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1.
Sci Signal ; 12(578)2019 Apr 23.
Artigo em Inglês | MEDLINE | ID: mdl-31015290

RESUMO

Store-operated Ca2+ entry (SOCE) channels are highly selective Ca2+ channels activated by the endoplasmic reticulum (ER) sensors STIM1 and STIM2. Their direct interaction with the pore-forming plasma membrane ORAI proteins (ORAI1, ORAI2, and ORAI3) leads to sustained Ca2+ fluxes that are critical for many cellular functions. Mutations in the human ORAI1 gene result in immunodeficiency, anhidrotic ectodermal dysplasia, and enamel defects. In our investigation of the role of ORAI proteins in enamel, we identified enamel defects in a patient with an ORAI1 null mutation. Targeted deletion of the Orai1 gene in mice showed enamel defects and reduced SOCE in isolated enamel cells. However, Orai2-/- mice showed normal enamel despite having increased SOCE in the enamel cells. Knockdown experiments in the enamel cell line LS8 suggested that ORAI2 and ORAI3 modulated ORAI1 function, with ORAI1 and ORAI2 being the main contributors to SOCE. ORAI1-deficient LS8 cells showed altered mitochondrial respiration with increased oxygen consumption rate and ATP, which was associated with altered redox status and enhanced ER Ca2+ uptake, likely due to S-glutathionylation of SERCA pumps. Our findings demonstrate an important role of ORAI1 in Ca2+ influx in enamel cells and establish a link between SOCE, mitochondrial function, and redox homeostasis.

2.
Blood ; 132(22): 2362-2374, 2018 Nov 29.
Artigo em Inglês | MEDLINE | ID: mdl-30254128

RESUMO

ARPC1B is a key factor for the assembly and maintenance of the ARP2/3 complex that is involved in actin branching from an existing filament. Germline biallelic mutations in ARPC1B have been recently described in 6 patients with clinical features of combined immunodeficiency (CID), whose neutrophils and platelets but not T lymphocytes were studied. We hypothesized that ARPC1B deficiency may also lead to cytoskeleton and functional defects in T cells. We have identified biallelic mutations in ARPC1B in 6 unrelated patients with early onset disease characterized by severe infections, autoimmune manifestations, and thrombocytopenia. Immunological features included T-cell lymphopenia, low numbers of naïve T cells, and hyper-immunoglobulin E. Alteration in ARPC1B protein structure led to absent/low expression by flow cytometry and confocal microscopy. This molecular defect was associated with the inability of patient-derived T cells to extend an actin-rich lamellipodia upon T-cell receptor (TCR) stimulation and to assemble an immunological synapse. ARPC1B-deficient T cells additionally displayed impaired TCR-mediated proliferation and SDF1-α-directed migration. Gene transfer of ARPC1B in patients' T cells using a lentiviral vector restored both ARPC1B expression and T-cell proliferation in vitro. In 2 of the patients, in vivo somatic reversion restored ARPC1B expression in a fraction of lymphocytes and was associated with a skewed TCR repertoire. In 1 revertant patient, memory CD8+ T cells expressing normal levels of ARPC1B displayed improved T-cell migration. Inherited ARPC1B deficiency therefore alters T-cell cytoskeletal dynamics and functions, contributing to the clinical features of CID.

3.
J Allergy Clin Immunol ; 142(4): 1297-1310.e11, 2018 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-29155098

RESUMO

BACKGROUND: Store-operated Ca2+ entry (SOCE) through Ca2+ release-activated Ca2+ channels is an essential signaling pathway in many cell types. Ca2+ release-activated Ca2+ channels are formed by ORAI1, ORAI2, and ORAI3 proteins and activated by stromal interaction molecule (STIM) 1 and STIM2. Mutations in the ORAI1 and STIM1 genes that abolish SOCE cause a combined immunodeficiency (CID) syndrome that is accompanied by autoimmunity and nonimmunologic symptoms. OBJECTIVE: We performed molecular and immunologic analysis of patients with CID, anhidrosis, and ectodermal dysplasia of unknown etiology. METHODS: We performed DNA sequencing of the ORAI1 gene, modeling of mutations on ORAI1 crystal structure, analysis of ORAI1 mRNA and protein expression, SOCE measurements, immunologic analysis of peripheral blood lymphocyte populations by using flow cytometry, and histologic and ultrastructural analysis of patient tissues. RESULTS: We identified 3 novel autosomal recessive mutations in ORAI1 in unrelated kindreds with CID, autoimmunity, ectodermal dysplasia with anhidrosis, and muscular dysplasia. The patients were homozygous for p.V181SfsX8, p.L194P, and p.G98R mutations in the ORAI1 gene that suppressed ORAI1 protein expression and SOCE in the patients' lymphocytes and fibroblasts. In addition to impaired T-cell cytokine production, ORAI1 mutations were associated with strongly reduced numbers of invariant natural killer T and regulatory T (Treg) cells and altered composition of γδ T-cell and natural killer cell subsets. CONCLUSION: ORAI1 null mutations are associated with reduced numbers of invariant natural killer T and Treg cells that likely contribute to the patients' immunodeficiency and autoimmunity. ORAI1-deficient patients have dental enamel defects and anhidrosis, representing a new form of anhidrotic ectodermal dysplasia with immunodeficiency that is distinct from previously reported patients with anhidrotic ectodermal dysplasia with immunodeficiency caused by mutations in the nuclear factor κB signaling pathway (IKBKG and NFKBIA).

5.
J Clin Invest ; 126(11): 4303-4318, 2016 11 01.
Artigo em Inglês | MEDLINE | ID: mdl-27721237

RESUMO

Eccrine sweat glands are essential for sweating and thermoregulation in humans. Loss-of-function mutations in the Ca2+ release-activated Ca2+ (CRAC) channel genes ORAI1 and STIM1 abolish store-operated Ca2+ entry (SOCE), and patients with these CRAC channel mutations suffer from anhidrosis and hyperthermia at high ambient temperatures. Here we have shown that CRAC channel-deficient patients and mice with ectodermal tissue-specific deletion of Orai1 (Orai1K14Cre) or Stim1 and Stim2 (Stim1/2K14Cre) failed to sweat despite normal sweat gland development. SOCE was absent in agonist-stimulated sweat glands from Orai1K14Cre and Stim1/2K14Cre mice and human sweat gland cells lacking ORAI1 or STIM1 expression. In Orai1K14Cre mice, abolishment of SOCE was associated with impaired chloride secretion by primary murine sweat glands. In human sweat gland cells, SOCE mediated by ORAI1 was necessary for agonist-induced chloride secretion and activation of the Ca2+-activated chloride channel (CaCC) anoctamin 1 (ANO1, also known as TMEM16A). By contrast, expression of TMEM16A, the water channel aquaporin 5 (AQP5), and other regulators of sweat gland function was normal in the absence of SOCE. Our findings demonstrate that Ca2+ influx via store-operated CRAC channels is essential for CaCC activation, chloride secretion, and sweat production in humans and mice.


Assuntos
Sinalização do Cálcio/fisiologia , Canais de Cloreto/metabolismo , Proteínas de Neoplasias/metabolismo , Proteína ORAI1/metabolismo , Glândulas Sudoríparas/metabolismo , Suor/metabolismo , Animais , Anoctamina-1 , Aquaporina 5/genética , Aquaporina 5/metabolismo , Canais de Cloreto/genética , Feminino , Humanos , Masculino , Camundongos , Camundongos Knockout , Proteínas de Neoplasias/genética , Proteína ORAI1/genética , Molécula 1 de Interação Estromal/genética , Molécula 1 de Interação Estromal/metabolismo , Molécula 2 de Interação Estromal/genética , Molécula 2 de Interação Estromal/metabolismo
6.
Pediatr Blood Cancer ; 63(11): 2046-9, 2016 11.
Artigo em Inglês | MEDLINE | ID: mdl-27354010

RESUMO

We describe five cases of children who completed chemotherapy for infantile acute lymphoblastic leukemia (ALL) and soon after were diagnosed with severe T-cell, non-HIV immunodeficiency, with varying B-cell and NK-cell depletion. There was near absence of CD3(+) , CD4(+) , and CD8(+) cells. All patients developed multiple, primarily opportunistic infections. Unfortunately, four patients died, although one was successfully treated by hematopoietic stem cell transplantation. These immunodeficiencies appeared to be secondary to intensive infant ALL chemotherapy. Our report highlights the importance of the early consideration of this life-threatening immune complication in patients who received chemotherapy for infantile ALL.


Assuntos
Síndromes de Imunodeficiência/etiologia , Leucemia-Linfoma Linfoblástico de Células Precursoras/tratamento farmacológico , Linfócitos T/imunologia , Criança , Pré-Escolar , Evolução Fatal , Transplante de Células-Tronco Hematopoéticas , Humanos , Leucemia-Linfoma Linfoblástico de Células Precursoras/imunologia
7.
J Gastroenterol ; 51(10): 985-98, 2016 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-26891909

RESUMO

BACKGROUND: Lymphocyte recruitment into the portal tract is crucial not only for homeostatic immune surveillance but also for many liver diseases. However, the exact route of entry for lymphocytes into portal tract is still obscure. We investigated this question using a rat hepatic allograft rejection model. METHODS: A migration route was analyzed by immunohistological methods including a recently developed scanning electron microscopy method. Transmigration-associated molecules such as selectins, integrins, and chemokines and their receptors expressed by hepatic vessels and recruited T-cells were analyzed by immunohistochemistry and flow cytometry. RESULTS: The immunoelectron microscopic analysis clearly showed CD8ß(+) cells passing through the portal vein (PV) endothelia. Furthermore, the migrating pathway seemed to pass through the endothelial cell body. Local vascular cell adhesion molecule-1 (VCAM-1) expression was induced in PV endothelial cells from day 2 after liver transplantation. Although intercellular adhesion molecule-1 (ICAM-1) expression was also upregulated, it was restricted to sinusoidal endothelia. Recipient T-cells in the graft perfusate were CD25(+)CD44(+)ICAM-1(+)CXCR3(+)CCR5(-) and upregulated α4ß1 or αLß2 integrins. Immunohistochemistry showed the expression of CXCL10 in donor MHCII(high) cells in the portal tract as well as endothelial walls of PV. CONCLUSIONS: We show for the first time direct evidence of T-cell transmigration across PV endothelial cells during hepatic allograft rejection. Interactions between VCAM-1 on endothelia and α4ß1 integrin on recipient effector T-cells putatively play critical roles in adhesion and transmigration through endothelia. A chemokine axis of CXCL10 and CXCR3 also may be involved.


Assuntos
Linfócitos T CD8-Positivos/fisiologia , Rejeição de Enxerto/imunologia , Transplante de Fígado/efeitos adversos , Migração Transendotelial e Transepitelial , Aloenxertos/imunologia , Animais , Linfócitos T CD8-Positivos/química , Quimiocina CXCL10/análise , Endotélio/química , Endotélio/metabolismo , Receptores de Hialuronatos/análise , Imuno-Histoquímica , Integrina alfa4beta1/metabolismo , Molécula 1 de Adesão Intercelular/análise , Molécula 1 de Adesão Intercelular/metabolismo , Subunidade alfa de Receptor de Interleucina-2/análise , Antígeno-1 Associado à Função Linfocitária/metabolismo , Masculino , Microscopia Eletrônica de Varredura , Veia Porta , Ratos Endogâmicos ACI , Ratos Endogâmicos Lew , Receptores CCR5/análise , Receptores CXCR3/análise , Regulação para Cima , Molécula 1 de Adesão de Célula Vascular/metabolismo
8.
Nature ; 530(7590): 349-53, 2016 Feb 18.
Artigo em Inglês | MEDLINE | ID: mdl-26863192

RESUMO

In multiple sclerosis, brain-reactive T cells invade the central nervous system (CNS) and induce a self-destructive inflammatory process. T-cell infiltrates are not only found within the parenchyma and the meninges, but also in the cerebrospinal fluid (CSF) that bathes the entire CNS tissue. How the T cells reach the CSF, their functionality, and whether they traffic between the CSF and other CNS compartments remains hypothetical. Here we show that effector T cells enter the CSF from the leptomeninges during Lewis rat experimental autoimmune encephalomyelitis (EAE), a model of multiple sclerosis. While moving through the three-dimensional leptomeningeal network of collagen fibres in a random Brownian walk, T cells were flushed from the surface by the flow of the CSF. The detached cells displayed significantly lower activation levels compared to T cells from the leptomeninges and CNS parenchyma. However, they did not represent a specialized non-pathogenic cellular sub-fraction, as their gene expression profile strongly resembled that of tissue-derived T cells and they fully retained their encephalitogenic potential. T-cell detachment from the leptomeninges was counteracted by integrins VLA-4 and LFA-1 binding to their respective ligands produced by resident macrophages. Chemokine signalling via CCR5/CXCR3 and antigenic stimulation of T cells in contact with the leptomeningeal macrophages enforced their adhesiveness. T cells floating in the CSF were able to reattach to the leptomeninges through steps reminiscent of vascular adhesion in CNS blood vessels, and invade the parenchyma. The molecular/cellular conditions for T-cell reattachment were the same as the requirements for detachment from the leptomeningeal milieu. Our data indicate that the leptomeninges represent a checkpoint at which activated T cells are licensed to enter the CNS parenchyma and non-activated T cells are preferentially released into the CSF, from where they can reach areas of antigen availability and tissue damage.


Assuntos
Movimento Celular , Líquido Cefalorraquidiano/citologia , Encefalomielite Autoimune Experimental/patologia , Meninges/patologia , Esclerose Múltipla/patologia , Linfócitos T/patologia , Transferência Adotiva , Animais , Adesão Celular , Líquido Cefalorraquidiano/imunologia , Quimiocinas/metabolismo , Plexo Corióideo , Colágeno/metabolismo , Modelos Animais de Doenças , Encefalomielite Autoimune Experimental/imunologia , Feminino , Integrina alfa4beta1/metabolismo , Ativação Linfocitária , Antígeno-1 Associado à Função Linfocitária/metabolismo , Macrófagos/imunologia , Macrófagos/metabolismo , Masculino , Meninges/imunologia , Esclerose Múltipla/imunologia , Ratos , Ratos Endogâmicos Lew , Receptores CCR5/metabolismo , Receptores CXCR3/metabolismo , Linfócitos T/imunologia
9.
Am J Pathol ; 184(8): 2310-21, 2014 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-25043620

RESUMO

Pseudomonas aeruginosa, an opportunistic pathogen, is the leading cause of morbidity and mortality in immune-compromised individuals. Maintaining the integrity of the respiratory epithelium is critical for an effective host response to P. aeruginosa. Given the close spatial relationship between mast cells and the respiratory epithelium, and the importance of tightly regulated epithelial permeability during lung infections, we examined whether mast cells influence airway epithelial integrity during P. aeruginosa lung infection in a mouse model. We found that mast cell-deficient Kit(W-sh)/Kit(W-sh) mice displayed greatly increased epithelial permeability, bacterial dissemination, and neutrophil accumulation compared with wild-type animals after P. aeruginosa infection; these defects were corrected on reconstitution with mast cells. An in vitro Transwell co-culture model further demonstrated that a secreted mast cell factor decreased epithelial cell apoptosis and tumor necrosis factor production after P. aeruginosa infection. Together, our data demonstrate a previously unrecognized role for mast cells in the maintenance of epithelial integrity during P. aeruginosa infection, through a mechanism that likely involves prevention of epithelial apoptosis and tumor necrosis factor production. Our understanding of mechanisms of the host response to P. aeruginosa will open new avenues for the development of successful preventative and treatment strategies.


Assuntos
Lesão Pulmonar/patologia , Mastócitos/imunologia , Infecções por Pseudomonas/patologia , Infecções Respiratórias/patologia , Animais , Western Blotting , Linhagem Celular , Técnicas de Cocultura , Modelos Animais de Doenças , Feminino , Humanos , Lesão Pulmonar/imunologia , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Microscopia de Fluorescência , Infecções por Pseudomonas/imunologia , Pseudomonas aeruginosa , Mucosa Respiratória/imunologia , Mucosa Respiratória/patologia , Infecções Respiratórias/imunologia
10.
Eur J Immunol ; 44(6): 1633-43, 2014 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-24700244

RESUMO

CCR4 and CXCR3 are expressed on several T-cell subsets in inflamed tissues, yet their role in tissue-specific recruitment is unclear. We examined the contributions of CCR4 and CXCR3 to T-cell recruitment into inflamed joints in collagen-induced arthritis, antigen-draining lymph nodes (LNs) and dermal inflammatory sites (poly I:C, LPS, concanavalin A, and delayed type hypersensitivity), using labeled activated T cells from CXCR3(-/-), CCR4(-/-), and WT mice. Both CXCR3 and CCR4 deficiency reduced the development of arthritis, but did not affect Th1-cell recruitment to the inflamed joints. Accumulation in inflamed LNs was highly CXCR3 dependent. In contrast, CCR4-deficient Th1 cells had an increased accumulation in these LNs. Migration to all four dermal inflammatory sites by activated Th1 and T cytotoxic cells and memory CD4(+) T cells was partially CXCR3-dependent, but Treg-cell migration was independent of CXCR3. The subset of cells expressing CCR4 has skin-migrating properties, but CCR4 itself is not required for the migration. Thus, migration into these inflamed tissues is CCR4-independent, and partially dependent on CXCR3, except for Treg cells, which require neither receptor. CCR4 may therefore affect retention of T cells in different tissues rather than trafficking out of the blood.


Assuntos
Artrite Experimental/imunologia , Movimento Celular/imunologia , Dermatite/imunologia , Articulações/imunologia , Linfonodos/imunologia , Receptores CCR4/imunologia , Receptores CXCR3/imunologia , Linfócitos T/imunologia , Animais , Artrite Experimental/genética , Artrite Experimental/patologia , Dermatite/genética , Dermatite/patologia , Articulações/patologia , Linfonodos/patologia , Camundongos , Camundongos Knockout , Especificidade de Órgãos/genética , Especificidade de Órgãos/imunologia , Receptores CCR4/genética , Receptores CXCR3/genética , Pele/imunologia , Pele/patologia , Linfócitos T/patologia
11.
J Clin Immunol ; 34(3): 267-71, 2014 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-24596024

RESUMO

UNLABELLED: IRAK-4 deficiency causes IL-1R and TLR signaling failure, resulting in minimal clinical features despite invasive bacterial infection. We report the course of a 7-year-old IRAK-4-deficient girl presenting in the first year with multiple occult Staphylococcus aureus lymphadenitis. She was managed with antibiotic prophylaxis (sulfa/trimethoprim/PenV, then - due to neutropenia - Cefprozil), pneumococcal vaccination (PCV-7, Pneumovax23, PCV-13) and vigilance. Pneumococcal-specific IgG levels were monitored. No bacterial infections occurred on prophylaxis for 6 years after initial presentation. IgG response to pneumococcal polysaccharide was satisfactory but short-lived, requiring frequent boosting. At age 7, patient developed a morning headache and vomited once. Cefprozil was administered and re-dosed. Over 12 h, she was fatigued without other symptoms. Low fever accompanied another emesis. A few hours later she was confused, and purpuric rash appeared. Emergency physicians diagnosed sepsis/meningitis and started vancomycin-ceftriaxone. Respiratory failure and cerebellar herniation occurred <24 h after first symptoms. Blood and CSF grew Streptococcus pneumoniae type 6C resistant to second-generation cephalosporins. The patient's latest PCV-13 vaccination was 6 weeks before death, which included serotype 6A. Immunoglobulins were normal except IgG4 was increased (3.4 g/L). IgG response to vaccine antigens was satisfactory. IgG to 6A is reported to cross-react with 6C, but this was not the case here. CONCLUSION: Despite antibiotic prophylaxis and repeated vaccination, even older IRAK-4-deficient patients are at high risk of rapidly fatal infection due to emergence of antibiotic resistance. These patients need early assessment at any age, bacterial culturing, alternative empiric antibiotic therapy and close observation when even vaguely unwell. Based on increasingly recognized immunological and/or clinical impairments in B cell function, and possibly other defects, long-term IgG prophylaxis in addition to antibiotics is recommended.


Assuntos
Antibioticoprofilaxia , Imunoglobulina G/imunologia , Síndromes de Imunodeficiência/imunologia , Meningite Pneumocócica/tratamento farmacológico , Meningite Pneumocócica/etiologia , Vacinas Pneumocócicas/imunologia , Streptococcus pneumoniae/imunologia , Criança , Evolução Fatal , Feminino , Humanos , Quinases Associadas a Receptores de Interleucina-1/imunologia
12.
Am J Pathol ; 183(2): 459-69, 2013 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-23731726

RESUMO

Fibroblast progenitor cells (fibrocytes) are important to the development of myocardial fibrosis and are suggested to migrate to the heart via CXCL12 and chemokine ligand (CCL) 2. We hypothesized that if these chemokines are recruiting fibrocytes, disrupting their signaling will reduce early (3-day) fibrocyte infiltration and, consequently, fibrosis in the myocardium. C57/Bl6 and CCR2(-/-) mice were infused with saline or angiotensin (Ang) II, with or without CXC receptor 4 blockade (AMD3100). Hearts were assessed for chemokine up-regulation, immunofluorescence, and histological features. AngII caused early myocardial up-regulation of CXCL12 and CCL2, which corresponded to significant myocardial infiltration and fibrosis compared with controls. Animals receiving AMD3100 and/or with the genotype CCR2(-/-) failed to demonstrate reductions in infiltrate or fibrosis after 3 days of AngII, and AngII + AMD3100 animals showed exacerbated fibrocyte infiltration and fibrosis compared with AngII alone. CCR2(-/-) mice demonstrated significant reductions in myocardial fibrosis relative to wild type, but this was after 28 days of AngII infusion and was the result of reduced infiltrating cell proliferation. An alternative CCR2 ligand, CCL12, was found to be increasing infiltrating cell proliferation in the heart after AngII infusion, which we confirmed in vitro. In conclusion, early fibrocyte recruitment cannot be inhibited through modulating CXCL12 or CCL2, as previously thought. Ablating CCR2 signaling did confer myocardial fibrosis reductions, but these benefits were not observed until much later and were likely the result of modulated proliferation through ablating the CCL12-CCR2 interaction.


Assuntos
Angiotensina II/farmacologia , Quimiocina CCL2/fisiologia , Quimiocina CXCL12/fisiologia , Fibroblastos/fisiologia , Miocárdio/metabolismo , Vasoconstritores/farmacologia , Animais , Movimento Celular/fisiologia , Proliferação de Células/efeitos dos fármacos , Fibrose/patologia , Compostos Heterocíclicos/farmacologia , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Miocárdio/patologia , Receptores CXCR4/antagonistas & inibidores , Células-Tronco/fisiologia , Regulação para Cima
13.
J Immunol ; 189(1): 337-46, 2012 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-22664869

RESUMO

CCR4 on T cells is suggested to mediate skin homing in mice. Our objective was to determine the interaction of CCR4, E-selectin ligand (ESL), and α(4)ß(1) on memory and activated T cells in recruitment to dermal inflammation. mAbs to rat CCR4 were developed. CCR4 was on 5-21% of memory CD4 cells, and 20% were also ESL(+). Anti-TCR-activated CD4 and CD8 cells were 40-55% CCR4(+), and ∼75% of both CCR4(+) and CCR4(-) cells were ESL(+). CCR4(+) memory CD4 cells migrated 4- to 7-fold more to dermal inflammation induced by IFN-γ, TNF, TLR agonists, and delayed-type hypersensitivity than CCR4(-) cells. CCR4(+) activated CD4 cells migrated only 5-50% more than CCR4(-) cells to these sites. E-selectin blockade inhibited ∼60% of CCR4(+) activated CD4 cell migration but was less effective on memory cells where α(4)ß(1) was more important. Anti-α(4)ß(1) also inhibited CCR4(-) activated CD4 cells more than CCR4(+) cells. Anti-E-selectin reduced activated CD8 more than CD4 cell migration. These findings modify our understanding of CCR4, ESL, α(4)ß(1), and dermal tropism. There is no strict relationship between CCR4 and ESL for skin homing of CD4 cells, because the activation state and inflammatory stimulus are critical determinants. Dermal homing memory CD4 cells express CCR4 and depend more on α(4)ß(1) than ESL. Activated CD4 cells do not require CCR4, but CCR4(+) cells are more dependent on ESL than on α(4)ß(1), and CCR4(-) cells preferentially use α(4)ß(1). The differentiation from activated to memory CD4 cells increases the dependence on CCR4 for skin homing and decreases the requirement for ESL.


Assuntos
Movimento Celular/imunologia , Selectina E/fisiologia , Memória Imunológica , Integrina alfa4beta1/fisiologia , Ativação Linfocitária/imunologia , Receptores CCR4/fisiologia , Pele/imunologia , Subpopulações de Linfócitos T/imunologia , Animais , Células CHO , Inibição de Migração Celular/imunologia , Cricetinae , Cricetulus , Modelos Animais de Doenças , Selectina E/biossíntese , Selectina E/metabolismo , Inflamação/imunologia , Inflamação/metabolismo , Inflamação/patologia , Integrina alfa4beta1/antagonistas & inibidores , Masculino , Glicoproteínas de Membrana/biossíntese , Glicoproteínas de Membrana/fisiologia , Ratos , Ratos Endogâmicos Lew , Receptores CCR4/biossíntese , Receptores CCR4/deficiência , Receptores de Fatores de Crescimento de Fibroblastos/biossíntese , Sialoglicoproteínas/biossíntese , Pele/patologia , Subpopulações de Linfócitos T/metabolismo , Subpopulações de Linfócitos T/patologia
14.
FASEB J ; 26(3): 1280-9, 2012 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-22125314

RESUMO

The trafficking of effector cells to sites of infection is crucial for antiviral responses. However, the mechanisms of recruitment of the interferon-γ-producing and cytotoxic CD56(+) T cells are poorly understood. Human mast cells are sentinel cells found in the skin and airway and produce selected proinflammatory mediators in response to multiple pathogen-associated signals. The role of human mast cell-derived chemokines in T-cell recruitment to virus infection was examined. Supernatants from primary human cord blood-derived mast cells (CBMCs) infected with mammalian reovirus were examined for chemokine production and utilized in chemotaxis assays. Virus-infected CBMCs produced several chemokines, including CCL3, CCL4, and CCL5. Supernatants from reovirus-infected CBMCs selectively induced the chemotaxis of CD8(+) T cells (10±1%) and CD3(+)CD56(+) T cells (19±5%). CD56(+) T-cell migration was inhibited by pertussis toxin (65±9%) and met-RANTES (56±7%), a CCR1/CCR5 antagonist. CD56(+) T cells expressed CCR5, but little CCR1. The depletion of CCL3, CCL4, and CCL5 from reovirus-infected CBMC supernatants significantly (41±10%) inhibited CD56(+) T-cell chemotaxis. This study demonstrates a novel role for mast cells and CCR5 in CD56(+) T-cell trafficking and suggests that human mast cells enhance immunity to viruses through the selective recruitment of cytotoxic effector cells to virus infection sites. These findings could be exploited to enhance local T-cell responses in chronic viral infection and malignancies at mast cell-rich sites.


Assuntos
Antígeno CD56/imunologia , Orthoreovirus Mamífero 3/imunologia , Mastócitos/imunologia , Linfócitos T/imunologia , Antígeno CD56/metabolismo , Movimento Celular/efeitos dos fármacos , Movimento Celular/imunologia , Células Cultivadas , Quimiocina CCL3/imunologia , Quimiocina CCL3/metabolismo , Quimiocina CCL3/farmacologia , Quimiocina CCL4/imunologia , Quimiocina CCL4/metabolismo , Quimiocina CCL4/farmacologia , Quimiocina CCL5/imunologia , Quimiocina CCL5/metabolismo , Quimiocina CCL5/farmacologia , Quimiocinas/imunologia , Quimiocinas/metabolismo , Quimiocinas/farmacologia , Quimiotaxia/efeitos dos fármacos , Quimiotaxia/imunologia , Meios de Cultivo Condicionados/farmacologia , Relação Dose-Resposta a Droga , Sangue Fetal/citologia , Citometria de Fluxo , Imunofluorescência , Interações Hospedeiro-Patógeno/imunologia , Humanos , Ligantes , Orthoreovirus Mamífero 3/fisiologia , Mastócitos/metabolismo , Mastócitos/virologia , Receptores CCR5/imunologia , Receptores CCR5/metabolismo , Linfócitos T/metabolismo
15.
Arthritis Rheum ; 63(11): 3467-76, 2011 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-21739422

RESUMO

OBJECTIVE: To investigate P- and E-selectin ligand coexpression with chemokine receptors (CKRs) on T cells in the synovial fluid (SF) and blood of children with juvenile idiopathic arthritis (JIA). METHODS: Sixteen patients with polyarticular or persistent oligoarticular JIA (ages 5.3-15.1 years) were studied. SF and venous blood were collected, and immunostaining for the expression of CCR4, CCR5, CXCR3, and P- or E-selectin ligands was performed. RESULTS: Compared to blood, SF was greatly enriched for CD4+ T cells bearing CCR5, CCR4, CXCR3, and both P- and E-selectin ligand. Twenty-five percent of the CD4+ T cells in SF expressed both CCR5 and CCR4, some also coexpressing CXCR3. Such cells were rare in blood. Half of the few CCR5+ T cells in blood coexpressed P- or E-selectin ligand, a phenotype that was enriched up to 50-fold in SF. A minority of CCR4+ and CXCR3+ cells in blood (∼25%) coexpressed selectin ligand; these were enriched 4-8-fold in SF. Most CCR4-expressing CD4+ T cells expressed both E-selectin ligand and cutaneous lymphocyte antigen. CONCLUSION: CCR4-, CCR5-, CXCR3-, and selectin ligand-expressing CD4+ T cells preferentially accumulate in the joints of children with JIA. The marked enrichment of CCR5+ T cells coexpressing P-selectin and/or E-selectin ligand in CD4+ SF T cells suggests that the few such cells in blood selectively migrate to inflamed joints via endothelial P- and E-selectin- and CCR5-activating chemokines. The predominance of CCR4-expressing CD4+ T cells coexpressing E-selectin ligand suggests that such cells migrate not only to areas of cutaneous inflammation, as previously reported, but also to the joints in JIA. Combined targeting of CCR5- and E-selectin-dependent mechanisms may be a relevant treatment strategy.


Assuntos
Artrite Juvenil/imunologia , Selectina E/metabolismo , Selectina-P/metabolismo , Receptores CCR4/metabolismo , Receptores CCR5/metabolismo , Receptores CXCR3/metabolismo , Linfócitos T/imunologia , Adolescente , Artrite Juvenil/genética , Criança , Pré-Escolar , Selectina E/genética , Feminino , Humanos , Ligantes , Masculino , Selectina-P/genética , Receptores CCR4/genética , Receptores CCR5/genética , Receptores CXCR3/genética
16.
Eur J Immunol ; 40(10): 2751-61, 2010 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-21038468

RESUMO

Autoreactive T-cell infiltration into the CNS is critical in MS and EAE. The chemokine receptor CXCR3 and its ligands are implicated in MS and mouse EAE, but the contribution of CXCR3 to T-cell migration into the inflamed CNS remains controversial. During active disease in a rat EAE model, blood T-cell, spleen T-cell and T lymphoblast migration into the CNS was inhibited by a CXCR3 blocking mAb by, 30-70%, ∼75% and 50-80%, respectively. However, CXCR3 blockade after active immunization did not inhibit EAE, did not alter total T-cell accumulation in the CNS and did not affect Treg accumulation or the presence of cells producing IFN-γ or IL-17. Conversely, CXCR3 blockade during EAE induced by adoptive transfer of myelin basic protein-activated T cells delayed disease onset, shortened its duration and reduced disease severity. Moreover, CXCR3 blockade inhibited leukocyte infiltration of the CNS>95%, virtually abolishing infiltration of transferred T cells. Thus, CXCR3 plays a major role in T-cell migration to the CNS and can be critical for encephalitogenic T-cell migration into the CNS to induce disease, but CXCR3-independent recruitment can also produce EAE.


Assuntos
Movimento Celular/imunologia , Sistema Nervoso Central/imunologia , Encefalomielite Autoimune Experimental/imunologia , Receptores CXCR3/antagonistas & inibidores , Linfócitos T/imunologia , Transferência Adotiva/métodos , Animais , Anticorpos Monoclonais/farmacologia , Encefalomielite Autoimune Experimental/terapia , Citometria de Fluxo , Histocitoquímica , Interferon gama/genética , Interferon gama/imunologia , Interleucina-17/genética , Interleucina-17/imunologia , RNA Mensageiro/química , RNA Mensageiro/genética , Ratos , Ratos Endogâmicos Lew , Receptores CXCR3/administração & dosagem , Receptores CXCR3/imunologia , Reação em Cadeia da Polimerase Via Transcriptase Reversa
17.
Transfus Med Rev ; 24 Suppl 1: S28-50, 2010 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-19962579

RESUMO

The standard treatment for patients with primary antibody deficiency is immunoglobulin (IG), but the care of these patients is complex. These guidelines, initiated by the Canadian Blood Services and the National Advisory Committee on Blood and Blood Products, have been developed to facilitate and standardize the care of these patients by the various physician specialties that are responsible for their care. A panel of national expert immunologists and methodologists developed salient clinical questions; and a systematic, expert, and bibliography literature search up to July 2008 was conducted. One thousand eighty-seven citations were retrieved, and 102 reports were used in the preparation of this guideline. The recommendations provide guidance (1) on the complexity of the treatment of these patients; (2) the established benefits of IG on morbidity and mortality; (3) dosage, routes of administration, and management of reactions; (4) the various IG formulations available; (5) vaccination of these patients; and (6) research priorities.


Assuntos
Medicina Baseada em Evidências , Imunoglobulinas Intravenosas/uso terapêutico , Síndromes de Imunodeficiência/tratamento farmacológico , Fatores Imunológicos/uso terapêutico , Guias de Prática Clínica como Assunto , Canadá , Humanos , Síndromes de Imunodeficiência/mortalidade
18.
Nature ; 462(7269): 94-8, 2009 Nov 05.
Artigo em Inglês | MEDLINE | ID: mdl-19829296

RESUMO

The tissues of the central nervous system are effectively shielded from the blood circulation by specialized vessels that are impermeable not only to cells, but also to most macromolecules circulating in the blood. Despite this seemingly absolute seclusion, central nervous system tissues are subject to immune surveillance and are vulnerable to autoimmune attacks. Using intravital two-photon imaging in a Lewis rat model of experimental autoimmune encephalomyelitis, here we present in real-time the interactive processes between effector T cells and cerebral structures from their first arrival to manifest autoimmune disease. We observed that incoming effector T cells successively scanned three planes. The T cells got arrested to leptomeningeal vessels and immediately monitored the luminal surface, crawling preferentially against the blood flow. After diapedesis, the cells continued their scan on the abluminal vascular surface and the underlying leptomeningeal (pial) membrane. There, the T cells encountered phagocytes that effectively present antigens, foreign as well as myelin proteins. These contacts stimulated the effector T cells to produce pro-inflammatory mediators, and provided a trigger to tissue invasion and the formation of inflammatory infiltrations.


Assuntos
Doenças do Sistema Nervoso Central/imunologia , Doenças do Sistema Nervoso Central/patologia , Encefalomielite Autoimune Experimental/imunologia , Encefalomielite Autoimune Experimental/patologia , Meninges/irrigação sanguínea , Meninges/imunologia , Linfócitos T/imunologia , Animais , Células Apresentadoras de Antígenos/imunologia , Antígenos/imunologia , Movimento Celular , Células Cultivadas , Meninges/patologia , Camundongos , Ovalbumina/imunologia , Fagócitos/imunologia , Ratos , Ratos Endogâmicos Lew
19.
Immunobiology ; 214(3): 211-22, 2009.
Artigo em Inglês | MEDLINE | ID: mdl-19215803

RESUMO

Pseudomonas aeruginosa is a common cause of lung infection in immune compromised individuals. Studies in humans and mice have demonstrated that P. aeruginosa lung infection is associated with a predominant Th2 immune response, whereas Th1 responses are accompanied by a better pulmonary outcome. Regulatory T cells (Tregs) are a subpopulation of T cells with unique immunologic characteristics that suppress effector T cell functions. Whether Tregs contribute to P. aeruginosa-induced host responses has not been studied previously. We found that P. aeruginosa lung infection induced an increase in natural Treg cells (CD4+CD25+FOXP3+ T cells) in the spleen of mice. To investigate a role of natural CD4+CD25+ Tregs in the host response to P. aeruginosa lung infection in vivo, anti-CD25 Ab was used to deplete endogenous CD4+CD25+ Tregs. Anti-CD25 treatment depleted 90% of CD4+CD25+FOXP3+ cells. Surprisingly, no differences of P. aeruginosa-induced NF-kappaB activation and cytokine/chemokine production (IL-1beta, TNF, IL-6, IL-10, RANTES or MIP-2) were observed between anti-CD25-treated and isotype control Ab-treated animals. Similarly, no differences in lung histology and airway neutrophil infiltration were observed between anti-CD25 and control Ab-treated animals. Furthermore, no difference in survival outcome was found between anti-CD25 and control Ab-treated animals. These data demonstrate that although P. aeruginosa lung infection causes an increase of Tregs, the endogenous natural CD4+CD25+ Treg cells do not contribute significantly to the host response to this bacterium.


Assuntos
Subunidade alfa de Receptor de Interleucina-2/imunologia , Infecções por Pseudomonas/imunologia , Pseudomonas aeruginosa/imunologia , Linfócitos T Reguladores/imunologia , Linfócitos T Reguladores/metabolismo , Animais , Anticorpos Monoclonais/administração & dosagem , Citocinas/metabolismo , Fatores de Transcrição Forkhead/imunologia , Fatores de Transcrição Forkhead/metabolismo , Pulmão/microbiologia , Pulmão/patologia , Depleção Linfocítica , Masculino , Camundongos , Camundongos Endogâmicos C57BL , NF-kappa B/metabolismo , Ativação de Neutrófilo , Neutrófilos/patologia , Infecções por Pseudomonas/mortalidade , Infecções por Pseudomonas/patologia , Infecções por Pseudomonas/fisiopatologia , Pseudomonas aeruginosa/patogenicidade , Transdução de Sinais , Linfócitos T Reguladores/patologia
20.
Blood ; 111(12): 5467-76, 2008 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-18424663

RESUMO

Human mast cells are found in skin and mucosal surfaces and next to blood vessels. They play a sentinel cell role in immunity, recognizing invading pathogens and producing proinflammatory mediators. Mast cells can recruit granulocytes, and monocytes in allergic disease and bacterial infection, but their ability to recruit antiviral effector cells such as natural killer (NK) cells and T cells has not been fully elucidated. To investigate the role of human mast cells in response to virus-associated stimuli, human cord blood-derived mast cells (CBMCs) were stimulated with polyinosinic.polycytidylic acid, a double-stranded RNA analog, or infected with the double-stranded RNA virus, reovirus serotype 3 Dearing for 24 hours. CBMCs responded to stimulation with polyinosinic.polycytidylic acid by producing a distinct chemokine profile, including CCL4, CXCL8, and CXCL10. CBMCs produced significant amounts of CXCL8 in response to low levels of reovirus infection, while both skin- and lung-derived fibroblasts were unresponsive unless higher doses of reovirus were used. Supernatants from CBMCs infected with reovirus induced substantial NK cell chemotaxis that was highly dependent on CXCL8 and CXCR1. These results suggest a novel role for mast cells in the recruitment of human NK cells to sites of early viral infection via CXCL8.


Assuntos
Quimiotaxia de Leucócito/imunologia , Interleucina-8/imunologia , Células Matadoras Naturais/citologia , Orthoreovirus Mamífero 3 , Mastócitos/virologia , Infecções por Reoviridae/imunologia , Antivirais/farmacologia , Antígeno CD56/metabolismo , Comunicação Celular/imunologia , Células Cultivadas , Meios de Cultivo Condicionados , Fibroblastos/citologia , Humanos , Interleucina-8/metabolismo , Queratinócitos/citologia , Células Matadoras Naturais/imunologia , Células Matadoras Naturais/metabolismo , Mastócitos/citologia , Mastócitos/imunologia , Poli I-C/farmacologia , Receptores CXCR3/metabolismo , Subpopulações de Linfócitos T/citologia , Subpopulações de Linfócitos T/imunologia , Subpopulações de Linfócitos T/metabolismo
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