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1.
Fluids Barriers CNS ; 17(1): 3, 2020 Feb 03.
Artigo em Inglês | MEDLINE | ID: mdl-32008573

RESUMO

BACKGROUND: The brain barriers establish compartments in the central nervous system (CNS) that significantly differ in their communication with the peripheral immune system. In this function they strictly control T-cell entry into the CNS. T cells can reach the CNS by either crossing the endothelial blood-brain barrier (BBB) or the epithelial blood-cerebrospinal fluid barrier (BCSFB) of the choroid plexus (ChP). OBJECTIVE: Analysis of the cellular and molecular mechanisms involved in the migration of different human CD4+ T-cell subsets across the BBB versus the BCSFB. METHODS: Human in vitro models of the BBB and BCSFB were employed to study the migration of circulating and CNS-entry experienced CD4+ T helper cell subsets (Th1, Th1*, Th2, Th17) across the BBB and BCSFB under inflammatory and non-inflammatory conditions in vitro. RESULTS: While under non-inflammatory conditions Th1* and Th1 cells preferentially crossed the BBB, under inflammatory conditions the migration rate of all Th subsets across the BBB was comparable. The migration of all Th subsets across the BCSFB from the same donor was 10- to 20-fold lower when compared to their migration across the BBB. Interestingly, Th17 cells preferentially crossed the BCSFB under both, non-inflamed and inflamed conditions. Barrier-crossing experienced Th cells sorted from CSF of MS patients showed migratory characteristics indistinguishable from those of circulating Th cells of healthy donors. All Th cell subsets could additionally cross the BCSFB from the CSF to ChP stroma side. T-cell migration across the BCSFB involved epithelial ICAM-1 irrespective of the direction of migration. CONCLUSIONS: Our observations underscore that different Th subsets may use different anatomical routes to enter the CNS during immune surveillance versus neuroinflammation with the BCSFB establishing a tighter barrier for T-cell entry into the CNS compared to the BBB. In addition, CNS-entry experienced Th cell subsets isolated from the CSF of MS patients do not show an increased ability to cross the brain barriers when compared to circulating Th cell subsets from healthy donors underscoring the active role of the brain barriers in controlling T-cell entry into the CNS. Also we identify ICAM-1 to mediate T cell migration across the BCSFB.

2.
J Neuroinflammation ; 16(1): 232, 2019 Nov 21.
Artigo em Inglês | MEDLINE | ID: mdl-31752904

RESUMO

BACKGROUND: Echovirus 30 (E-30) is one of the most frequently isolated pathogens in aseptic meningitis worldwide. To gain access to the central nervous system (CNS), E-30 and immune cells have to cross one of the two main barriers of the CNS, the epithelial blood-cerebrospinal fluid barrier (BCSFB) or the endothelial blood-brain barrier (BBB). In an in vitro model of the BCSFB, it has been shown that E-30 can infect human immortalized brain choroid plexus papilloma (HIBCPP) cells. METHODS: In this study we investigated the migration of different T cell subpopulations, naive and effector T cells, through HIBCPP cells during E-30 infection. Effects of E-30 infection and the migration process were evaluated via immunofluorescence and flow cytometry analysis, as well as transepithelial resistance and dextran flux measurement. RESULTS: Th1 effector cells and enterovirus-specific effector T cells migrated through HIBCPP cells more efficiently than naive CD4+ T cells following E-30 infection of HIBCPP cells. Among the different naive T cell populations, CD8+ T cells crossed the E-30-infected HIBCPP cell layer in a significantly higher number than CD4+ T cells. A large amount of effector T cells also remained attached to the basolateral side of the HIBCPP cells compared with naive T cells. Analysis of HIBCPP barrier function showed significant alteration after E-30 infection and trans- as well as paracellular migration of T cells independent of the respective subpopulation. Morphologic analysis of migrating T cells revealed that a polarized phenotype was induced by the chemokine CXCL12, but reversed to a round phenotype after E-30 infection. Further characterization of migrating Th1 effector cells revealed a downregulation of surface adhesion proteins such as LFA-1 PSGL-1, CD44, and CD49d. CONCLUSION: Taken together these results suggest that naive CD8+ and Th1 effector cells are highly efficient to migrate through the BCSFB in an inflammatory environment. The T cell phenotype is modified during the migration process through HIBCPP cells.

3.
Sci Immunol ; 3(30)2018 12 21.
Artigo em Inglês | MEDLINE | ID: mdl-30578351

RESUMO

Hundreds of patients with autosomal recessive, complete IL-12p40 or IL-12Rß1 deficiency have been diagnosed over the last 20 years. They typically suffer from invasive mycobacteriosis and, occasionally, from mucocutaneous candidiasis. Susceptibility to these infections is thought to be due to impairments of IL-12-dependent IFN-γ immunity and IL-23-dependent IL-17A/IL-17F immunity, respectively. We report here patients with autosomal recessive, complete IL-12Rß2 or IL-23R deficiency, lacking responses to IL-12 or IL-23 only, all of whom, unexpectedly, display mycobacteriosis without candidiasis. We show that αß T, γδ T, B, NK, ILC1, and ILC2 cells from healthy donors preferentially produce IFN-γ in response to IL-12, whereas NKT cells and MAIT cells preferentially produce IFN-γ in response to IL-23. We also show that the development of IFN-γ-producing CD4+ T cells, including, in particular, mycobacterium-specific TH1* cells (CD45RA-CCR6+), is dependent on both IL-12 and IL-23. Last, we show that IL12RB1, IL12RB2, and IL23R have similar frequencies of deleterious variants in the general population. The comparative rarity of symptomatic patients with IL-12Rß2 or IL-23R deficiency, relative to IL-12Rß1 deficiency, is, therefore, due to lower clinical penetrance. There are fewer symptomatic IL-23R- and IL-12Rß2-deficient than IL-12Rß1-deficient patients, not because these genetic disorders are rarer, but because the isolated absence of IL-12 or IL-23 is, in part, compensated by the other cytokine for the production of IFN-γ, thereby providing some protection against mycobacteria. These experiments of nature show that human IL-12 and IL-23 are both required for optimal IFN-γ-dependent immunity to mycobacteria, both individually and much more so cooperatively.


Assuntos
Imunidade Inata/imunologia , Interferon gama/imunologia , Interleucina-12/imunologia , Interleucina-23/imunologia , Infecções por Micobactéria não Tuberculosa/imunologia , Mycobacterium/imunologia , Humanos , Interleucina-12/deficiência , Interleucina-12/genética , Interleucina-23/deficiência , Interleucina-23/genética , Linhagem
4.
Nature ; 562(7725): 63-68, 2018 10.
Artigo em Inglês | MEDLINE | ID: mdl-30232458

RESUMO

Narcolepsy is a chronic sleep disorder caused by the loss of neurons that produce hypocretin. The close association with HLA-DQB1*06:02, evidence for immune dysregulation and increased incidence upon influenza vaccination together suggest that this disorder has an autoimmune origin. However, there is little evidence of autoreactive lymphocytes in patients with narcolepsy. Here we used sensitive cellular screens and detected hypocretin-specific CD4+ T cells in all 19 patients that we tested; T cells specific for tribbles homologue 2-another self-antigen of hypocretin neurons-were found in 8 out of 13 patients. Autoreactive CD4+ T cells were polyclonal, targeted multiple epitopes, were restricted primarily by HLA-DR and did not cross-react with influenza antigens. Hypocretin-specific CD8+ T cells were also detected in the blood and cerebrospinal fluid of several patients with narcolepsy. Autoreactive clonotypes were serially detected in the blood of the same-and even of different-patients, but not in healthy control individuals. These findings solidify the autoimmune aetiology of narcolepsy and provide a basis for rapid diagnosis and treatment of this disease.


Assuntos
Autoantígenos/imunologia , Autoantígenos/metabolismo , Linfócitos T CD4-Positivos/imunologia , Narcolepsia/imunologia , Neurônios/imunologia , Neurônios/metabolismo , Orexinas/imunologia , Orexinas/metabolismo , Antígenos Virais , Doenças Autoimunes/diagnóstico , Doenças Autoimunes/imunologia , Doenças Autoimunes/patologia , Autoimunidade/imunologia , Linfócitos T CD4-Positivos/patologia , Linfócitos T CD8-Positivos/imunologia , Linfócitos T CD8-Positivos/patologia , Proteínas Quinases Dependentes de Cálcio-Calmodulina/imunologia , Proteínas Quinases Dependentes de Cálcio-Calmodulina/metabolismo , Estudos de Casos e Controles , Separação Celular , Reações Cruzadas , Humanos , Memória Imunológica , Peptídeos e Proteínas de Sinalização Intracelular/imunologia , Peptídeos e Proteínas de Sinalização Intracelular/metabolismo , Narcolepsia/sangue , Narcolepsia/líquido cefalorraquidiano , Narcolepsia/diagnóstico , Orthomyxoviridae/imunologia
5.
Nat Immunol ; 19(9): 973-985, 2018 09.
Artigo em Inglês | MEDLINE | ID: mdl-30127434

RESUMO

Human inborn errors of IFN-γ immunity underlie mycobacterial diseases. We describe patients with Mycobacterium bovis (BCG) disease who are homozygous for loss-of-function mutations of SPPL2A. This gene encodes a transmembrane protease that degrades the N-terminal fragment (NTF) of CD74 (HLA invariant chain) in antigen-presenting cells. The CD74 NTF therefore accumulates in the HLA class II+ myeloid and lymphoid cells of SPPL2a-deficient patients. This toxic fragment selectively depletes IL-12- and IL-23-producing CD1c+ conventional dendritic cells (cDC2s) and their circulating progenitors. Moreover, SPPL2a-deficient memory TH1* cells selectively fail to produce IFN-γ when stimulated with mycobacterial antigens in vitro. Finally, Sppl2a-/- mice lack cDC2s, have CD4+ T cells that produce small amounts of IFN-γ after BCG infection, and are highly susceptible to infection with BCG or Mycobacterium tuberculosis. These findings suggest that inherited SPPL2a deficiency in humans underlies mycobacterial disease by decreasing the numbers of cDC2s and impairing IFN-γ production by mycobacterium-specific memory TH1* cells.


Assuntos
Ácido Aspártico Endopeptidases/genética , Ácido Aspártico Endopeptidases/metabolismo , Células Dendríticas/imunologia , Proteínas de Membrana/metabolismo , Infecções por Mycobacterium/imunologia , Mycobacterium bovis/fisiologia , Mycobacterium tuberculosis/fisiologia , Células Th1/imunologia , Tuberculose/imunologia , Animais , Antígenos de Diferenciação de Linfócitos B/metabolismo , Células Cultivadas , Antígenos HLA/metabolismo , Antígenos de Histocompatibilidade Classe II/metabolismo , Humanos , Imunidade , Memória Imunológica , Lactente , Interferon gama/metabolismo , Linfadenopatia , Masculino , Proteínas de Membrana/genética , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Mutação/genética , Infecções por Mycobacterium/genética , Vacinação
6.
Toxins (Basel) ; 7(12): 5472-83, 2015 Dec 17.
Artigo em Inglês | MEDLINE | ID: mdl-26694465

RESUMO

Lactoferrin (LF) exhibits a wide range of immunomodulatory activities including modulation of cytokine and chemokine secretion. In this study, we demonstrate that bovine LF (bLF) up-modulates, in a concentration- and time-dependent manner, CCL1 secretion in monocytes (Mo) at the early stage of differentiation toward dendritic cells (DCs), and in fully differentiated immature Mo-derived DCs (MoDCs). In both cell types, up-modulation of CCL1 secretion is an early event following bLF-mediated enhanced accumulation of CCL1 transcripts. Notably, bLF-mediated up-regulation of CCL1 involves the engagement of distinct surface receptors in MoDCs and their Mo precursors. We show that bLF-mediated engagement of CD36 contributes to CCL1 induction in differentiating Mo. Conversely, toll-like receptor (TLR)2 blocking markedly reduces bLF-induced CCL1 production in MoDCs. These findings add further evidence for cell-specific differential responses elicited by bLF through the engagement of distinct TLRs and surface receptors. Furthermore, the different responses observed at early and late stages of Mo differentiation towards DCs may be relevant in mediating bLF effects in specific body districts, where these cell types may be differently represented in physiopathological conditions.


Assuntos
Quimiocina CCL1/metabolismo , Células Dendríticas/efeitos dos fármacos , Lactoferrina/farmacologia , Monócitos/efeitos dos fármacos , Animais , Bovinos , Células Cultivadas , Quimiocina CCL1/genética , Células Dendríticas/metabolismo , Humanos , Monócitos/citologia , Monócitos/metabolismo , RNA Mensageiro/metabolismo
7.
Science ; 349(6248): 606-613, 2015 Aug 07.
Artigo em Inglês | MEDLINE | ID: mdl-26160376

RESUMO

Human inborn errors of immunity mediated by the cytokines interleukin-17A and interleukin-17F (IL-17A/F) underlie mucocutaneous candidiasis, whereas inborn errors of interferon-γ (IFN-γ) immunity underlie mycobacterial disease. We report the discovery of bi-allelic RORC loss-of-function mutations in seven individuals from three kindreds of different ethnic origins with both candidiasis and mycobacteriosis. The lack of functional RORγ and RORγT isoforms resulted in the absence of IL-17A/F-producing T cells in these individuals, probably accounting for their chronic candidiasis. Unexpectedly, leukocytes from RORγ- and RORγT-deficient individuals also displayed an impaired IFN-γ response to Mycobacterium. This principally reflected profoundly defective IFN-γ production by circulating γδ T cells and CD4(+)CCR6(+)CXCR3(+) αß T cells. In humans, both mucocutaneous immunity to Candida and systemic immunity to Mycobacterium require RORγ, RORγT, or both.


Assuntos
Candida albicans/imunologia , Candidíase Mucocutânea Crônica/genética , Imunidade/genética , Membro 3 do Grupo F da Subfamília 1 de Receptores Nucleares/genética , Imunodeficiência Combinada Severa/genética , Tuberculose Bovina/genética , Tuberculose Pulmonar/genética , Alelos , Animais , Candidíase Mucocutânea Crônica/complicações , Candidíase Mucocutânea Crônica/imunologia , Bovinos , Criança , Pré-Escolar , Análise Mutacional de DNA , Exoma/genética , Feminino , Rearranjo Gênico da Cadeia alfa dos Receptores de Antígenos dos Linfócitos T , Humanos , Interferon gama/imunologia , Interleucina-17/imunologia , Camundongos , Mutação , Mycobacterium bovis/imunologia , Mycobacterium bovis/isolamento & purificação , Mycobacterium tuberculosis/imunologia , Mycobacterium tuberculosis/isolamento & purificação , Linhagem , Receptores de Antígenos de Linfócitos T alfa-beta/genética , Receptores de Antígenos de Linfócitos T alfa-beta/imunologia , Receptores de Antígenos de Linfócitos T gama-delta/genética , Receptores de Antígenos de Linfócitos T gama-delta/imunologia , Linfócitos T/imunologia , Timo/anormalidades , Timo/imunologia , Tuberculose Bovina/imunologia , Tuberculose Pulmonar/imunologia
8.
Nat Commun ; 6: 6431, 2015 Mar 16.
Artigo em Inglês | MEDLINE | ID: mdl-25775432

RESUMO

T helper (TH) cell polarization during priming is modulated by a number of signals, but whether polarization to a given phenotype also influences recall responses of memory TH cells is relatively unknown. Here we show that miR-181a is selectively induced in both human and mouse naive T cells differentiating into the TH17, but not TH1 or TH2 subset. In human memory TH17 cells, miR-181a regulates responses to cognate antigens through modulation of ERK phosphorylation. By enhancing the signalling cascade from the T-cell receptor, such molecular network reduces the threshold of TH17 cell activation. Moreover, at a late time point, the same network induces a self-regulatory mechanism dependent on ID3, a negative regulator of transcription factors that control RORC expression, thus modulating TH17 activity. Our results demonstrate that the phenotype acquired by TH cells during priming contributes to their threshold of activation to secondary antigenic stimulations, thus influencing memory responses.


Assuntos
MAP Quinases Reguladas por Sinal Extracelular/metabolismo , Memória Imunológica , MicroRNAs/metabolismo , Células Th17/citologia , Animais , Antígenos/química , Candida albicans/metabolismo , Diferenciação Celular , Feminino , Humanos , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , MicroRNAs/genética , Fenótipo , Fosforilação , Interferência de RNA , Transdução de Sinais
9.
Science ; 347(6220): 400-6, 2015 Jan 23.
Artigo em Inglês | MEDLINE | ID: mdl-25477212

RESUMO

Distinct types of CD4(+) T cells protect the host against different classes of pathogens. However, it is unclear whether a given pathogen induces a single type of polarized T cell. By combining antigenic stimulation and T cell receptor deep sequencing, we found that human pathogen- and vaccine-specific T helper 1 (T(H)1), T(H)2, and T(H)17 memory cells have different frequencies but comparable diversity and comprise not only clones polarized toward a single fate, but also clones whose progeny have acquired multiple fates. Single naïve T cells primed by a pathogen in vitro could also give rise to multiple fates. Our results unravel an unexpected degree of interclonal and intraclonal functional heterogeneity of the human T cell response and suggest that polarized responses result from preferential expansion rather than priming.


Assuntos
Linfócitos T CD4-Positivos/imunologia , Candida albicans/imunologia , Interações Hospedeiro-Patógeno/imunologia , Memória Imunológica , Mycobacterium tuberculosis/imunologia , Subpopulações de Linfócitos T/imunologia , Vacinas/imunologia , Sequência de Aminoácidos , Células Cultivadas , Células Clonais , Sequenciamento de Nucleotídeos em Larga Escala , Humanos , Ativação Linfocitária , Dados de Sequência Molecular , Receptores de Antígenos de Linfócitos T/genética , Células Th1/imunologia , Células Th17/imunologia , Células Th2/imunologia
10.
Biochem Cell Biol ; 90(3): 269-78, 2012 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-22300429

RESUMO

Lactoferrin (LF), an iron-binding glycoprotein expressed in most biological fluids, represents a major component of mammalian innate immune system. The multiple activities of LF rely not only on its capacity to bind iron but also to interact with molecular and cellular components of both the host and pathogens. LF can bind and sequester lipopolysaccharide thus preventing proinflammatory pathway activation, sepsis, and tissue damage. However, the interplay between LF and lipopolysaccharide is complex and may lead to different outcomes including both the suppression of inflammatory response and immune activation. Understanding the molecular basis and the functional consequences of this complex interaction is critically relevant in the development of LF-based therapeutic interventions in humans.


Assuntos
Fatores Imunológicos/fisiologia , Lactoferrina/fisiologia , Lipopolissacarídeos/metabolismo , Animais , Interações Hospedeiro-Patógeno , Humanos , Imunidade Inata , Fatores Imunológicos/metabolismo , Lactoferrina/metabolismo , Lipopolissacarídeos/antagonistas & inibidores , Ligação Proteica , Receptor 4 Toll-Like/metabolismo
11.
PLoS One ; 6(7): e22504, 2011.
Artigo em Inglês | MEDLINE | ID: mdl-21799877

RESUMO

Lactoferrin (LF), a key element in mammalian immune system, plays pivotal roles in host defence against infection and excessive inflammation. Its protective effects range from direct antimicrobial activities against a large panel of microbes, including bacteria, viruses, fungi and parasites, to antinflammatory and anticancer activities. In this study, we show that monocyte-derived dendritic cells (MD-DCs) generated in the presence of bovine LF (bLF) fail to undergo activation by up-modulating CD83, co-stimulatory and major histocompatibility complex molecules, and cytokine/chemokine secretion. Moreover, these cells are weak activators of T cell proliferation and retain antigen uptake activity. Consistent with an impaired maturation, bLF-MD-DC primed T lymphocytes exhibit a functional unresponsiveness characterized by reduced expression of CD154 and impaired expression of IFN-γ and IL-2. The observed imunosuppressive effects correlate with an increased expression of molecules with negative regulatory functions (i.e. immunoglobulin-like transcript 3 and programmed death ligand 1), indoleamine 2,3-dioxygenase, and suppressor of cytokine signaling-3. Interestingly, bLF-MD-DCs produce IL-6 and exhibit constitutive signal transducer and activator of transcription 3 activation. Conversely, bLF exposure of already differentiated MD-DCs completely fails to induce IL-6, and partially inhibits Toll-like receptor (TLR) agonist-induced activation. Cell-specific differences in bLF internalization likely account for the distinct response elicited by bLF in monocytes versus immature DCs, providing a mechanistic base for its multiple effects. These results indicate that bLF exerts a potent anti-inflammatory activity by skewing monocyte differentiation into DCs with impaired capacity to undergo activation and to promote Th1 responses. Overall, these bLF-mediated effects may represent a strategy to block excessive DC activation upon TLR-induced inflammation, adding further evidence for a critical role of bLF in directing host immune function.


Assuntos
Anti-Inflamatórios/farmacologia , Células Dendríticas/efeitos dos fármacos , Lactoferrina/farmacologia , Transdução de Sinais/efeitos dos fármacos , Receptores Toll-Like/antagonistas & inibidores , Receptores Toll-Like/metabolismo , Transporte Ativo do Núcleo Celular/efeitos dos fármacos , Animais , Anti-Inflamatórios/metabolismo , Bovinos , Diferenciação Celular/efeitos dos fármacos , Diferenciação Celular/imunologia , Núcleo Celular/efeitos dos fármacos , Núcleo Celular/metabolismo , Células Dendríticas/citologia , Células Dendríticas/imunologia , Células Dendríticas/metabolismo , Regulação da Expressão Gênica/efeitos dos fármacos , Regulação da Expressão Gênica/imunologia , Humanos , Indolamina-Pirrol 2,3,-Dioxigenase/metabolismo , Interferon gama/biossíntese , Interleucina-2/biossíntese , Interleucina-6/biossíntese , Interleucina-6/metabolismo , Lactoferrina/metabolismo , Receptores de Lipopolissacarídeos/metabolismo , Monócitos/citologia , Transdução de Sinais/imunologia , Proteína 3 Supressora da Sinalização de Citocinas , Proteínas Supressoras da Sinalização de Citocina/metabolismo , Linfócitos T/citologia , Linfócitos T/efeitos dos fármacos , Linfócitos T/imunologia , Linfócitos T/metabolismo , Receptor 2 Toll-Like/metabolismo , Receptor 4 Toll-Like/metabolismo
12.
Biometals ; 23(3): 387-97, 2010 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-20191308

RESUMO

Lactoferrin (Lf) is a mammalian exclusive protein widely distributed in milk and exocrine secretions exhibiting multifunctional properties. Many of the proven or proposed functions of Lf, apart from its iron binding activity, depend on its capacity to bind to other macromolecules. Lf can bind and sequester lipopolysaccharide (LPS), thus preventing pro-inflammatory pathway activation, sepsis and tissue damage. However, the interplay between Lf and LPS is complex, and may result in different outcomes, including both suppression of the inflammatory response and immune activation. These findings are critically relevant in the development of Lf-based therapeutic interventions in humans. Understanding the molecular basis and functional consequences of Lf-LPS interaction will provide insights for determining its role in health and disease.


Assuntos
Lactoferrina/imunologia , Lactoferrina/metabolismo , Lipopolissacarídeos/imunologia , Lipopolissacarídeos/metabolismo , Animais , Humanos
13.
Toxins (Basel) ; 2(1): 54-68, 2010 01.
Artigo em Inglês | MEDLINE | ID: mdl-22069546

RESUMO

Lactoferrin (Lf), an iron-binding glycoprotein expressed in most biological fluids, represents a major component of the mammalian innate immune system. Lf's multiple activities rely not only on its capacity to bind iron, but also to interact with molecular and cellular components of both host and pathogens. Lf can bind and sequester lipopolysaccharide (LPS), thus preventing pro-inflammatory pathway activation, sepsis and tissue damage. However, Lf-bound LPS may retain the capacity to induce cell activation via Toll-like receptor 4-dependent and -independent mechanisms. This review discusses the complex interplay between Lf and LPS and its relevance in the regulation of the immune response.


Assuntos
Lactoferrina , Receptor 4 Toll-Like , Animais , Humanos , Sistema Imunitário/metabolismo , Ferro/metabolismo , Lipopolissacarídeos/metabolismo , Receptor 4 Toll-Like/metabolismo
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