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1.
Int Immunol ; 34(5): 263-276, 2022 04 20.
Artículo en Inglés | MEDLINE | ID: mdl-35031803

RESUMEN

γδ T cells expressing Vγ5Vδ1 TCR originally develop in the embryonic thymus and migrate to the epidermis, forming dendritic epidermal T cells (DETCs) throughout life. It is thought that a TCR signal is essential for their development; e.g., lack of TCR signal-transducer ZAP70 significantly decreases DETC numbers. On the other hand, lack of ZAP70 does not affect Vγ5Vδ1+ T cells in the embryonic thymus; thus, the involvement of TCR signaling remains elusive. Here, we used SKG mice with attenuated TCR signaling rather than gene-knockout mice. In SKG mice, Vγ5+ T cells showed a marked decrease [10% of wild-type (WT)] in adult epidermis; however, there was just a moderate decrease (50% of WT) in the embryonic thymus. In early postnatal epidermis in SKG mice, substantial numbers of Vγ5+ T cells were observed (50% of WT). Their activation markers including CD122, a component of the IL-15 receptor indispensable for DETC proliferation, were comparable to those of WT. However, the Vγ5+ T cells in SKG mice did not proliferate and form DETCs thereafter. Furthermore, in SKG/+ mice, the number of thymic Vγ5Vδ1+ T cells increased, compared to SKG mice; however, the number of DETCs remained significantly lower than in WT, similar to SKG mice. Our results suggest that signaling via Vγ5Vδ1 TCR is indispensable for DETC development, with distinct contributions to embryonic development and postnatal proliferation.


Asunto(s)
Células Epidérmicas , Linfocitos T , Animales , Epidermis , Ratones , Ratones Endogámicos C57BL , Receptores de Antígenos de Linfocitos T , Receptores de Antígenos de Linfocitos T gamma-delta , Transducción de Señal , Linfocitos T/fisiología
2.
J Immunol ; 204(4): 844-857, 2020 02 15.
Artículo en Inglés | MEDLINE | ID: mdl-31924648

RESUMEN

T cell development and homeostasis requires IL-7R α-chain (IL-7Rα) signaling. Tyrosine Y449 of the IL-7Rα is essential to activate STAT5 and PI3K, whereas PI3K recruitment requires IL-7Rα methionine M452. How IL-7Rα activates and regulates both signaling pathways differentially remains unclear. To characterize differential signaling, we established two lines of IL-7Rα mutant mice: IL-7R-Y449F mice and IL-7R-M452L mice. IL-7R-Y449F mice showed decreased PI3K and STAT5 signals, whereas IL-7R-M452L mice showed decreased PI3K but significantly increased STAT5 signaling, owing to a competition between PI3K and STAT5 signaling through Y449 of IL-7Rα. The number of T, B, and mature innate lymphoid cells were markedly reduced in IL-7R-Y449F mice, whereas IL-7R-M452L mice showed impaired early T cell development and memory precursor effector T cell maintenance with the downregulation of transcription factor T cell factor-1. Peripheral T cell numbers increased in IL-7R-M452L mice with enhanced survival and homeostatic proliferation. Furthermore, although wild type and IL-7R-Y449F mice showed comparable Th1/Th2 differentiation, IL-7R-M452L mice exhibited impaired Th17 differentiation. We conclude that PI3K competes with STAT5 under IL-7Rα and maintains an appropriate signal balance for modulating T cell development and homeostasis. To our knowledge, this study provides a new insight into complex regulation of IL-7Rα signaling, which supports immune development and responses.


Asunto(s)
Homeostasis/inmunología , Fosfatidilinositol 3-Quinasas/inmunología , Receptores de Interleucina-7/inmunología , Factor de Transcripción STAT5/inmunología , Linfocitos T/inmunología , Animales , Diferenciación Celular/inmunología , Inmunidad Innata , Ratones , Ratones Endogámicos C57BL , Ratones Mutantes , Fosfatidilinositol 3-Quinasas/metabolismo , Receptores de Interleucina-7/metabolismo , Factor de Transcripción STAT5/metabolismo , Transducción de Señal/inmunología
3.
J Biol Chem ; 292(48): 19721-19732, 2017 12 01.
Artículo en Inglés | MEDLINE | ID: mdl-29038291

RESUMEN

Oncogenic signaling in cancer cells alters glucose uptake and utilization to supply sufficient energy and biosynthetic intermediates for survival and sustained proliferation. Oncogenic signaling also prevents oxidative stress and cell death caused by increased production of reactive oxygen species. However, elevated glucose metabolism in cancer cells, especially in glioblastoma, results in the cells becoming sensitive to glucose deprivation (i.e. in high glucose dependence), which rapidly induces cell death. However, the precise mechanism of this type of cell death remains unknown. Here, we report that glucose deprivation alone does not trigger glioblastoma cell death. We found that, for cell death to occur in glucose-deprived glioblastoma cells, cystine and glutamine also need to be present in culture media. We observed that cystine uptake through the cystine/glutamate antiporter xCT under glucose deprivation rapidly induces NADPH depletion, reactive oxygen species accumulation, and cell death. We conclude that although cystine uptake is crucial for production of antioxidant glutathione in cancer cells its transport through xCT also induces oxidative stress and cell death in glucose-deprived glioblastoma cells. Combining inhibitors targeting cancer-specific glucose metabolism with cystine and glutamine treatment may offer a therapeutic approach for glioblastoma tumors exhibiting high xCT expression.


Asunto(s)
Sistemas de Transporte de Aminoácidos Acídicos/metabolismo , Neoplasias Encefálicas/patología , Muerte Celular , Cistina/metabolismo , Glioblastoma/patología , Glucosa/metabolismo , Animales , Neoplasias Encefálicas/metabolismo , Línea Celular Tumoral , Glioblastoma/metabolismo , NADP/metabolismo , Ratas , Especies Reactivas de Oxígeno/metabolismo
4.
Eur J Immunol ; 47(4): 704-712, 2017 04.
Artículo en Inglés | MEDLINE | ID: mdl-28127756

RESUMEN

Dendritic cell immunoreceptor (DCIR) is a C-type lectin with an immunoreceptor tyrosine-based inhibitory motif (ITIM). Mice lacking DCIR1 (Dcir1-/- mice) show higher susceptibility to chronic arthritis with increasing age, suggesting that DCIR1 is involved in immune modulation via its ITIM. However, the role of DCIR1 in acute immune responses is not clear. In this study, we explored its role in acute experimental hepatitis. Upon injection of d-galactosamine and lipopolysaccharide, Dcir1-/- mice showed decreased mortality rates and serum levels of alanine aminotransferase. In early onset hepatitis, serum levels of TNF-α, which primarily cause inflammation and hepatocyte apoptosis, were significantly lower in Dcir1-/- mice than in WT mice. In the liver of Dcir1-/- mice, influx of neutrophils and other leukocytes decreased. Consistently, the levels of neutrophil-chemoattractant chemokine CXCL1/KC, but not CXCL2/MIP-2, were lower in Dcir1-/- mice than in WT mice. However, chemotaxis of Dcir1-/- neutrophils to CXCL1/KC appeared normal. Pervanadate treatment induced binding of DCIR1 and Src homology region 2 domain-containing phosphatase (SHP)-2, possibly leading to CXCL1/KC expression. These results suggest that DCIR1 is involved in exacerbation of endotoxemic hepatitis, providing a new therapeutic target for lethal hepatitis.


Asunto(s)
Enfermedad Hepática Inducida por Sustancias y Drogas/inmunología , Células Dendríticas/fisiología , Endotoxemia/inmunología , Lectinas Tipo C/metabolismo , Neutrófilos/inmunología , Animales , Movimiento Celular/genética , Células Cultivadas , Enfermedad Hepática Inducida por Sustancias y Drogas/tratamiento farmacológico , Quimiocina CXCL1/metabolismo , Quimiocina CXCL2/metabolismo , Endotoxemia/tratamiento farmacológico , Galactosamina/administración & dosificación , Humanos , Lectinas Tipo C/genética , Lipopolisacáridos/administración & dosificación , Ratones , Ratones Endogámicos C57BL , Ratones Noqueados , Terapia Molecular Dirigida , Vanadatos/farmacología
5.
BMC Immunol ; 16: 64, 2015 Oct 23.
Artículo en Inglés | MEDLINE | ID: mdl-26497661

RESUMEN

BACKGROUND: Ulcerative colitis, an inflammatory bowel disease, is associated with the massive infiltration of neutrophils. Although the initial infiltration of neutrophils is beneficial for killing bacteria, it is presumed that persistent infiltration causes tissue damage by releasing antibacterial products as well as inflammatory cytokines. A murine C-type lectin receptor, dendritic cell immunoreceptor 1 (Dcir1), is expressed on CD11b(+) myeloid cells, such as macrophages, dendritic cells and neutrophils. It was reported that Dcir1 is required to maintain homeostasis of the immune system to prevent autoimmunity, but it is also involved in the development of infectious disease resulting in the enhanced severity of cerebral malaria. However, the role of Dcir1 in intestinal immune responses during colitis remains unclear. In this study, we investigated the role of Dcir1 in intestinal inflammation using an experimental colitis model induced with dextran sodium sulfate (DSS). RESULTS: In contrast to wild type (WT) mice, Dcir1 (-/-) mice exhibited mild body weight loss during the course of DSS colitis accompanied by reduced colonic inflammation. Dcir1 deficiency caused a reduced accumulation of neutrophils in the inflamed colon on day 5 of DSS colitis compared with WT mice. Consistently, the production of a neutrophil-attracting chemokine, MIP-2, was also decreased in the Dcir1 (-/-) colon compared with the WT colon on day 5. There were fewer myeloperoxidase-positive neutrophils in the inflamed colon of Dcir1 (-/-) mice than in that of WT mice. Moreover, bone marrow neutrophils from Dcir1 (-/-) mice produced less reactive oxygen species (ROS) by lipopolysaccharide stimulation than those from WT mice. This suggests that Dcir1 deficiency decreases the accumulation of tissue destructive neutrophils during DSS colitis. CONCLUSION: Dcir1 enhances the pathogenesis of DSS colitis by altering neutrophil recruitment and their functions.


Asunto(s)
Colitis/etiología , Colitis/metabolismo , Lectinas Tipo C/genética , Lectinas Tipo C/metabolismo , Neutrófilos/inmunología , Neutrófilos/metabolismo , Animales , Quimiocina CXCL2/biosíntesis , Colitis/patología , Citocinas/metabolismo , Sulfato de Dextran/efectos adversos , Modelos Animales de Enfermedad , Recuento de Leucocitos , Lipopolisacáridos/inmunología , Ratones , Ratones Noqueados , Infiltración Neutrófila/genética , Infiltración Neutrófila/inmunología , Peroxidasa/metabolismo , Especies Reactivas de Oxígeno/metabolismo , Estallido Respiratorio/genética , Estallido Respiratorio/inmunología
6.
Biochem Biophys Res Commun ; 458(3): 561-567, 2015 Mar 13.
Artículo en Inglés | MEDLINE | ID: mdl-25680460

RESUMEN

Amyloid ß (Aß) peptide, a causative agent of Alzheimer's disease, forms two types of aggregates: oligomers and fibrils. These aggregates induce inflammatory responses, such as interleukin-1ß (IL-1ß) production by microglia, which are macrophage-like cells located in the brain. In this study, we examined the effect of the two forms of Aß aggregates on IL-1ß production in mouse primary microglia. We prepared Aß oligomer and fibril from Aß (1-42) peptide in vitro. We analyzed the characteristics of these oligomers and fibrils by electrophoresis and atomic force microscopy. Interestingly, Aß oligomers but not Aß monomers or fibrils induced robust IL-1ß production in the presence of lipopolysaccharide. Moreover, Aß oligomers induced endo/phagolysosome rupture, which released cathepsin B into the cytoplasm. Aß oligomer-induced IL-1ß production was inhibited not only by the cathepsin B inhibitor CA-074-Me but also by the reactive oxygen species (ROS) inhibitor N-acetylcysteine. Random chemical crosslinking abolished the ability of the oligomers to induce IL-1ß. Thus, multimerization and fibrillization causes Aß oligomers to lose the ability to induce IL-1ß. These results indicate that Aß oligomers, but not fibrils, induce IL-1ß production in primary microglia in a cathepsin B- and ROS-dependent manner.


Asunto(s)
Péptidos beta-Amiloides/inmunología , Catepsina B/inmunología , Interleucina-1beta/inmunología , Microglía/inmunología , Fragmentos de Péptidos/inmunología , Especies Reactivas de Oxígeno/inmunología , Acetilcisteína/farmacología , Péptidos beta-Amiloides/química , Péptidos beta-Amiloides/ultraestructura , Animales , Catepsina B/antagonistas & inhibidores , Reactivos de Enlaces Cruzados/química , Dipéptidos/farmacología , Ratones , Ratones Endogámicos BALB C , Microglía/efectos de los fármacos , Fragmentos de Péptidos/química , Fragmentos de Péptidos/ultraestructura
7.
Commun Biol ; 7(1): 782, 2024 Jun 29.
Artículo en Inglés | MEDLINE | ID: mdl-38951147

RESUMEN

Acute immune responses with excess production of cytokines, lipid/chemical mediators, or coagulation factors, often result in lethal damage. In addition, the innate immune system utilizes multiple types of receptors that recognize neurotransmitters as well as pathogen-associated molecular patterns, making immune responses complex and clinically unpredictable. We here report an innate immune and adrenergic link inducing lethal levels of platelet-activating factor. Injecting mice with toll-like receptor (TLR) 4 ligand lipopolysaccharide (LPS), cell wall N-glycans of Candida albicans, and the α2-adrenergic receptor (α2-AR) agonist medetomidine induces lethal damage. Knocking out the C-type lectin Dectin-2 prevents the lethal damage. In spleen, large amounts of platelet-activating factor (PAF) are detected, and knocking out lysophospholipid acyltransferase 9 (LPLAT9/LPCAT2), which encodes an enzyme that converts inactive lyso-PAF to active PAF, protects mice from the lethal damage. These results reveal a linkage/crosstalk between the nervous and the immune system, possibly inducing lethal levels of PAF.


Asunto(s)
Factor de Activación Plaquetaria , Animales , Factor de Activación Plaquetaria/metabolismo , Ratones , Ratones Noqueados , Ratones Endogámicos C57BL , Lipopolisacáridos , Candida albicans , Inmunidad Innata , Masculino , 1-Acilglicerofosfocolina O-Aciltransferasa/metabolismo , 1-Acilglicerofosfocolina O-Aciltransferasa/genética , Receptor Toll-Like 4/metabolismo , Receptor Toll-Like 4/genética , Agonistas de Receptores Adrenérgicos alfa 2/farmacología
8.
Int Immunol ; 24(2): 89-96, 2012 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-22207132

RESUMEN

SIGNR1, a mouse C-type lectin, binds various pathogens, including Candida albicans. In this study, we explore the impact of SIGNR1 in the recognition of C. albicans/zymosan and the subsequent tumor necrosis factor (TNF)-α production using SIGNR1-transfected RAW264.7 (RAW-SIGNR1) cells and resident peritoneal macrophages. Compared with RAW-control cells, RAW-SIGNR1 cells dramatically enhanced TNF-α production upon the stimulation with heat-killed C. albicans and zymosan. Recognition of microbes via carbohydrate recognition domain (CRD) of SIGNR1 was crucial for the enhanced TNF-α production. Consistently, such an enhancement was significantly decreased by anti-SIGNR1 mAb. Laminarin, antagonistic Dectin-1 ligand, cooperated to further diminish the response, although no effect was observed by itself in RAW-SIGNR1 cells. However, it moderately reduced the response of RAW-control cells. Zymosan depleted of toll-like receptor (TLR) ligands decreased the response, even though it was recognized by SIGNR1 and Dectin-1. Moreover, antagonistic anti-TLR2 abolished the response, suggesting that TNF-α production largely relies on TLR2-mediated signaling. Resident peritoneal macrophages expressing SIGNR1 predominantly captured zymosan injected intra-peritoneally and produced TNF-α, which was dependent on TLR2 and partly inhibited by anti-SIGNR1 mAb. Finally, physical association of SIGNR1 with the extracellular portion of TLR2 through CRD was confirmed by immunoprecipitation using various deletion mutants. These results suggest that SIGNR1 recognizing microbes participates in the enhanced TNF-α production by Mϕ in cooperation with TLR2.


Asunto(s)
Candida albicans/inmunología , Moléculas de Adhesión Celular/metabolismo , Lectinas Tipo C/metabolismo , Macrófagos Peritoneales/metabolismo , Receptores de Superficie Celular/metabolismo , Receptor Toll-Like 2/metabolismo , Factor de Necrosis Tumoral alfa/metabolismo , Animales , Anticuerpos Monoclonales/farmacología , Antígenos Bacterianos/inmunología , Moléculas de Adhesión Celular/genética , Moléculas de Adhesión Celular/inmunología , Línea Celular , Interacciones Huésped-Patógeno/efectos de los fármacos , Lectinas Tipo C/genética , Lectinas Tipo C/inmunología , Macrófagos Peritoneales/efectos de los fármacos , Macrófagos Peritoneales/inmunología , Macrófagos Peritoneales/patología , Ratones , Ratones Endogámicos BALB C , Ratones Noqueados , Receptores de Superficie Celular/genética , Receptores de Superficie Celular/inmunología , Transducción de Señal/inmunología , Receptor Toll-Like 2/genética , Receptor Toll-Like 2/inmunología , Transgenes/genética , Factor de Necrosis Tumoral alfa/genética , Factor de Necrosis Tumoral alfa/inmunología , Regulación hacia Arriba/efectos de los fármacos , Zimosan/administración & dosificación , Zimosan/inmunología
9.
Int Immunol ; 24(9): 573-81, 2012 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-22773153

RESUMEN

Interferon regulatory factor (IRF)-2 is a transcription factor involved in type I (IFN- α/ß) signaling. It has been reported that IRF-2 deficiency results in various immune dysfunctions. However, the role of IRF-2 in B-cell functions needs to be elucidated. Unlike wild-type (WT) B cells, IRF-2(-/-) B2 cells were refractory to anti-IgM, but not LPS. Such a defect in proliferation was dependent on IFN- α/ß receptor (IFNAR). Marginal zone B cells increased in the proportion relative to B2 cells in IRF-2(-/-) mice produced IgM normally to LPS stimulation. However, IRF-2(-/-) B2 cells were defective in IgM production in an IFNAR-independent manner, although both B-cell subsets differentiated phenotypically to plasma cells at elevated efficiencies. Class switch recombination of IRF-2(-/-) B2 cells by LPS plus IL-4 was also impaired. Their reduced IgM production was conceivably due to an inefficient up-regulation of Blimp-1. Consistent with these in vitro observations, specific antibody production in vivo to a T-dependent antigen by B2 cells was severely impaired in IRF-2(-/- )mice. However, a low, but significant, level of IgG was detected at a late time point, and this IgG exhibited comparable binding affinity to that in WT mice. Follicular helper T-cell development and germinal center formation were normal. A similar tendency was observed when µ chain(-/-) mice were reconstituted with IRF-2(-/- )B cells. These results revealed a multi-faceted role of IRF-2 in the function of B cells, particularly B2 cells, through regulating proliferation in an IFNAR-dependent manner and antibody production via up-regulation of Blimp-1.


Asunto(s)
Linfocitos B/inmunología , Factor 2 Regulador del Interferón/metabolismo , Células Plasmáticas/inmunología , Receptor de Interferón alfa y beta/metabolismo , Factores de Transcripción/metabolismo , Animales , Formación de Anticuerpos/genética , Linfocitos B/trasplante , Diferenciación Celular/genética , Proliferación Celular , Células Cultivadas , Regulación de la Expresión Génica , Cambio de Clase de Inmunoglobulina/genética , Cadenas mu de Inmunoglobulina/genética , Factor 2 Regulador del Interferón/genética , Lipopolisacáridos/inmunología , Ratones , Ratones Endogámicos C57BL , Ratones Noqueados , Células Plasmáticas/trasplante , Factor 1 de Unión al Dominio 1 de Regulación Positiva , Linfocitos T Colaboradores-Inductores/inmunología , Factores de Transcripción/genética
10.
Infect Immun ; 80(5): 1699-706, 2012 May.
Artículo en Inglés | MEDLINE | ID: mdl-22331432

RESUMEN

C-type lectin SIGNR1 directly recognizes Candida albicans and zymosan and has been considered to share properties of polysaccharide recognition with human DC-SIGN (hDC-SIGN). However, the precise specificity of SIGNR1 and the difference from that of hDC-SIGN remain to be elucidated. We prepared soluble forms of SIGNR1 and hDC-SIGN and conducted experiments to examine their respective specificities. Soluble SIGNR1 (sSIGNR1) bound several types of live C. albicans clinical isolate strains in an EDTA-sensitive manner. Inhibition analyses of sSIGNR1 binding by glycans from various yeast strains demonstrated that SIGNR1 preferentially recognizes N-glycan α-mannose side chains in Candida mannoproteins, as reported in hDC-SIGN. Unlike shDC-SIGN, however, sSIGNR1 recognized not only Saccharomyces cerevisiae, but also C. albicans J-1012 glycan, even after α-mannosidase treatment that leaves only ß1,2-mannose-capped α-mannose side chains. In addition, glycomicroarray analyses showed that sSIGNR1 binds mannans from C. albicans and S. cerevisiae but does not recognize Lewis(a/b/x/y) antigen polysaccharides as in shDC-SIGN. Consistent with these results, RAW264.7 cells expressing hDC-SIGN in which the carbohydrate recognition domain (CRD) was replaced with that of SIGNR1 (RAW-chimera) produced comparable amounts of interleukin 10 (IL-10) in response to glycans from C. albicans and S. cerevisiae, but those expressing hDC-SIGN produced less IL-10 in response to S. cerevisiae than C. albicans. Furthermore, RAW-hDC-SIGN cells remarkably reduced IL-10 production after α-mannosidase treatment compared with RAW-chimera cells. These results indicate that SIGNR1 recognizes C. albicans/yeast through a specificity partly distinct from that of its homologue hDC-SIGN.


Asunto(s)
Candida albicans/inmunología , Candida albicans/metabolismo , Moléculas de Adhesión Celular/metabolismo , Lectinas Tipo C/metabolismo , Polisacáridos/metabolismo , Receptores de Superficie Celular/metabolismo , Animales , Regulación de la Expresión Génica , Células HEK293 , Humanos , Interleucina-10/genética , Interleucina-10/metabolismo , Macrófagos , Ratones , Polisacáridos/química , Unión Proteica , Proteínas Recombinantes , Saccharomyces cerevisiae
11.
Eur J Immunol ; 41(5): 1435-44, 2011 May.
Artículo en Inglés | MEDLINE | ID: mdl-21400494

RESUMEN

We investigated the role of SIGNR1 in the recognition of Candida albicans and the subsequent cellular oxidative burst response. Soluble SIGNR1 (sSIGNR1) tetramer bound equally to zymosan and both heat-killed (HK) and live C. albicans in an EDTA-sensitive manner, whereas sDectin-1 tetramer predominantly bound to zymosan and HK-microbes in an EDTA-independent manner. In cellular response, enhanced oxidative burst was observed in RAW264.7 cells expressing SIGNR1 (RAW-SIGNR1) compared with RAW-control cells upon stimulation with HK-C. albicans and zymosan. This response was independent of TLR2 and the cytosolic portion of SIGNR1 but dependent on the recognition by SIGNR1 via carbohydrate recognition domain. Antagonistic laminarin and anti-Dectin-1 mAb cooperatively reduced the response with mannan and anti-SIGNR1 mAb, respectively, although they had no effect by themselves. Moreover, oxidative response and bactericidal activity largely relied on Syk-mediated signaling. RAW-SIGNR1 cells not only captured microbes more efficiently but also showed higher responses than RAW-control cells. Similar enhanced responses were observed in SIGNR-1-expressing resident peritoneal Mϕ. Interestingly, Dectin-1 was recruited to the phagosomal membrane upon the stimulation and physically associated with SIGNR1. These results suggest that SIGNR1 plays a significant role in inducing oxidative response to C. albicans by Syk-dependent signaling, possibly through Dectin-1.


Asunto(s)
Candida albicans/inmunología , Moléculas de Adhesión Celular/metabolismo , Lectinas Tipo C/metabolismo , Proteínas de la Membrana/metabolismo , Proteínas del Tejido Nervioso/metabolismo , Receptores de Superficie Celular/metabolismo , Estallido Respiratorio , Animales , Anticuerpos Monoclonales/inmunología , Candida albicans/metabolismo , Moléculas de Adhesión Celular/inmunología , Línea Celular , Línea Celular Tumoral , Ácido Edético , Femenino , Glucanos , Péptidos y Proteínas de Señalización Intracelular/metabolismo , Lectinas Tipo C/inmunología , Macrófagos/inmunología , Macrófagos Peritoneales/inmunología , Mananos , Proteínas de la Membrana/inmunología , Ratones , Ratones Endogámicos BALB C , Proteínas del Tejido Nervioso/inmunología , Fagosomas , Reacción en Cadena de la Polimerasa , Polisacáridos/metabolismo , Proteínas Tirosina Quinasas/metabolismo , Receptores de Superficie Celular/inmunología , Transducción de Señal , Quinasa Syk , Receptor Toll-Like 2/inmunología , Zimosan/metabolismo
12.
Commun Biol ; 4(1): 342, 2021 03 16.
Artículo en Inglés | MEDLINE | ID: mdl-33727664

RESUMEN

Severe infection often causes a septic cytokine storm followed by immune exhaustion/paralysis. Not surprisingly, many pathogens are equipped with various anti-inflammatory mechanisms. Such mechanisms might be leveraged clinically to control septic cytokine storms. Here we show that N-glycan from pathogenic C. albicans ameliorates mouse sepsis through immunosuppressive cytokine IL-10. In a sepsis model using lipopolysaccharide (LPS), injection of the N-glycan upregulated serum IL-10, and suppressed pro-inflammatory IL-1ß, TNF-α and IFN-γ. The N-glycan also improved the survival of mice challenged by LPS. Analyses of structurally defined N-glycans from several yeast strains revealed that the mannose core is key to the upregulation of IL-10. Knocking out the C-type lectin Dectin-2 abrogated the N-glycan-mediated IL-10 augmentation. Furthermore, C. albicans N-glycan ameliorated immune exhaustion/immune paralysis after acute inflammation. Our results suggest a strategy where the immunosuppressive mechanism of one pathogen can be applied to attenuate a severe inflammation/cytokine storm caused by another pathogen.


Asunto(s)
Candida albicans/inmunología , Candidiasis/inmunología , Pared Celular/inmunología , Citocinas/inmunología , Glicoproteínas de Membrana/inmunología , Polisacáridos/inmunología , Sepsis/inmunología , Animales , Candida albicans/metabolismo , Candidiasis/metabolismo , Candidiasis/microbiología , Pared Celular/metabolismo , Células Cultivadas , Citocinas/metabolismo , Células Dendríticas/inmunología , Células Dendríticas/metabolismo , Modelos Animales de Enfermedad , Interacciones Huésped-Patógeno , Interferón gamma/inmunología , Interferón gamma/metabolismo , Interleucina-10/inmunología , Interleucina-10/metabolismo , Interleucina-1beta/inmunología , Interleucina-1beta/metabolismo , Lectinas Tipo C/genética , Lectinas Tipo C/metabolismo , Macrófagos/inmunología , Macrófagos/metabolismo , Glicoproteínas de Membrana/metabolismo , Ratones Endogámicos BALB C , Ratones Endogámicos C57BL , Ratones Noqueados , Polisacáridos/metabolismo , Sepsis/metabolismo , Sepsis/microbiología , Linfocitos T/inmunología , Linfocitos T/metabolismo , Factores de Tiempo , Factor de Necrosis Tumoral alfa/inmunología , Factor de Necrosis Tumoral alfa/metabolismo
13.
J Exp Med ; 195(10): 1289-302, 2002 May 20.
Artículo en Inglés | MEDLINE | ID: mdl-12021309

RESUMEN

Dendritic cells (DCs) are able in tissue culture to phagocytose and present antigens derived from infected, malignant, and allogeneic cells. Here we show directly that DCs in situ take up these types of cells after fluorescent labeling with carboxyfluorescein succinimidyl ester (CFSE) and injection into mice. The injected cells include syngeneic splenocytes and tumor cell lines, induced to undergo apoptosis ex vivo by exposure to osmotic shock, and allogeneic B cells killed by NK cells in situ. The CFSE-labeled cells in each case are actively endocytosed by DCs in vivo, but only the CD8+ subset. After uptake, all of the phagocytic CD8+ DCs can form major histocompatibility complex class II-peptide complexes, as detected with a monoclonal antibody specific for these complexes. The CD8+ DCs also selectively present cell-associated antigens to both CD4+ and CD8+ T cells. Similar events take place with cultured DCs; CD8+ DCs again selectively take up and present dying cells. In contrast, both CD8+ and CD8- DCs phagocytose latex particles in culture, and both DC subsets present soluble ovalbumin captured in vivo. Therefore CD8+ DCs are specialized to capture dying cells, and this helps to explain their selective ability to cross present cellular antigens to both CD4+ and CD8+ T cells.


Asunto(s)
Antígenos CD8/metabolismo , Células Dendríticas/citología , Células Dendríticas/metabolismo , Fagocitosis , Animales , Apoptosis , Linfocitos B/citología , Linfocitos B/metabolismo , Muerte Celular , Células Dendríticas/inmunología , Citometría de Flujo , Células Asesinas Naturales/inmunología , Hígado/citología , Ganglios Linfáticos/citología , Ratones , Presión Osmótica , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Bazo/citología , Factores de Tiempo , Células Tumorales Cultivadas
14.
Cell Microbiol ; 10(8): 1608-21, 2008 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-18373632

RESUMEN

Mycobacterium abscessus (Mab) is an emerging and rapidly growing non-tuberculous mycobacterium (NTM). Compared with M. tuberculosis, which is responsible for tuberculosis, much less is known about NTM-induced innate immune mechanisms. Here we investigated the involvement of pattern-recognition receptors and associated signalling in Mab-mediated innate immune responses. Mab activated the extracellular signal-regulated kinase (ERK)1/2 and p38 mitogen-activated protein kinases (MAPKs), and induced the secretion of tumour necrosis factor-alpha, interleukin (IL)-6 and IL-12p40 in murine macrophages via Toll-like receptor (TLR) 2. Notably, the activation of ERK1/2, but not p38, was crucial for Mab-induced pro-inflammatory cytokine production. The ITAM-like motif of dectin-1 critically contributed to Mab internalization and cytokine secretion by macrophages. In addition, dectin-1, in cooperation with TLR2, was required for the efficient phagocytosis of Mab, ERK1/2 activation and pro-inflammatory cytokine secretion. Co-immunoprecipitation and confocal analysis showed the physical interaction and colocalization of dectin-1 with TLR2 following Mab stimulation. Moreover, dectin-1-induced Syk activation was essential for the production of inflammatory cytokines and the release of reactive oxygen species by Mab-infected macrophages. Collectively, these data demonstrate that Mab actively internalizes into and robustly activates innate immune responses in macrophages through a physical and functional interaction between TLR2 and dectin-1.


Asunto(s)
Inmunidad Innata , Macrófagos/inmunología , Proteínas de la Membrana/inmunología , Infecciones por Mycobacterium/inmunología , Mycobacterium/inmunología , Proteínas del Tejido Nervioso/inmunología , Receptor Toll-Like 2/inmunología , Animales , Citocinas/inmunología , Péptidos y Proteínas de Señalización Intracelular/metabolismo , Lectinas Tipo C , Activación de Macrófagos , Ratones , Proteínas Quinasas Activadas por Mitógenos/metabolismo , Infecciones por Mycobacterium/microbiología , Fagocitosis , Proteínas Tirosina Quinasas/metabolismo , Especies Reactivas de Oxígeno/metabolismo , Quinasa Syk
15.
Immunol Lett ; 168(2): 300-5, 2015 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-26481266

RESUMEN

Conventional dendritic cells (cDCs) present α-galactosylceramide (αGC) to invariant natural killer T (iNKT) cells through CD1d. Among cDC subsets, CD8(+) DCs efficiently induce IFN-γ production in iNKT cells. Using fluorescence-labeled αGC, we showed that CD8(+) DCs incorporated larger amounts of αGC and kept it intact longer than CD8(-) DCs. Histological analyses revealed that Langerin(+)CD8(+) DCs in the splenic marginal zone, which was the unique equipment to capture blood-borne antigens, preferably incorporated αGC, and the depletion of Langerin(+) cells decreased IFN-γ and IL-12 production in response to αGC. Furthermore, splenic Langerin(+)CD8(+) DCs expressed more membrane-bound CXCL16, which possibly anchored iNKT cells in the marginal zone, than CD8(-) DCs. Collectively, it is suggested that the cellular properties and localization of CD8(+) DCs are important for stimulation of iNKT cells by αGC.


Asunto(s)
Células Dendríticas/inmunología , Fluorescencia , Galactosilceramidas/inmunología , Animales , Antígenos de Superficie/inmunología , Antígenos de Superficie/metabolismo , Antígenos CD8/inmunología , Antígenos CD8/metabolismo , Carbocianinas/química , Quimiocina CXCL16 , Quimiocina CXCL6/inmunología , Quimiocina CXCL6/metabolismo , Técnicas de Cocultivo , Células Dendríticas/citología , Células Dendríticas/metabolismo , Citometría de Flujo , Colorantes Fluorescentes/química , Galactosilceramidas/metabolismo , Galactosilceramidas/farmacocinética , Interferón gamma/inmunología , Interferón gamma/metabolismo , Interleucina-12/inmunología , Interleucina-12/metabolismo , Lectinas Tipo C/inmunología , Lectinas Tipo C/metabolismo , Lectinas de Unión a Manosa/inmunología , Lectinas de Unión a Manosa/metabolismo , Ratones Endogámicos BALB C , Ratones Endogámicos C57BL , Ratones Noqueados , Microscopía Fluorescente , Células T Asesinas Naturales/citología , Células T Asesinas Naturales/inmunología , Células T Asesinas Naturales/metabolismo , Bazo/citología , Bazo/inmunología , Bazo/metabolismo
16.
Cancer Genet Cytogenet ; 137(2): 133-7, 2002 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-12393284

RESUMEN

Uterine leiomyomata (UL) are benign tumors affecting many women of reproductive age. Cytogenetic studies have indicated that a significant percentage of leiomyomata have chromosomal rearrangements, including those involving the long arm of chromosome 7. Several candidate genes that map to chromosome 7 have been studied for possible roles in the pathogenesis of these tumors. PCOLCE, a gene whose product is involved in the cleavage of type I procollagen C-propeptide, has been mapped to the critical interval on chromosome 7, band q22. Here we evaluate by reverse-transcriptase polymerase chain reaction (RT-PCR) and fluorescence in situ hybridization the expression and deletion status of PCOLCE in a series of karyotyped uterine leiomyomata.


Asunto(s)
Regulación Neoplásica de la Expresión Génica , Glicoproteínas/genética , Leiomioma/genética , Neoplasias Uterinas/genética , Proteínas de la Matriz Extracelular , Femenino , Eliminación de Gen , Perfilación de la Expresión Génica , Humanos , Hibridación Fluorescente in Situ , ARN Mensajero/genética , ARN Mensajero/metabolismo , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa
17.
PLoS One ; 8(7): e68499, 2013.
Artículo en Inglés | MEDLINE | ID: mdl-23874646

RESUMEN

Macrophages (Mϕ) are well documented to produce IL-1ß through various signaling pathways in response to small particles such as silica, asbestos and urea crystals, in the presence of lipopolysaccharide (LPS). However, it has not been clear to what extent particle size affects the response. To investigate this point, we stimulated bone marrow-derived macrophages (BMDM) with size-defined latex beads (LxB). Although both nano-sized (20 nm) and micro-sized (1,000 nm) LxB induced IL-1ß production, only the nano-sized particles formed large intracellular vacuoles. In contrast, 100 nm LxB did not induce either of the responses. The same cellular responses were also observed in primary microglia cells. Although K(+) efflux and NLRP3 activation in BMDM were crucial in response to both 20 and 1,000 nm LxB, only IL-1ß production by 20 nm LxB was sensitive to cathepsin B and P2X7, a receptor for ATP. The response by 1,000 nm LxB relied on a robust production of reactive oxygen species (ROS), since IL-1ß production was remarkably reduced by ROS inhibitors such as diphenylene iodonium (DPI) and N-acetylcysteine (NAC). In contrast, IL-1ß production by 20 nm LxB was augmented by NAC and in BMDM deficient in thioredoxin-binding protein-2 (TBP-2), a negative regulator of the ROS scavenger thioredoxin. These results suggest that the cells responded differently in their secretion of IL-1ß depending on particle size, and that there is a range within which neither pathway works.


Asunto(s)
Interleucina-1beta/biosíntesis , Macrófagos/inmunología , Macrófagos/metabolismo , Microesferas , Tamaño de la Partícula , Acetilcisteína , Adenosina Trifosfato/metabolismo , Animales , Catepsina B/metabolismo , Lipopolisacáridos , Macrófagos/citología , Ratones , Fagosomas/metabolismo , Especies Reactivas de Oxígeno/metabolismo , Receptores Purinérgicos P2X7/metabolismo , Transducción de Señal
18.
J Leukoc Biol ; 88(5): 913-24, 2010 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-20724666

RESUMEN

The C-type lectin SIGNR3 is a mouse homologue of human DC-SIGN, which shares carbohydrate-binding specificity with human DC-SIGN. However, the expression profile of SIGNR3 is largely unknown. To examine the expression of SIGNR3 in immune cells, we generated SIGNR3-specific mAb and investigated SIGNR3 expression in vivo. SIGNR3 was expressed on a fraction of MHC II(+) DCs and Mϕs in the dermis and CD115(+)Ly6C(int-low) monocytes in the blood and BM. In the LNs, SIGNR3(+) cells localized adjacent to PNAd(+) HEV-like vessels. They were also found in interfollicular regions in sLNs but not mLNs. Those SIGNR3(+) cells expressed CD11b and variable levels of CD11c and MHC II. As in LNs, SIGNR3 was expressed on a large proportion of the CD11b(+)CD11c(int-high) cells in the spleen. In the lung, SIGNR3(+) cells belonged to the CD11b(+)CD11c(int) population, and Mϕs in the airway and lung faintly expressed SIGNR3. When PKH67-labeled CD115(+)Ly6C(high) BM monocytes were transferred into normal recipients, they up-regulated SIGNR3 expression along with the decrease in Ly6C expression during the circulation and upon arrival at the peripheral LNs through HEV. In addition, CD11b(high)Ly6C(high) monocytes that entered sLNs differentiated into CD11b(+) DCs in a couple of days, whereas those in the spleen, mLNs, and lung differentiated into CD11c(int) monocytic cells. These results suggest that SIGNR3 is a new differentiation marker for myeloid mononuclear cells and indicate that some DCs, especially in the sLNs, are possibly replenished by Ly6C(high) monocytes.


Asunto(s)
Antígenos CD/genética , Células Dendríticas/inmunología , Lectinas Tipo C/genética , Macrófagos/inmunología , Monocitos/inmunología , Animales , Cricetinae , Cricetulus , Células Dendríticas/patología , Citometría de Flujo , Vectores Genéticos , Humanos , Linfoma/genética , Linfoma/inmunología , Macrófagos/patología , Ratones , Ratones Endogámicos BALB C , Microscopía Fluorescente , Monocitos/patología , Mieloma Múltiple/genética , Mieloma Múltiple/inmunología , Mieloma Múltiple/patología , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Bazo/inmunología , Bazo/patología
20.
Int Immunol ; 17(7): 827-36, 2005 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-15908446

RESUMEN

SIGNR1, a member of a new family of mouse C-type lectins, is expressed at high levels in macrophages (Mphi) within the splenic marginal zone, lymph node medulla, and in some strains, in peritoneal cavity. We previously reported that SIGNR1 captures gram-negative bacteria, such as Escherichia coli and Salmonella typhimurium, as well as Candida albicans. We have now investigated the precise ligands and innate responses that involve SIGNR1. The interaction of SIGNR1 with FITC-dextran and E. coli was completely inhibited by LPS from E. coli and Salmonella minnesota. Using LPS from various types of rough mutants of Salmonella, we found that SIGNR1 primarily recognizes oligosaccharides in the non-reductive end of the LPS core region. In transfectants, expression of SIGNR1 enhanced the oligomerization of Toll-like receptor (TLR) 4 molecules as well as the degradation of IkappaB-alpha after stimulation with E. coli under low-serum conditions. The enhanced TLR4 oligomerization was inhibited by pre-treatment of the cells with anti-SIGNR1 mAb or with mannan. A physical association between SIGNR1 and the TLR4-MD-2 complex was also observed by immunoprecipitation. Finally, we found that transfection of SIGNR1 into the macrophage-like RAW264.7 cells resulted in significant augmentation of cytokine production. These results suggest that SIGNR1 associates with TLR4 to capture gram-negative bacteria and facilitate signal transduction to activate innate M responses.


Asunto(s)
Moléculas de Adhesión Celular/inmunología , Escherichia coli/inmunología , Lectinas Tipo C/inmunología , Lipopolisacáridos/inmunología , Macrófagos/inmunología , Glicoproteínas de Membrana/inmunología , Receptores de Superficie Celular/inmunología , Salmonella/inmunología , Transducción de Señal/inmunología , Animales , Línea Celular , Citocinas/biosíntesis , Femenino , Expresión Génica , Lectinas Tipo C/genética , Lipopolisacáridos/farmacología , Activación de Macrófagos/efectos de los fármacos , Activación de Macrófagos/inmunología , Ratones , Ratones Endogámicos BALB C , Transducción de Señal/efectos de los fármacos , Receptor Toll-Like 4/inmunología
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