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1.
Nature ; 582(7810): 109-114, 2020 06.
Artigo em Inglês | MEDLINE | ID: mdl-32494068

RESUMO

Advances in genetics and sequencing have identified a plethora of disease-associated and disease-causing genetic alterations. To determine causality between genetics and disease, accurate models for molecular dissection are required; however, the rapid expansion of transcriptional populations identified through single-cell analyses presents a major challenge for accurate comparisons between mutant and wild-type cells. Here we generate mouse models of human severe congenital neutropenia (SCN) using patient-derived mutations in the GFI1 transcription factor. To determine the effects of SCN mutations, we generated single-cell references for granulopoietic genomic states with linked epitopes1, aligned mutant cells to their wild-type equivalents and identified differentially expressed genes and epigenetic loci. We find that GFI1-target genes are altered sequentially, as cells go through successive states of differentiation. These insights facilitated the genetic rescue of granulocytic specification but not post-commitment defects in innate immune effector function, and underscore the importance of evaluating the effects of mutations and therapy within each relevant cell state.


Assuntos
Modelos Animais de Doenças , Células Precursoras de Granulócitos/patologia , Mutação , Neutropenia/genética , Neutropenia/patologia , Neutrófilos/patologia , Animais , Candida albicans/imunologia , Candida albicans/patogenicidade , Linhagem da Célula , Proteínas de Ligação a DNA/genética , Feminino , Humanos , Imunidade Inata , Masculino , Camundongos , Camundongos Transgênicos , Neutropenia/congênito , Neutropenia/imunologia , Neutrófilos/imunologia , Fatores de Transcrição/genética
3.
PLoS Pathog ; 16(4): e1008408, 2020 04.
Artigo em Inglês | MEDLINE | ID: mdl-32251450

RESUMO

Candida bloodstream infection, i.e. candidemia, is the most frequently encountered life-threatening fungal infection worldwide, with mortality rates up to almost 50%. In the majority of candidemia cases, Candida albicans is responsible. Worryingly, a global increase in the number of patients who are susceptible to infection (e.g. immunocompromised patients), has led to a rise in the incidence of candidemia in the last few decades. Therefore, a better understanding of the anti-Candida host response is essential to overcome this poor prognosis and to lower disease incidence. Here, we integrated genome-wide association studies with bulk and single-cell transcriptomic analyses of immune cells stimulated with Candida albicans to further our understanding of the anti-Candida host response. We show that differential expression analysis upon Candida stimulation in single-cell expression data can reveal the important cell types involved in the host response against Candida. This confirmed the known major role of monocytes, but more interestingly, also uncovered an important role for NK cells. Moreover, combining the power of bulk RNA-seq with the high resolution of single-cell RNA-seq data led to the identification of 27 Candida-response QTLs and revealed the cell types potentially involved herein. Integration of these response QTLs with a GWAS on candidemia susceptibility uncovered a potential new role for LY86 in candidemia susceptibility. Finally, experimental follow-up confirmed that LY86 knockdown results in reduced monocyte migration towards the chemokine MCP-1, thereby implying that this reduced migration may underlie the increased susceptibility to candidemia. Altogether, our integrative systems genetics approach identifies previously unknown mechanisms underlying the immune response to Candida infection.


Assuntos
Antígenos de Superfície/genética , Antígenos de Superfície/imunologia , Candida albicans/fisiologia , Candidíase/genética , Candida albicans/imunologia , Candidemia/genética , Candidemia/imunologia , Candidemia/microbiologia , Candidíase/imunologia , Candidíase/microbiologia , Estudos de Coortes , Predisposição Genética para Doença , Estudo de Associação Genômica Ampla , Humanos , Células Matadoras Naturais , Análise de Sequência de RNA , Análise de Célula Única
4.
Adv Exp Med Biol ; 1204: 1-30, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32152941

RESUMO

Most fungal species are harmless to humans and some exist as commensals on mucocutaneous surfaces. Yet many fungi are opportunistic pathogens, causing life-threatening invasive infections when the immune system becomes compromised. The fungal cell wall contains conserved pathogen-associated molecular patterns (PAMPs), which allow the immune system to distinguish between self (endogenous molecular patterns) and foreign material. Sensing of invasive microbial pathogens is achieved through recognition of PAMPs by pattern recognition receptors (PRRs). One of the predominant fungal-sensing PRRs is the C-type lectin receptor (CLR) family. These receptors bind to structures present on the fungal cell wall, eliciting various innate immune responses as well as shaping adaptive immunity. In this chapter, we specifically focus on the four major human fungal pathogens, Candida albicans, Aspergillus fumigatus, Cryptococcus neoformans and Pneumocystis jirovecii, reviewing our current understanding of the CLRs that are involved in their recognition and protection of the host.


Assuntos
Fungos/imunologia , Imunidade Inata/imunologia , Lectinas Tipo C/imunologia , Aspergillus fumigatus/imunologia , Candida albicans/imunologia , Cryptococcus neoformans/imunologia , Humanos , Padrões Moleculares Associados a Patógenos/imunologia , Pneumocystis carinii/imunologia
5.
Infect Immun ; 88(4)2020 03 23.
Artigo em Inglês | MEDLINE | ID: mdl-31932331

RESUMO

Candida albicans is a pervasive commensal fungus that is the most common pathogen responsible for invasive fungal infection (IFI). With incidence of IFI on the rise due to increasing susceptible populations, it is imperative that we investigate how Candida albicans interacts with blood components. When stimulating either human or mouse whole blood with thrombin, we saw a significant decrease in C. albicans survival. We then repeated Candida killing assays with thrombin-stimulated or unstimulated washed platelets and saw a similar decrease in CFU. To investigate whether killing was mediated through surface components or releasable products, platelets were pretreated with an inhibitor of actin polymerization (cytochalasin D [CytoD]). CytoD was able to abrogate C. albicans killing. Moreover, dilution of releasates from thrombin-stimulated platelets showed that the toxicity of the releasates on C. albicans is concentration dependent. We then investigated C. albicans actions on platelet activation, granule release, and aggregation. While C. albicans does not appear to affect alpha or dense granule release, C. albicans exerts a significant attenuation of platelet aggregation to multiple agonists. These results illustrate for the first time that platelets can directly kill C. albicans through release of their granular contents. Additionally, C. albicans can also exert inhibitory effects on platelet aggregation.


Assuntos
Antifúngicos/metabolismo , Plaquetas/metabolismo , Plaquetas/microbiologia , Candida albicans/imunologia , Fatores Imunológicos/metabolismo , Animais , Candida albicans/fisiologia , Contagem de Colônia Microbiana , Humanos , Camundongos , Viabilidade Microbiana/efeitos dos fármacos
6.
PLoS Pathog ; 15(12): e1008115, 2019 12.
Artigo em Inglês | MEDLINE | ID: mdl-31887131

RESUMO

The opportunistic fungal pathogen Candida albicans can cause invasive infections in susceptible hosts and the innate immune system, in particular myeloid cell-mediated immunity, is critical for rapid immune protection and host survival during systemic candidiasis. Using a mouse model of the human disease, we identified a novel role of IL-23 in antifungal defense. IL-23-deficient mice are highly susceptible to systemic infection with C. albicans. We found that this results from a drastic reduction in all subsets of myeloid cells in the infected kidney, which in turn leads to rapid fungal overgrowth and renal tissue injury. The loss in myeloid cells is not due to a defect in emergency myelopoiesis or the recruitment of newly generated cells to the site of infection but, rather, is a consequence of impaired survival of myeloid cells at the site of infection. In fact, the absence of a functional IL-23 pathway causes massive myeloid cell apoptosis upon C. albicans infection. Importantly, IL-23 protects myeloid cells from apoptosis independently of the IL-23-IL-17 immune axis and independently of lymphocytes and innate lymphoid cells. Instead, our results suggest that IL-23 acts in a partially autocrine but not cell-intrinsic manner within the myeloid compartment to promote host protection from systemic candidiasis. Collectively, our data highlight an unprecedented and non-canonical role of IL-23 in securing survival of myeloid cells, which is key for maintaining sufficient numbers of cells at the site of infection to ensure efficient host protection.


Assuntos
Candida albicans/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Imunidade Inata/efeitos dos fármacos , Interleucina-23/farmacologia , Células Progenitoras Mieloides/efeitos dos fármacos , Animais , Candida albicans/imunologia , Interações Hospedeiro-Patógeno/efeitos dos fármacos , Interações Hospedeiro-Patógeno/imunologia , Interleucina-17/metabolismo , Interleucina-23/metabolismo , Linfócitos/efeitos dos fármacos , Linfócitos/metabolismo , Camundongos Endogâmicos C57BL , Células Mieloides/metabolismo
7.
Nat Commun ; 10(1): 5315, 2019 11 22.
Artigo em Inglês | MEDLINE | ID: mdl-31757950

RESUMO

To colonise their host, pathogens must counter local environmental and immunological challenges. Here, we reveal that the fungal pathogen Candida albicans exploits diverse host-associated signals to promote immune evasion by masking of a major pathogen-associated molecular pattern (PAMP), ß-glucan. Certain nutrients, stresses and antifungal drugs trigger ß-glucan masking, whereas other inputs, such as nitrogen sources and quorum sensing molecules, exert limited effects on this PAMP. In particular, iron limitation triggers substantial changes in the cell wall that reduce ß-glucan exposure. This correlates with reduced phagocytosis by macrophages and attenuated cytokine responses by peripheral blood mononuclear cells. Iron limitation-induced ß-glucan masking depends on parallel signalling via the iron transceptor Ftr1 and the iron-responsive transcription factor Sef1, and the protein kinase A pathway. Our data reveal that C. albicans exploits a diverse range of specific host signals to trigger protective anticipatory responses against impending phagocytic attack and promote host colonisation.


Assuntos
Candida albicans/metabolismo , Citocinas/imunologia , Evasão da Resposta Imune/fisiologia , Ferro/metabolismo , Macrófagos/imunologia , Fagocitose/imunologia , beta-Glucanas/metabolismo , Animais , Candida albicans/imunologia , Parede Celular/metabolismo , Subunidade alfa 1 de Fator de Ligação ao Core/metabolismo , Proteínas Quinases Dependentes de AMP Cíclico/metabolismo , Proteínas Fúngicas/metabolismo , Humanos , Evasão da Resposta Imune/imunologia , Imunidade Inata/imunologia , Leucócitos Mononucleares/imunologia , Proteínas de Membrana Transportadoras/metabolismo , Camundongos , Padrões Moleculares Associados a Patógenos/imunologia , Padrões Moleculares Associados a Patógenos/metabolismo , Transdução de Sinais , beta-Glucanas/imunologia
8.
PLoS Pathog ; 15(11): e1008096, 2019 11.
Artigo em Inglês | MEDLINE | ID: mdl-31693704

RESUMO

Candida albicans is one of the top leading causes of healthcare-associated bloodstream infection. Neutrophil extracellular traps (NET) are known to capture and kill pathogens. It is reported that opsonized C. albicans-triggered NETosis is NADPH oxidase-dependent. We discovered a NADPH oxidase-independent NETosis pathway in neutrophil response to unopsonized C. albicans. While CR3 engagement with opsonized C. albicans triggered NET, dectin-2 recognized unopsonized C. albicans and mediated NET formation. Engagement of dectin-2 activated the downstream Syk-Ca2+-PKCδ-protein arginine deiminase 4 (PAD4) signaling pathway which modulated nuclear translocation of neutrophil elastase (NE), histone citrullination and NETosis. In a C. albicans peritonitis model we observed Ki67+Ly6G+ NETotic cells in the peritoneal exudate and mesenteric tissues within 3 h of infection. Treatment with PAD4 inhibitor GSK484 or dectin-2 deficiency reduced % Ki67+Ly6G+ cells and the intensity of Ki67 in peritoneal neutrophils. Employing DNA digestion enzyme micrococcal nuclease, GSK484 as well as dectin-2-deficient mice, we further showed that dectin-2-mediated PAD4-dependent NET formation in vivo restrained the spread of C. albicans from the peritoneal cavity to kidney. Taken together, this study reveals that unopsonized C. albicans evokes NADPH oxidase-independent NETosis through dectin-2 and its downstream signaling pathway and dectin-2-mediated NET helps restrain fungal dissemination.


Assuntos
Candida albicans/imunologia , Candidíase/imunologia , Armadilhas Extracelulares/imunologia , Rim/imunologia , Lectinas Tipo C/metabolismo , NADPH Oxidases/metabolismo , Peritônio/imunologia , Animais , Candidíase/metabolismo , Candidíase/microbiologia , Rim/metabolismo , Lectinas Tipo C/genética , Camundongos , Camundongos Endogâmicos C57BL , NADPH Oxidases/genética , Peritônio/metabolismo , Fagocitose , Espécies Reativas de Oxigênio , Transdução de Sinais
9.
mBio ; 10(6)2019 11 12.
Artigo em Inglês | MEDLINE | ID: mdl-31719181

RESUMO

Invasive growth in tissues by the human fungal pathogen Candida albicans is promoted by a switch from budding to hyphal morphogenesis that is stimulated by multiple environmental factors that can vary at different sites of infection. To identify genes that promote invasive growth in the oral cavity to cause oropharyngeal candidiasis (OPC), we first identified C. albicans mutants that failed to invade agar medium. Analysis of nine severely defective mutants in a mouse model of OPC revealed that the strongest defects were seen for the rvs161Δ and rvs167Δ mutants, which lack amphiphysin proteins needed for endocytosis. The rvsΔ mutants initially adhered to the tongue but failed to invade efficiently and were lost from the oral cavity. Previous studies indicated that rvsΔ mutants formed filamentous hyphae in the kidney albeit with morphological abnormalities, suggesting that the rvsΔ mutants were influenced by factors that vary at different sites of infection. Consistent with this, increasing concentrations of CO2, an inducer of hyphal growth that is more abundant in internal organs than air, partially rescued the invasive-growth defects of the rvsΔ mutants in vitro Interestingly, preinduction of the rvsΔ mutants to form hyphae prior to introduction into the oral cavity restored their ability to cause OPC, identifying a key role for endocytosis in initiating invasive hyphal growth. These results highlight the influence of distinct environmental factors in promoting invasive hyphal growth in the oral cavity and indicate that blocking endocytosis could have therapeutic value in preventing the initiation of OPC.IMPORTANCE Oropharyngeal candidiasis (OPC) is a common fungal infection that is associated with severe morbidity. Another concern is that patients at risk for developing OPC often take long courses of antifungal drugs, which can lead to the emergence of drug-resistant C. albicans strains. We therefore identified nine mutants with defects in undergoing invasive hyphal growth in the oral cavity, increasing the number of genes known to be involved in OPC by more than 30%. The two strongest mutants, rvs161Δ and rvs167Δ, have defects in endocytosis. The rvsΔ mutants appear to have a specific defect in initiating invasive growth, as preinducing the cells to form hyphae prior to infection restored their ability to cause OPC. These results indicate that blocking endocytosis could have therapeutic value in preventing the initiation of OPC without leading to development of resistance against drugs currently used to treat fungal infections.


Assuntos
Candida albicans/genética , Candida albicans/imunologia , Candidíase Bucal/imunologia , Candidíase Bucal/microbiologia , Proteínas do Citoesqueleto/genética , Endocitose , Interações Hospedeiro-Patógeno , Deleção de Sequência , Animais , Modelos Animais de Doenças , Proteínas Fúngicas/genética , Proteínas Fúngicas/metabolismo , Interações Hospedeiro-Patógeno/imunologia , Hifas/crescimento & desenvolvimento , Camundongos
10.
Proc Natl Acad Sci U S A ; 116(47): 23643-23652, 2019 11 19.
Artigo em Inglês | MEDLINE | ID: mdl-31672911

RESUMO

The cross-talk between the microbiota and the immune system plays a fundamental role in the control of host physiology. However, the tissue-specific factors controlling this dialogue remain poorly understood. Here we demonstrate that T cell responses to commensal colonization are associated with the development of organized cellular clusters within the skin epithelium. These organized lymphocyte clusters are surrounded by keratinocytes expressing a discrete program associated with antigen presentation and antimicrobial defense. Notably, IL-22-mediated keratinocyte-intrinsic MHC class II expression was required for the selective accumulation of commensal-induced IFN-γ, but not IL-17A-producing CD4+ T cells within the skin. Taking these data together, this work uncovers an unexpected role for MHC class II expression by keratinocytes in the control of homeostatic type 1 responses to the microbiota. Our findings have important implications for the understanding of the tissue-specific rules governing the dialogue between a host and its microbiota.


Assuntos
Epiderme/microbiologia , Antígenos de Histocompatibilidade Classe II/biossíntese , Interações entre Hospedeiro e Microrganismos/imunologia , Queratinócitos/imunologia , Microbiota/imunologia , Células Th1/imunologia , Animais , Apresentação do Antígeno , Candida albicans/imunologia , Epiderme/imunologia , Genes MHC da Classe II , Interferon gama/biossíntese , Queratinócitos/metabolismo , Camundongos , Camundongos Endogâmicos C57BL , Especificidade de Órgãos , Quimera por Radiação , Organismos Livres de Patógenos Específicos , Staphylococcus aureus/imunologia , Staphylococcus epidermidis/imunologia , Simbiose , Células Th1/metabolismo
11.
Mycopathologia ; 184(6): 747-757, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31637573

RESUMO

Candida albicans is a commensal fungus of the skin and mucous membranes in humans, but it is also responsible for mucocutaneous and systemic infections in immunocompromised patients like low birth weight neonates and premature newborns. The epicutaneous application of C. albicans is widely used to study the immune response against this pathogen in adult mice models. However, the immune response of newborns against infections caused by the genus Candida is poorly understood. In order to mimic premature human infection, we developed a model of C. albicans epicutaneous infection in newborn mice. We found that yeasts were able to colonize while the pseudohyphae invaded the epidermis. Recruitment of polymorphonuclear and mononuclear cells at the infection zone was observed. Fungal invasion, fungal burden and cellular infiltration displayed a time- and dose-dependent response. Interestingly, newborn mice were able to control C. albicans primary infection. Finally, we showed that the epicutaneous infection of C. albicans in newborn mice at birth results in the induction of cell-mediated immunity as evinced by delayed-type hypersensitivity assays.


Assuntos
Animais Recém-Nascidos/microbiologia , Candida albicans/imunologia , Candidíase/imunologia , Imunidade Celular , Animais , Candida albicans/crescimento & desenvolvimento , Candidíase/microbiologia , Epiderme/microbiologia , Camundongos , Modelos Animais , Pele/microbiologia
12.
Nat Commun ; 10(1): 4566, 2019 10 08.
Artigo em Inglês | MEDLINE | ID: mdl-31594939

RESUMO

Fungal dissemination into the bloodstream is a critical step leading to invasive fungal infections. Here, using intravital imaging, we show that Kupffer cells (KCs) in the liver have a prominent function in the capture of circulating Cryptococcus neoformans and Candida albicans, thereby reducing fungal dissemination to target organs. Complement C3 but not C5, and complement receptor CRIg but not CR3, are involved in capture of C. neoformans. Internalization of C. neoformans by KCs is subsequently mediated by multiple receptors, including CR3, CRIg, and scavenger receptors, which work synergistically along with C5aR signaling. Following phagocytosis, the growth of C. neoformans is inhibited by KCs in an IFN-γ independent manner. Thus, the liver filters disseminating fungi from circulation via KCs, providing a mechanistic explanation for the enhanced risk of cryptococcosis among individuals with liver diseases, and suggesting a therapeutic strategy to prevent fungal dissemination through enhancing KC functions.


Assuntos
Infecções Fúngicas Invasivas/imunologia , Macrófagos do Fígado/imunologia , Fígado/imunologia , Fagocitose , Animais , Candida albicans/imunologia , Candida albicans/isolamento & purificação , Candida albicans/patogenicidade , Complemento C3/genética , Complemento C3/imunologia , Complemento C3/metabolismo , Cryptococcus neoformans/imunologia , Cryptococcus neoformans/isolamento & purificação , Cryptococcus neoformans/patogenicidade , Modelos Animais de Doenças , Feminino , Humanos , Microscopia Intravital , Infecções Fúngicas Invasivas/sangue , Infecções Fúngicas Invasivas/microbiologia , Macrófagos do Fígado/metabolismo , Macrófagos do Fígado/microbiologia , Fígado/citologia , Fígado/diagnóstico por imagem , Masculino , Camundongos , Camundongos Knockout , Microscopia Confocal , Receptores de Complemento/genética , Receptores de Complemento/imunologia , Receptores de Complemento/metabolismo
13.
PLoS One ; 14(7): e0219715, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31295309

RESUMO

Gene manipulation and epitope tagging are essential tools for understanding the molecular function of specific genes. The opportunistic human pathogen Candida albicans is a diploid fungus that utilizes a non-canonical genetic code. Since selection markers available in this organism are scarce, several tools based on recyclable markers have been developed for gene disruption, such as the Clox system. This system relies on the Cre recombinase, which recycles selection markers flanked by loxP sites with high efficiency, facilitating single marker or multi-marker recycling. However, PCR-based modules for epitope tagging, such the pFA-modules, mainly use limited non-recyclable auxotrophic markers. To solve this problem, we have used a Gibson assembly strategy to construct a set of new plasmids where the auxotrophic markers of the pFA vectors were swapped with five recyclable marker modules of the Clox system, enhancing the versatility of the pFA plasmids. This new toolkit, named pFA-Clox, is composed of 36 new vectors for gene disruption and epitope tagging (GFP, 3xGFP, mCherry, 3xHA, 5xmyc and TAP). These plasmids contain the dominant NAT1 marker, as well as URA3, HIS1 and ARG4 cassettes, thereby permitting functional analysis of laboratory strains as well as clinical isolates of C. albicans. In summary, we have adapted the Clox system to the pFA-backbone vectors. Thus, the set of primers used for the amplification of previously published pFA modules can also be utilized in this new pFA-Clox system. Therefore, this new toolkit harbors the advantages of both systems, allowing accelerated gene modification strategies that could reduce time and costs in strain construction for C. albicans.


Assuntos
Candida albicans/genética , Epitopos/genética , Técnicas Genéticas , Transformação Genética , Candida albicans/imunologia , Candida albicans/patogenicidade , Mapeamento de Epitopos/métodos , Epitopos/imunologia , Vetores Genéticos/genética , Proteínas de Fluorescência Verde/genética , Humanos , Integrases/genética , Plasmídeos/genética
14.
Cell ; 178(4): 919-932.e14, 2019 08 08.
Artigo em Inglês | MEDLINE | ID: mdl-31353219

RESUMO

Cutaneous TRPV1+ neurons directly sense noxious stimuli, inflammatory cytokines, and pathogen-associated molecules and are required for innate immunity against some skin pathogens. Important unanswered questions are whether TRPV1+ neuron activation in isolation is sufficient to initiate innate immune responses and what is the biological function for TRPV1+ neuron-initiated immune responses. We used TRPV1-Ai32 optogenetic mice and cutaneous light stimulation to activate cutaneous neurons in the absence of tissue damage or pathogen-associated products. We found that TRPV1+ neuron activation was sufficient to elicit a local type 17 immune response that augmented host defense to C. albicans and S. aureus. Moreover, local neuron activation elicited type 17 responses and augmented host defense at adjacent, unstimulated skin through a nerve reflex arc. These data show the sufficiency of TRPV1+ neuron activation for host defense and demonstrate the existence of functional anticipatory innate immunity at sites adjacent to infection that depends on antidromic neuron activation.


Assuntos
Imunidade Inata/imunologia , Interleucina-23/metabolismo , Interleucina-6/metabolismo , Células Receptoras Sensoriais/imunologia , Pele/imunologia , Canais de Cátion TRPV/metabolismo , Fator de Necrose Tumoral alfa/metabolismo , Animais , Candida albicans/imunologia , Inflamação/imunologia , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , Optogenética/métodos , Pele/microbiologia , Staphylococcus aureus/imunologia , Canais de Cátion TRPV/genética
15.
PLoS Pathog ; 15(6): e1007850, 2019 06.
Artigo em Inglês | MEDLINE | ID: mdl-31242262

RESUMO

Invasive candidiasis, mainly caused by Candida albicans, is a serious healthcare problem with high mortality rates, particularly in immunocompromised patients. Innate immune cells express pathogen recognition receptors (PRRs) including C-type lectin-like receptors (CLRs) that bind C. albicans to initiate an immune response. Multiple CLRs including Dectin-1, Dectin-2 and Mincle have been proposed individually to contribute to the immune response to C. albicans. However how these receptors collaborate to clear a fungal infection is unknown. Herein, we used novel multi-CLR knockout (KO) mice to decipher the individual, collaborative and collective roles of Dectin-1, Dectin-2 and Mincle during systemic C. albicans infection. These studies revealed an unappreciated and profound role for CLR co-operation in anti-fungal immunity. The protective effect of multiple CLRs was markedly greater than any single receptor, and was mediated through inflammatory monocytes via recognition and phagocytosis of C. albicans, and production of C. albicans-induced cytokines and chemokines. These CLRs were dispensable for mediating similar responses from neutrophils, likely due to lower expression of these CLRs on neutrophils compared to inflammatory monocytes. Concurrent deletion of Dectin-1 and Dectin-2, or all three CLRs, resulted in dramatically increased susceptibility to systemic C. albicans infection compared to mice lacking a single CLR. Multi-CLR KO mice were unable to control fungal growth due to an inadequate early inflammatory monocyte-mediated response. In response to excessive fungal growth, the multi-CLR KO mice mounted a hyper-inflammatory response, likely leading to multiple organ failure. Thus, these data reveal a critical role for CLR co-operation in the effective control of C. albicans and maintenance of organ function during infection.


Assuntos
Candida albicans/imunologia , Candidíase/imunologia , Lectinas Tipo C/imunologia , Proteínas de Membrana/imunologia , Monócitos/imunologia , Animais , Candidíase/genética , Quimiocinas/genética , Quimiocinas/imunologia , Inflamação/genética , Inflamação/imunologia , Inflamação/patologia , Lectinas Tipo C/genética , Proteínas de Membrana/genética , Camundongos , Camundongos Knockout , Monócitos/patologia , Neutrófilos/patologia
16.
Mycopathologia ; 184(4): 461-478, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31230200

RESUMO

The details of how gut-associated lymphoid tissues such as Peyer's patches (PPs) in the small intestine play a role in immune surveillance, microbial differentiation and the mucosal barrier protection in response to fungal organisms such as Candida albicans are still unclear. We particularly focus on PPs as they are the immune sensors and inductive sites of the gut that influence inflammation and tolerance. We have previously demonstrated that CD11c+ phagocytes that include dendritic cells and macrophages are located in the sub-epithelial dome within PPs sample C. albicans. To gain insight on how specific cells within PPs sense and respond to the sampling of fungi, we gavaged naïve mice with C. albicans strains ATCC 18804 and SC5314 as well as Saccharomyces cerevisiae. We measured the differential gene expression of sorted CD45+ B220+ B-cells, CD3+ T-cells and CD11c+ DCs within the first 24 h post-gavage using nanostring nCounter® technology. The results reveal that at 24 h, PP phagocytes were the cell type that displayed differential gene expression. These phagocytes were able to sample C. albicans and discriminate between strains. In particular, strain ATCC 18804 upregulated fungal-specific pro-inflammatory genes pertaining to innate and adaptive immune responses. Interestingly, PP CD11c+ phagocytes also differentially expressed genes in response to C. albicans that were important in the protection of the mucosal barrier. These results highlight that the mucosal barrier not only responds to C. albicans, but also aids in the protection of the host.


Assuntos
Candida albicans/imunologia , Perfilação da Expressão Gênica , Interações Hospedeiro-Patógeno , Inflamação/patologia , Nódulos Linfáticos Agregados/imunologia , Nódulos Linfáticos Agregados/patologia , Administração Oral , Animais , Antígenos CD/análise , Linfócitos B/química , Linfócitos B/imunologia , Células Dendríticas/química , Células Dendríticas/imunologia , Feminino , Camundongos , Saccharomyces cerevisiae/imunologia , Linfócitos T/química , Linfócitos T/imunologia
17.
Dermatol Ther ; 32(5): e12997, 2019 09.
Artigo em Inglês | MEDLINE | ID: mdl-31225688

RESUMO

Intralesional immunotherapy is one of the therapeutic tools of warts. Intralesional Candida antigen was reported as successful treatment of warts. Topical and intralesional vitamin D have been used recently for wart treatment. We aim to evaluate the efficacy and safety of intralesional injection of vitamin D3 in treatment of multiple recalcitrant plantar warts in comparison with intralesional Candida antigen. Sixty patients were divided into three groups: Group I received intralesional vitamin D3, Group II intralesional Candida antigen, and Group III intralesional saline (control group). Injection was done every 3 weeks until clearance of warts or a maximum of three treatments. There was a statistically significant more reduction of warts numbers after treatment in Group I than in the other groups (p < .05). Group I showed better clinical response than Group II (p = .021). In both Groups I and II, clinical response was less favorable in patients with longer disease duration (p = .026). There was also limitation as it is a small study population. Intralesional vitamin D3 injection in multiple recalcitrant plantar warts is a simple, safe, cost effective treatment modality with minimal side effects, and superior results compared with intralesional injection of Candida antigen.


Assuntos
Antígenos de Fungos/administração & dosagem , Candida albicans/imunologia , Colecalciferol/administração & dosagem , Dermatoses do Pé/terapia , Imunoterapia/métodos , Verrugas/terapia , Adulto , Estudos de Casos e Controles , Dermoscopia , Feminino , Seguimentos , Dermatoses do Pé/diagnóstico , Humanos , Injeções Intralesionais , Masculino , Fatores de Tempo , Resultado do Tratamento , Vitaminas/administração & dosagem , Verrugas/diagnóstico , Adulto Jovem
18.
Arch Oral Biol ; 103: 55-61, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-31136880

RESUMO

OBJECTIVE: The aim of this study was to investigate the effects of Candida albicans on the production of defense effector molecules by human oral mucosal epithelial cells in vitro. DESIGN: Immortalized human oral mucosal epithelial (Leuk-1) cells and C. albicans strain 5314 were cocultured at different cell-to-C. albicans ratios. The viability of Leuk-1 cells was determined by MTT and RTCA measurements. The secretory levels of multiple defense effector molecules were determined by Enzyme-linked immunosorbent assay (ELISA). RESULTS: Our results indicated that C. albicans significantly decreased the secretion of IgG, cystatin C, lactoferrin, and TGF-ß1 in a dose-dependent manner and remarkably reduced the production of IgA independent of the cell-to-C. albicans ratio. However, C. albicans clearly enhanced the secretion of IgM, galectin-3, P-selectin, granzyme B and perforin. CONCLUSION: These results suggest that C. albicans may exert a regulatory role in the defense response of oral mucosal epithelial cells by altering secretory levels of defense effector molecules.


Assuntos
Candida albicans/imunologia , Candidíase , Imunidade nas Mucosas/genética , Imunidade nas Mucosas/fisiologia , Fatores Imunológicos/genética , Técnicas de Cocultura , Células Epiteliais , Humanos , Mucosa Bucal
19.
Nat Commun ; 10(1): 2297, 2019 05 24.
Artigo em Inglês | MEDLINE | ID: mdl-31127085

RESUMO

Candida albicans is a fungal pathobiont, able to cause epithelial cell damage and immune activation. These functions have been attributed to its secreted toxin, candidalysin, though the molecular mechanisms are poorly understood. Here, we identify epidermal growth factor receptor (EGFR) as a critical component of candidalysin-triggered immune responses. We find that both C. albicans and candidalysin activate human epithelial EGFR receptors and candidalysin-deficient fungal mutants poorly induce EGFR phosphorylation during murine oropharyngeal candidiasis. Furthermore, inhibition of EGFR impairs candidalysin-triggered MAPK signalling and release of neutrophil activating chemokines in vitro, and diminishes neutrophil recruitment, causing significant mortality in an EGFR-inhibited zebrafish swimbladder model of infection. Investigation into the mechanism of EGFR activation revealed the requirement of matrix metalloproteinases (MMPs), EGFR ligands and calcium. We thus identify a PAMP-independent mechanism of immune stimulation and highlight candidalysin and EGFR signalling components as potential targets for prophylactic and therapeutic intervention of mucosal candidiasis.


Assuntos
Candida albicans/imunologia , Proteínas Fúngicas/imunologia , Interações Hospedeiro-Patógeno/imunologia , Sacos Aéreos/microbiologia , Animais , Candida albicans/genética , Candida albicans/metabolismo , Candidíase/imunologia , Candidíase/microbiologia , Linhagem Celular Tumoral , Modelos Animais de Doenças , Células Epiteliais/imunologia , Células Epiteliais/metabolismo , Células Epiteliais/microbiologia , Receptores ErbB/genética , Receptores ErbB/imunologia , Receptores ErbB/metabolismo , Feminino , Proteínas Fúngicas/genética , Proteínas Fúngicas/metabolismo , Humanos , Sistema de Sinalização das MAP Quinases/imunologia , Metaloproteinases da Matriz/imunologia , Metaloproteinases da Matriz/metabolismo , Camundongos , Camundongos Endogâmicos BALB C , Membrana Mucosa/imunologia , Membrana Mucosa/microbiologia , Faringite/imunologia , Faringite/microbiologia , Fosforilação , Peixe-Zebra
20.
Int J Mol Sci ; 20(9)2019 May 11.
Artigo em Inglês | MEDLINE | ID: mdl-31083555

RESUMO

Candida albicans and Candida glabrata are the two most prevalent etiologic agents of candidiasis worldwide. Although both are recognized as pathogenic, their choice of virulence traits is highly divergent. Indeed, it appears that these different approaches to fungal virulence may be equally successful in causing human candidiasis. In this review, the virulence mechanisms employed by C. albicans and C. glabrata are analyzed, with emphasis on the differences between the two systems. Pathogenesis features considered in this paper include dimorphic growth, secreted enzymes and signaling molecules, and stress resistance mechanisms. The consequences of these traits in tissue invasion, biofilm formation, immune system evasion, and macrophage escape, in a species dependent manner, are discussed. This review highlights the observation that C. albicans and C. glabrata follow different paths leading to a similar outcome. It also highlights the lack of knowledge on some of the specific mechanisms underlying C. glabrata pathogenesis, which deserve future scrutiny.


Assuntos
Candida albicans/patogenicidade , Candida glabrata/patogenicidade , Animais , Biofilmes/crescimento & desenvolvimento , Candida albicans/imunologia , Candida albicans/fisiologia , Candida glabrata/imunologia , Candida glabrata/fisiologia , Interações Hospedeiro-Patógeno/imunologia , Humanos , Evasão da Resposta Imune , Virulência/imunologia
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