RESUMEN
Pseudomonas aeruginosa is a ubiquitous nosocomial opportunistic pathogen that harbors many virulence determinants. Part of P. aeruginosa success colonizing a variety of habitats resides in its metabolic robustness and plasticity, which are the basis of its capability of adaptation to different nutrient sources and ecological conditions, including the infected host. Given this situation, it is conceivable that P. aeruginosa virulence might be, at least in part, under metabolic control, in such a way that virulence determinants are produced just when needed. Indeed, it has been shown that the catabolite repression control protein Crc, which together with the RNA chaperon Hfq regulates the P. aeruginosa utilization of carbon sources at the post-transcriptional level, also regulates, directly or indirectly, virulence-related processes in P. aeruginosa. Among them, Crc regulates P. aeruginosa cytotoxicity, likely by modulating the activity of the Type III Secretion System (T3SS), which directly injects toxins into eukaryotic host cells. The present work shows that the lack of Crc produces a Type III Secretion-defective phenotype in P. aeruginosa. The observed impairment is a consequence of a reduced expression of the genes encoding the T3SS, together with an impaired secretion of the proteins involved. Our results support that the impaired T3SS activity of the crc defective mutant is, at least partly, a consequence of a defective protein export, probably due to a reduced proton motive force. This work provides new information about the complex regulation of the expression and the activity of the T3SS in P. aeruginosa. Our results highlight the need of a robust bacterial metabolism, which is defective in the ∆crc mutant, to elicit complex and energetically costly virulence strategies, as that provided by the T3SS.
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Pseudomonas aeruginosa , Sistemas de Secreción Tipo III , Sistemas de Secreción Tipo III/genética , Sistemas de Secreción Tipo III/metabolismo , Virulencia/genética , Pseudomonas aeruginosa/metabolismo , Factores de Virulencia/metabolismo , Fenómenos Fisiológicos Celulares , Proteínas Bacterianas/genética , Proteínas Bacterianas/metabolismo , Regulación Bacteriana de la Expresión GénicaRESUMEN
Macrophages are involved in the primary human response to Candida albicans. After pathogen recognition, signaling pathways are activated, leading to the production of cytokines, chemokines, and antimicrobial peptides. ATP binding proteins are crucial for this regulation. Here, a quantitative proteomic and phosphoproteomic approach was carried out for the study of human macrophage ATP-binding proteins after interaction with C. albicans. From a total of 547 nonredundant quantified proteins, 137 were ATP binding proteins and 59 were detected as differentially abundant. From the differentially abundant ATP-binding proteins, 6 were kinases (MAP2K2, SYK, STK3, MAP3K2, NDKA, and SRPK1), most of them involved in signaling pathways. Furthermore, 85 phosphopeptides were quantified. Macrophage proteomic alterations including an increase of protein synthesis with a consistent decrease in proteolysis were observed. Besides, macrophages showed changes in proteins of endosomal trafficking together with mitochondrial proteins, including some involved in the response to oxidative stress. Regarding cell death mechanisms, an increase of antiapoptotic over pro-apoptotic signals is suggested. Furthermore, a high pro-inflammatory response was detected, together with no upregulation of key mi-RNAs involved in the negative feedback of this response. These findings illustrate a strategy to deepen the knowledge of the complex interactions between the host and the clinically important pathogen C. albicans.
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Proteínas Reguladoras de la Apoptosis/genética , Candida albicans/crecimiento & desarrollo , Proteínas Portadoras/genética , Interacciones Huésped-Patógeno , Proteínas Mitocondriales/genética , Fosfoproteínas/genética , Adenosina Trifosfato/inmunología , Adenosina Trifosfato/metabolismo , Proteínas Reguladoras de la Apoptosis/clasificación , Proteínas Reguladoras de la Apoptosis/inmunología , Candida albicans/patogenicidad , Proteínas Portadoras/clasificación , Proteínas Portadoras/inmunología , Muerte Celular/genética , Muerte Celular/inmunología , Retroalimentación Fisiológica , Humanos , Marcaje Isotópico , Proteínas Mitocondriales/clasificación , Proteínas Mitocondriales/inmunología , Fagocitosis/inmunología , Fosfopéptidos/química , Fosfopéptidos/aislamiento & purificación , Fosfoproteínas/clasificación , Fosfoproteínas/inmunología , Biosíntesis de Proteínas , Mapeo de Interacción de Proteínas , Proteómica/métodos , Transducción de Señal , Células THP-1RESUMEN
The effectiveness of macrophages in the response to systemic candidiasis is crucial to an effective clearance of the pathogen. The secretion of proteins, mRNAs, noncoding RNAs and lipids through extracellular vesicles (EVs) is one of the mechanisms of communication between immune cells. EVs change their cargo to mediate different responses, and may play a role in the response against infections. Thus we have undertaken the first quantitative proteomic analysis on the protein composition of THP-1 macrophage-derived EVs during the interaction with Candida albicans. This study revealed changes in EVs sizes and in protein composition, and allowed the identification and quantification of 717 proteins. Of them, 133 proteins changed their abundance due to the interaction. The differentially abundant proteins were involved in functions relating to immune response, signaling, or cytoskeletal reorganization. THP-1-derived EVs, both from control and from Candida-infected macrophages, had similar effector functions on other THP-1-differenciated macrophages, activating ERK and p38 kinases, and increasing both the secretion of proinflammatory cytokines and the candidacidal activity; while in THP-1 nondifferenciated monocytes, only EVs from infected macrophages increased significantly the TNF-α secretion. Our findings provide new information on the role of macrophage-derived EVs in response to C. albicans infection and in macrophages communication.
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Candida albicans/patogenicidad , Vesículas Extracelulares/inmunología , Interacciones Huésped-Patógeno/inmunología , Macrófagos/inmunología , Proteoma/inmunología , Candida albicans/crecimiento & desarrollo , Diferenciación Celular , Línea Celular , Biología Computacional , Citocinas/genética , Citocinas/inmunología , Citoesqueleto/inmunología , Citoesqueleto/microbiología , Quinasas MAP Reguladas por Señal Extracelular/genética , Quinasas MAP Reguladas por Señal Extracelular/inmunología , Vesículas Extracelulares/química , Vesículas Extracelulares/microbiología , Regulación de la Expresión Génica/inmunología , Ontología de Genes , Humanos , Macrófagos/microbiología , Anotación de Secuencia Molecular , Proteoma/genética , Transducción de Señal , Factor de Necrosis Tumoral alfa/genética , Factor de Necrosis Tumoral alfa/inmunologíaRESUMEN
In response to different stimuli, macrophages can differentiate into either a pro-inflammatory subtype (M1, classically activated macrophages) or acquire an anti-inflammatory phenotype (M2, alternatively activated macrophages). Candida albicans is the most important opportunistic fungus in nosocomial infections, and it is contended by neutrophils and macrophages during the first steps of the invasive infection. Murine macrophages responses to C. albicans have been widely studied, whereas the responses of human-polarized macrophages remain less characterized. In this study, we have characterized the proteomic differences between human M1- and M2-polarized macrophages, both in basal conditions and in response to C. albicans, by quantitative proteomics (2DE). This proteomic approach allowed us to identify metabolic routes and cytoskeletal rearrangement components that are the most relevant differences between M1 and M2 macrophages. The analysis has revealed fructose-1,6-bisphosphatase 1, a critical enzyme in gluconeogenesis, up-regulated in M1, as a novel protein marker for macrophage polarization. Regarding the response to C. albicans, an M1-to-M2 switch in polarization was observed. This M1-to-M2 switch might contribute to Candida pathogenicity by decreasing the generation of specific immune responses, thus enhancing fungal survival and colonization, or instead, may be part of the host attempt to reduce the inflammation and limit the damage of the infection.
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Antiinflamatorios/metabolismo , Biomarcadores/análisis , Candida albicans/metabolismo , Candidiasis/metabolismo , Inflamación/metabolismo , Macrófagos/metabolismo , Macrófagos/microbiología , Western Blotting , Candida albicans/patogenicidad , Candidiasis/inmunología , Candidiasis/microbiología , Células Cultivadas , Citocinas/genética , Citocinas/metabolismo , Electroforesis en Gel Bidimensional , Ensayo de Inmunoadsorción Enzimática , Humanos , Inflamación/inmunología , Inflamación/microbiología , Macrófagos/inmunología , Microscopía Fluorescente , Fagocitosis , Proteómica , ARN Mensajero/genética , Reacción en Cadena en Tiempo Real de la Polimerasa , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Espectrometría de Masa por Láser de Matriz Asistida de Ionización DesorciónRESUMEN
Engineered T cells transiently expressing tumor-targeting receptors are an attractive form of engineered T cell therapy as they carry no risk of insertional mutagenesis or long-term adverse side-effects. However, multiple rounds of treatment are often required, increasing patient discomfort and cost. To mitigate this, we sought to improve the antitumor activity of transient engineered T cells by screening a panel of small molecules targeting epigenetic regulators for their effect on T cell cytotoxicity. Using a model for engineered T cells targetting hepatocellular carcinoma, we find that short-term inhibition of G9a/GLP increases T cell antitumor activity in in vitro models and an orthotopic mouse model. G9a/GLP inhibition increases granzyme expression without terminal T cell differentiation or exhaustion and results in specific changes in expression of genes and proteins involved in pro-inflammatory pathways, T cell activation and cytotoxicity.
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Carcinoma Hepatocelular , Neoplasias Hepáticas , Ratones , Animales , Carcinoma Hepatocelular/genética , Carcinoma Hepatocelular/terapia , Linfocitos T , Neoplasias Hepáticas/genética , Neoplasias Hepáticas/terapia , Modelos Animales de EnfermedadRESUMEN
Despite diagnostic and therapeutic advances, liver cancer kills more than 18 million people every year worldwide, urging new strategies to model the disease and to improve the current therapeutic options. In vitro tumor models of human cancer continue to evolve, and they represent an important screening tool. However, there is a tremendous need to improve the physiological relevance and reliability of these in vitro models to fulfill today's research requirements for better understanding of cancer progression and treatment options at different stages of the disease. This review describes the hepatocellular carcinoma microenvironmental characteristics and illustrates the current immunotherapy strategy to fight the disease. Moreover, we present a recent collection of 2D and 3D in vitro liver cancer models and address the next generation of in vitro systems recapitulating the tumor microenvironment complexity in more detail.
RESUMEN
Serial passaging of the human fungal pathogen Candida albicans in the gastrointestinal tract of antibiotics-treated mice selects for virulence-attenuated strains. These gut-evolved strains protect the host from infection by a wide range of pathogens via trained immunity. Here, we further investigated the molecular and cellular mechanisms underlying this innate immune memory. Both Dectin-1 (the main receptor for ß-glucan; a well-described immune training molecule in the fungal cell wall) and Nod2 (a receptor described to mediate BCG-induced trained immunity), were redundant for the protection induced by gut-evolved C. albicans against a virulent C. albicans strain, suggesting that gut-evolved C. albicans strains induce trained immunity via other pathways. Cytometry by time of flight (CyTOF) analysis of mouse splenocytes revealed that immunization with gut-evolved C. albicans resulted in an expansion of neutrophils and a reduction in natural killer (NK) cells, but no significant numeric changes in monocytes, macrophages or dendritic cell populations. Systemic depletion of phagocytes or neutrophils, but not of macrophages or NK cells, reduced protection mediated by gut-evolved C. albicans. Splenocytes and bone marrow cells of mice immunized with gut-evolved C. albicans demonstrated metabolic changes. In particular, splenic neutrophils displayed significantly elevated glycolytic and respiratory activity in comparison to those from mock-immunized mice. Although further investigation is required for fully deciphering the trained immunity mechanism induced by gut-evolved C. albicans strains, this data is consistent with the existence of several mechanisms of trained immunity, triggered by different training stimuli and involving different immune molecules and cell types.
Asunto(s)
Candida albicans , beta-Glucanos , Animales , Pared Celular , Macrófagos , Ratones , NeutrófilosRESUMEN
Murine macrophages (RAW 264.7) were allowed to interact with heat-inactivated cells of Candida albicans SC5314 during 45 min. The proteomic response of the macrophages was then analyzed using 2-D gel electrophoresis. Many proteins having differential expression with respect to control macrophages were identified, and their functions were related to important processes, such as cytoskeletal organization, signal transduction, metabolism, protein biosynthesis, stress response and protein fate. Several of these proteins have been described as being involved in the process of inflammation, such as Erp29, Hspa9a, AnxaI, Ran GTPase, P4hb, Clic1 and Psma1. The analysis of the consequences of their variation unravels an overall anti-inflammatory response of macrophages during the interaction with heat-inactivated cells. This result was corroborated by the measurement of TNF-alpha and of ERK1/2 phosphorylation levels. This anti-inflammatory effect was contrary to the one observed with live C. albicans cells, which induced higher TNF-alpha secretion and higher ERK1/2 phosphorylation levels with respect to control macrophages.
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Candida albicans/fisiología , Macrófagos/microbiología , Proteómica/métodos , Animales , Candida albicans/inmunología , Candida albicans/metabolismo , Línea Celular Tumoral , Citoplasma/química , Electroforesis en Gel Bidimensional , Inflamación , Macrófagos/inmunología , Macrófagos/metabolismo , Ratones , Proteínas Quinasas Activadas por Mitógenos/metabolismo , Transducción de Señal , Factor de Necrosis Tumoral alfa/metabolismoRESUMEN
Bacterial physiology is regulated at different levels, from mRNA synthesis to translational regulation and protein modification. Herein, we propose a parameter, dubbed post-transcriptional variation (PTV), that allows extracting information on post-transcriptional regulation from the combined analysis of transcriptomic and proteomic data. We have applied this parameter for getting a deeper insight in the regulon of the Pseudomonas aeruginosa post-transcriptional regulator Crc. P. aeruginosa is a free-living microorganism, and part of its ecological success relies on its capability of using a large number of carbon sources. The hierarchical assimilation of these sources when present in combination is regulated by Crc that, together with Hfq (the RNA-binding chaperon in the complex), impedes their translation when catabolite repression is triggered. Most studies on Crc regulation are based either in transcriptomics or in proteomics data, which cannot provide information on post-transcriptional regulation when analysed independently. Using the PTV parameter, we present a comprehensive map of the Crc post-transcriptional regulon. In addition of controlling the use of primary and secondary carbon sources, Crc regulates as well cell respiration, c-di-GMP mediated signalling, and iron utilization. Thus, besides controlling the hyerarchical assimilation of carbon sources, Crc is an important element for keeping bacterial homeostasis and, consequently, metabolic robustness.
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Regulación Bacteriana de la Expresión Génica , Pseudomonas aeruginosa/genética , Regulón/genética , Proteínas Bacterianas/análisis , Proteínas Bacterianas/genética , Proteínas Bacterianas/fisiología , Represión Catabólica , Perfilación de la Expresión Génica/métodos , Métodos , Proteómica/métodos , ARN Bacteriano/análisis , ARN Bacteriano/genética , Proteínas Represoras/fisiologíaRESUMEN
Candidemia is a bloodstream fungal infection caused by Candida species and is most commonly observed in hospitalized patients. Even with proper antifungal drug treatment, mortality rates remain high at 40-50%. Therefore, prophylactic or preemptive antifungal medications are currently recommended in order to prevent infections in high-risk patients. Moreover, the majority of women experience at least one episode of vulvovaginal candidiasis (VVC) throughout their lifetime and many of them suffer from recurrent VVC (RVVC) with frequent relapses for the rest of their lives. While there currently exists no definitive cure, the only available treatment for RVVC is again represented by antifungal drug therapy. However, due to the limited number of existing antifungal drugs, their associated side effects and the increasing occurrence of drug resistance, other approaches are greatly needed. An obvious prevention measure for candidemia or RVVC relapse would be to immunize at-risk patients with a vaccine effective against Candida infections. In spite of the advanced and proven techniques successfully applied to the development of antibacterial or antiviral vaccines, however, no antifungal vaccine is still available on the market. In this review, we first summarize various efforts to date in the development of anti-Candida vaccines, highlighting advantages and disadvantages of each strategy. We next unfold and discuss general hurdles encountered along these efforts, such as the existence of large genomic variation and phenotypic plasticity across Candida strains and species, and the difficulty in mounting protective immune responses in immunocompromised or immunosuppressed patients. Lastly, we review the concept of "trained immunity" and discuss how induction of this rapid and nonspecific immune response may potentially open new and alternative preventive strategies against opportunistic infections by Candida species and potentially other pathogens.
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Candida/inmunología , Candidemia/prevención & control , Candidiasis Vulvovaginal/prevención & control , Vacunas Fúngicas/inmunología , Infecciones Oportunistas/prevención & control , Antifúngicos/farmacología , Antifúngicos/uso terapéutico , Candida/efectos de los fármacos , Candidemia/tratamiento farmacológico , Candidemia/inmunología , Candidemia/microbiología , Candidiasis Vulvovaginal/tratamiento farmacológico , Candidiasis Vulvovaginal/inmunología , Candidiasis Vulvovaginal/microbiología , Farmacorresistencia Fúngica/inmunología , Femenino , Vacunas Fúngicas/uso terapéutico , Humanos , Huésped Inmunocomprometido/inmunología , Infecciones Oportunistas/tratamiento farmacológico , Infecciones Oportunistas/inmunología , Infecciones Oportunistas/microbiología , Resultado del TratamientoRESUMEN
Gut microbes live in symbiosis with their hosts, but how mutualistic animal-microbe interactions emerge is not understood. By adaptively evolving the opportunistic fungal pathogen Candida albicans in the mouse gastrointestinal tract, we selected strains that not only had lost their main virulence program but also protected their new hosts against a variety of systemic infections. This protection was independent of adaptive immunity, arose as early as a single day postpriming, was dependent on increased innate cytokine responses, and was thus reminiscent of "trained immunity." Because both the microbe and its new host gain some advantages from their interaction, this experimental system might allow direct study of the evolutionary forces that govern the emergence of mutualism between a mammal and a fungus.
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Inmunidad Adaptativa , Candida albicans/inmunología , Candida albicans/patogenicidad , Microbioma Gastrointestinal/inmunología , Tracto Gastrointestinal/microbiología , Interacciones Huésped-Patógeno , Animales , Evolución Biológica , Candida albicans/genética , Candida albicans/crecimiento & desarrollo , Proteínas Fúngicas/genética , Ratones , Ratones Endogámicos C57BL , Mutación , Simbiosis , Factores de Transcripción/genética , Factores de Virulencia/genéticaRESUMEN
Bacterial multidrug efflux pumps are antibiotic resistance determinants present in all microorganisms. With few exceptions, they are chromosomally encoded and present a conserved organization both at the genetic and at the protein levels. In addition, most, if not all, strains of a given bacterial species present the same chromosomally-encoded efflux pumps. Altogether this indicates that multidrug efflux pumps are ancient elements encoded in bacterial genomes long before the recent use of antibiotics for human and animal therapy. In this regard, it is worth mentioning that efflux pumps can extrude a wide range of substrates that include, besides antibiotics, heavy metals, organic pollutants, plant-produced compounds, quorum sensing signals or bacterial metabolites, among others. In the current review, we present information on the different functions that multidrug efflux pumps may have for the bacterial behaviour in different habitats as well as on their regulation by specific signals. Since, in addition to their function in non-clinical ecosystems, multidrug efflux pumps contribute to intrinsic, acquired, and phenotypic resistance of bacterial pathogens, the review also presents information on the search for inhibitors of multidrug efflux pumps, which are currently under development, in the aim of increasing the susceptibility of bacterial pathogens to antibiotics.
RESUMEN
Recent research indicates that the post-transcriptional regulator Crc modulates susceptibility to antibiotics and virulence in Pseudomonas aeruginosa. Several P. aeruginosa virulence factors are secreted or engulfed in vesicles. To decipher the Crc modulation of P. aeruginosa virulence, we constructed a crc deficient mutant and measure the proteome associated extracellular vesicles and the vesicle-free secretome using iTRAQ. Fifty vesicle-associated proteins were more abundant and 14 less abundant in the crc-defective strain, whereas 37 were more abundant and 17 less abundant in the vesicle-free secretome. Among them, virulence determinants, such as ToxA, protease IV, azurin, chitin-binding protein, PlcB and Hcp1, were less abundant in the crc-defective mutant. Transcriptomic analysis revealed that some of the observed changes were post-transcriptional and, thus, could be attributed to a direct Crc regulatory role; whereas, for other differentially secreted proteins, the regulatory role was likely indirect. We also observed that the crc mutant presented an impaired vesicle-associated secretion of quorum sensing signal molecules and less cytotoxicity than its wild-type strain. Our results offer new insights into the mechanisms by which Crc regulates P. aeruginosa virulence, through the modulation of vesicle formation and secretion of both virulence determinants and quorum sensing signals. This article is part of a Special Issue entitled: HUPO 2014.
Asunto(s)
Proteínas Bacterianas/metabolismo , Mutación , Proteómica/métodos , Pseudomonas aeruginosa/metabolismo , Proteínas Represoras/metabolismo , Vesículas Secretoras/metabolismo , Factores de Virulencia/metabolismo , Proteínas Bacterianas/genética , Pseudomonas aeruginosa/genética , Proteínas Represoras/genética , Vesículas Secretoras/genéticaRESUMEN
Crc is a post-transcriptional regulator in Pseudomonas aeruginosa that modulates its metabolism, but also its susceptibility to antibiotics and virulence. Most of P. aeruginosa virulence factors are secreted or engulfed in vesicles. A Crc deficient mutant was created and the extracellular vesicles associated exoproteome and the vesicle-free secretome was quantified using iTRAQ. Fifty vesicles-associated proteins were more abundant and 14 less abundant in the Crc-defective strain, whereas 37 were more abundant and 17 less abundant in the vesicle-free secretome. Different virulence determinants, such as ToxA, protease IV, azurin, chitin-binding protein, PlcB and Hcp1, were less abundant in the Crc-defective mutant. We also observed that the crc mutant presented an impaired vesicle-associated secretion of quorum sensing signal molecules and less cytotoxicity than its wild-type strain, in agreement with the low secretion of proteins related to virulence. Our results offer new insights into the mechanisms by which Crc regulates P. aeruginosa virulence, through the modulation of vesicle formation and secretion of both virulence determinants and quorum sensing signals.
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The ability to switch from yeast to hyphal growth is essential for virulence in Candida albicans. The cell surface is the initial point of contact between the fungus and the host. In this work, a free-gel proteomic strategy based on tryptic digestion of live yeast and hyphae cells and protein identification using LC-MS/MS methodology was used to identify cell surface proteins. Using this strategy, a total of 943 proteins were identified, of which 438 were in yeast and 928 were in hyphae. Of these proteins, 79 were closely related to the organization and biogenesis of the cell wall, including 28 GPI-anchored proteins, such as Hyr1 and Sod5 which were detected exclusively in hyphae, and Als2 and Sap10which were detected only in yeast. A group of 17 proteins of unknown function were subsequently studied by analysis of the corresponding deletion mutants. We found that four new proteins, Pst3, Tos1, Orf19.3060 and Orf19.5352 are involved in cell wall integrity and in C. albicans' engulfment by macrophages. Moreover, the putative NADH-ubiquinone-related proteins, Ali1, Mci4, Orf19.287 and Orf19.7590, are also involved in osmotic and oxidative resistance, yeast to hypha transition and the ability to damage and invade oral epithelial cells. This article is part of a Special Issue entitled: HUPO 2014.
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Candida albicans/fisiología , Pared Celular/metabolismo , Proteínas Fúngicas/metabolismo , Interacciones Huésped-Patógeno , Hifa/metabolismo , Estrés Fisiológico , Animales , Línea Celular , HumanosRESUMEN
Macrophages play a pivotal role in the prevention of Candida albicans infections. Yeast recognition and phagocytosis by macrophages is mediated by Pattern Recognition Receptors (PRRs) that initiate downstream signal transduction cascades by protein phosphorylation and dephosphorylation. We exposed RAW 264.7 macrophages to C. albicans for 3h and used SILAC to quantify macrophage proteins and phosphoproteins by mass spectrometry to study the effects of infection. We identified 53 macrophage up-regulated proteins and 15 less abundant in the presence of C. albicans out of a total of 2071 identified proteins. 922 unique protein phosphorylation sites were identified by phosphopeptide enrichment and mass spectrometry, including 327 previously unidentified mouse protein phosphorylation sites. 126 peptides showed an increase and 70 a decrease in their phosphorylation level. The majority of the differentially expressed and phosphorylated proteins are receptors, mitochondrial ribosomal proteins, cytoskeletal proteins, and transcription factor activators involved in inflammatory and oxidative responses. In addition, we identified 22 proteins and phosphoproteins related to apoptosis. The analysis of apoptotic markers revealed that anti-apoptotic signals prevailed during the interaction of the yeast. Our proteomics study suggests that besides inflammation, apoptosis is a central pathway in the immune defense against C. albicans infection. BIOLOGICAL SIGNIFICANCE: This work uses SILAC and SIMAC methodology combined with CPP (+ TiO2) to study protein and phosphopeptide changes in RAW 264.7 macrophages in response to coincubation with Candida albicans for 3h. We show that the presence of C. albicans induces inflammatory responses and inhibits apoptosis in the macrophages. Our phosphoproteomic analysis identified 327 new mouse protein phosphorylation sites.
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Apoptosis , Candida albicans/metabolismo , Inflamación/metabolismo , Macrófagos/microbiología , Macrófagos/patología , Fosfoproteínas/química , Animales , Línea Celular , Cromatina/química , Citoesqueleto/metabolismo , Ratones , Péptidos/química , Fagocitosis , Fosforilación , Proteómica , Transducción de Señal , Vimentina/químicaRESUMEN
In previous proteomic studies on the response of murine macrophages against Candida albicans, many differentially expressed proteins involved in processes like inflammation, cytoskeletal rearrangement, stress response and metabolism were identified. In order to look for proteins important for the macrophage response, but in a lower concentration in the cell, 3 sub-cellular extracts were analyzed: cytosol, organelle/membrane and nucleus enriched fractions from RAW 264.7 macrophages exposed or not to C. albicans SC5314 for 3 h. The samples were studied using DIGE technology, and 17 new differentially expressed proteins were identified. This sub-cellular fractionation permitted the identification of 2 mitochondrion proteins, a membrane receptor, Galectin-3, and some ER related proteins, that are not easily detected in total cell extracts. Besides, the study of different fractions allowed us to detect, not only total increase in Galectin-3 protein amount, but its distinct allocation along the interaction. The identified proteins are involved in the pro-inflammatory and oxidative responses, immune response, unfolded protein response and apoptosis. Some of these processes increase the host response and others could be the effect of C. albicans resistance to phagocytosis. Thus, the sub-proteomic approach has been a very useful tool to identify new proteins involved in macrophage-fungus interaction. This article is part of a Special Issue entitled: Translational Proteomics.