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1.
PLoS One ; 15(8): e0233818, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32857777

RESUMO

Macrophages serve as a first line of defense against infection with the facultative intracellular pathogen, Cryptococcus neoformans (Cn). However, the ability of these innate phagocytic cells to destroy ingested Cn is strongly influenced by polarization state with classically (M1) activated macrophages better able to control cryptococcal infections than alternatively (M2) activated cells. While earlier studies have demonstrated that intracellular Cn minimally affects the expression of M1 and M2 markers, the impact on the broader transcriptome associated with these states remains unclear. To investigate this, an in vitro cell culture model of intracellular infection together with RNA sequencing-based transcriptome profiling was used to measure the impact of Cn infection on gene expression in both polarization states. The gene expression profile of both M1 and M2 cells was extensively altered to become more like naive (M0) macrophages. Gene ontology analysis suggested that this involved changes in the activity of the Janus kinase-signal transducers and activators of transcription (JAK-STAT), p53, and nuclear factor-κB (NF-κB) pathways. Analyses of the principle polarization markers at the protein-level also revealed discrepancies between the RNA- and protein-level responses. In contrast to earlier studies, intracellular Cn was found to increase protein levels of the M1 marker iNos. In addition, common gene expression changes were identified that occurred post-Cn infection, independent of polarization state. This included upregulation of the transcriptional co-regulator Cited1, which was also apparent at the protein level in M1-polarized macrophages. These changes constitute a transcriptional signature of macrophage Cn infection and provide new insights into how Cn impacts gene expression and the phenotype of host phagocytes.


Assuntos
Cryptococcus neoformans/patogenicidade , Macrófagos/metabolismo , Macrófagos/microbiologia , Animais , Proteínas Reguladoras de Apoptose/genética , Proteínas Reguladoras de Apoptose/metabolismo , Cryptococcus neoformans/imunologia , Ontologia Genética , Redes Reguladoras de Genes , Imunidade Inata/genética , Ativação de Macrófagos/genética , Ativação de Macrófagos/imunologia , Macrófagos/imunologia , Camundongos , Óxido Nítrico Sintase Tipo II/metabolismo , Células RAW 264.7 , Transativadores/genética , Transativadores/metabolismo , Transcriptoma
2.
Nat Commun ; 11(1): 4035, 2020 08 12.
Artigo em Inglês | MEDLINE | ID: mdl-32788578

RESUMO

Polyphosphates are linear polymers and ubiquitous metabolites. Bacterial polyphosphates are long chains of hundreds of phosphate units. Here, we report that mouse survival of peritoneal Escherichia coli sepsis is compromised by long-chain polyphosphates, and improves with bacterial polyphosphatekinase deficiency or neutralization using recombinant exopolyphosphatase. Polyphosphate activities are chain-length dependent, impair pathogen clearance, antagonize phagocyte recruitment, diminish phagocytosis and decrease production of iNOS and cytokines. Macrophages bind and internalize polyphosphates, in which their effects are independent of P2Y1 and RAGE receptors. The M1 polarization driven by E. coli derived LPS is misdirected by polyphosphates in favor of an M2 resembling phenotype. Long-chain polyphosphates modulate the expression of more than 1800 LPS/TLR4-regulated genes in macrophages. This interference includes suppression of hundreds of type I interferon-regulated genes due to lower interferon production and responsiveness, blunted STAT1 phosphorylation and reduced MHCII expression. In conclusion, prokaryotic polyphosphates disturb multiple macrophage functions for evading host immunity.


Assuntos
Infecções por Escherichia coli/imunologia , Infecções por Escherichia coli/microbiologia , Escherichia coli/metabolismo , Interações Hospedeiro-Patógeno/imunologia , Imunidade Inata , Polifosfatos/metabolismo , Animais , Apresentação do Antígeno/imunologia , Polaridade Celular , Antígenos de Histocompatibilidade Classe II/metabolismo , Interferon Tipo I/metabolismo , Lipopolissacarídeos , Macrófagos/imunologia , Macrófagos/microbiologia , Camundongos Endogâmicos C57BL , Células Mieloides/imunologia , Fenótipo , Sepse/imunologia , Análise de Sobrevida , Transcriptoma/genética
3.
PLoS Pathog ; 16(8): e1008695, 2020 08.
Artigo em Inglês | MEDLINE | ID: mdl-32750090

RESUMO

The NLRP3 inflammasome has emerged as a central immune regulator that senses virulence factors expressed by microbial pathogens for triggering inflammation. Inflammation can be harmful and therefore this response must be tightly controlled. The mechanisms by which immune cells, such as macrophages, discriminate benign from pathogenic microbes to control the NLRP3 inflammasome remain poorly defined. Here we used live cell imaging coupled with a compendium of diverse clinical isolates to define how macrophages respond and activate NLRP3 when faced with the human yeast commensal and pathogen Candida albicans. We show that metabolic competition by C. albicans, rather than virulence traits such as hyphal formation, activates NLRP3 in macrophages. Inflammasome activation is triggered by glucose starvation in macrophages, which occurs when fungal load increases sufficiently to outcompete macrophages for glucose. Consistently, reducing Candida's ability to compete for glucose and increasing glucose availability for macrophages tames inflammatory responses. We define the mechanistic requirements for glucose starvation-dependent inflammasome activation by Candida and show that it leads to inflammatory cytokine production, but it does not trigger pyroptotic macrophage death. Pyroptosis occurs only with some Candida isolates and only under specific experimental conditions, whereas inflammasome activation by glucose starvation is broadly relevant. In conclusion, macrophages use their metabolic status, specifically glucose metabolism, to sense fungal metabolic activity and activate NLRP3 when microbial load increases. Therefore, a major consequence of Candida-induced glucose starvation in macrophages is activation of inflammatory responses, with implications for understanding how metabolism modulates inflammation in fungal infections.


Assuntos
Candida albicans/imunologia , Candidíase/imunologia , Glucose/deficiência , Interações Hospedeiro-Patógeno/imunologia , Inflamação/imunologia , Macrófagos/imunologia , Proteína 3 que Contém Domínio de Pirina da Família NLR/fisiologia , Animais , Células 3T3 BALB , Candida albicans/metabolismo , Candidíase/metabolismo , Candidíase/microbiologia , Caspase 1/fisiologia , Caspases Iniciadoras/fisiologia , Feminino , Hifas , Inflamação/metabolismo , Inflamação/microbiologia , Peptídeos e Proteínas de Sinalização Intracelular/fisiologia , Macrófagos/metabolismo , Macrófagos/microbiologia , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Proteínas de Ligação a Fosfato/fisiologia , Piroptose
4.
PLoS Pathog ; 16(8): e1008414, 2020 08.
Artigo em Inglês | MEDLINE | ID: mdl-32776983

RESUMO

The host innate immune system has developed elegant processes for the detection and clearance of invasive fungal pathogens. These strategies may also aid in the spread of pathogens in vivo, although technical limitations have previously hindered our ability to view the host innate immune and endothelial cells to probe their roles in spreading disease. Here, we have leveraged zebrafish larvae as a model to view the interactions of these host processes with the fungal pathogen Candida albicans in vivo. We examined three potential host-mediated mechanisms of fungal spread: movement inside phagocytes in a "Trojan Horse" mechanism, inflammation-assisted spread, and endothelial barrier passage. Utilizing both chemical and genetic tools, we systematically tested the loss of neutrophils and macrophages and the loss of blood flow on yeast cell spread. Both neutrophils and macrophages respond to yeast-locked and wild type C. albicans in our model and time-lapse imaging revealed that macrophages can support yeast spread in a "Trojan Horse" mechanism. Surprisingly, loss of immune cells or inflammation does not alter dissemination dynamics. On the other hand, when blood flow is blocked, yeast can cross into blood vessels but they are limited in how far they travel. Blockade of both phagocytes and circulation reduces rates of dissemination and significantly limits the distance of fungal spread from the infection site. Together, this data suggests a redundant two-step process whereby (1) yeast cross the endothelium inside phagocytes or via direct uptake, and then (2) they utilize blood flow or phagocytes to travel to distant sites.


Assuntos
Candida albicans/imunologia , Candidíase/imunologia , Células Endoteliais/imunologia , Interações Hospedeiro-Patógeno/imunologia , Neutrófilos/imunologia , Fagócitos/imunologia , Peixe-Zebra/microbiologia , Animais , Candidíase/microbiologia , Larva , Macrófagos/imunologia , Macrófagos/microbiologia , Neutrófilos/microbiologia , Fagócitos/microbiologia
5.
Proc Natl Acad Sci U S A ; 117(33): 20235-20243, 2020 08 18.
Artigo em Inglês | MEDLINE | ID: mdl-32753384

RESUMO

All cells require Mg2+ to replicate and proliferate. The macrophage protein Slc11a1 is proposed to protect mice from invading microbes by causing Mg2+ starvation in host tissues. However, the Mg2+ transporter MgtB enables the facultative intracellular pathogen Salmonella enterica serovar Typhimurium to cause disease in mice harboring a functional Slc11a1 protein. Here, we report that, unexpectedly, the Salmonella small protein MgtR promotes MgtB degradation by the protease FtsH, which raises the question: How does Salmonella preserve MgtB to promote survival inside macrophages? We establish that the Salmonella small protein MgtU prevents MgtB proteolysis, even when MgtR is absent. Like MgtB, MgtU is necessary for survival in Slc11a1 +/+ macrophages, resistance to oxidative stress, and growth under Mg2+ limitation conditions. The Salmonella Mg2+ transporter MgtA is not protected by MgtU despite sharing 50% amino acid identity with MgtB and being degraded in an MgtR- and FtsH-dependent manner. Surprisingly, the mgtB, mgtR, and mgtU genes are part of the same transcript, providing a singular example of transcript-specifying proteins that promote and hinder degradation of the same target. Our findings demonstrate that small proteins can confer pathogen survival inside macrophages by altering the abundance of related transporters, thereby furthering homeostasis.


Assuntos
Proteínas de Bactérias/metabolismo , Proteínas de Transporte de Cátions/metabolismo , Macrófagos/microbiologia , Magnésio/metabolismo , Salmonella typhimurium/fisiologia , Animais , Proteínas de Bactérias/genética , Proteínas de Transporte de Cátions/genética , Linhagem Celular , Macrófagos/fisiologia , Camundongos , Plasmídeos/genética , Salmonella typhimurium/genética , Virulência
6.
PLoS One ; 15(8): e0237752, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32817626

RESUMO

Pseudomonas aeruginosa remains a leading cause of nosocomial and serious life-threatening infections, and contributes to increased mortality in immunocompromised individuals. P. aeruginosa infection triggers host immune response and often provokes potent inflammatory mediators, which do not necessarily eradicate the causative pathogen. On the other hand, it causes severe airway damage and eventually decreased lung function. Such unfavorable outcomes of inflammatory injury have necessitated the development of novel effective agents that can combat with P. aeruginosa-mediated inflammation. Herein, we investigated the potential of quercetin in regulating P. aeruginosa-induced inflammation, with particular emphasized on the interleukin-1ß (IL-1ß). Our results showed that quercetin exerted the potent inhibitory activity against the production of IL-1ß in macrophages infected by live P. aeruginosa PAO1, without exhibiting cytotoxicity. According to our settings, such the potent inhibitory activity of quercetin was clearly demonstrated through its ability to efficiently inhibit IL-1ß during P. aeruginosa infection, pre- or even post-infection. In addition, quercetin strongly suppressed MAPK signaling pathway by inhibiting phosphorylation of the p38 MAPK and JNK2, and molecular docking study supported well with this observation. Moreover, quercetin reduced the NLRP3 expression and inhibited the P. aeruginosa-mediated cleavage of caspase-1 as well as mature IL-1ß. These results thus indicated that quercetin inhibition of P. aeruginosa-induced IL-1ß production is mediated by suppressing the initial priming step and by inhibiting the NLRP3 inflammasome activation. Taken together, our findings demonstrated the promising regulatory activity of quercetin against IL-1ß production in P. aeruginosa-infected macrophages, and indicated that quercetin has the potential to be effective as a novel therapeutic agent for treatment of P. aeruginosa-induced inflammation.


Assuntos
Interleucina-1beta/genética , Proteína 3 que Contém Domínio de Pirina da Família NLR/genética , Infecções por Pseudomonas/tratamento farmacológico , Quercetina/farmacologia , Proteínas Quinases p38 Ativadas por Mitógeno/genética , Linhagem Celular , Regulação da Expressão Gênica/efeitos dos fármacos , Humanos , Inflamassomos/efeitos dos fármacos , Inflamassomos/genética , Macrófagos/efeitos dos fármacos , Macrófagos/microbiologia , Infecções por Pseudomonas/genética , Infecções por Pseudomonas/microbiologia , Pseudomonas aeruginosa/efeitos dos fármacos , Pseudomonas aeruginosa/patogenicidade , Transdução de Sinais/efeitos dos fármacos
7.
PLoS One ; 15(8): e0237886, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32810191

RESUMO

Salmonella enterica subsp. enterica serovar Typhimurium (S. Typhimurium) causes gastroenteritis in many countries. However, in Brazil there are few studies that have conducted a virulence characterization of this serovar. The aim of this study was to evaluate the virulence potential of S. Typhimurium strains isolated in Brazil. Forty S. Typhimurium strains isolated from humans (n = 20) and food (n = 20) from Brazil were studied regarding their invasion and survival in human epithelial cells (Caco-2) and macrophages (U937). Their virulence potential was determined using the Galleria mellonella larvae model combined with the analysis of virulence genes by whole genome sequencing (WGS). A total of 67.5% of the S. Typhimurium studied (32.5% isolated from humans and 35% isolated from food) invaded Caco-2 epithelial cells at levels similar to or greater than the S. Typhimurium SL1344 prototype strain. In addition, 37.5% of the studied strains (25% isolated from humans and 12.5% isolated from food) survived in U937 human macrophages at levels similar to or greater than SL1344. S. Typhimurium strains isolated from humans (40%) and food (25%) showed high or intermediate virulence in G. mellonella larvae after seven days exposure. Approximately, 153 virulence genes of chromosomal and plasmidial origin were detected in the strains studied. In conclusion, the ability of the S. Typhimurium to invade Caco-2 epithelial cells was strain dependent and was not related to the source or the year of isolation. However, S. Typhimurium strains isolated from humans showed greater survival rates in U937 human macrophages, and presented higher proportion of isolates with a virulent profile in G. mellonella in comparison to strains isolated from food suggesting that this difference may be related to the higher frequency of human isolates which contained plasmid genes, such as spvABCDR operon, pefABCD operon, rck and mig-5.


Assuntos
Microbiologia de Alimentos , Salmonella typhimurium/genética , Salmonella typhimurium/isolamento & purificação , Animais , Brasil , Células CACO-2 , Sobrevivência Celular , Células Epiteliais/microbiologia , Genes Bacterianos , Genótipo , Humanos , Macrófagos/microbiologia , Mariposas/microbiologia , Fenótipo , Plasmídeos/genética , Salmonella typhimurium/patogenicidade , Células U937 , Virulência/genética
8.
PLoS One ; 15(7): e0236887, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32735621

RESUMO

Lawsonia intracellularis, an obligately intracellular enteric bacterium, infects intestinal epithelial cells, but may also be found within macrophages in the intestinal lamina propria of affected pigs. Macrophages play an important role in host defense against infectious agents, but the role of this cell in L. intracellularis infection is not well understood. The aim of this study was to evaluate the permissibility of macrophages to L. intracellularis infection in vitro. Pure culture of L. intracellularis was added to swine peripheral blood monocyte-derived macrophages. Viability of intracytoplasmic L. intracellularis was evaluated at different time points by transmission electron microscopy (TEM). Potential replication of L. intracellularis in macrophages was also evaluated by qPCR. By TEM, phagocytosis L. intracellularis within of phagolysosomes were observed 1-hour post-infection (hpi) and bacterial structures in binary fission at 48 hpi. The number of intracellular bacteria was determined at 1, 4, 24, 48, and 72 hpi by qPCR in infected macrophages and compared to the number of intracellular bacteria from culture in McCoy cells. In both cell lines, the amount of L. intracellularis was decreased at 4 hpiand increased at 24 hpi. The number of intracellular bacteria continued to increase in McCoy cells over time. This is the first study showing interaction, survival and propagation of L. intracellularis in macrophages. These findings are critical to establish an experimental model for future studies of the pathogenesis of porcine proliferative enteropathy and the potential persistence of L. intracellularis in macrophages during chronic infections.


Assuntos
Infecções por Desulfovibrionaceae/veterinária , Lawsonia (Bactéria) , Macrófagos/microbiologia , Animais , Linhagem Celular , Enteropatias/microbiologia , Enteropatias/veterinária , Lawsonia (Bactéria)/crescimento & desenvolvimento , Lawsonia (Bactéria)/ultraestrutura , Fagocitose , Suínos , Doenças dos Suínos/microbiologia
9.
PLoS Pathog ; 16(8): e1008763, 2020 08.
Artigo em Inglês | MEDLINE | ID: mdl-32834002

RESUMO

The various sub-species of Salmonella enterica cause a range of disease in human hosts. The human-adapted Salmonella enterica serovar Typhi enters the gastrointestinal tract and invades systemic sites to cause enteric (typhoid) fever. In contrast, most non-typhoidal serovars of Salmonella are primarily restricted to gut tissues. Across Africa, invasive non-typhoidal Salmonella (iNTS) have emerged with an ability to spread beyond the gastrointestinal tract and cause systemic bloodstream infections with increased morbidity and mortality. To investigate this evolution in pathogenesis, we compared the genomes of African iNTS isolates with other Salmonella enterica serovar Typhimurium and identified several macA and macB gene variants unique to African iNTS. MacAB forms a tripartite efflux pump with TolC and is implicated in Salmonella pathogenesis. We show that macAB transcription is upregulated during macrophage infection and after antimicrobial peptide exposure, with macAB transcription being supported by the PhoP/Q two-component system. Constitutive expression of macAB improves survival of Salmonella in the presence of the antimicrobial peptide C18G. Furthermore, these macAB variants affect replication in macrophages and influence fitness during colonization of the murine gastrointestinal tract. Importantly, the infection outcome resulting from these macAB variants depends upon both the Salmonella Typhimurium genetic background and the host gene Nramp1, an important determinant of innate resistance to intracellular bacterial infection. The variations we have identified in the MacAB-TolC efflux pump in African iNTS may reflect evolution within human host populations that are compromised in their ability to clear intracellular Salmonella infections.


Assuntos
Transportadores de Cassetes de Ligação de ATP/genética , Proteínas de Bactérias/genética , Colite/patologia , Variação Genética , Macrófagos/imunologia , Salmonelose Animal/patologia , Salmonella typhimurium/imunologia , Transportadores de Cassetes de Ligação de ATP/metabolismo , Animais , Proteínas de Bactérias/metabolismo , Linhagem da Célula , Colite/induzido quimicamente , Colite/imunologia , Colite/microbiologia , Análise Mutacional de DNA , Modelos Animais de Doenças , Macrófagos/metabolismo , Macrófagos/microbiologia , Camundongos , Camundongos Endogâmicos C57BL , Salmonelose Animal/imunologia , Salmonelose Animal/microbiologia , Replicação Viral
10.
PLoS Pathog ; 16(6): e1008566, 2020 06.
Artigo em Inglês | MEDLINE | ID: mdl-32492066

RESUMO

Host-derived glutathione (GSH) is an essential source of cysteine for the intracellular pathogen Francisella tularensis. In a comprehensive transposon insertion sequencing screen, we identified several F. tularensis genes that play central and previously unappreciated roles in the utilization of GSH during the growth of the bacterium in macrophages. We show that one of these, a gene we named dptA, encodes a proton-dependent oligopeptide transporter that enables growth of the organism on the dipeptide Cys-Gly, a key breakdown product of GSH generated by the enzyme γ-glutamyltranspeptidase (GGT). Although GGT was thought to be the principal enzyme involved in GSH breakdown in F. tularensis, our screen identified a second enzyme, referred to as ChaC, that is also involved in the utilization of exogenous GSH. However, unlike GGT and DptA, we show that the importance of ChaC in supporting intramacrophage growth extends beyond cysteine acquisition. Taken together, our findings provide a compendium of F. tularensis genes required for intracellular growth and identify new players in the metabolism of GSH that could be attractive targets for therapeutic intervention.


Assuntos
Proteínas de Bactérias , Francisella tularensis/fisiologia , Glutationa , Interações Hospedeiro-Patógeno/fisiologia , Macrófagos , Transglutaminases , Tularemia , Animais , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo , Linhagem Celular , Dipeptídeos/genética , Dipeptídeos/metabolismo , Feminino , Glutationa/genética , Glutationa/metabolismo , Macrófagos/metabolismo , Macrófagos/microbiologia , Macrófagos/patologia , Camundongos , Transglutaminases/genética , Transglutaminases/metabolismo , Tularemia/genética , Tularemia/metabolismo
11.
J Med Microbiol ; 69(7): 1020-1033, 2020 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-32589124

RESUMO

Introduction. The incidence of Mycobacterium avium complex (MAC) pulmonary disease (MAC PD), a refractory chronic respiratory tract infection, is increasing worldwide. MAC has three predominant colony morphotypes: smooth opaque (SmO), smooth transparent (SmT) and rough (Rg).Aim. To determine whether colony morphotypes can predict the prognosis of MAC PD, we evaluated the virulence of SmO, SmT and Rg in mice and in human macrophages.Methodology. We compared the characteristics of mice and human macrophages infected with the SmO, SmT, or Rg morphotypes of M. avium subsp. hominissuis 104. C57BL/6 mice and human macrophages derived from peripheral mononuclear cells were used in these experiments.Results. In comparison to SmO- or SmT-infected mice, Rg-infected mice revealed severe pathologically confirmed pneumonia, increased lung weight and increased lung bacterial burden. Rg-infected macrophages revealed significant cytotoxicity, increased bacterial burden, secretion of proinflammatory cytokines (TNF-α and IL-6) and chemokines (CCL5 and CCL3), and formation of cell clusters. Rg formed larger bacterial aggregates than SmO and SmT. Cytotoxicity, bacterial burden and secretion of IL-6, CCL5 and CCL3 were induced strongly by Rg infection, and were decreased by disaggregation of the bacteria.Conclusion. M. avium Rg, which is associated with bacterial aggregation, has the highest virulence among the predominant colony morphotypes.


Assuntos
Macrófagos/metabolismo , Mycobacterium avium/genética , Mycobacterium avium/metabolismo , Animais , Citocinas , Feminino , Humanos , Incidência , Macrófagos/microbiologia , Camundongos , Camundongos Endogâmicos C57BL , Mycobacterium avium/patogenicidade , Complexo Mycobacterium avium/metabolismo , Complexo Mycobacterium avium/patogenicidade , Infecção por Mycobacterium avium-intracellulare/epidemiologia , Infecção por Mycobacterium avium-intracellulare/metabolismo , Fenótipo , Virulência/fisiologia
12.
PLoS Pathog ; 16(5): e1008569, 2020 05.
Artigo em Inglês | MEDLINE | ID: mdl-32463840

RESUMO

Mycobacterial infection leads to activation of the RIG-I/MAVS/TBK1 RNA sensing pathway in macrophages but the consequences of this activation remains poorly defined. In this study, we determined that activation of this RNA sensing pathway stimulates ICAM-1 expression in M.avium-infected macrophage through the inhibition of the E3 ubiquitin ligase CRL4COP1/DET1. CRL4 when active targets the transcription factor ETV5 for degradation by the ubiquitin-proteasome system. In the absence of the ETV5 transcription factor, ICAM-1 expression is significantly decreased. The M.avium-induced ICAM-1 production is required for the formation of immune synapse between infected macrophages and antigen-specific CD4+ T lymphocytes, and is essential for CD4+ T lymphocyte-mediated mycobacterial killing in vitro and in mice. This study demonstrates a previously undefined mechanism by which a host cytosolic RNA sensing pathway contributes to the interplay between mycobacteria infected macrophages and antigen-specific T lymphocytes.


Assuntos
Proteínas Adaptadoras de Transdução de Sinal/imunologia , Linfócitos T CD4-Positivos/imunologia , Proteína DEAD-box 58/imunologia , Macrófagos , Mycobacterium avium/imunologia , Proteínas Serina-Treonina Quinases/imunologia , Tuberculose/imunologia , Proteínas Adaptadoras de Transdução de Sinal/genética , Animais , Linfócitos T CD4-Positivos/microbiologia , Linfócitos T CD4-Positivos/patologia , Proteína DEAD-box 58/genética , Macrófagos/imunologia , Macrófagos/microbiologia , Macrófagos/patologia , Camundongos , Camundongos Knockout , Proteínas Serina-Treonina Quinases/genética , Tuberculose/genética , Tuberculose/patologia
13.
Science ; 368(6494): 973-980, 2020 05 29.
Artigo em Inglês | MEDLINE | ID: mdl-32467386

RESUMO

Bacteria were first detected in human tumors more than 100 years ago, but the characterization of the tumor microbiome has remained challenging because of its low biomass. We undertook a comprehensive analysis of the tumor microbiome, studying 1526 tumors and their adjacent normal tissues across seven cancer types, including breast, lung, ovary, pancreas, melanoma, bone, and brain tumors. We found that each tumor type has a distinct microbiome composition and that breast cancer has a particularly rich and diverse microbiome. The intratumor bacteria are mostly intracellular and are present in both cancer and immune cells. We also noted correlations between intratumor bacteria or their predicted functions with tumor types and subtypes, patients' smoking status, and the response to immunotherapy.


Assuntos
Bactérias/classificação , Microbiota , Neoplasias/microbiologia , Bactérias/genética , Bactérias/isolamento & purificação , Mama/microbiologia , Colo/microbiologia , Feminino , Humanos , Imunoterapia , Pulmão/microbiologia , Macrófagos/microbiologia , Masculino , Neoplasias/terapia , Ovário/microbiologia , RNA Ribossômico 16S/genética
14.
Nat Commun ; 11(1): 2200, 2020 05 04.
Artigo em Inglês | MEDLINE | ID: mdl-32366839

RESUMO

Bacterial persister cells are phenotypic variants that exhibit a transient non-growing state and antibiotic tolerance. Here, we provide in vitro evidence of Staphylococcus aureus persisters within infected host cells. We show that the bacteria surviving antibiotic treatment within host cells are persisters, displaying biphasic killing and reaching a uniformly non-responsive, non-dividing state when followed at the single-cell level. This phenotype is stable but reversible upon antibiotic removal. Intracellular S. aureus persisters remain metabolically active but display an altered transcriptomic profile consistent with activation of stress responses, including the stringent response as well as cell wall stress, SOS and heat shock responses. These changes are associated with multidrug tolerance after exposure to a single antibiotic. We hypothesize that intracellular S. aureus persisters may constitute a reservoir for relapsing infection and could contribute to therapeutic failures.


Assuntos
Antibacterianos/farmacologia , Farmacorresistência Bacteriana Múltipla/efeitos dos fármacos , Viabilidade Microbiana/efeitos dos fármacos , Staphylococcus aureus/efeitos dos fármacos , Células A549 , Animais , Linhagem Celular , Linhagem Celular Tumoral , Células Cultivadas , Farmacorresistência Bacteriana Múltipla/genética , Metabolismo Energético/efeitos dos fármacos , Metabolismo Energético/genética , Perfilação da Expressão Gênica/métodos , Regulação Bacteriana da Expressão Gênica/efeitos dos fármacos , Humanos , Células MCF-7 , Macrófagos/efeitos dos fármacos , Macrófagos/microbiologia , Camundongos , Testes de Sensibilidade Microbiana , Viabilidade Microbiana/genética , Microscopia Confocal , Staphylococcus aureus/genética , Staphylococcus aureus/fisiologia , Células THP-1
15.
PLoS One ; 15(5): e0232251, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32407412

RESUMO

Lipids represent an important source of nutrition for infecting mycobacteria, accumulating within the necrotic core of granulomas and present in foamy macrophages associated with mycobacterial infection. In order to better understand the timing, process and importance of lipid accumulation, we developed methods for direct in vivo visualization and quantification of this process using the zebrafish-M. marinum larval model of infection. We find that neutral lipids accumulate cell-autonomously in mycobacterium-infected macrophages in vivo during early infection, with detectable levels of accumulation by two days post-infection. Treatment with ezetimibe, an FDA-approved drug, resulted in decreased levels of free cholesterol and neutral lipids, and a reduction of bacterial growth in vivo. The effect of ezetimibe in reducing bacterial growth was dependent on the mce4 operon, a key bacterial determinant of lipid utilization. Thus, in vivo, lipid accumulation can occur cell-autonomously at early timepoints of mycobacterial infection, and limitation of this process results in decreased bacterial burden.


Assuntos
Metabolismo dos Lipídeos , Mycobacterium marinum/crescimento & desenvolvimento , Ezetimiba/farmacologia , Macrófagos/metabolismo , Macrófagos/microbiologia , Mutação , Mycobacterium marinum/efeitos dos fármacos , Mycobacterium marinum/genética , Mycobacterium marinum/fisiologia , Óperon/genética
16.
Nat Commun ; 11(1): 2282, 2020 05 08.
Artigo em Inglês | MEDLINE | ID: mdl-32385235

RESUMO

In response to infection, macrophages adapt their metabolism rapidly to enhance glycolysis and fuel specialized antimicrobial effector functions. Here we show that fungal melanin is an essential molecule required for the metabolic rewiring of macrophages during infection with the fungal pathogen Aspergillus fumigatus. Using pharmacological and genetic tools, we reveal a molecular link between calcium sequestration by melanin inside the phagosome and induction of glycolysis required for efficient innate immune responses. By remodeling the intracellular calcium machinery and impairing signaling via calmodulin, melanin drives an immunometabolic signaling axis towards glycolysis with activation of hypoxia-inducible factor 1 subunit alpha (HIF-1α) and phagosomal recruitment of mammalian target of rapamycin (mTOR). These data demonstrate a pivotal mechanism in the immunometabolic regulation of macrophages during fungal infection and highlight the metabolic repurposing of immune cells as a potential therapeutic strategy.


Assuntos
Aspergillus fumigatus/imunologia , Imunidade , Macrófagos/imunologia , Macrófagos/microbiologia , Melaninas/metabolismo , Fagossomos/metabolismo , Animais , Sinalização do Cálcio , Glucose/metabolismo , Glicólise , Humanos , Subunidade alfa do Fator 1 Induzível por Hipóxia/metabolismo , Lactatos/metabolismo , Camundongos Endogâmicos C57BL , Serina-Treonina Quinases TOR/metabolismo , Transcriptoma/genética
17.
Nucleic Acids Res ; 48(11): 6081-6091, 2020 06 19.
Artigo em Inglês | MEDLINE | ID: mdl-32402089

RESUMO

Herein, we characterize the cellular uptake of a DNA structure generated by rolling circle DNA amplification. The structure, termed nanoflower, was fluorescently labeled by incorporation of ATTO488-dUTP allowing the intracellular localization to be followed. The nanoflower had a hydrodynamic diameter of approximately 300 nanometer and was non-toxic for all mammalian cell lines tested. It was internalized specifically by mammalian macrophages by phagocytosis within a few hours resulting in specific compartmentalization in phagolysosomes. Maximum uptake was observed after eight hours and the nanoflower remained stable in the phagolysosomes with a half-life of 12 h. Interestingly, the nanoflower co-localized with both Mycobacterium tuberculosis and Leishmania infantum within infected macrophages although these pathogens escape lysosomal degradation by affecting the phagocytotic pathway in very different manners. These results suggest an intriguing and overlooked potential application of DNA structures in targeted treatment of infectious diseases such as tuberculosis and leishmaniasis that are caused by pathogens that escape the human immune system by modifying macrophage biology.


Assuntos
DNA/química , DNA/metabolismo , Leishmania infantum/metabolismo , Macrófagos/microbiologia , Macrófagos/parasitologia , Mycobacterium tuberculosis/metabolismo , Fagossomos/metabolismo , DNA/análise , Replicação do DNA , Fluorescência , Meia-Vida , Humanos , Leishmaniose/terapia , Macrófagos/citologia , Macrófagos/imunologia , Nanoestruturas/análise , Nanoestruturas/química , Técnicas de Amplificação de Ácido Nucleico , Fagocitose , Fagossomos/química , Fagossomos/microbiologia , Fagossomos/parasitologia , Tuberculose/terapia
18.
Nat Commun ; 11(1): 1949, 2020 04 23.
Artigo em Inglês | MEDLINE | ID: mdl-32327653

RESUMO

Genetic diversity of Mycobacterium tuberculosis affects immune responses and clinical outcomes of tuberculosis (TB). However, how bacterial diversity orchestrates immune responses to direct distinct TB severities is unknown. Here we study 681 patients with pulmonary TB and show that M. tuberculosis isolates from cases with mild disease consistently induce robust cytokine responses in macrophages across multiple donors. By contrast, bacteria from patients with severe TB do not do so. Secretion of IL-1ß is a good surrogate of the differences observed, and thus to classify strains as probable drivers of different TB severities. Furthermore, we demonstrate that M. tuberculosis isolates that induce low levels of IL-1ß production can evade macrophage cytosolic surveillance systems, including cGAS and the inflammasome. Isolates exhibiting this evasion strategy carry candidate mutations, generating sigA recognition boxes or affecting components of the ESX-1 secretion system. Therefore, we provide evidence that M. tuberculosis strains manipulate host-pathogen interactions to drive variable TB severities.


Assuntos
Citosol/imunologia , Interleucina-1beta/metabolismo , Mycobacterium tuberculosis/patogenicidade , Transdução de Sinais/imunologia , Tuberculose Pulmonar/imunologia , Animais , Proteínas de Bactérias/genética , Células Cultivadas , Citocinas/metabolismo , Feminino , Genoma Bacteriano/genética , Humanos , Evasão da Resposta Imune , Imunomodulação , Inflamassomos/imunologia , Macrófagos/imunologia , Macrófagos/microbiologia , Masculino , Camundongos , Mutação , Mycobacterium tuberculosis/classificação , Mycobacterium tuberculosis/genética , Mycobacterium tuberculosis/isolamento & purificação , Filogenia , Polimorfismo de Nucleotídeo Único , Tuberculose Pulmonar/microbiologia , Virulência/genética
19.
Nat Commun ; 11(1): 1960, 2020 04 23.
Artigo em Inglês | MEDLINE | ID: mdl-32327655

RESUMO

Gene rv3722c of Mycobacterium tuberculosis is essential for in vitro growth, and encodes a putative pyridoxal phosphate-binding protein of unknown function. Here we use metabolomic, genetic and structural approaches to show that Rv3722c is the primary aspartate aminotransferase of M. tuberculosis, and mediates an essential but underrecognized role in metabolism: nitrogen distribution. Rv3722c deficiency leads to virulence attenuation in macrophages and mice. Our results identify aspartate biosynthesis and nitrogen distribution as potential species-selective drug targets in M. tuberculosis.


Assuntos
Aspartato Aminotransferases/metabolismo , Ácido Aspártico/metabolismo , Proteínas de Bactérias/metabolismo , Mycobacterium tuberculosis/enzimologia , Nitrogênio/metabolismo , Animais , Aspartato Aminotransferases/química , Aspartato Aminotransferases/genética , Proteínas de Bactérias/química , Proteínas de Bactérias/genética , Células Cultivadas , Feminino , Macrófagos/metabolismo , Macrófagos/microbiologia , Camundongos , Camundongos Endogâmicos C57BL , Mycobacterium tuberculosis/genética , Mycobacterium tuberculosis/crescimento & desenvolvimento , Mycobacterium tuberculosis/patogenicidade , Ligação Proteica , Conformação Proteica , Virulência/genética
20.
PLoS Pathog ; 16(3): e1008364, 2020 03.
Artigo em Inglês | MEDLINE | ID: mdl-32150572

RESUMO

Innate immunity responds to pathogens by producing alarm signals and activating pathways that make host cells inhospitable for pathogen replication. The intracellular bacterium Burkholderia thailandensis invades the cytosol, hijacks host actin, and induces cell fusion to spread to adjacent cells, forming multinucleated giant cells (MNGCs) which promote bacterial replication. We show that type I interferon (IFN) restricts macrophage MNGC formation during B. thailandensis infection. Guanylate-binding proteins (GBPs) expressed downstream of type I IFN were required to restrict MNGC formation through inhibition of bacterial Arp2/3-dependent actin motility during infection. GTPase activity and the CAAX prenylation domain were required for GBP2 recruitment to B. thailandensis, which restricted bacterial actin polymerization required for MNGC formation. Consistent with the effects in in vitro macrophages, Gbp2-/-, Gbp5-/-, GbpChr3-KO mice were more susceptible to intranasal infection with B. thailandensis than wildtype mice. Our findings reveal that IFN and GBPs play a critical role in restricting cell-cell fusion and bacteria-induced pathology during infection.


Assuntos
Infecções por Burkholderia/imunologia , Burkholderia/imunologia , Proteínas de Ligação ao GTP/imunologia , Células Gigantes/imunologia , Macrófagos/imunologia , Doenças Nasais/imunologia , Prenilação de Proteína/imunologia , Animais , Infecções por Burkholderia/genética , Infecções por Burkholderia/patologia , Fusão Celular , Proteínas de Ligação ao GTP/genética , Células Gigantes/microbiologia , Células Gigantes/patologia , Interferon Tipo I/genética , Interferon Tipo I/imunologia , Macrófagos/microbiologia , Macrófagos/patologia , Camundongos , Camundongos Knockout , Doenças Nasais/genética , Doenças Nasais/microbiologia , Doenças Nasais/patologia
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