Your browser doesn't support javascript.
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 2.069
Filtrar
1.
Pol J Microbiol ; 68(4): 439-447, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31880888

RESUMO

Salmonella infection is most common in patients with infected aortic aneurysm, especially in Asia. When the aortic wall is heavily atherosclerotic, the intima is vulnerable to invasion by Salmonella, leading to the development of infected aortic aneurysm. By using THP-1 macrophage-derived foam cells to mimic atherosclerosis, we investigated the role of three Salmonella enterica serotypes - Typhimurium, Enteritidis, and Choleraesuis - in foam cell autophagy and inflammasome formation. Herein, we provide possible pathogenesis of Salmonella-associated infected aortic aneurysms. Three S. enterica serotypes with or without virulence plasmid were studied. Through Western blotting, we investigated cell autophagy induction and inflammasome formation in Salmonella-infected THP-1 macrophage-derived foam cells, detected CD36 expression after Salmonella infection through flow cytometry, and measured interleukin (IL)-1ß, IL-12, and interferon (IFN)-α levels through enzyme-linked immunosorbent assay. At 0.5 h after infection, plasmid-bearing S. Enteritidis OU7130 induced the highest foam cell autophagy - significantly higher than that induced by plasmid-less OU7067. However, plasmid-bearing S. Choleraesuis induced less foam cell autophagy than did its plasmid-less strain. In foam cells, plasmid-less Salmonella infection (particularly S. Choleraesuis OU7266 infection) led to higher CD36 expression than did plasmid-bearing strains infection. OU7130 and OU7266 infection induced the highest IL-1ß secretion. OU7067-infected foam cells secreted the highest IL-12p35 level. Plasmid-bearing S. Typhimurium OU5045 induced a higher IFN-α level than did other Salmonella serotypes. Salmonella serotypes are correlated with foam cell autophagy and IL-1ß secretion. Salmonella may affect the course of foam cells formation, or even aortic aneurysm, through autophagy.Salmonella infection is most common in patients with infected aortic aneurysm, especially in Asia. When the aortic wall is heavily atherosclerotic, the intima is vulnerable to invasion by Salmonella, leading to the development of infected aortic aneurysm. By using THP-1 macrophage-derived foam cells to mimic atherosclerosis, we investigated the role of three Salmonella enterica serotypes ­ Typhimurium, Enteritidis, and Choleraesuis ­ in foam cell autophagy and inflammasome formation. Herein, we provide possible pathogenesis of Salmonella-associated infected aortic aneurysms. Three S. enterica serotypes with or without virulence plasmid were studied. Through Western blotting, we investigated cell autophagy induction and inflammasome formation in Salmonella-infected THP-1 macrophage-derived foam cells, detected CD36 expression after Salmonella infection through flow cytometry, and measured interleukin (IL)-1ß, IL-12, and interferon (IFN)-α levels through enzyme-linked immunosorbent assay. At 0.5 h after infection, plasmid-bearing S. Enteritidis OU7130 induced the highest foam cell autophagy ­ significantly higher than that induced by plasmid-less OU7067. However, plasmid-bearing S. Choleraesuis induced less foam cell autophagy than did its plasmid-less strain. In foam cells, plasmid-less Salmonella infection (particularly S. Choleraesuis OU7266 infection) led to higher CD36 expression than did plasmid-bearing strains infection. OU7130 and OU7266 infection induced the highest IL-1ß secretion. OU7067-infected foam cells secreted the highest IL-12p35 level. Plasmid-bearing S. Typhimurium OU5045 induced a higher IFN-α level than did other Salmonella serotypes. Salmonella serotypes are correlated with foam cell autophagy and IL-1ß secretion. Salmonella may affect the course of foam cells formation, or even aortic aneurysm, through autophagy.


Assuntos
Aneurisma Aórtico/microbiologia , Infecções por Salmonella/microbiologia , Salmonella typhimurium/patogenicidade , Animais , Aneurisma Aórtico/genética , Aneurisma Aórtico/imunologia , Linhagem Celular , Humanos , Interferon-alfa/genética , Interferon-alfa/imunologia , Interleucina-12/genética , Interleucina-12/imunologia , Interleucina-1beta/genética , Interleucina-1beta/imunologia , Antígeno Ki-1/genética , Antígeno Ki-1/imunologia , Macrófagos/imunologia , Macrófagos/microbiologia , Monócitos/imunologia , Monócitos/microbiologia , Plasmídeos/genética , Plasmídeos/metabolismo , Infecções por Salmonella/genética , Infecções por Salmonella/imunologia , Salmonella typhimurium/genética , Salmonella typhimurium/fisiologia , Sorogrupo , Virulência
2.
PLoS One ; 14(12): e0226778, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31877174

RESUMO

Francisella tularensis, a category-A bioterrorism agent causes tularemia. F. tularensis suppresses the immune response of host cells and intracellularly proliferates. However, the detailed mechanisms of immune suppression and intracellular growth are largely unknown. Here we developed a transposon mutant library to identify novel pathogenic factors of F. tularensis. Among 750 transposon mutants of F. tularensis subsp. novicida (F. novicida), 11 were isolated as less cytotoxic strains, and the genes responsible for cytotoxicity were identified. Among them, the function of slt, which encodes soluble lytic transglycosylase (SLT) was investigated in detail. An slt deletion mutant (Δslt) was less toxic to the human monocyte cell line THP-1 vs the wild-type strain. Although the wild-type strain proliferated in THP-1 cells, the number of intracellular Δslt mutant decreased in comparison. The Δslt mutant escaped from phagosomes during the early stages of infection, but the mutant was detected within the autophagosome, followed by degradation in lysosomes. Moreover, the Δslt mutant induced host cells to produce high levels of cytokines such as tumor necrosis factor-α, interleukin (IL)-6, and IL-1ß, compared with the wild-type strain. These results suggest that the SLT of F. novicida is required for immune suppression and escape from autophagy to allow its survival in host cells.


Assuntos
Proteínas de Bactérias/imunologia , Francisella tularensis/imunologia , Glicosiltransferases/imunologia , Tularemia/imunologia , Animais , Linhagem Celular , Francisella tularensis/crescimento & desenvolvimento , Humanos , Evasão da Resposta Imune , Lisossomos/imunologia , Lisossomos/microbiologia , Camundongos , Monócitos/imunologia , Monócitos/microbiologia , Fagossomos/imunologia , Fagossomos/microbiologia , Tularemia/microbiologia
3.
BMC Med Genomics ; 12(1): 127, 2019 09 06.
Artigo em Inglês | MEDLINE | ID: mdl-31492148

RESUMO

BACKGROUND: Burkholderia mallei (Bm) is a facultative intracellular bacterial pathogen causing highly-fatal glanders in solipeds and humans. The ability of Bm to thrive intracellularly is thought to be related to exploitation of host immune response-related genes and pathways. Relatively little is known of the molecular strategies employed by this pathogen to modulate these pathways and evade intracellular killing. This manuscript seeks to fill gaps in the understanding of the interface between Bm and innate immunity by examining gene expression changes during infection of host monocytes. METHODS: The transcriptome of Bm-infected human Mono Mac-6 (MM6) monocytes was profiled on Affymetrix Human Transcriptome GeneChips 2.0. Gene expression changes in Bm-infected monocytes were compared to those of Burkholderia thailandensis (Bt)-infected monocytes and to uninfected monocytes. The resulting dataset was normalized using Robust Multichip Average and subjected to statistical analyses employing a univariate F test with a random variance model. Differentially expressed genes significant at p < 0.001 were subjected to leave-one-out cross-validation studies and 1st and 3rd nearest neighbor prediction model. Significant probe sets were used to populate human pathways in Ingenuity Pathway Analysis, with statistical significance determined by Fisher's exact test or z-score. RESULTS: The Pattern Recognition Receptor (PRR) pathway was represented among significantly enriched immune response-related human canonical pathways, with evidence of upregulation across both infections. Among members of this pathway, pentraxin-3 was significantly upregulated by Bm- or Bt-infected monocytes. Pentraxin-3 (PTX3) was demonstrated to bind to both Bt and Burkholderia pseudomallei (Bp), but not Bm. Subsequent assays did not identify a role for PTX3 in potentiating complement-mediated lysis of Bt or in enhancing phagocytosis or replication of Bt in human monocytes. CONCLUSION: We report on the novel binding of PTX3 to Bt and Bp, with lack of interaction with Bm, suggesting that a possible evasive mechanism by Bm warrants further exploration. We determined that (1) PTX3 may not play a role in activating the lytic pathway of complement in different bacterial species and that (2) the opsonophagocytic properties of PTX3 should be investigated in different primary or immortalized cell lines representing host phagocytes, given lack of binding of PTX3 to MM6 monocytes.


Assuntos
Burkholderia/imunologia , Proteína C-Reativa/metabolismo , Perfilação da Expressão Gênica , Imunidade Inata , Monócitos/imunologia , Monócitos/microbiologia , Componente Amiloide P Sérico/metabolismo , Anticorpos/metabolismo , Burkholderia/crescimento & desenvolvimento , Linhagem Celular , Proteínas do Sistema Complemento/metabolismo , Humanos , Imunidade Inata/genética , Viabilidade Microbiana , Proteínas Opsonizantes/metabolismo , Fagocitose , Ligação Proteica , Regulação para Cima/genética
4.
mSphere ; 4(4)2019 08 21.
Artigo em Inglês | MEDLINE | ID: mdl-31434744

RESUMO

Vibrio cholerae infection provides long-lasting protective immunity, while oral, inactivated cholera vaccines (OCV) result in more-limited protection. To identify characteristics of the innate immune response that may distinguish natural V. cholerae infection from OCV, we stimulated differentiated, macrophage-like THP-1 cells with live versus heat-inactivated V. cholerae with and without endogenous or exogenous cholera holotoxin (CT). Interleukin 23A gene (IL23A) expression was higher in cells exposed to live V. cholerae than in cells exposed to inactivated organisms (mean change, 38-fold; 95% confidence interval [95% CI], 4.0 to 42; P < 0.01). IL-23 secretion was also higher in cells exposed to live V. cholerae than in cells exposed to inactivated V. cholerae (mean change, 5.6-fold; 95% CI, 4.4 to 11; P < 0.001). This increase in IL-23 secretion was more marked than for other key innate immune cytokines (e.g., IL-1ß and IL-6) and dependent on exposure to the combination of both live V. cholerae and CT. While IL-23 secretion was reduced following stimulation with either heat-inactivated wild-type V. cholerae or a live isogenic ctxAB mutant of V. cholerae, the addition of exogenous CT restored IL-23 secretion in combination with the live isogenic ctxAB mutant V. cholerae, but not when it was paired with stimulation by heat-inactivated V. cholerae The posttranslational regulation of IL-23 under these conditions was dependent on the activity of the cysteine protease cathepsin B. In humans, IL-23 promotes the differentiation of Th17 cells to T follicular helper cells, which maintain and support long-term memory B cell generation after infection. Based on these findings, the stimulation of IL-23 production may be a determinant of protective immunity following V. cholerae infection.IMPORTANCE An episode of cholera provides better protection against reinfection than oral cholera vaccines, and the reasons for this are still under study. To better understand this, we compared the immune responses of human cells exposed to live Vibrio cholerae with those of cells exposed to heat-killed V. cholerae (similar to the contents of oral cholera vaccines). We also compared the effects of active cholera toxin and the inactive cholera toxin B subunit (which is included in some cholera vaccines). One key immune signaling molecule, IL-23, was uniquely produced in response to the combination of live bacteria and active cholera holotoxin. Stimulation with V. cholerae that did not produce the active toxin or was killed did not produce an IL-23 response. The stimulation of IL-23 production by cholera toxin-producing V. cholerae may be important in conferring long-term immunity after cholera.


Assuntos
Antígenos de Bactérias/imunologia , Imunidade Inata , Subunidade p19 da Interleucina-23/genética , Monócitos/imunologia , Processamento Pós-Transcricional do RNA/imunologia , Vibrio cholerae/imunologia , Anticorpos Antibacterianos/imunologia , Antígenos de Bactérias/química , Toxina da Cólera/imunologia , Vacinas contra Cólera/imunologia , Citocinas/imunologia , Regulação da Expressão Gênica/imunologia , Temperatura Alta , Humanos , Subunidade p19 da Interleucina-23/imunologia , Monócitos/microbiologia , Células THP-1 , Vacinas de Produtos Inativados/imunologia , Vacinas Vivas não Atenuadas/imunologia , Vibrio cholerae/patogenicidade
5.
PLoS Pathog ; 15(8): e1007923, 2019 08.
Artigo em Inglês | MEDLINE | ID: mdl-31449558

RESUMO

IL-1ß is a potent pro-inflammatory cytokine that promotes immunity and host defense, and its dysregulation is associated with immune pathology. Toxoplasma gondii infection of myeloid cells triggers the production and release of IL-1ß; however, the mechanisms regulating this pathway, particularly in human immune cells, are incompletely understood. We have identified a novel pathway of T. gondii induction of IL-1ß via a Syk-CARD9-NF-κB signaling axis in primary human peripheral blood monocytes. Syk was rapidly phosphorylated during T. gondii infection of primary monocytes, and inhibiting Syk with the pharmacological inhibitors R406 or entospletinib, or genetic ablation of Syk in THP-1 cells, reduced IL-1ß release. Inhibition of Syk in primary cells or deletion of Syk in THP-1 cells decreased parasite-induced IL-1ß transcripts and the production of pro-IL-1ß. Furthermore, inhibition of PKCδ, CARD9/MALT-1 and IKK reduced p65 phosphorylation and pro-IL-1ß production in T. gondii-infected primary monocytes, and genetic knockout of PKCδ or CARD9 in THP-1 cells also reduced pro-IL-1ß protein levels and IL-1ß release during T. gondii infection, indicating that Syk functions upstream of this NF-κB-dependent signaling pathway for IL-1ß transcriptional activation. IL-1ß release from T. gondii-infected primary human monocytes required the NLRP3-caspase-1 inflammasome, but interestingly, was independent of gasdermin D (GSDMD) cleavage and pyroptosis. Moreover, GSDMD knockout THP-1 cells released comparable amounts of IL-1ß to wild-type THP-1 cells after T. gondii infection. Taken together, our data indicate that T. gondii induces a Syk-CARD9/MALT-1-NF-κB signaling pathway and activation of the NLRP3 inflammasome for the release of IL-1ß in a cell death- and GSDMD-independent manner. This research expands our understanding of the molecular basis for human innate immune regulation of inflammation and host defense during parasite infection.


Assuntos
Proteínas Adaptadoras de Sinalização CARD/metabolismo , Interleucina-1beta/metabolismo , Peptídeos e Proteínas de Sinalização Intracelular/metabolismo , Monócitos/metabolismo , NF-kappa B/metabolismo , Proteínas de Ligação a Fosfato/metabolismo , Quinase Syk/metabolismo , Toxoplasmose/metabolismo , Proteínas Adaptadoras de Sinalização CARD/genética , Células Cultivadas , Humanos , Inflamassomos , Peptídeos e Proteínas de Sinalização Intracelular/genética , Monócitos/imunologia , Monócitos/microbiologia , NF-kappa B/genética , Proteínas de Ligação a Fosfato/genética , Transdução de Sinais , Quinase Syk/genética , Toxoplasma/fisiologia , Toxoplasmose/imunologia , Toxoplasmose/microbiologia
6.
Immunology ; 158(3): 230-239, 2019 11.
Artigo em Inglês | MEDLINE | ID: mdl-31408534

RESUMO

Immune evasion is a critical survival mechanism for bacterial colonization of deeper tissues and may lead to life-threatening conditions such as endotoxaemia and sepsis. Understanding these immune evasion pathways would be an important step for the development of novel anti-microbial therapeutics. Here, we report a hitherto unknown mechanism by which Salmonella exploits an anti-inflammatory pathway in human immune cells to obtain survival advantage. We show that Salmonella enterica serovar Typhimurium strain 4/74 significantly (P < 0·05) increased expression of mRNA and surface protein of the type 1 receptor (VPAC1) for anti-inflammatory vasoactive intestinal peptide (VIP) in human monocytes. However, we also show that S. Typhimurium induced retrograde recycling of VPAC1 from early endosomes to Rab11a-containing sorting endosomes, associated with the Golgi apparatus, and anterograde trafficking via Rab3a and calmodulin 1. Expression of Rab3a and calmodulin 1 were significantly increased by S. Typhimurium infection and W-7 (calmodulin antagonist) decreased VPAC1 expression on the cell membrane while CALP-1 (calmodulin agonist) increased VPAC1 expression (P < 0·05). When infected monocytes were co-cultured with VIP, a significantly higher number of S. Typhimurium were recovered from these monocytes, compared with S. Typhimurium recovered from monocytes cultured only in cell media. We conclude that S. Typhimurium infection exploits host VPAC1/VIP to gain survival advantage in human monocytes.


Assuntos
Regulação da Expressão Gênica/imunologia , Evasão da Resposta Imune , Monócitos , Receptores Tipo I de Polipeptídeo Intestinal Vasoativo/imunologia , Infecções por Salmonella/imunologia , Salmonella typhimurium/imunologia , Endossomos/imunologia , Endossomos/microbiologia , Endossomos/patologia , Humanos , Monócitos/imunologia , Monócitos/microbiologia , Monócitos/patologia , Infecções por Salmonella/patologia , Proteínas rab de Ligação ao GTP/imunologia , Proteína rab3A de Ligação ao GTP/imunologia
7.
Biomed Res Int ; 2019: 8601346, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31355284

RESUMO

Legionella pneumophila is known as a human pathogen and is ubiquitous in natural and artificial aquatic environments. Many studies have revealed the virulence traits of L. pneumophila using clinical strains and a number of studies for characterizing environmental strains are also reported. However, the association between the virulence and survivability in the environment is unclear. In the present study, L. pneumophila was isolated from environmental water sites (Ashiyu foot spa, water fountain, and public bath), and the serogroups of isolated strains were determined by serological tests. Isolated strains were found to belong to serogroups SG1, SG2, SG3, SG4, SG5, SG8, SG9, and SG13. Untypeable strains were also obtained. Isolated strains were used for intracellular growth assay in a human monocytic cell line, THP-1. Among these strains, only an untypeable strain, named AY3, failed to replicate in THP-1. In addition, AY3 was maintained for a long period in an environmental water site, Ashiyu foot spa 2. Further, we compared the characteristics of several strains isolated from Ashiyu foot spa 2 and a clinical strain, Togus-1. AY3 failed to replicate in THP-1 cells but replicated in an amoeba model, Dictyostelium discoideum. Compared with Togus-1, the culturable cell number of environmental strains under stress conditions was higher. Moreover, biofilm formation was assessed, and AY3 showed the same degree of biofilm formation as Togus-1. Biofilm formation, replication in amoebae, and resistance against stress factors would explain the predominance of AY3 at one environmental site. Although the mechanism underlying the difference in the ability of AY3 to replicate in THP-1 cells or amoebae is still unclear, AY3 may abandon the ability to replicate in THP-1 cells to survive in one environment for a long period. Understanding the mechanisms of L. pneumophila in replication within different hosts should help in the control of Legionnaires' disease, but further study is necessary.


Assuntos
Legionella pneumophila , Doença dos Legionários , Viabilidade Microbiana , Monócitos/microbiologia , Microbiologia da Água , Água , Humanos , Legionella pneumophila/genética , Legionella pneumophila/crescimento & desenvolvimento , Legionella pneumophila/patogenicidade , Doença dos Legionários/genética , Doença dos Legionários/metabolismo , Monócitos/metabolismo , Monócitos/patologia , Células THP-1 , Fatores de Tempo
8.
Artigo em Inglês | MEDLINE | ID: mdl-31174697

RESUMO

TLRs, Siglecs and CD163 are cell surface receptors that play an important role in immune response and sepsis. The objective of this study was to assess changes in the expression levels of several of these receptors (TLR2, TLR4, CD163, Siglec-1, Siglec-3, Siglec-5 and Siglec-10) on the surface of peripheral blood mononuclear cells from pigs with sepsis caused by Haemophilus parasuis. Flow cytometry was employed to analyze samples from an experimental infection and from cell cultures. A significant increase in CD163, TLR2 and Siglec-3 expression during infection was seen. However, in vitro exposure of peripheral blood monocytes to bacteria or sera from infected pigs did not increase the expression of these receptors. These changes may be due to recruitment of monocytes into the blood compartment in response to H. parasuis-induced sepsis.


Assuntos
Antígenos CD/genética , Antígenos de Diferenciação Mielomonocítica/genética , Infecções por Haemophilus/veterinária , Monócitos/imunologia , Receptores de Superfície Celular/genética , Sepse/veterinária , Lectina 3 Semelhante a Ig de Ligação ao Ácido Siálico/genética , Doenças dos Suínos/imunologia , Receptor 2 Toll-Like/genética , Animais , Antígenos CD/imunologia , Antígenos de Diferenciação Mielomonocítica/imunologia , Células Cultivadas , Infecções por Haemophilus/imunologia , Haemophilus parasuis , Monócitos/microbiologia , Receptores de Superfície Celular/imunologia , Sepse/imunologia , Sepse/microbiologia , Lectina 3 Semelhante a Ig de Ligação ao Ácido Siálico/imunologia , Suínos , Doenças dos Suínos/microbiologia , Receptor 2 Toll-Like/imunologia
9.
Dev Comp Immunol ; 99: 103408, 2019 10.
Artigo em Inglês | MEDLINE | ID: mdl-31173786

RESUMO

Mannose-binding lectin (MBL) is a vital component in host's innate immune system and the initiator of the lectin pathway of complement cascade. However, its opsonic role has rarely been reported. In this study, we revealed the biological function of Ctenopharyngodon idella MBL (CiMBL) in regulating monocytes/macrophages (MO/MФ) in the grass carp (C. idella). Flow cytometry results indicated that recombinant CiMBL (rCiMBL) significantly enhanced the phagocytotic activity of MO/MФ. Recombinant CiMBL also enhanced bactericidal activity and respiratory burst capacity in Aeromonas hydrophila-infected MO/MФ, regulated A. hydrophila-induced polarization of MO/MФ including down- and up-regulated pro- and anti-inflammatory cytokines, respectively, suppressed the inducible nitric oxide synthase activity, and enhanced the arginase activity. In addition, rCiMBL suppressed the bacteria burden in tissues and blood in vivo and enhanced the survival rate of juvenile A. hydrophila-infected grass carp. We provide evidence that CiMBL was synthesized by MO/MФ, regulating the biological function of MO/MФ against A. hydrophila infection.


Assuntos
Carpas/imunologia , Doenças dos Peixes/imunologia , Proteínas de Peixes/imunologia , Infecções por Bactérias Gram-Negativas/veterinária , Macrófagos/imunologia , Lectina de Ligação a Manose/imunologia , Monócitos/imunologia , Aeromonas hydrophila/fisiologia , Animais , Carga Bacteriana , Carpas/microbiologia , Células Cultivadas , Doenças dos Peixes/microbiologia , Proteínas de Peixes/antagonistas & inibidores , Proteínas de Peixes/genética , Perfilação da Expressão Gênica , Infecções por Bactérias Gram-Negativas/imunologia , Infecções por Bactérias Gram-Negativas/microbiologia , Imunidade Inata , Macrófagos/microbiologia , Lectina de Ligação a Manose/antagonistas & inibidores , Lectina de Ligação a Manose/genética , Viabilidade Microbiana , Monócitos/microbiologia , Fagocitose , Explosão Respiratória , Análise de Sobrevida
10.
Mol Immunol ; 112: 131-139, 2019 08.
Artigo em Inglês | MEDLINE | ID: mdl-31102985

RESUMO

BACKGROUND: Sepsis is a dysregulated host response to infection. The aim of this study was to investigate the effects of complement- and CD14 inhibition on phagocytosis of live and dead Gram-negative and Gram-positive bacteria in human whole blood. METHODS: Lepirudin-anticoagulated blood was incubated with live or dead E. coli or S. aureus at 37 °C for 120 min with or without the C5aR1 antagonist PMX53 and/or anti-CD14. Granulocyte and monocyte phagocytosis were measured by flow cytometry, and five plasma cytokines by multiplex, yielding a total of 28 mediators of inflammation tested for. RESULTS: 16/28 conditions were reduced by PMX53, 7/28 by anti-CD14, and 24/28 by combined PMX53 and CD14 inhibition. The effect of complement inhibition was quantitatively more pronounced, in particular for the responses to S. aureus. The effect of anti-CD14 was modest, except for a marked reduction in INF-ß. The responses to live and dead S. aureus were equally inhibited, whereas the responses to live E. coli were inhibited less than those to dead E. coli. CONCLUSION: C5aR1 inhibited phagocytosis-induced inflammation by live and dead E. coli and S. aureus. CD14 blockade potentiated the effect of C5aR1 blockade, thus attenuating inflammation.


Assuntos
Escherichia coli/imunologia , Receptores de Lipopolissacarídeos/antagonistas & inibidores , Fagocitose/imunologia , Receptor da Anafilatoxina C5a/antagonistas & inibidores , Infecções Estafilocócicas/imunologia , Staphylococcus aureus/imunologia , Ativação do Complemento/imunologia , Proteínas do Sistema Complemento/imunologia , Citocinas/imunologia , Infecções por Escherichia coli/imunologia , Granulócitos/imunologia , Humanos , Inflamação/imunologia , Inflamação/microbiologia , Interferon beta/imunologia , Receptores de Lipopolissacarídeos/imunologia , Monócitos/imunologia , Monócitos/microbiologia , Peptídeos Cíclicos/imunologia , Receptor da Anafilatoxina C5a/imunologia , Sepse/imunologia , Sepse/microbiologia
11.
BMC Microbiol ; 19(1): 91, 2019 05 09.
Artigo em Inglês | MEDLINE | ID: mdl-31072343

RESUMO

BACKGROUND: 'Candidatus Berkiella cookevillensis' and 'Ca. Berkiella aquae' have previously been described as intranuclear bacteria of amoebae. Both bacteria were isolated from amoebae and were described as appearing within the nuclei of Acanthamoeba polyphaga and ultimately lysing their host cells within 4 days. Both bacteria are Gammaproteobacteria in the order Legionellales with the greatest similarity to Coxiella burnetii. Neither bacterium grows axenically in artificial culture media. In this study, we further characterized 'Ca. B. cookevillensis' by demonstrating association with nuclei of human phagocytic and nonphagocytic cell lines. RESULTS: Transmission electron microscopy (TEM) and confocal microscopy were used to confirm nuclear co-localization of 'Ca. B. cookevillensis' in the amoeba host A. polyphaga with 100% of cells having bacteria co-localized with host nuclei by 48 h. TEM and confocal microscopy demonstrated that the bacterium was also observed to be closely associated with nuclei of human U937 and THP-1 differentiated macrophage cell lines and nonphagocytic HeLa human epithelial-like cells. Immunofluorescent staining revealed that the bacteria-containing vacuole invaginates the nuclear membranes and appears to cross from the cytoplasm into the nucleus as an intact vacuole. CONCLUSION: Results of this study indicate that a novel coccoid bacterium isolated from amoebae can infect human cell lines by associating with the host cell nuclei, either by crossing the nuclear membranes or by deeply invaginating the nuclear membranes. When associated with the nuclei, the bacteria appear to be bound within a vacuole and replicate to high numbers by 48 h. We believe this is the first report of such a process involving bacteria and human cell lines.


Assuntos
Amoeba/microbiologia , Núcleo Celular/microbiologia , Gammaproteobacteria/fisiologia , Interações entre Hospedeiro e Microrganismos , Monócitos/microbiologia , Citoplasma/microbiologia , Gammaproteobacteria/ultraestrutura , Células HeLa , Humanos , Microscopia Eletrônica de Transmissão , Monócitos/ultraestrutura , Simbiose , Células THP-1 , Células U937
12.
Mol Immunol ; 111: 43-52, 2019 07.
Artigo em Inglês | MEDLINE | ID: mdl-30959420

RESUMO

Salmonella enterica serovar Typhimurium (S. Typhimurium) changes the structure of its lipopolysaccharide (LPS) in response to the environment. The two main LPS variants found in S. Typhimurium correspond to LPS with a hepta-acylated lipid A (LPS 430) and LPS with modified phosphate groups on its lipid A (LPS 435). We have previously shown that these modified LPS have a lower capacity than wild type (WT) LPS to induce the production of pro-inflammatory cytokines in mice. Nevertheless, it is not know if LPS 430 and LPS 435 could also subvert the innate immune responses in human cells. In this study, we found that LPS 430 and LPS 435 were less efficient than WT LPS to induce the production of pro-inflammatory cytokines by human monocytes, in addition we found a decreased dimerization of the TLR4/MD-2 complex in response to LPS 430, suggesting that structurally modified LPS are sensed differently than WT LPS by this receptor; however, LPS 430 and 435 induced similar activation of the transcription factors NF-κB p65, IRF3, p38 and ERK1/2 than WT LPS. Microarray analysis of LPS 430- and LPS 435-activated monocytes revealed a gene transcription profile with differences only in the expression levels of microRNA genes compared to the profile induced by WT LPS, suggesting that the lipid A modifications present in LPS 430 and LPS 435 have a moderate effect on the activation of the human TLR4/MD-2 complex. Our results are relevant to understand LPS modulation of immune responses and this knowledge could be useful for the development of novel adjuvants and immunomodulators.


Assuntos
Citocinas/imunologia , Inflamação/imunologia , Lipopolissacarídeos/imunologia , Antígeno 96 de Linfócito/imunologia , Monócitos/imunologia , Salmonella typhimurium/imunologia , Receptor 4 Toll-Like/imunologia , Acilação/imunologia , Dimerização , Humanos , Inflamação/microbiologia , Lipídeo A/imunologia , Monócitos/microbiologia , Infecções por Salmonella/imunologia , Infecções por Salmonella/microbiologia , Transdução de Sinais/imunologia , Fatores de Transcrição/imunologia , Transcrição Genética/imunologia
13.
Int J Antimicrob Agents ; 54(1): 85-88, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-31029736

RESUMO

Disulfiram (DSF) can help treat alcohol dependency by inhibiting aldehyde dehydrogenase (ALDH). Genomic analysis revealed that Francisella tularensis, the causative agent of tularemia, has lost all but one ALDH-like domain and that this domain retains the target of DSF. In this study, minimum inhibitory concentration (MIC) assays demonstrated that both DSF and its primary metabolite diethyldithiocarbamate (DDC) have strong antimicrobial activity against F. tularensis strain SCHU S4, with the MIC of DSF determined as 2 µg/mL in comparison with 8 µg/mL for DDC. The activity of DSF was further confirmed using an in vitro human macrophage infection assay. Francisella tularensis bacteria in DSF-treated cells were reduced in comparison with untreated and DDC-treated cells, comparable with that observed in doxycycline-treated cells. This suggests that DSF may be suitable for further investigation as an in vivo therapy for tularemia.


Assuntos
Inibidores de Acetaldeído Desidrogenases/farmacologia , Dissuasores de Álcool/farmacologia , Antibacterianos/farmacologia , Dissulfiram/farmacologia , Francisella tularensis/efeitos dos fármacos , Francisella tularensis/crescimento & desenvolvimento , Carga Bacteriana , Humanos , Testes de Sensibilidade Microbiana , Monócitos/efeitos dos fármacos , Monócitos/microbiologia , Células THP-1
14.
Arch Oral Biol ; 100: 86-92, 2019 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-30818128

RESUMO

OBJECTIVE: Fusobacterium nucleatum (F. nucleatum) is an important pathogen in periodontitis. Previous studies have demonstrated its ability to spread via haematogenesis and modulate host immune responses. However, little is known regarding its effect on endothelial cells (ECs) and leukocytes. The aim of this study was to assess the effect of F. nucleatum on monocyte attachment and transmigration through ECs. DESIGN: Human umbilical vein endothelial cells (HUVECs) and human leukemic monocyte (THP-1) cells were infected with F. nucleatum and assessed for monocyte adhesion, transendothelial migration, and HUVEC proliferation/apoptosis. Real-time PCR, western blotting and ELISA were performed to assess the expression of proinflammatory cytokines, adhesion molecules and chemokines in both cells. RESULTS: F. nucleatum challenge significantly induced THP-1 cell adhesion and transmigration and markedly impaired cell proliferation and apoptosis in HUVECs. A parallel increase in vascular cell adhesion molecule-1, intercellular adhesion molecule-1 and E-selectin expression in HUVECs and an upregulation of tumour necrosis factor-α, interleukin (IL)-1ß, IL-6, IL-8, and monocyte chemoattractant protein-1 in both HUVECs and THP-1 cells were observed. The expression of nuclear factor-kappa B was also enhanced in HUVECs and THP-1 cells upon F. nucleatum infection. CONCLUSIONS: F. nucleatum triggers an inflammatory response against infection in cells and promotes the recruitment and transmigration of monocytes through ECs.


Assuntos
Adesão Celular , Fusobacterium nucleatum , Células Endoteliais da Veia Umbilical Humana/citologia , Monócitos/microbiologia , Movimento Celular , Selectina E/metabolismo , Humanos , Inflamação , Molécula 1 de Adesão Intercelular/metabolismo , Interleucinas/metabolismo , Monócitos/citologia , Células THP-1 , Fator de Necrose Tumoral alfa/metabolismo , Molécula 1 de Adesão de Célula Vascular/metabolismo
15.
Int J Mol Sci ; 20(6)2019 Mar 20.
Artigo em Inglês | MEDLINE | ID: mdl-30897723

RESUMO

Background: Cleaving ligands and receptors of the tumor necrosis factor (TNF) superfamily can critically regulate the induction of apoptosis. Matrix metalloproteinases (MMPs) such as MMP-9 and tumor necrosis factor-α-converting enzyme (TACE) have been shown to cleave CD95-Ligand (CD95L) and TNF/(TNF receptor-1) TNFR1 which induce phagocytosis induced cell death (PICD) in adult monocytes. This process is reduced in neonatal monocytes. Methods: Here we tested in vitro, whether Escherichia coli infection mounts for activation of MMP-9 and TACE in monocytes and whether this process regulates PICD. Results: The surface expression of TACE was most prominent on infected adult monocytes. In contrast, surface presentation of MMP-9 was highest on infected neonatal monocytes. Selective blocking of MMP-9 decreased CD95L secretion, while inhibition of TACE left CD95L secretion unaltered. Blocking of MMP-9 increased surface CD95L (memCD95L) expression on infected neonatal monocytes to levels comparable to infected adult monocytes. Moreover, MMP-9 inhibition raised PICD of infected neonatal monocytes to levels observed for infected adult monocytes. In contrast, TACE inhibition decreased PICD in infected monocytes. Addition of extracellular TNF effectively induced memCD95L presentation and PICD of adult monocytes and less of neonatal monocytes. Conclusion: MMP-9 activity is crucial for downregulating cell-contact dependent PICD in E. coli infected neonatal monocytes. By this mechanism, MMP-9 could contribute to reducing sustained inflammation in neonates.


Assuntos
Proteína ADAM17/metabolismo , Escherichia coli/patogenicidade , Metaloproteinase 9 da Matriz/metabolismo , Monócitos/metabolismo , Monócitos/microbiologia , Apoptose/fisiologia , Membrana Celular/metabolismo , Células Cultivadas , Proteína Ligante Fas/metabolismo , Humanos , Recém-Nascido , Inflamação/imunologia , Inflamação/metabolismo , Fagocitose/fisiologia , Receptores Tipo I de Fatores de Necrose Tumoral/genética , Receptores Tipo I de Fatores de Necrose Tumoral/metabolismo
16.
PLoS Pathog ; 15(3): e1007627, 2019 03.
Artigo em Inglês | MEDLINE | ID: mdl-30897162

RESUMO

Cryptococcus neoformans is a leading cause of invasive fungal infections among immunocompromised patients. However, the cellular constituents of the innate immune response that promote clearance versus progression of infection upon respiratory acquisition of C. neoformans remain poorly defined. In this study, we found that during acute C. neoformans infection, CCR2+ Ly6Chi inflammatory monocytes (IM) rapidly infiltrate the lungs and mediate fungal trafficking to lung-draining lymph nodes. Interestingly, this influx of IM is detrimental to the host, since ablating IM or impairing their recruitment to the lungs improves murine survival and reduces fungal proliferation and dissemination. Using a novel conditional gene deletion strategy, we determined that MHC class II expression by IM did not mediate their deleterious impact on the host. Furthermore, although ablation of IM reduced the number of lymphocytes, innate lymphoid cells, and eosinophils in the lungs, the effects of IM were not dependent on these cells. We ascertained that IM in the lungs upregulated transcripts associated with alternatively activated (M2) macrophages in response to C. neoformans, consistent with the model that IM assume a cellular phenotype that is permissive for fungal growth. We also determined that conditional knockout of the prototypical M2 marker arginase 1 in IM and deletion of the M2-associated transcription factor STAT6 were not sufficient to reverse the harmful effects of IM. Overall, our findings indicate that C. neoformans can subvert the fungicidal potential of IM to enable the progression of infection through a mechanism that is not dependent on lymphocyte priming, eosinophil recruitment, or downstream M2 macrophage polarization pathways. These results give us new insight into the plasticity of IM function during fungal infections and the level of control that C. neoformans can exert on host immune responses.


Assuntos
Criptococose/imunologia , Monócitos/fisiologia , Receptores CCR2/metabolismo , Animais , Criptococose/patologia , Cryptococcus neoformans/metabolismo , Cryptococcus neoformans/patogenicidade , Modelos Animais de Doenças , Interações Hospedeiro-Patógeno/imunologia , Imunidade Inata/imunologia , Imunidade Inata/fisiologia , Inflamação/imunologia , Inflamação/microbiologia , Pulmão/patologia , Pneumopatias Fúngicas/fisiopatologia , Macrófagos , Camundongos , Camundongos Endogâmicos C57BL , Monócitos/imunologia , Monócitos/microbiologia , Receptores CCR2/genética
17.
BMC Vet Res ; 15(1): 98, 2019 Mar 25.
Artigo em Inglês | MEDLINE | ID: mdl-30909903

RESUMO

BACKGROUND: Haemophilus parasuis (HPS) is the causative agent of Glässer's disease, characterized by arthritis, fibrinous polyserositis and meningitis, and resulting in worldwide economic losses in the swine industry. Baicalin (BA), a commonly used traditional Chinese medication, has been shown to possess a series of activities, such as anti-bacterial, anti-viral, anti-tumor, anti-oxidant and anti-inflammatory activities. However, whether BA has anti-apoptotic effects following HPS infection is unclear. Here, we investigated the anti-apoptotic effects and mechanisms of BA in HPS-induced apoptosis via the protein kinase C (PKC)-mitogen-activated protein kinase (MAPK) pathway in piglet's mononuclear phagocytes (PMNP). RESULTS: Our data demonstrated that HPS could induce reactive oxygen species (ROS) production, arrest the cell cycle and promote apoptosis via the PKC-MAPK signaling pathway in PMNP. Moreover, when BA was administered, we observed a reduction in ROS production, suppression of cleavage of caspase-3 in inducing apoptosis, and inhibition of activation of the PKC-MAPK signaling pathway for down-regulating p-JNK, p-p38, p-ERK, p-PKC-α and PKC-δ in PMNP triggered by HPS. CONCLUSIONS: Our data strongly suggest that BA can reverse the apoptosis initiated by HPS through regulating the PKC-MAPK signaling pathway, which represents a promising therapeutic agent in the treatment of HPS infection.


Assuntos
Antibacterianos/uso terapêutico , Flavonoides/uso terapêutico , Haemophilus parasuis/efeitos dos fármacos , Sistema de Sinalização das MAP Quinases/efeitos dos fármacos , Monócitos/metabolismo , Doenças dos Suínos/tratamento farmacológico , Animais , Animais Recém-Nascidos/metabolismo , Animais Recém-Nascidos/microbiologia , Antibacterianos/farmacologia , Apoptose/efeitos dos fármacos , Relação Dose-Resposta a Droga , Flavonoides/farmacologia , Infecções por Haemophilus/tratamento farmacológico , Infecções por Haemophilus/metabolismo , Infecções por Haemophilus/veterinária , Monócitos/efeitos dos fármacos , Monócitos/microbiologia , Espécies Reativas de Oxigênio/metabolismo , Suínos , Doenças dos Suínos/metabolismo , Doenças dos Suínos/microbiologia
18.
Methods Mol Biol ; 1954: 99-113, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30864127

RESUMO

Partial N-deacetylation and certain N-reacylations of low-molecular-weight hyaluronic acid (hyaluronan) abate its proinflammatory properties in mammalian systems. Here, we describe the treatment of bacterial hyaluronic acid by hydrazine or NaOH to yield smaller partially deacetylated polymers. These N-deacetylated polymers can be reacylated with acyl anhydrides to yield substituted hyaluronic acid derivatives of equivalent size and equimolar N-acyl substitutions.


Assuntos
Citocinas/imunologia , Ácido Hialurônico/análogos & derivados , Ácido Hialurônico/imunologia , Infecções Estreptocócicas/imunologia , Streptococcus equi/química , Streptococcus equi/imunologia , Acilação , Linhagem Celular , Colorimetria/métodos , Humanos , Hidrazinas/química , Espectrometria de Massas/métodos , Monócitos/imunologia , Monócitos/microbiologia , Espectroscopia de Prótons por Ressonância Magnética/métodos , Hidróxido de Sódio/química , Infecções Estreptocócicas/microbiologia
19.
Tuberculosis (Edinb) ; 114: 30-41, 2019 01.
Artigo em Inglês | MEDLINE | ID: mdl-30711155

RESUMO

Severe obesity and diabetes lead to a significant decrease in quality of life. Although controversial, population-wide studies have implicated obesity in the development of tuberculosis (TB). Non-classical monocytes have been described in obesity and TB, whereas in diabetes they have been associated with poorer clinical outcomes. The present study focuses on the functional significance of several monocyte populations of obese, obesity-related diabetic (OBDM), non-obese/diabetic tuberculosis and non-obese healthy control patients. Monocytes were evaluated by measuring expression of CD86, CD206, TLR-2 and TLR-4 as well as production of IL-6, IL-12, and by using a mycobacterial growth inhibition assay for both Mycobacterium tuberculosis and M. abscessus subsp. massiliense. Non-classical monocytes from OBDM and non-obese TB patients exhibited similar activation profiles (CD86/CD206/TLR-2 and TLR-4 expressions). Only monocytes from TB patients had a higher positivity for IL-12 and IL-6, whereas adiponectin serum levels increased similarly between TB and OBDM patients. Monocytes from active TB patients and OBDM were more permissive to Mtb growth than obese individuals, but this susceptibility was not observed for M. abscessus subsp. massiliense. From these findings, we conclude that diabetes and tuberculosis had similarities in the population of circulating non-classical monocytes, improving our understanding of the association of these diseases.


Assuntos
Diabetes Mellitus Tipo 2/imunologia , Monócitos/imunologia , Obesidade Mórbida/imunologia , Tuberculose/imunologia , Adulto , Idoso , Coleta de Amostras Sanguíneas/métodos , Estudos de Casos e Controles , Células Cultivadas , Diabetes Mellitus Tipo 2/complicações , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Monócitos/microbiologia , Mycobacterium tuberculosis/crescimento & desenvolvimento , Obesidade Mórbida/complicações , Fatores de Risco , Tuberculose/etiologia
20.
J Immunol ; 202(7): 2027-2034, 2019 04 01.
Artigo em Inglês | MEDLINE | ID: mdl-30745458

RESUMO

Methicillin-resistant Staphylococcus aureus has emerged as a significant contributor to morbidity and mortality associated with influenza infection. In this study, we show in a mouse model that preceding influenza infection promotes S. aureus resistance to killing by antibiotics. This resistance coincides with influenza-induced accumulation of inflammatory monocytes in the lung. CCR type 2 (CCR2) is responsible for pulmonary monocyte recruitment after influenza infection. We found that antibiotic-treated Ccr2-deficient (Ccr2-/-) mice exhibit significantly improved bacterial control and survival from influenza and methicillin-resistant S. aureus coinfection, despite a delay in viral clearance. Mechanistically, our results from in vivo studies indicate that influenza-induced monocytes serve as reservoirs for intracellular S. aureus survival, thereby promoting bacterial resistance to antibiotic treatment. Blocking CCR2 with a small molecular inhibitor (PF-04178903), in conjunction with antibiotic treatment, enhanced lung bacterial clearance and significantly improved animal survival. Collectively, our study demonstrates that inflammatory monocytes constitute an important and hitherto underappreciated mechanism of the conflicting immune requirements for viral and bacterial clearance by hosts, which subsequently leads to exacerbated outcomes of influenza and S. aureus coinfection.


Assuntos
Coinfecção/imunologia , Staphylococcus aureus Resistente à Meticilina/imunologia , Monócitos/imunologia , Monócitos/microbiologia , Infecções por Orthomyxoviridae/complicações , Animais , Farmacorresistência Bacteriana/imunologia , Feminino , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Infecções por Orthomyxoviridae/imunologia , Receptores CCR2/imunologia
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA