Nat Immunol ; 22(9): 1140-1151, 2021 09.
Artigo em Inglês | MEDLINE | ID: mdl-34426691

RESUMO

Tissue-resident memory T (TRM) cells are non-recirculating cells that exist throughout the body. Although TRM cells in various organs rely on common transcriptional networks to establish tissue residency, location-specific factors adapt these cells to their tissue of lodgment. Here we analyze TRM cell heterogeneity between organs and find that the different environments in which these cells differentiate dictate TRM cell function, durability and malleability. We find that unequal responsiveness to TGFß is a major driver of this diversity. Notably, dampened TGFß signaling results in CD103- TRM cells with increased proliferative potential, enhanced function and reduced longevity compared with their TGFß-responsive CD103+ TRM counterparts. Furthermore, whereas CD103- TRM cells readily modified their phenotype upon relocation, CD103+ TRM cells were comparatively resistant to transdifferentiation. Thus, despite common requirements for TRM cell development, tissue adaptation of these cells confers discrete functional properties such that TRM cells exist along a spectrum of differentiation potential that is governed by their local tissue microenvironment.


Assuntos
Linfócitos T CD8-Positivos/imunologia , Diferenciação Celular/imunologia , Plasticidade Celular/imunologia , Microambiente Celular/imunologia , Memória Imunológica/imunologia , Animais , Antígenos CD/imunologia , Linfócitos T CD8-Positivos/citologia , Feminino , Cadeias alfa de Integrinas/imunologia , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Transdução de Sinais/imunologia , Fator de Crescimento Transformador beta1/metabolismo
3.
Immunity ; 54(6): 1219-1230.e7, 2021 06 08.
Artigo em Inglês | MEDLINE | ID: mdl-33915109

RESUMO

The sympathetic nervous system (SNS) controls various physiological functions via the neurotransmitter noradrenaline. Activation of the SNS in response to psychological or physical stress is frequently associated with weakened immunity. Here, we investigated how adrenoceptor signaling influences leukocyte behavior. Intravital two-photon imaging after injection of noradrenaline revealed transient inhibition of CD8+ and CD4+ T cell locomotion in tissues. Expression of ß-adrenergic receptor in hematopoietic cells was not required for NA-mediated inhibition of motility. Rather, chemogenetic activation of the SNS or treatment with adrenergic receptor agonists induced vasoconstriction and decreased local blood flow, resulting in abrupt hypoxia that triggered rapid calcium signaling in leukocytes and halted cell motility. Oxygen supplementation reversed these effects. Treatment with adrenergic receptor agonists impaired T cell responses induced in response to viral and parasitic infections, as well as anti-tumor responses. Thus, stimulation of the SNS impairs leukocyte mobility, providing a mechanistic understanding of the link between adrenergic receptors and compromised immunity.


Assuntos
Adrenérgicos/imunologia , Movimento Celular/imunologia , Imunidade/imunologia , Leucócitos/imunologia , Sistema Nervoso Simpático/imunologia , Animais , Sinalização do Cálcio/imunologia , Linhagem Celular Tumoral , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BL , Receptores Adrenérgicos/imunologia , Transdução de Sinais/imunologia , Linfócitos T/imunologia
4.
Nat Immunol ; 22(4): 434-448, 2021 04.
Artigo em Inglês | MEDLINE | ID: mdl-33649580

RESUMO

T cells dynamically interact with multiple, distinct cellular subsets to determine effector and memory differentiation. Here, we developed a platform to quantify cell location in three dimensions to determine the spatial requirements that direct T cell fate. After viral infection, we demonstrated that CD8+ effector T cell differentiation is associated with positioning at the lymph node periphery. This was instructed by CXCR3 signaling since, in its absence, T cells are confined to the lymph node center and alternatively differentiate into stem-like memory cell precursors. By mapping the cellular sources of CXCR3 ligands, we demonstrated that CXCL9 and CXCL10 are expressed by spatially distinct dendritic and stromal cell subsets. Unlike effector cells, retention of stem-like memory precursors in the paracortex is associated with CCR7 expression. Finally, we demonstrated that T cell location can be tuned, through deficiency in CXCL10 or type I interferon signaling, to promote effector or stem-like memory fates.


Assuntos
Infecções por Arenaviridae/metabolismo , Linfócitos T CD8-Positivos/metabolismo , Diferenciação Celular , Quimiocina CXCL10/metabolismo , Quimiocina CXCL9/metabolismo , Memória Imunológica , Linfonodos/metabolismo , Células Precursoras de Linfócitos T/metabolismo , Receptores CXCR3/metabolismo , Animais , Infecções por Arenaviridae/genética , Infecções por Arenaviridae/imunologia , Infecções por Arenaviridae/virologia , Linfócitos T CD8-Positivos/imunologia , Linfócitos T CD8-Positivos/virologia , Linhagem da Célula , Células Cultivadas , Quimiocina CXCL10/genética , Quimiocina CXCL9/genética , Quimiotaxia de Leucócito , Células Dendríticas/imunologia , Células Dendríticas/metabolismo , Modelos Animais de Doenças , Interações Hospedeiro-Patógeno , Interferon Tipo I/metabolismo , Ligantes , Linfonodos/imunologia , Linfonodos/virologia , Vírus da Coriomeningite Linfocítica/imunologia , Vírus da Coriomeningite Linfocítica/patogenicidade , Camundongos Endogâmicos C57BL , Camundongos Knockout , Fenótipo , Células Precursoras de Linfócitos T/imunologia , Células Precursoras de Linfócitos T/virologia , Receptor de Interferon alfa e beta/genética , Receptor de Interferon alfa e beta/metabolismo , Receptores CCR7/metabolismo , Receptores CXCR3/genética , Transdução de Sinais , Nicho de Células-Tronco , Células Estromais/imunologia , Células Estromais/metabolismo
5.
Cell Rep ; 33(13): 108567, 2020 12 29.
Artigo em Inglês | MEDLINE | ID: mdl-33378682

RESUMO

Concurrent infection with multiple pathogens occurs frequently in individuals and can result in exacerbated infections and altered immunity. However, the impact of such coinfections on immune responses remains poorly understood. Here, we reveal that systemic infection results in an inflammation-induced suppression of local immunity. During localized infection or vaccination in barrier tissues including the skin or respiratory tract, concurrent systemic infection induces a type I interferon-dependent lymphopenia that impairs lymphocyte recruitment to the draining lymph node (dLN) and induces sequestration of lymphocytes in non-draining LN. This contributes to suppressed fibroblastic reticular cell and endothelial cell expansion and dLN remodeling and impairs induction of B cell responses and antibody production. Our data suggest that contemporaneous systemic inflammation constrains the induction of regional immunity.

6.
Front Immunol ; 9: 2805, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30564233

RESUMO

Type 1 conventional DCs (cDC1) excel in the cross-priming of CD8+ T cells, which is crucial for orchestrating efficient immune responses against viruses or tumors. However, our understanding of their physiological functions and molecular regulation has been limited by the lack of proper mutant mouse models allowing their conditional genetic targeting. Because the Xcr1 and A530099j19rik (Karma/Gpr141b) genes belong to the core transcriptomic fingerprint of mouse cDC1, we used them to engineer two novel Cre-driver lines, the Xcr1 Cre and Karma Cre mice, by knocking in an IRES-Cre expression cassette into their 3'-UTR. We used genetic tracing to characterize the specificity and efficiency of these new models in several lymphoid and non-lymphoid tissues, and compared them to the Clec9a Cre mouse model, which targets the immediate precursors of cDCs. Amongst the three Cre-driver mouse models examined, the Xcr1 Cre model was the most efficient and specific for the fate mapping of all cDC1, regardless of the tissues examined. The Karma Cre model was rather specific for cDC1 when compared with the Clec9a Cre mouse, but less efficient than the Xcr1 Cre model. Unexpectedly, the Xcr1 Cre model targeted a small fraction of CD4+ T cells, and the Karma Cre model a significant proportion of mast cells in the skin. Importantly, the targeting specificity of these two mouse models was not changed upon inflammation. A high frequency of germline recombination was observed solely in the Xcr1 Cre mouse model when both the Cre and the floxed alleles were brought by the same gamete irrespective of its gender. Xcr1, Karma, and Clec9a being differentially expressed within the cDC1 population, the three CRE-driver lines examined showed distinct recombination patterns in cDC1 phenotypic subsets. This advances our understanding of cDC1 subset heterogeneity and the differentiation trajectory of these cells. Therefore, to the best of our knowledge, upon informed use, the Xcr1 Cre and Karma Cre mouse models represent the best tools currently reported to specifically and faithfully target cDC1 in vivo, both at steady state and upon inflammation. Future use of these mutant mouse models will undoubtedly boost our understanding of the biology of cDC1.


Assuntos
Apresentação Cruzada/genética , Células Dendríticas/fisiologia , Receptores de Quimiocinas/genética , Regiões 3' não Traduzidas/genética , Animais , Linfócitos T CD4-Positivos/fisiologia , Linfócitos T CD8-Positivos/fisiologia , Diferenciação Celular/genética , Inflamação/genética , Camundongos , Camundongos Endogâmicos C57BL , Pele/fisiopatologia
7.
Immunol Rev ; 283(1): 77-85, 2018 05.
Artigo em Inglês | MEDLINE | ID: mdl-29664562

RESUMO

Secondary lymphoid organs (SLO), including the spleen and lymph nodes (LN) are a meeting place for immune cells to initiate adaptive immune responses. Lymphocytes constantly circulate between SLO through the blood and lymph in search of their cognate antigen and are activated within the organized microarchitecture of SLO. Lymphoid stromal cells (LSC) of mesenchymal and endothelial origin construct and support the microarchitecture of SLO by defining distinct compartments and providing signals that can either promote or inhibit immune responses. Here, we discuss recent studies indicating that LSC, including fibroblastic reticular cells (FRC), contribute substantially to immune responses and may tune responses to secondary challenge.


Assuntos
Comunicação Celular/imunologia , Imunidade , Células Estromais/imunologia , Células Estromais/metabolismo , Animais , Linfócitos B/imunologia , Linfócitos B/metabolismo , Homeostase , Humanos , Sistema Imunitário/citologia , Sistema Imunitário/imunologia , Sistema Imunitário/metabolismo , Memória Imunológica , Imunomodulação , Ativação Linfocitária/imunologia , Tecido Linfoide/citologia , Tecido Linfoide/imunologia , Tecido Linfoide/metabolismo , Linfócitos T/imunologia , Linfócitos T/metabolismo
8.
Nat Immunol ; 19(2): 183-191, 2018 02.
Artigo em Inglês | MEDLINE | ID: mdl-29311695

RESUMO

Although tissue-resident memory T cells (TRM cells) are critical in fighting infection, their fate after local pathogen re-encounter is unknown. Here we found that skin TRM cells engaged virus-infected cells, proliferated in situ in response to local antigen encounter and did not migrate out of the epidermis, where they exclusively reside. As a consequence, secondary TRM cells formed from pre-existing TRM cells, as well as from precursors recruited from the circulation. Newly recruited antigen-specific or bystander TRM cells were generated in the skin without displacement of the pre-existing TRM cell pool. Thus, pre-existing skin TRM cell populations are not displaced after subsequent infections, which enables multiple TRM cell specificities to be stably maintained within the tissue.


Assuntos
Linfócitos T CD8-Positivos/imunologia , Memória Imunológica/imunologia , Pele/imunologia , Animais , Proliferação de Células/fisiologia , Herpes Simples/imunologia , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Transgênicos
9.
Cell Rep ; 18(2): 406-418, 2017 01 10.
Artigo em Inglês | MEDLINE | ID: mdl-28076785

RESUMO

Lymph nodes (LNs) are constructed of intricate networks of endothelial and mesenchymal stromal cells. How these lymphoid stromal cells (LSCs) regulate lymphoid tissue remodeling and contribute to immune responses remains poorly understood. We performed a comprehensive functional and transcriptional analysis of LSC responses to skin viral infection and found that LSC subsets responded robustly, with different kinetics for distinct pathogens. Recruitment of cells to inflamed LNs induced LSC expansion, while B cells sustained stromal responses in an antigen-independent manner. Infection induced rapid transcriptional responses in LSCs. This transcriptional program was transient, returning to homeostasis within 1 month of infection, yet expanded fibroblastic reticular cell networks persisted for more than 3 months after infection, and this altered LN composition reduced the magnitude of LSC responses to subsequent heterologous infection. Our results reveal the complexity of LSC responses during infection and suggest that amplified networks of LN stromal cells support successive immune responses.


Assuntos
Linfonodos/patologia , Viroses/imunologia , Viroses/patologia , Animais , Antígenos Virais/imunologia , Linfócitos B/imunologia , Proliferação de Células , Coinfecção/imunologia , Regulação da Expressão Gênica , Cinética , Camundongos Endogâmicos C57BL , Células Estromais/patologia , Transcrição Genética , Viroses/genética
10.
J Exp Med ; 213(1): 75-92, 2016 Jan 11.
Artigo em Inglês | MEDLINE | ID: mdl-26694969

RESUMO

Naive CD8(+) T cell priming during tumor development or many primary infections requires cross-presentation by XCR1(+) dendritic cells (DCs). Memory CD8(+) T lymphocytes (mCTLs) harbor a lower activation threshold as compared with naive cells. However, whether their recall responses depend on XCR1(+) DCs is unknown. By using a new mouse model allowing fluorescent tracking and conditional depletion of XCR1(+) DCs, we demonstrate a differential requirement of these cells for mCTL recall during secondary infections by different pathogens. XCR1(+) DCs were instrumental to promote this function upon secondary challenges with Listeria monocytogenes, vesicular stomatitis virus, or Vaccinia virus, but dispensable in the case of mouse cytomegalovirus. We deciphered how XCR1(+) DCs promote mCTL recall upon secondary infections with Listeria. By visualizing for the first time the in vivo choreography of XCR1(+) DCs, NK cells and mCTLs during secondary immune responses, and by neutralizing in vivo candidate molecules, we demonstrate that, very early after infection, mCTLs are activated, and attracted in a CXCR3-dependent manner, by NK cell-boosted, IL-12-, and CXCL9-producing XCR1(+) DCs. Hence, depending on the infectious agent, strong recall of mCTLs during secondary challenges can require cytokine- and chemokine-dependent cross-talk with XCR1(+) DCs and NK cells.


Assuntos
Linfócitos T CD8-Positivos/imunologia , Linfócitos T CD8-Positivos/metabolismo , Células Dendríticas/imunologia , Células Dendríticas/metabolismo , Memória Imunológica , Listeria monocytogenes/imunologia , Receptores de Quimiocinas/metabolismo , Vírus/imunologia , Animais , Quimiocina CXCL9/biossíntese , Expressão Gênica , Perfilação da Expressão Gênica , Genes Reporter , Interações Hospedeiro-Patógeno , Interferon gama/biossíntese , Interleucina-12/metabolismo , Células Matadoras Naturais/imunologia , Células Matadoras Naturais/metabolismo , Listeriose/genética , Listeriose/imunologia , Listeriose/metabolismo , Listeriose/microbiologia , Ativação Linfocitária/imunologia , Camundongos , Camundongos Knockout , Camundongos Transgênicos , Linfócitos T Citotóxicos/imunologia , Linfócitos T Citotóxicos/metabolismo
11.
Front Microbiol ; 5: 378, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-25120535

RESUMO

Infection of mice with murine cytomegalovirus (MCMV) recapitulates many physiopathological characteristics of human CMV infection and enables studying the interactions between a virus and its natural host. Dendritic cells (DC) are mononuclear phagocytes linking innate and adaptive immunity which are both necessary for MCMV control. DC are critical for the induction of cellular immunity because they are uniquely efficient for the activation of naïve T cells during their first encounter with a pathogen. DC are equipped with a variety of innate immune recognition receptors (I2R2) allowing them to detect pathogens or infections and to engulf molecules, microorganisms or cellular debris. The combinatorial engagement of I2R2 during infections controls DC maturation and shapes their response in terms of cytokine production, activation of natural killer (NK) cells and functional polarization of T cells. Several DC subsets exist which express different arrays of I2R2 and are specialized in distinct functions. The study of MCMV infection helped deciphering the physiological roles of DC subsets and their molecular regulation. It allowed the identification and first in vivo studies of mouse plasmacytoid DC which produce high level of interferons-α/ß early after infection. Despite its ability to infect DC and dampen their functions, MCMV induces very robust, efficient and long-lasting CD8 T cell responses. Their priming may rely on the unique ability of uninfected XCR1(+) DC to cross-present engulfed viral antigens and thus to counter MCMV interference with antigen presentation. A balance appears to have been reached during co-evolution, allowing controlled replication of the virus for horizontal spread without pathological consequences for the immunocompetent host. We will discuss the role of the interplay between the virus and DC in setting this balance, and how advancing this knowledge further could help develop better vaccines against other intracellular infectious agents.

SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...