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Zhou X, Li Z, Chen K, Wei Y, Cao Z, Yu D. The expansion of oligopeptide transporters in Melampsora larici-populina may reflect its adaptation to a phytoparasitic lifestyle. Gene 2024; 920:148506. [PMID: 38670390 DOI: 10.1016/j.gene.2024.148506] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2024] [Revised: 04/13/2024] [Accepted: 04/23/2024] [Indexed: 04/28/2024]
Abstract
The acquisition of nutrients from host plants by phytopathogenic fungi is critically important for their invasion success. Melampsora larici-populina, an obligate biotrophic pathogenic fungus, causes the poplar leaf rust disease and can severely damage host poplar plants. Previously, we found that oligopeptide transporters (OPTs) have undergone a convergent expansion, which might reflect adaptation to a phytoparasitic lifestyle. Here, we used various methods to evaluate this hypothesis, including conserved motif identification, positive selection signal mining, expression pattern clustering analysis, and neutral selection tests. The motif composition of the five clades in the OPT family differed, and positive selection was observed during clade differentiation. This suggests that OPTs in these five clades may be functionally differentiated, which would increase the range of transported substrates and promote the absorption of more types of nitrogen compounds from the hosts. According to clustering analysis of gene expression patterns, the expression of most genes from the two expanded clades (clade 2 and 4) was up-regulated during the infection of poplar trees, indicating that the expansion of OPTs likely occurred to promote the uptake of oligopeptides from host poplar plants. The MellpOPT4g gene was determined to be under significant balancing selection based on the neutral selection tests, suggesting that it plays a role in the pathogenic process. In conclusion, these three observations provide preliminary evidence supporting our hypothesis, as they indicate that the expansion of OPTs in M. larici-populina has aided the ability of this pathogen to acquire nutrients from host plants.
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Affiliation(s)
- Xianzhen Zhou
- College of Forestry, Northwest A&F University, No. 3 Taicheng Road, Yangling, Shaanxi 712100, China.
| | - Ziye Li
- College of Forestry, Northwest A&F University, No. 3 Taicheng Road, Yangling, Shaanxi 712100, China.
| | - Kaiyue Chen
- College of Forestry, Northwest A&F University, No. 3 Taicheng Road, Yangling, Shaanxi 712100, China.
| | - Yefan Wei
- College of Forestry, Northwest A&F University, No. 3 Taicheng Road, Yangling, Shaanxi 712100, China.
| | - Zhimin Cao
- College of Forestry, Northwest A&F University, No. 3 Taicheng Road, Yangling, Shaanxi 712100, China.
| | - Dan Yu
- College of Forestry, Northwest A&F University, No. 3 Taicheng Road, Yangling, Shaanxi 712100, China.
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2
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Baker RP, Liu AZ, Casadevall A. Cell wall melanin impedes growth of the Cryptococcus neoformans polysaccharide capsule by sequestering calcium. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.06.20.599928. [PMID: 38948764 PMCID: PMC11212976 DOI: 10.1101/2024.06.20.599928] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/02/2024]
Abstract
Cryptococcus neoformans has emerged as a frontrunner among deadly fungal pathogens and is particularly life-threatening for many HIV-infected individuals with compromised immunity. Multiple virulence factors contribute to the growth and survival of C. neoformans within the human host, the two most prominent of which are the polysaccharide capsule and melanin. As both of these features are associated with the cell wall, we were interested to explore possible cooperative or competitive interactions between these two virulence factors. Whereas capsule thickness had no effect on the rate at which cells became melanized, build-up of the melanin pigment layer resulted in a concomitant loss of polysaccharide material, leaving melanized cells with significantly thinner capsules than their non-melanized counterparts. When melanin was provided exogenously to cells in a transwell culture system we observed a similar inhibition of capsule growth and maintenance. Our results show that melanin sequesters calcium thereby limiting its availability to form divalent bridges between polysaccharide subunits required for outer capsule assembly. The decreased ability of melanized cells to incorporate exported polysaccharide into the growing capsule correlated with the amount of shed polysaccharide, which could have profound negative impacts on the host immune response. Significance Statement Cryptococcus neoformans is an opportunistic fungal pathogen that presents a significant health risk for immunocompromised individuals. We report an interaction between the two major cryptococcal virulence factors, the polysaccharide capsule and melanin. Melanin impacted the growth and maintenance of the polysaccharide capsule, resulting in loss of capsular material during melanization. Our results suggest that melanin can act as a sink for calcium, thereby limiting its availability to form ionic bridges between polysaccharide chains on the growing surface of the outer capsule. As polysaccharide is continuously exported to support capsule growth, failure of melanized cells to incorporate this material results in a higher concentration of shed polysaccharide in the extracellular milieu, which is expected to interfere with host immunity.
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3
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Hughes ES, Tuck LR, He Z, Ballou ER, Wallace EWJ. A trade-off between proliferation and defense in the fungal pathogen Cryptococcus at alkaline pH is controlled by the transcription factor GAT201. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2023.06.14.543486. [PMID: 37398450 PMCID: PMC10312749 DOI: 10.1101/2023.06.14.543486] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/04/2023]
Abstract
Cryptococcus is a fungal pathogen whose virulence relies on proliferation in and dissemination to host sites, and on synthesis of a defensive yet metabolically costly polysaccharide capsule. Regulatory pathways required for Cryptococcus virulence include a GATA-like transcription factor, Gat201, that regulates Cryptococcal virulence in both capsule-dependent and capsule-independent ways. Here we show that Gat201 is part of a negative regulatory pathway that limits fungal survival at alkaline pH. RNA-seq analysis found strong induction of GAT201 expression within minutes of transfer to RPMI media at alkaline pH. Microscopy, growth curves, and colony forming unit assays show that in RPMI at alkaline pH wild-type Cryptococcus neoformans yeast cells produce capsule but do not bud or maintain viability, while gat201Δ cells make buds and maintain viability, yet fail to produce capsule. GAT201 is required for transcriptional upregulation of a specific set of genes, the majority of which are direct Gat201 targets. Evolutionary analysis shows that Gat201 is in a subfamily of GATA-like transcription factors that is conserved within pathogenic fungi but absent in model yeasts. This work identifies the Gat201 pathway as controlling a trade-off between proliferation and production of defensive capsule. The assays established here will allow characterisation of the mechanisms of action of the Gat201 pathway. Together, our findings urge improved understanding of the regulation of proliferation as a driver of fungal pathogenesis.
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Affiliation(s)
- Elizabeth S Hughes
- Institute for Cell Biology, and Centre for Engineering Biology, School of Biological Sciences, The University of Edinburgh
| | - Laura R Tuck
- Institute for Cell Biology, and Centre for Engineering Biology, School of Biological Sciences, The University of Edinburgh
| | - Zhenzhen He
- Institute for Cell Biology, and Centre for Engineering Biology, School of Biological Sciences, The University of Edinburgh
| | | | - Edward W J Wallace
- Institute for Cell Biology, and Centre for Engineering Biology, School of Biological Sciences, The University of Edinburgh
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4
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Luo Z, Xiong D, Tian C. The Roles of Gti1/Pac2 Family Proteins in Fungal Growth, Morphogenesis, Stress Response, and Pathogenicity. MOLECULAR PLANT-MICROBE INTERACTIONS : MPMI 2024; 37:488-497. [PMID: 38427716 DOI: 10.1094/mpmi-11-23-0198-cr] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 03/03/2024]
Abstract
Gti1/Pac2 is a fungal-specific transcription factor family with a stable and conserved N-terminal domain. Generally, there are two members in this family, named Gti1/Wor1/Rpy1/Mit1/Reg1/Ros1/Sge1 and Pac2, which are involved in fungal growth, development, stress response, spore production, pathogenicity, and so on. The Gti1/Pac2 family proteins share some conserved and distinct functions. For example, in Schizosaccharomyces pombe, Gti1 promotes the initiation of gluconate uptake during glucose starvation, while Pac2 controls the onset of sexual development in a pathway independent of the cAMP cascade. In the last two decades, more attention was focused on the Gti1 and its orthologs because of their significant effect on morphological switching and fungal virulence. By contrast, limited work was published on the functions of Pac2, which is required for stress responses and conidiation, but plays a minor role in fungal virulence. In this review, we present an overview of our current understanding of the Gti1/Pac2 proteins that contribute to fungal development and/or pathogenicity and of the regulation mechanisms during infection related development. Understanding the working networks of the conserved Gti1/Pac2 transcription factors in fungal pathogenicity not only advances our knowledge of the highly elaborate infection process but may also lead to the development of novel strategies for the control of plant disease. [Formula: see text] Copyright © 2024 The Author(s). This is an open access article distributed under the CC BY-NC-ND 4.0 International license.
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Affiliation(s)
- Zheng Luo
- State Key laboratory of Efficient Production of Forest Resources, Beijing Forestry University, Beijing 100083, China
- Beijing Key Laboratory for Forest Pest Control, Beijing Forestry University, Beijing 100083, China
- The Key Laboratory for Silviculture and Conservation of Ministry of Education, College of Forestry, Beijing Forestry University, Beijing 100083, China
| | - Dianguang Xiong
- State Key laboratory of Efficient Production of Forest Resources, Beijing Forestry University, Beijing 100083, China
- Beijing Key Laboratory for Forest Pest Control, Beijing Forestry University, Beijing 100083, China
- The Key Laboratory for Silviculture and Conservation of Ministry of Education, College of Forestry, Beijing Forestry University, Beijing 100083, China
| | - Chengming Tian
- State Key laboratory of Efficient Production of Forest Resources, Beijing Forestry University, Beijing 100083, China
- Beijing Key Laboratory for Forest Pest Control, Beijing Forestry University, Beijing 100083, China
- The Key Laboratory for Silviculture and Conservation of Ministry of Education, College of Forestry, Beijing Forestry University, Beijing 100083, China
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5
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Gutierrez-Gongora D, Woods M, Prosser RS, Geddes-McAlister J. Natural compounds from freshwater mussels disrupt fungal virulence determinants and influence fluconazole susceptibility in the presence of macrophages in Cryptococcus neoformans. Microbiol Spectr 2024; 12:e0284123. [PMID: 38329361 PMCID: PMC10913472 DOI: 10.1128/spectrum.02841-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2023] [Accepted: 01/12/2024] [Indexed: 02/09/2024] Open
Abstract
Cryptococcus neoformans is a human fungal pathogen responsible for fatal infections, especially in patients with a depressed immune system. Overexposure to antifungal drugs due to prolonged treatment regimens and structure-similar applications in agriculture have weakened the efficacy of current antifungals in the clinic. The rapid evolution of antifungal resistance urges the discovery of new compounds that inhibit fungal virulence determinants, rather than directly killing the pathogen, as alternative strategies to overcome disease and reduce selective pressure toward resistance. Here, we evaluated the efficacy of freshwater mussel extracts (crude and clarified) against the production of well-defined virulence determinants (i.e., thermotolerance, melanin, capsule, and biofilm) and fluconazole resistance in C. neoformans. We demonstrated the extracts' influence on fungal thermotolerance, capsule production, and biofilm formation, as well as susceptibility to fluconazole in the presence of macrophages. Additionally, we measured the inhibitory activity of extracts against commercial peptidases (family representatives of cryptococcal orthologs) related to fungal virulence determinants and fluconazole resistance, and integrated these phenotypic findings with quantitative proteomics profiling. Our approach defined distinct signatures of each treatment and validated a new mechanism of anti-virulence action toward the polysaccharide capsule from a selected extract following fractionation. By understanding the mechanisms driving the antifungal activity of mussels, we may develop innovative treatment options to overcome fungal infections and promote susceptibility to fluconazole in resistant strains. IMPORTANCE As the prevalence and severity of global fungal infections rise, along with an increasing incidence of antifungal resistance, new strategies to combat fungal pathogens and overcome resistance are urgently needed. Critically, our current methods to overcome fungal infections are limited and drive the evolution of resistance forward; however, an anti-virulence approach to disarm virulence factors of the pathogen and promote host cell clearance is promising. Here, we explore the efficacy of natural compounds derived from freshwater mussels against classical fungal virulence determinants, including thermotolerance, capsule production, stress response, and biofilm formation. We integrate our phenotypic discoveries with state-of-the-art mass spectrometry-based proteomics to identify mechanistic drivers of these antifungal properties and propose innovative avenues to reduce infection and support the treatment of resistant strains.
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Affiliation(s)
| | - Michael Woods
- Department of Molecular and Cellular Biology, University of Guelph, Guelph, Ontario, Canada
| | - Ryan S. Prosser
- School of Environmental Sciences, University of Guelph, Guelph, Ontario, Canada
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6
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Pham T, Li Y, Watford W, Lin X. Vaccination with a ZNF2oe Strain of Cryptococcus Provides Long-Lasting Protection against Cryptococcosis and Is Effective in Immunocompromised Hosts. Infect Immun 2023:e0019823. [PMID: 37338404 DOI: 10.1128/iai.00198-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2023] [Accepted: 05/31/2023] [Indexed: 06/21/2023] Open
Abstract
Systemic cryptococcosis is fatal without treatment. Even with the current antifungal therapies, this disease kills 180,000 of 225,000 infected people annually. Exposure to the causative environmental fungus Cryptococcus neoformans is universal. Either reactivation of a latent infection or an acute infection after high exposure to cryptococcal cells can result in cryptococcosis. Currently, there is no vaccine to prevent cryptococcosis. Previously, we discovered that Znf2, a transcription factor that directs Cryptococcus yeast-to-hypha transition, profoundly affects cryptococcal interaction with the host. Overexpression of ZNF2 drives filamentous growth, attenuates cryptococcal virulence, and elicits protective host immune responses. Importantly, immunization with cryptococcal cells overexpressing ZNF2, in either live or heat-inactivated form, offers significant protection to the host from a subsequent challenge by the otherwise lethal clinical isolate H99. In this study, we found that the heat-inactivated ZNF2oe vaccine offered long-lasting protection with no relapse upon challenge with the wild-type H99. Vaccination with heat-inactivated ZNF2oe cells provides partial protection in hosts with preexisting asymptomatic cryptococcal infection. Importantly, once animals have been vaccinated with heat-inactivated or live short-lived ZNF2oe cells, they are protected against cryptococcosis even when their CD4+ T cells are depleted at the time of fungal challenge. Remarkably, vaccination with live, short-lived ZNF2oe cells in CD4-depleted hosts still provides strong protection to these hosts with preexisting immunodeficiency at the time of vaccination. This work raises hope for developing effective vaccines with long-lasting protection for individuals who are immunocompromised or could become immunocompromised later in life.
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Affiliation(s)
- Tuyetnhu Pham
- Department of Plant Biology, University of Georgia, Athens, Georgia, USA
| | - Yeqi Li
- Department of Microbiology, University of Georgia, Athens, Georgia, USA
| | - Wendy Watford
- Department of Infectious Diseases, University of Georgia, Athens, Georgia, USA
| | - Xiaorong Lin
- Department of Plant Biology, University of Georgia, Athens, Georgia, USA
- Department of Microbiology, University of Georgia, Athens, Georgia, USA
- Department of Infectious Diseases, University of Georgia, Athens, Georgia, USA
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7
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Gutierrez-Gongora D, Raouf-Alkadhimi F, Prosser RS, Geddes-McAlister J. Differentiated extracts from freshwater and terrestrial mollusks inhibit virulence factor production in Cryptococcus neoformans. Sci Rep 2023; 13:4928. [PMID: 36967422 PMCID: PMC10040410 DOI: 10.1038/s41598-023-32140-3] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2022] [Accepted: 03/23/2023] [Indexed: 03/29/2023] Open
Abstract
The human fungal pathogen, Cryptococcus neoformans, is responsible for deadly infections among immunocompromised individuals with the evolution of antifungal resistance driving the solution to discover new compounds that inhibit fungal virulence factors rather than kill the pathogen. Recently, exploration into natural sources (e.g., plants, invertebrates, microbes) of antifungal agents has garnered attention by integrating a One Health approach for new compound discovery. Here, we explore extracts from three mollusk species (freshwater and terrestrial) and evaluate effects against the growth and virulence factor production (i.e., thermotolerance, melanin, capsule, and biofilm) in C. neoformans. We demonstrate that clarified extracts of Planorbella pilsbryi have a fungicidal effect on cryptococcal cells comparable to fluconazole. Similarly, all extracts of Cipangopaludina chinensis affect cryptococcal thermotolerance and impair biofilm and capsule production, with clarified extracts of Cepaea nemoralis also conveying the latter effect. Next, inhibitory activity of extracts against peptidases related to specific virulence factors, combined with stress assays and quantitative proteomics, defined distinct proteome signatures and proposed proteins driving the observed anti-virulence properties. Overall, this work highlights the potential of compounds derived from natural sources to inhibit virulence factor production in a clinically important fungal pathogen.
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Affiliation(s)
| | | | - Ryan S Prosser
- Department of Environmental Toxicology, University of Guelph, Guelph, ON, Canada
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8
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Similar evolutionary trajectories in an environmental Cryptococcus neoformans isolate after human and murine infection. Proc Natl Acad Sci U S A 2023; 120:e2217111120. [PMID: 36603033 PMCID: PMC9926274 DOI: 10.1073/pnas.2217111120] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023] Open
Abstract
A pet cockatoo was the suspected source of Cryptococcus neoformans recovered from an immunocompromised patient with cryptococcosis based on molecular analyses available in 2000. Here, we report whole genome sequence analysis of the clinical and cockatoo strains. Both are closely related MATα strains belonging to the VNII lineage, confirming that the human infection likely originated from pet bird exposure. The two strains differ by 61 single nucleotide polymorphisms, including eight nonsynonymous changes involving seven genes. To ascertain whether changes in these genes are selected for during mammalian infection, we passaged the cockatoo strain in mice. Remarkably, isolates obtained from mouse tissue possess a frameshift mutation in one of the seven genes altered in the human sample (LQVO5_000317), a gene predicted to encode an SWI-SNF chromatin-remodeling complex protein. In addition, both cockatoo and patient strains as well as mouse-passaged isolates obtained from brain tissue had a premature stop codon in a homologue of ZFC3 (LQVO5_004463), a predicted single-zinc finger containing protein, which is associated with larger capsules when deleted and reverted to a full-length protein in the mouse-passaged isolates obtained from lung tissue. The patient strain and mouse-passaged isolates show variability in virulence factors, with differences in capsule size, melanization, rates of nonlytic expulsion from macrophages, and amoeba predation resistance. Our results establish that environmental strains undergo genomic and phenotypic changes during mammalian passage, suggesting that animal virulence can be a mechanism for genetic change and that the genomes of clinical isolates may provide a readout of mutations acquired during infection.
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9
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Regulatory basis for reproductive flexibility in a meningitis-causing fungal pathogen. Nat Commun 2022; 13:7938. [PMID: 36566249 PMCID: PMC9790007 DOI: 10.1038/s41467-022-35549-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2022] [Accepted: 12/09/2022] [Indexed: 12/25/2022] Open
Abstract
Pathogenic fungi of the genus Cryptococcus can undergo two sexual cycles, involving either bisexual diploidization (after fusion of haploid cells of different mating type) or unisexual diploidization (by autodiploidization of a single cell). Here, we construct a gene-deletion library for 111 transcription factor genes in Cryptococcus deneoformans, and explore the roles of these regulatory networks in the two reproductive modes. We show that transcription factors crucial for bisexual syngamy induce the expression of known mating determinants as well as other conserved genes of unknown function. Deletion of one of these genes, which we term FMP1, leads to defects in bisexual reproduction in C. deneoformans, its sister species Cryptococcus neoformans, and the ascomycete Neurospora crassa. Furthermore, we show that a recently evolved regulatory cascade mediates pre-meiotic unisexual autodiploidization, supporting that this reproductive process is a recent evolutionary innovation. Our findings indicate that genetic circuits with different evolutionary ages govern hallmark events distinguishing unisexual and bisexual reproduction in Cryptococcus.
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10
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Denham ST, Brammer B, Chung KY, Wambaugh MA, Bednarek JM, Guo L, Moreau CT, Brown JCS. A dissemination-prone morphotype enhances extrapulmonary organ entry by Cryptococcus neoformans. Cell Host Microbe 2022; 30:1382-1400.e8. [PMID: 36099922 PMCID: PMC9588642 DOI: 10.1016/j.chom.2022.08.017] [Citation(s) in RCA: 18] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2022] [Revised: 06/01/2022] [Accepted: 08/18/2022] [Indexed: 01/08/2023]
Abstract
Environmental pathogens move from ecological niches to mammalian hosts, requiring adaptation to dramatically different environments. Microbes that disseminate farther, including the fungal meningitis pathogen Cryptococcus neoformans, require additional adaptation to diverse tissues. We demonstrate that the formation of a small C. neoformans morphotype-called "seed" cells due to their colonizing ability-is critical for extrapulmonary organ entry. Seed cells exhibit changes in fungal cell size and surface expression that result in an enhanced macrophage update. Seed cell formation is triggered by environmental factors, including C. neoformans' environmental niche, and pigeon guano with phosphate plays a central role. Seed cells show the enhanced expression of phosphate acquisition genes, and mutants unable to acquire phosphate fail to adopt the seed cell morphotype. Additionally, phosphate can be released by tissue damage, potentially establishing a feed-forward loop of seed cell formation and dissemination. Thus, C. neoformans' size variation represent inducible morphotypes that change host interactions to facilitate microbe spread.
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Affiliation(s)
- Steven T Denham
- Division of Microbiology and Immunology, Department of Pathology, University of Utah, Salt Lake City, UT 84112, USA
| | - Brianna Brammer
- Division of Microbiology and Immunology, Department of Pathology, University of Utah, Salt Lake City, UT 84112, USA
| | - Krystal Y Chung
- Division of Microbiology and Immunology, Department of Pathology, University of Utah, Salt Lake City, UT 84112, USA
| | - Morgan A Wambaugh
- Division of Microbiology and Immunology, Department of Pathology, University of Utah, Salt Lake City, UT 84112, USA
| | - Joseph M Bednarek
- Division of Microbiology and Immunology, Department of Pathology, University of Utah, Salt Lake City, UT 84112, USA
| | - Li Guo
- Molecular Medicine Program, University of Utah, Salt Lake City, UT 84112, USA
| | - Christian T Moreau
- Division of Microbiology and Immunology, Department of Pathology, University of Utah, Salt Lake City, UT 84112, USA
| | - Jessica C S Brown
- Division of Microbiology and Immunology, Department of Pathology, University of Utah, Salt Lake City, UT 84112, USA.
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11
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Dang EV, Lei S, Radkov A, Volk RF, Zaro BW, Madhani HD. Secreted fungal virulence effector triggers allergic inflammation via TLR4. Nature 2022; 608:161-167. [PMID: 35896747 PMCID: PMC9744105 DOI: 10.1038/s41586-022-05005-4] [Citation(s) in RCA: 27] [Impact Index Per Article: 13.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2021] [Accepted: 06/21/2022] [Indexed: 12/14/2022]
Abstract
Invasive fungal pathogens are major causes of human mortality and morbidity1,2. Although numerous secreted effector proteins that reprogram innate immunity to promote virulence have been identified in pathogenic bacteria, so far, there are no examples of analogous secreted effector proteins produced by human fungal pathogens. Cryptococcus neoformans, the most common cause of fungal meningitis and a major pathogen in AIDS, induces a pathogenic type 2 response characterized by pulmonary eosinophilia and alternatively activated macrophages3-8. Here, we identify CPL1 as an effector protein secreted by C. neoformans that drives alternative activation (also known as M2 polarization) of macrophages to enable pulmonary infection in mice. We observed that CPL1-enhanced macrophage polarization requires Toll-like receptor 4, which is best known as a receptor for bacterial endotoxin but is also a poorly understood mediator of allergen-induced type 2 responses9-12. We show that this effect is caused by CPL1 itself and not by contaminating lipopolysaccharide. CPL1 is essential for virulence, drives polarization of interstitial macrophages in vivo, and requires type 2 cytokine signalling for its effect on infectivity. Notably, C. neoformans associates selectively with polarized interstitial macrophages during infection, suggesting a mechanism by which C. neoformans generates its own intracellular replication niche within the host. This work identifies a circuit whereby a secreted effector protein produced by a human fungal pathogen reprograms innate immunity, revealing an unexpected role for Toll-like receptor 4 in promoting the pathogenesis of infectious disease.
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Affiliation(s)
- Eric V. Dang
- Department of Biochemistry and Biophysics, University of California, San Francisco, CA, United States of America
| | - Susan Lei
- Department of Biochemistry and Biophysics, University of California, San Francisco, CA, United States of America
| | - Atanas Radkov
- Department of Biochemistry and Biophysics, University of California, San Francisco, CA, United States of America
| | - Regan F. Volk
- Department of Pharmaceutical Chemistry, University of California, San Francisco, CA, United States of America,Cardiovascular Research Institute, University of California, San Francisco, CA, United States of America
| | - Balyn W. Zaro
- Department of Pharmaceutical Chemistry, University of California, San Francisco, CA, United States of America,Cardiovascular Research Institute, University of California, San Francisco, CA, United States of America
| | - Hiten D. Madhani
- Department of Biochemistry and Biophysics, University of California, San Francisco, CA, United States of America,Chan-Zuckerberg Biohub, San Francisco, CA, United States of America,
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12
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Saidykhan L, Correia J, Romanyuk A, Peacock AFA, Desanti GE, Taylor-Smith L, Makarova M, Ballou ER, May RC. An in vitro method for inducing titan cells reveals novel features of yeast-to-titan switching in the human fungal pathogen Cryptococcus gattii. PLoS Pathog 2022; 18:e1010321. [PMID: 35969643 PMCID: PMC9426920 DOI: 10.1371/journal.ppat.1010321] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2022] [Revised: 08/30/2022] [Accepted: 07/07/2022] [Indexed: 12/15/2022] Open
Abstract
Cryptococcosis is a potentially lethal fungal infection of humans caused by organisms within the Cryptococcus neoformans/gattii species complex. Whilst C. neoformans is a relatively common pathogen of immunocompromised individuals, C. gattii is capable of acting as a primary pathogen of immunocompetent individuals. Within the host, both species undergo morphogenesis to form titan cells: exceptionally large cells that are critical for disease establishment. To date, the induction, defining attributes, and underlying mechanism of titanisation have been mainly characterized in C. neoformans. Here, we report the serendipitous discovery of a simple and robust protocol for in vitro induction of titan cells in C. gattii. Using this in vitro approach, we reveal a remarkably high capacity for titanisation within C. gattii, especially in strains associated with the Pacific Northwest Outbreak, and characterise strain-specific differences within the clade. In particular, this approach demonstrates for the first time that cell size changes, DNA amplification, and budding are not always synchronous during titanisation. Interestingly, however, exhibition of these cell cycle phenotypes was correlated with genes associated with cell cycle progression including CDC11, CLN1, BUB2, and MCM6. Finally, our findings reveal exogenous p-Aminobenzoic acid to be a key inducer of titanisation in this organism. Consequently, this approach offers significant opportunities for future exploration of the underlying mechanism of titanisation in this genus.
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Affiliation(s)
- Lamin Saidykhan
- Institute of Microbiology & Infection and School of Biosciences, University of Birmingham, Edgbaston, United Kingdom
- Division of Physical and Natural Science, University of The Gambia, Brikama, The Gambia
| | - Joao Correia
- Institute of Microbiology & Infection and School of Biosciences, University of Birmingham, Edgbaston, United Kingdom
| | - Andrey Romanyuk
- Institute of Microbiology & Infection and School of Biosciences, University of Birmingham, Edgbaston, United Kingdom
- School of Chemistry, University of Birmingham, Edgbaston, United Kingdom
| | - Anna F. A. Peacock
- School of Chemistry, University of Birmingham, Edgbaston, United Kingdom
| | - Guillaume E. Desanti
- Institute of Microbiology & Infection and School of Biosciences, University of Birmingham, Edgbaston, United Kingdom
| | - Leanne Taylor-Smith
- Institute of Microbiology & Infection and School of Biosciences, University of Birmingham, Edgbaston, United Kingdom
| | - Maria Makarova
- Institute of Microbiology & Infection and School of Biosciences, University of Birmingham, Edgbaston, United Kingdom
| | - Elizabeth R. Ballou
- Institute of Microbiology & Infection and School of Biosciences, University of Birmingham, Edgbaston, United Kingdom
- MRC Centre for Medical Mycology, University of Exeter, Exeter, United Kingdom
- * E-mail: (ERB); (RCM)
| | - Robin C. May
- Institute of Microbiology & Infection and School of Biosciences, University of Birmingham, Edgbaston, United Kingdom
- * E-mail: (ERB); (RCM)
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Cheong JH, Qiu X, Liu Y, Al-Omari A, Griffith J, Schüttler HB, Mao L, Arnold J. The macroscopic limit to synchronization of cellular clocks in single cells of Neurospora crassa. Sci Rep 2022; 12:6750. [PMID: 35468928 PMCID: PMC9039089 DOI: 10.1038/s41598-022-10612-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2021] [Accepted: 03/29/2022] [Indexed: 11/09/2022] Open
Abstract
AbstractWe determined the macroscopic limit for phase synchronization of cellular clocks in an artificial tissue created by a “big chamber” microfluidic device to be about 150,000 cells or less. The dimensions of the microfluidic chamber allowed us to calculate an upper limit on the radius of a hypothesized quorum sensing signal molecule of 13.05 nm using a diffusion approximation for signal travel within the device. The use of a second microwell microfluidic device allowed the refinement of the macroscopic limit to a cell density of 2166 cells per fixed area of the device for phase synchronization. The measurement of averages over single cell trajectories in the microwell device supported a deterministic quorum sensing model identified by ensemble methods for clock phase synchronization. A strong inference framework was used to test the communication mechanism in phase synchronization of quorum sensing versus cell-to-cell contact, suggesting support for quorum sensing. Further evidence came from showing phase synchronization was density-dependent.
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14
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Ke W, Xie Y, Hu Y, Ding H, Fan X, Huang J, Tian X, Zhang B, Xu Y, Liu X, Yang Y, Wang L. A forkhead transcription factor contributes to the regulatory differences of pathogenicity in closely related fungal pathogens. MLIFE 2022; 1:79-91. [PMID: 38818325 PMCID: PMC10989923 DOI: 10.1002/mlf2.12011] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/02/2021] [Revised: 01/21/2022] [Accepted: 02/10/2022] [Indexed: 06/01/2024]
Abstract
Cryptococcus neoformans and its sister species Cryptococcus deuterogattii are important human fungal pathogens. Despite their phylogenetically close relationship, these two Cryptococcus pathogens are greatly different in their clinical characteristics. However, the determinants underlying the regulatory differences of their pathogenicity remain largely unknown. Here, we show that the forkhead transcription factor Hcm1 promotes infection in C. neoformans but not in C. deuterogattii. Monitoring in vitro and in vivo fitness outcomes of multiple clinical isolates from the two pathogens indicates that Hcm1 mediates pathogenicity in C. neoformans through its key involvement in oxidative stress defense. By comparison, Hcm1 is not critical for antioxidation in C. deuterogattii. Furthermore, we identified SRX1, which encodes the antioxidant sulfiredoxin, as a conserved target of Hcm1 in two Cryptococcus pathogens. Like HCM1, SRX1 had a greater role in antioxidation in C. neoformans than in C. deuterogattii. Significantly, overexpression of SRX1 can largely rescue the defective pathogenicity caused by the absence of Hcm1 in C. neoformans. Conversely, Srx1 is dispensable for virulence in C. deuterogattii. Overall, our findings demonstrate that the difference in the contribution of the antioxidant sulfiredoxin to oxidative stress defense underlies the Hcm1-mediated regulatory differences of pathogenicity in two closely related pathogens.
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Affiliation(s)
- Weixin Ke
- State Key Laboratory of Mycology, Institute of MicrobiologyChinese Academy of SciencesBeijingChina
- College of Life SciencesUniversity of Chinese Academy of SciencesBeijingChina
| | - Yuyan Xie
- State Key Laboratory of Mycology, Institute of MicrobiologyChinese Academy of SciencesBeijingChina
- College of Life SciencesUniversity of Chinese Academy of SciencesBeijingChina
| | - Yue Hu
- State Key Laboratory of Mycology, Institute of MicrobiologyChinese Academy of SciencesBeijingChina
| | - Hao Ding
- State Key Laboratory of Mycology, Institute of MicrobiologyChinese Academy of SciencesBeijingChina
- College of Life SciencesUniversity of Chinese Academy of SciencesBeijingChina
| | - Xin Fan
- Department of Infectious Diseases and Clinical Microbiology, Beijing Chaoyang HospitalCapital Medical UniversityBeijingChina
| | - Jingjing Huang
- Department of Clinical Laboratory, Peking Union Medical College Hospital, Peking Union Medical CollegeChinese Academy of Medical SciencesBeijingChina
- Beijing Key Laboratory for Mechanisms Research and Precision Diagnosis of Invasive Fungal Diseases, Peking Union Medical College Hospital, Peking Union Medical CollegeChinese Academy of Medical SciencesBeijingChina
- Graduate School, Peking Union Medical CollegeChinese Academy of Medical SciencesBeijingChina
| | - Xiuyun Tian
- State Key Laboratory of Mycology, Institute of MicrobiologyChinese Academy of SciencesBeijingChina
| | - Baokun Zhang
- Beijing Key Laboratory of New Molecular Diagnosis Technologies for Infectious Disease, Department of BiotechnologyBeijing Institute of Radiation MedicineBeijingChina
| | - Yingchun Xu
- Department of Clinical Laboratory, Peking Union Medical College Hospital, Peking Union Medical CollegeChinese Academy of Medical SciencesBeijingChina
- Beijing Key Laboratory for Mechanisms Research and Precision Diagnosis of Invasive Fungal Diseases, Peking Union Medical College Hospital, Peking Union Medical CollegeChinese Academy of Medical SciencesBeijingChina
| | - Xiao Liu
- State Key Laboratory of Mycology, Institute of MicrobiologyChinese Academy of SciencesBeijingChina
- College of Life SciencesUniversity of Chinese Academy of SciencesBeijingChina
| | - Ying Yang
- Beijing Key Laboratory of New Molecular Diagnosis Technologies for Infectious Disease, Department of BiotechnologyBeijing Institute of Radiation MedicineBeijingChina
| | - Linqi Wang
- State Key Laboratory of Mycology, Institute of MicrobiologyChinese Academy of SciencesBeijingChina
- College of Life SciencesUniversity of Chinese Academy of SciencesBeijingChina
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15
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Gutierrez-Gongora D, Geddes-McAlister J. Peptidases: promising antifungal targets of the human fungal pathogen, Cryptococcus neoformans. Facets (Ott) 2022. [DOI: 10.1139/facets-2021-0157] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Cryptococcus neoformans is a globally important fungal pathogen, primarily inflicting disease on immunocompromised individuals. The widespread use of antifungal agents in medicine and agriculture supports the development of antifungal resistance through evolution, and the emergence of new strains with intrinsic resistance drives the need for new therapeutics. For C. neoformans, the production of virulence factors, including extracellular peptidases (e.g., CnMpr-1 and May1) with mechanistic roles in tissue invasion and fungal survival, constitute approximately 2% of the fungal proteome and cover five classes of enzymes. Given their role in fungal virulence, peptidases represent promising targets for anti-virulence discovery in the development of new approaches against C. neoformans. Additionally, intracellular peptidases, which are involved in resistance mechanisms against current treatment options (e.g., azole drugs), as well as capsule biosynthesis and elaboration of virulence factors, present additional opportunities to combat the pathogen. In this review, we highlight key cryptococcal peptidases with defined or predicted roles in fungal virulence and assess sequence alignments against their human homologs. With this information, we define the feasibility of the select peptidases as “druggable” targets for inhibition, representing prospective therapeutic options against the deadly fungus.
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Affiliation(s)
- Davier Gutierrez-Gongora
- The Department of Molecular and Cellular Biology, University of Guelph, Guelph, Ontario N1G 2W1, Canada
- Centro de Estudio de Proteínas, Facultad de Biología, Universidad de La Habana, La Habana, Cuba
| | - Jennifer Geddes-McAlister
- The Department of Molecular and Cellular Biology, University of Guelph, Guelph, Ontario N1G 2W1, Canada
- Canadian Proteomics and Artificial Intelligence Research and Training Consortium
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16
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From Naturally-Sourced Protease Inhibitors to New Treatments for Fungal Infections. J Fungi (Basel) 2021; 7:jof7121016. [PMID: 34946998 PMCID: PMC8704869 DOI: 10.3390/jof7121016] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2021] [Revised: 11/24/2021] [Accepted: 11/24/2021] [Indexed: 02/08/2023] Open
Abstract
Proteases are involved in a broad range of physiological processes, including host invasion by fungal pathogens, and enzymatic inhibition is a key molecular mechanism controlling proteolytic activity. Importantly, inhibitors from natural or synthetic sources have demonstrated applications in biochemistry, biotechnology, and biomedicine. However, the need to discover new reservoirs of these inhibitory molecules with improved efficacy and target range has been underscored by recent protease characterization related to infection and antimicrobial resistance. In this regard, naturally-sourced inhibitors show promise for application in diverse biological systems due to high stability at physiological conditions and low cytotoxicity. Moreover, natural sources (e.g., plants, invertebrates, and microbes) provide a large reservoir of undiscovered and/or uncharacterized bioactive molecules involved in host defense against predators and pathogens. In this Review, we highlight discoveries of protease inhibitors from environmental sources, propose new opportunities for assessment of antifungal activity, and discuss novel applications to combat biomedically-relevant fungal diseases with in vivo and clinical purpose.
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17
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Abstract
Cryptococcus neoformans is a major human central nervous system (CNS) fungal pathogen causing considerable morbidity and mortality. In this study, we provide the widest view to date of the yeast transcriptome directly from the human subarachnoid space and within cerebrospinal fluid (CSF). We captured yeast transcriptomes from C. neoformans of various genotypes in 31 patients with cryptococcal meningoencephalitis as well as several Cryptococcus gattii infections. Using transcriptome sequencing (RNA-seq) analyses, we compared the in vivo yeast transcriptomes to those from other environmental conditions, including in vitro growth on nutritious media or artificial CSF as well as samples collected from rabbit CSF at two time points. We ranked gene expressions and identified genetic patterns and networks across these diverse isolates that reveal an emphasis on carbon metabolism, fatty acid synthesis, transport, cell wall structure, and stress-related gene functions during growth in CSF. The most highly expressed yeast genes in human CSF included those known to be associated with survival or virulence and highlighted several genes encoding hypothetical proteins. From that group, a gene encoding the CMP1 putative glycoprotein (CNAG_06000) was selected for functional studies. This gene was found to impact the virulence of Cryptococcus in both mice and the CNS rabbit model, in agreement with a recent study also showing a role in virulence. This transcriptional analysis strategy provides a view of regulated yeast genes across genetic backgrounds important for human CNS infection and a relevant resource for the study of cryptococcal genes, pathways, and networks linked to human disease.
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18
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Abstract
Quorum sensing (QS) is one of the most studied cell-cell communication mechanisms in fungi. Research in the last 20 years has explored various fungal QS systems that are involved in a wide range of biological processes, especially eukaryote- or fungus-specific behaviors, mirroring the significant contribution of QS regulation to fungal biology and evolution. Based on recent progress, we summarize in this review fungal QS regulation, with an emphasis on its functional role in behaviors unique to fungi or eukaryotes. We suggest that using fungi as genetically amenable eukaryotic model systems to address why and how QS regulation is integrated into eukaryotic reproductive strategies and molecular or cellular processes could be an important direction for QS research. Expected final online publication date for the Annual Review of Microbiology, Volume 75 is October 2021. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.
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Affiliation(s)
- Xiuyun Tian
- State Key Laboratory of Mycology, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, China; .,University of Chinese Academy of Sciences, Beijing 100039, China
| | - Hao Ding
- State Key Laboratory of Mycology, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, China; .,University of Chinese Academy of Sciences, Beijing 100039, China
| | - Weixin Ke
- State Key Laboratory of Mycology, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, China; .,University of Chinese Academy of Sciences, Beijing 100039, China
| | - Linqi Wang
- State Key Laboratory of Mycology, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, China; .,University of Chinese Academy of Sciences, Beijing 100039, China
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19
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Boulware DR, Nalintya E, Rajasingham R, Kirumira P, Naluyima R, Turya F, Namanda S, Rutakingirwa MK, Skipper CP, Nikweri Y, Hullsiek KH, Bangdiwala AS, Meya DB. Adjunctive sertraline for asymptomatic cryptococcal antigenemia: A randomized clinical trial. Med Mycol 2021; 58:1037-1043. [PMID: 32415846 DOI: 10.1093/mmy/myaa033] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2020] [Revised: 04/09/2020] [Accepted: 05/12/2020] [Indexed: 12/13/2022] Open
Abstract
Cryptococcal antigen (CrAg) screening in HIV-infected persons with CD4 < 100 cells/µl can reduce meningitis and death, yet preemptive fluconazole therapy fails in ∼25%. Sertraline has in vitro and in vivo activity against Cryptococcus and is synergistic with fluconazole in mice. We evaluated the efficacy and safety of sertraline in asymptomatic cryptococcal antigenemia. We conducted a randomized trial of asymptomatic CrAg-positive Ugandans from November 2017 to February 2018. All subjects received WHO standard therapy of fluconazole 800 mg for 2 weeks, then 400 mg for 10 weeks, then 200 mg through 24 weeks. Participants were randomized to receive adjunctive sertraline or placebo, given in once-weekly escalating 100 mg/day doses up to 400 mg/day, which was then given for 8 weeks, then tapered. The primary endpoint was meningitis-free 6-month survival. The data and safety monitoring board halted the trial after 21 subjects were enrolled due to safety concerns. Meningitis-free 6-month survival occurred in 9 of 11 of placebo participants and 10 of 10 of sertraline participants. However, seven serious adverse events (SAEs) occurred (n = 4 sertraline group; n = 3 placebo group). Three SAEs in the sertraline group presented with psychosis and aggressive behavioral changes with one meeting Hunter's criteria for serotonin syndrome while receiving 200 mg/day sertraline. Two transient psychoses were associated with antecedent fluconazole and sertraline interruption. The serotonin syndrome resolved within 1 day, but psychosis persisted for 4 months after sertraline discontinuation. Sertraline was associated with excess SAEs of psychosis. Due to early stopping, we were unable to determine any efficacy for cryptococcal antigenemia.
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Affiliation(s)
| | | | | | - Paul Kirumira
- Infectious Diseases Institute, Makerere University, Uganda
| | - Rose Naluyima
- Infectious Diseases Institute, Makerere University, Uganda
| | - Fred Turya
- Infectious Diseases Institute, Makerere University, Uganda
| | - Sylvia Namanda
- Infectious Diseases Institute, Makerere University, Uganda
| | | | - Caleb P Skipper
- University of Minnesota, Minneapolis, MN, USA.,Infectious Diseases Institute, Makerere University, Uganda
| | - Yofesi Nikweri
- Medical Research Council/Uganda Virus Research Institute & London School of Hygiene and Tropical Medicine (MRC/UVRI & LSHTM), Uganda Research Unit, Masaka Station
| | | | | | - David B Meya
- University of Minnesota, Minneapolis, MN, USA.,Infectious Diseases Institute, Makerere University, Uganda.,Department of Medicine, School of Medicine, College of Health Sciences, Makerere University, Kampala, Uganda
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20
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Fu MS, Liporagi-Lopes LC, Dos Santos SR, Tenor JL, Perfect JR, Cuomo CA, Casadevall A. Amoeba Predation of Cryptococcus neoformans Results in Pleiotropic Changes to Traits Associated with Virulence. mBio 2021; 12:e00567-21. [PMID: 33906924 PMCID: PMC8092252 DOI: 10.1128/mbio.00567-21] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2021] [Accepted: 03/30/2021] [Indexed: 11/20/2022] Open
Abstract
Amoeboid predators, such as amoebae, are proposed to select for survival traits in soil microbes such as Cryptococcus neoformans; these traits can also function in animal virulence by defeating phagocytic immune cells, such as macrophages. Consistent with this notion, incubation of various fungal species with amoebae enhanced their virulence, but the mechanisms involved are unknown. In this study, we exposed three strains of C. neoformans (1 clinical and 2 environmental) to predation by Acanthamoeba castellanii for prolonged times and then analyzed surviving colonies phenotypically and genetically. Surviving colonies comprised cells that expressed either pseudohyphal or yeast phenotypes, which demonstrated variable expression of traits associated with virulence, such as capsule size, urease production, and melanization. Phenotypic changes were associated with aneuploidy and DNA sequence mutations in some amoeba-passaged isolates, but not in others. Mutations in the gene encoding the oligopeptide transporter (CNAG_03013; OPT1) were observed among amoeba-passaged isolates from each of the three strains. Isolates derived from environmental strains gained the capacity for enhanced macrophage toxicity after amoeba selection and carried mutations on the CNAG_00570 gene encoding Pkr1 (AMP-dependent protein kinase regulator) but manifested reduced virulence in mice because they elicited more effective fungal-clearing immune responses. Our results indicate that C. neoformans survival under constant amoeba predation involves the generation of strains expressing pleiotropic phenotypic and genetic changes. Given the myriad potential predators in soils, the diversity observed among amoeba-selected strains suggests a bet-hedging strategy whereby variant diversity increases the likelihood that some will survive predation.IMPORTANCECryptococcus neoformans is a ubiquitous environmental fungus that is also a leading cause of fatal fungal infection in humans, especially among immunocompromised patients. A major question in the field is how an environmental yeast such as C. neoformans becomes a human pathogen when it has no need for an animal host in its life cycle. Previous studies showed that C. neoformans increases its pathogenicity after interacting with its environmental predator amoebae. Amoebae, like macrophages, are phagocytic cells that are considered an environmental training ground for pathogens to resist macrophages, but the mechanism by which C. neoformans changes its virulence through interactions with protozoa is unknown. Our study indicates that fungal survival in the face of amoeba predation is associated with the emergence of pleiotropic phenotypic and genomic changes that increase the chance of fungal survival, with this diversity suggesting a bet-hedging strategy to ensure that some forms survive.
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Affiliation(s)
- Man Shun Fu
- Department of Molecular Microbiology and Immunology, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland, USA
| | - Livia C Liporagi-Lopes
- Department of Molecular Microbiology and Immunology, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland, USA
- Departamento de Análises Clínicas e Toxicológicas, Faculdade de Farmácia, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
| | - Samuel R Dos Santos
- Department of Molecular Microbiology and Immunology, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland, USA
- Departamento de Microbiologia, Instituto de Ciências Biomédicas, Universidade de São Paulo, São Paulo, Brazil
| | - Jennifer L Tenor
- Division of Infectious Diseases, Department of Medicine and Department of Molecular Genetics and Microbiology, Duke University, Durham, North Carolina, USA
| | - John R Perfect
- Division of Infectious Diseases, Department of Medicine and Department of Molecular Genetics and Microbiology, Duke University, Durham, North Carolina, USA
| | - Christina A Cuomo
- Infectious Disease and Microbiome Program, Broad Institute, Cambridge, Massachusetts, USA
| | - Arturo Casadevall
- Department of Molecular Microbiology and Immunology, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland, USA
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21
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The Transcription Factor Pdr802 Regulates Titan Cell Formation and Pathogenicity of Cryptococcus neoformans. mBio 2021; 12:mBio.03457-20. [PMID: 33688010 PMCID: PMC8092302 DOI: 10.1128/mbio.03457-20] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
The pathogenic yeast Cryptococcus neoformans presents a worldwide threat to human health, especially in the context of immunocompromise, and current antifungal therapy is hindered by cost, limited availability, and inadequate efficacy. After the infectious particle is inhaled, C. neoformans initiates a complex transcriptional program that integrates cellular responses and enables adaptation to the host lung environment. Cryptococcus neoformans is a ubiquitous, opportunistic fungal pathogen that kills almost 200,000 people worldwide each year. It is acquired when mammalian hosts inhale the infectious propagules; these are deposited in the lung and, in the context of immunocompromise, may disseminate to the brain and cause lethal meningoencephalitis. Once inside the host, C. neoformans undergoes a variety of adaptive processes, including secretion of virulence factors, expansion of a polysaccharide capsule that impedes phagocytosis, and the production of giant (Titan) cells. The transcription factor Pdr802 is one regulator of these responses to the host environment. Expression of the corresponding gene is highly induced under host-like conditions in vitro and is critical for C. neoformans dissemination and virulence in a mouse model of infection. Direct targets of Pdr802 include the quorum sensing proteins Pqp1, Opt1, and Liv3; the transcription factors Stb4, Zfc3, and Bzp4, which regulate cryptococcal brain infectivity and capsule thickness; the calcineurin targets Had1 and Crz1, important for cell wall remodeling and C. neoformans virulence; and additional genes related to resistance to host temperature and oxidative stress, and to urease activity. Notably, cryptococci engineered to lack Pdr802 showed a dramatic increase in Titan cells, which are not phagocytosed and have diminished ability to directly cross biological barriers. This explains the limited dissemination of pdr802 mutant cells to the central nervous system and the consequently reduced virulence of this strain. The role of Pdr802 as a negative regulator of Titan cell formation is thus critical for cryptococcal pathogenicity.
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22
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Treatment strategies for cryptococcal infection: challenges, advances and future outlook. Nat Rev Microbiol 2021; 19:454-466. [PMID: 33558691 PMCID: PMC7868659 DOI: 10.1038/s41579-021-00511-0] [Citation(s) in RCA: 135] [Impact Index Per Article: 45.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/07/2021] [Indexed: 01/31/2023]
Abstract
Cryptococcus spp., in particular Cryptococcus neoformans and Cryptococcus gattii, have an enormous impact on human health worldwide. The global burden of cryptococcal meningitis is almost a quarter of a million cases and 181,000 deaths annually, with mortality rates of 100% if infections remain untreated. Despite these alarming statistics, treatment options for cryptococcosis remain limited, with only three major classes of drugs approved for clinical use. Exacerbating the public health burden is the fact that the only new class of antifungal drugs developed in decades, the echinocandins, displays negligible antifungal activity against Cryptococcus spp., and the efficacy of the remaining therapeutics is hampered by host toxicity and pathogen resistance. Here, we describe the current arsenal of antifungal agents and the treatment strategies employed to manage cryptococcal disease. We further elaborate on the recent advances in our understanding of the intrinsic and adaptive resistance mechanisms that are utilized by Cryptococcus spp. to evade therapeutic treatments. Finally, we review potential therapeutic strategies, including combination therapy, the targeting of virulence traits, impairing stress response pathways and modulating host immunity, to effectively treat infections caused by Cryptococcus spp. Overall, understanding of the mechanisms that regulate anti-cryptococcal drug resistance, coupled with advances in genomics technologies and high-throughput screening methodologies, will catalyse innovation and accelerate antifungal drug discovery.
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23
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Yu CH, Chen Y, Desjardins CA, Tenor JL, Toffaletti DL, Giamberardino C, Litvintseva A, Perfect JR, Cuomo CA. Landscape of gene expression variation of natural isolates of Cryptococcus neoformans in response to biologically relevant stresses. Microb Genom 2020; 6. [PMID: 31860441 PMCID: PMC7067042 DOI: 10.1099/mgen.0.000319] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Cryptococcus neoformans is an opportunistic fungal pathogen that at its peak epidemic levels caused an estimated million cases of cryptococcal meningitis per year worldwide. This species can grow in diverse environmental (trees, soil and bird excreta) and host niches (intracellular microenvironments of phagocytes and free-living in host tissues). The genetic basic for adaptation to these different conditions is not well characterized, as most experimental work has relied on a single reference strain of C. neoformans. To identify genes important for yeast infection and disease progression, we profiled the gene expression of seven C. neoformans isolates grown in five representative in vitro environmental and in vivo conditions. We characterized gene expression differences using RNA-Seq (RNA sequencing), comparing clinical and environmental isolates from two of the major lineages of this species, VNI and VNBI. These comparisons highlighted genes showing lineage-specific expression that are enriched in subtelomeric regions and in lineage-specific gene clusters. By contrast, we find few expression differences between clinical and environmental isolates from the same lineage. Gene expression specific to in vivo stages reflects available nutrients and stresses, with an increase in fungal metabolism within macrophages, and an induction of ribosomal and heat-shock gene expression within the subarachnoid space. This study provides the widest view to date of the transcriptome variation of C. neoformans across natural isolates, and provides insights into genes important for in vitro and in vivo growth stages.
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Affiliation(s)
- Chen-Hsin Yu
- Division of Infectious Diseases, Department of Medicine, Duke University School of Medicine, Durham, NC 27710, USA
| | - Yuan Chen
- Division of Infectious Diseases, Department of Medicine, Duke University School of Medicine, Durham, NC 27710, USA
| | | | - Jennifer L Tenor
- Division of Infectious Diseases, Department of Medicine, Duke University School of Medicine, Durham, NC 27710, USA
| | - Dena L Toffaletti
- Division of Infectious Diseases, Department of Medicine, Duke University School of Medicine, Durham, NC 27710, USA
| | - Charles Giamberardino
- Division of Infectious Diseases, Department of Medicine, Duke University School of Medicine, Durham, NC 27710, USA
| | - Anastasia Litvintseva
- Mycotic Diseases Branch, National Center for Emerging and Zoonotic Infectious Diseases, Centers for Disease Control and Prevention, Atlanta, GA 30329, USA
| | - John R Perfect
- Division of Infectious Diseases, Department of Medicine, Duke University School of Medicine, Durham, NC 27710, USA
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24
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Miguel MG, Lourenço JP, Faleiro ML. Superparamagnetic Iron Oxide Nanoparticles and Essential Oils: A New Tool for Biological Applications. Int J Mol Sci 2020; 21:E6633. [PMID: 32927821 PMCID: PMC7555169 DOI: 10.3390/ijms21186633] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2020] [Revised: 09/02/2020] [Accepted: 09/03/2020] [Indexed: 02/07/2023] Open
Abstract
Essential oils are complex mixtures of volatile compounds with diverse biological properties. Antimicrobial activity has been attributed to the essential oils as well as their capacity to prevent pathogenic microorganisms from forming biofilms. The search of compounds or methodologies with this capacity is of great importance due to the fact that the adherence of these pathogenic microorganisms to surfaces largely contributes to antibiotic resistance. Superparamagnetic iron oxide nanoparticles have been assayed for diverse biomedical applications due to their biocompatibility and low toxicity. Several methods have been developed in order to obtain functionalized magnetite nanoparticles with adequate size, shape, size distribution, surface, and magnetic properties for medical applications. Essential oils have been evaluated as modifiers of the surface magnetite nanoparticles for improving their stabilization but particularly to prevent the growth of microorganisms. This review aims to provide an overview on the current knowledge about the use of superparamagnetic iron oxide nanoparticles and essential oils on the prevention of microbial adherence and consequent biofilm formation with the goal of being applied on the surface of medical devices. Some limitations found in the studies are discussed.
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Affiliation(s)
- Maria Graça Miguel
- Mediterranean Institute for Agriculture, Environment and Development, Faculty of Science and Technology, University of Algarve, Campus de Gambelas, 8005-139 Faro, Portugal
| | - João Paulo Lourenço
- Centro de Química Estrutural, Instituto Superior Técnico, Universidade de Lisboa, Av. Rovisco Pais, 1049-001 Lisboa, Portugal;
- Centro de Investigação em Química do Algarve (CIQA), Departamento de Química e Farmácia, Faculdade de Ciências e Tecnologia, Universidade do Algarve, Campus de Gambelas, 8005-139 Faro, Portugal
| | - Maria Leonor Faleiro
- CBMR, Algarve Biomedical Center, Faculdade de Ciências e Tecnologia, Universidade do Algarve, Campus de Gambelas, 8005-139 Faro, Portugal;
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25
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Summers DK, Perry DS, Rao B, Madhani HD. Coordinate genomic association of transcription factors controlled by an imported quorum sensing peptide in Cryptococcus neoformans. PLoS Genet 2020; 16:e1008744. [PMID: 32956370 PMCID: PMC7537855 DOI: 10.1371/journal.pgen.1008744] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2020] [Revised: 10/06/2020] [Accepted: 06/23/2020] [Indexed: 12/12/2022] Open
Abstract
Qsp1 is a secreted quorum sensing peptide required for virulence of the fungal meningitis pathogen Cryptococcus neoformans. Qsp1 functions to control cell wall integrity in vegetatively growing cells and also functions in mating. Rather than acting on a cell surface receptor, Qsp1 is imported to act intracellularly via the predicted oligopeptide transporter Opt1. Here, we identify a transcription factor network as a target of Qsp1. Using whole-genome chromatin immunoprecipitation, we find Qsp1 controls the genomic associations of three transcription factors to genes whose outputs are regulated by Qsp1. One of these transcription factors, Cqs2, is also required for the action of Qsp1 during mating, indicating that it might be a shared proximal target of Qsp1. Consistent with this hypothesis, deletion of CQS2 impacts the binding of other network transcription factors specifically to Qsp1-regulated genes. These genetic and genomic studies illuminate mechanisms by which an imported peptide acts to modulate eukaryotic gene expression.
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Affiliation(s)
- Diana K. Summers
- Department of Biochemistry and Biophysics, University of California, San Francisco, CA, United States of America
| | - Daniela S. Perry
- Department of Biochemistry and Biophysics, University of California, San Francisco, CA, United States of America
| | - Beiduo Rao
- Department of Biochemistry and Biophysics, University of California, San Francisco, CA, United States of America
| | - Hiten D. Madhani
- Department of Biochemistry and Biophysics, University of California, San Francisco, CA, United States of America
- Chan-Zuckerberg Biohub, San Francisco, CA, United States of America
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Gonçalves AP, Heller J, Rico-Ramírez AM, Daskalov A, Rosenfield G, Glass NL. Conflict, Competition, and Cooperation Regulate Social Interactions in Filamentous Fungi. Annu Rev Microbiol 2020; 74:693-712. [PMID: 32689913 DOI: 10.1146/annurev-micro-012420-080905] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Social cooperation impacts the development and survival of species. In higher taxa, kin recognition occurs via visual, chemical, or tactile cues that dictate cooperative versus competitive interactions. In microbes, the outcome of cooperative versus competitive interactions is conferred by identity at allorecognition loci, so-called kind recognition. In syncytial filamentous fungi, the acquisition of multicellularity is associated with somatic cell fusion within and between colonies. However, such intraspecific cooperation entails risks, as fusion can transmit deleterious genotypes or infectious components that reduce fitness, or give rise to cheaters that can exploit communal goods without contributing to their production. Allorecognition mechanisms in syncytial fungi regulate somatic cell fusion by operating precontact during chemotropic interactions, during cell adherence, and postfusion by triggering programmed cell death reactions. Alleles at fungal allorecognition loci are highly polymorphic, fall into distinct haplogroups, and show evolutionary signatures of balancing selection, similar to allorecognition loci across the tree of life.
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Affiliation(s)
- A Pedro Gonçalves
- Department of Plant and Microbial Biology, University of California, Berkeley, California 94720, USA.,Current Affiliation: Institute of Molecular Biology, Academia Sinica, Nangang District, Taipei 115, Taiwan
| | - Jens Heller
- Department of Plant and Microbial Biology, University of California, Berkeley, California 94720, USA.,Current Affiliation: Perfect Day, Inc., Emeryville, California 94608, USA
| | - Adriana M Rico-Ramírez
- Department of Plant and Microbial Biology, University of California, Berkeley, California 94720, USA
| | - Asen Daskalov
- Department of Plant and Microbial Biology, University of California, Berkeley, California 94720, USA.,Current Affiliation: Institut Européen de Chimie et Biologie, 33600 Pessac, France
| | - Gabriel Rosenfield
- Department of Plant and Microbial Biology, University of California, Berkeley, California 94720, USA.,Current Affiliation: Department of Genetics, Stanford University School of Medicine, Stanford, California 94305, USA
| | - N Louise Glass
- Department of Plant and Microbial Biology, University of California, Berkeley, California 94720, USA.,Environmental Genomics and Systems Biology Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA
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Yi J, Sang J, Zhao J, Gao L, Yang Y, Yan L, Zhang C, Pan W, Wang G, Liao W. Transcription factor Liv4 is required for growth and pathogenesis of Cryptococcus neoformans. FEMS Yeast Res 2020; 20:foaa015. [PMID: 32391887 DOI: 10.1093/femsyr/foaa015] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2019] [Accepted: 04/03/2020] [Indexed: 11/13/2022] Open
Abstract
Cryptococcus neoformans is an important invasive fungal pathogen that causes life-threatening meningoencephalitis in humans. Its biological and pathogenic regulatory mechanisms remain largely unknown, particularly due to the presence of those core transcription factors (TFs). Here, we conducted a detailed characterization of the TF Liv4 in the biology and virulence of C. neoformans. Deletion of TF Liv4 protein resulted in growth defect under both normal and stress conditions (such as high temperature and cell wall/membrane damaging agents), drastic morphological damage and also attenuated virulence in C. neoformans. These phenotypic changes might be contributed to transcriptional abnormality in the liv4Δ mutant, in which several cryptococcal genes involved in energy metabolism and cell wall integrity were downregulated. Furthermore, ChIP-seq and ChIP-qPCR assays suggested TF Liv4 might exert its regulatory function in transcription by its activation of RBP1 in C. neoformans. Taken together, our work highlights the importance of TF Liv4 in the growth and virulence of C. neoformans, and it facilitates a better understanding of cryptococcal pathogenesis mechanisms.
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Affiliation(s)
- Jiu Yi
- Department of Dermatology, Shanghai Changzheng Hospital, Second Military Medical University, Shanghai, 200003, China
- Shanghai Key Laboratory of Molecular Medical Mycology, Shanghai Institute of Medical Mycology, Shanghai Changzheng Hospital, Second Military Medical University, Shanghai, 200003, China
| | - Junjun Sang
- Shanghai Key Laboratory of Molecular Medical Mycology, Shanghai Institute of Medical Mycology, Shanghai Changzheng Hospital, Second Military Medical University, Shanghai, 200003, China
- Department of Dermatology, 900 Hospital of the Joint Logistics Team, Fuzhou, Fujian Province, 350025, China
| | - Jingyu Zhao
- Shanghai Key Laboratory of Molecular Medical Mycology, Shanghai Institute of Medical Mycology, Shanghai Changzheng Hospital, Second Military Medical University, Shanghai, 200003, China
- Department of Dermatology, Shanghai Eastern Hepatobiliary Surgery Hospital, Shanghai, 201805, China
| | - Lei Gao
- Shanghai Key Laboratory of Molecular Medical Mycology, Shanghai Institute of Medical Mycology, Shanghai Changzheng Hospital, Second Military Medical University, Shanghai, 200003, China
| | - Yali Yang
- Shanghai Key Laboratory of Molecular Medical Mycology, Shanghai Institute of Medical Mycology, Shanghai Changzheng Hospital, Second Military Medical University, Shanghai, 200003, China
| | - Lei Yan
- Shanghai Key Laboratory of Molecular Medical Mycology, Shanghai Institute of Medical Mycology, Shanghai Changzheng Hospital, Second Military Medical University, Shanghai, 200003, China
| | - Chao Zhang
- Department of Dermatology, Shanghai Changzheng Hospital, Second Military Medical University, Shanghai, 200003, China
- Shanghai Key Laboratory of Molecular Medical Mycology, Shanghai Institute of Medical Mycology, Shanghai Changzheng Hospital, Second Military Medical University, Shanghai, 200003, China
| | - Weihua Pan
- Department of Dermatology, Shanghai Changzheng Hospital, Second Military Medical University, Shanghai, 200003, China
- Shanghai Key Laboratory of Molecular Medical Mycology, Shanghai Institute of Medical Mycology, Shanghai Changzheng Hospital, Second Military Medical University, Shanghai, 200003, China
| | - Guizhen Wang
- Emergency room, Shanghai Tenth People's Hospital of Tongji University, 200072, Shanghai, China
| | - Wanqing Liao
- Department of Dermatology, Shanghai Changzheng Hospital, Second Military Medical University, Shanghai, 200003, China
- Shanghai Key Laboratory of Molecular Medical Mycology, Shanghai Institute of Medical Mycology, Shanghai Changzheng Hospital, Second Military Medical University, Shanghai, 200003, China
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Wu S, Liu J, Liu C, Yang A, Qiao J. Quorum sensing for population-level control of bacteria and potential therapeutic applications. Cell Mol Life Sci 2020; 77:1319-1343. [PMID: 31612240 PMCID: PMC11104945 DOI: 10.1007/s00018-019-03326-8] [Citation(s) in RCA: 84] [Impact Index Per Article: 21.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2019] [Revised: 09/13/2019] [Accepted: 09/30/2019] [Indexed: 02/07/2023]
Abstract
Quorum sensing (QS), a microbial cell-to-cell communication process, dynamically regulates a variety of metabolism and physiological activities. In this review, we provide an update on QS applications based on autoinducer molecules including acyl-homoserine lactones (AHLs), auto-inducing peptides (AIPs), autoinducer 2 (AI-2) and indole in population-level control of bacteria, and highlight the potential in developing novel clinical therapies. We summarize the development in the combination of various genetic circuits such as genetic oscillators, toggle switches and logic gates with AHL-based QS devices in Gram-negative bacteria. An overview is then offered to the state-of-the-art of much less researched applications of AIP-based QS devices with Gram-positive bacteria, followed by a review of the applications of AI-2 and indole based QS for interspecies communication among microbial communities. Building on these general-purpose QS applications, we highlight the disruptions and manipulations of QS devices as potential clinical therapies for diseases caused by biofilm formation, antibiotic resistance and the phage invasion. The last part of reviewed literature is dedicated to mathematical modelling for QS applications. Finally, the key challenges and future perspectives of QS applications in monoclonal synthetic biology and synthetic ecology are discussed.
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Affiliation(s)
- Shengbo Wu
- School of Chemical Engineering and Technology, Tianjin University, Tianjin, 300072, China
- State Key Laboratory of Chemical Engineering, Tianjin University, Tianjin, 300072, China
- Collaborative Innovation Center of Chemical Science and Engineering (Tianjin), Tianjin, 300072, China
| | - Jiaheng Liu
- School of Chemical Engineering and Technology, Tianjin University, Tianjin, 300072, China
- Collaborative Innovation Center of Chemical Science and Engineering (Tianjin), Tianjin, 300072, China
- Key Laboratory of Systems Bioengineering, Ministry of Education (Tianjin University), Tianjin, 300072, China
| | - Chunjiang Liu
- School of Chemical Engineering and Technology, Tianjin University, Tianjin, 300072, China
- State Key Laboratory of Chemical Engineering, Tianjin University, Tianjin, 300072, China
- Collaborative Innovation Center of Chemical Science and Engineering (Tianjin), Tianjin, 300072, China
| | - Aidong Yang
- Department of Engineering Science, University of Oxford, Oxford, OX1 3PJ, UK.
| | - Jianjun Qiao
- School of Chemical Engineering and Technology, Tianjin University, Tianjin, 300072, China.
- Collaborative Innovation Center of Chemical Science and Engineering (Tianjin), Tianjin, 300072, China.
- Key Laboratory of Systems Bioengineering, Ministry of Education (Tianjin University), Tianjin, 300072, China.
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Feldman D, Yarden O, Hadar Y. Seeking the Roles for Fungal Small-Secreted Proteins in Affecting Saprophytic Lifestyles. Front Microbiol 2020; 11:455. [PMID: 32265881 PMCID: PMC7105643 DOI: 10.3389/fmicb.2020.00455] [Citation(s) in RCA: 31] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2019] [Accepted: 03/03/2020] [Indexed: 11/24/2022] Open
Abstract
Small secreted proteins (SSPs) comprise 40–60% of the total fungal secretome and are present in fungi of all phylogenetic groups, representing the entire spectrum of lifestyles. They are characteristically shorter than 300 amino acids in length and have a signal peptide. The majority of SSPs are coded by orphan genes, which lack known domains or similarities to known protein sequences. Effectors are a group of SSPs that have been investigated extensively in fungi that interact with living hosts, either pathogens or mutualistic systems. They are involved in suppressing the host defense response and altering its physiology. Here, we aim to delineate some of the potential roles of SSPs in saprotrophic fungi, that have been bioinformatically predicted as effectors, and termed in this mini-review as “effector-like” proteins. The effector-like Ssp1 from the white-rot fungus Pleurotus ostreatus is presented as a case study, and its potential role in regulating the ligninolytic system, secondary metabolism, development, and fruiting body initiation are discussed. We propose that deciphering the nature of effector-like SSPs will contribute to our understanding of development and communication in saprophytic fungi, as well as help, to elucidate the origin, regulation, and mechanisms of fungal-host, fungal-fungal, and fungal-bacterial interactions.
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Affiliation(s)
- Daria Feldman
- Department of Plant Pathology and Microbiology, The R.H. Smith Faculty Agriculture, Food and Environment, The Hebrew University of Jerusalem, Jerusalem, Israel
| | - Oded Yarden
- Department of Plant Pathology and Microbiology, The R.H. Smith Faculty Agriculture, Food and Environment, The Hebrew University of Jerusalem, Jerusalem, Israel
| | - Yitzhak Hadar
- Department of Plant Pathology and Microbiology, The R.H. Smith Faculty Agriculture, Food and Environment, The Hebrew University of Jerusalem, Jerusalem, Israel
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Abstract
Among fungal pathogens, Cryptococcus neoformans has gained great importance among the scientific community of several reasons. This fungus is the causative agent of cryptococcosis, a disease mainly associated to HIV immunosuppression and characterized by the appearance of meningoencephalitis. Cryptococcal meningitis is responsible for hundreds of thousands of deaths every year. Research of the pathogenesis and virulence mechanisms of this pathogen has focused on three main different areas: Adaptation to the host environment (nutrients, pH, and free radicals), mechanism of immune evasion (which include phenotypic variations and the ability to behave as a facultative intracellular pathogen), and production of virulence factors. Cryptococcus neoformans has two phenotypic characteristics, the capsule and synthesis of melanin that have a profound effect in the virulence of the yeast because they both have protective effects and induce host damage as virulence factors. Finally, the mechanisms that result in dissemination and brain invasion are also of key importance to understand cryptococcal disease. In this review, I will provide a brief overview of the main mechanisms that makes C. neoformans a pathogen in susceptible patients. Abbreviations: RNS: reactive nitrogen species; BBB: brain blood barrier; GXM: glucuronoxylomannan; GXMGal: glucuronoxylomannogalactan
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Affiliation(s)
- Oscar Zaragoza
- a Mycology Reference Laboratory National Centre for Microbiology , Instituto de Salud Carlos III Carretera Majadahonda-Pozuelo , Madrid , Spain
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Abstract
The fungal human pathogen Cryptococcus neoformans undergoes melanization in response to nutrient starvation and exposure to exogenous melanin precursors. Melanization protects the fungus against host defense mechanisms such as oxidative damage and other environmental stressors (e.g., heat/cold stress, antimicrobial compounds, ionizing radiation). Conversely, the melanization process generates cytotoxic intermediates, and melanized cells are potentially susceptible to overheating and to certain melanin-binding drugs. Despite the importance of melanin in C. neoformans biology, the signaling mechanisms regulating its synthesis are poorly understood. The recent report by D. Lee, E.-H. Jang, M. Lee, S.-W. Kim, et al. [mBio 10(5):e02267-19, 2019, https://doi.org/10.1128/mBio.02267-19] provides new insights into how C. neoformans regulates melanization. The authors identified a core melanin regulatory network consisting of transcription factors and kinases required for melanization under low-nutrient conditions. The redundant and epistatic connections of this melanin-regulating network demonstrate that C. neoformans melanization is complex and carefully regulated at multiple levels. Such complex regulation reflects the multiple functions of melanin in C. neoformans biology.
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Catania S, Dumesic PA, Pimentel H, Nasif A, Stoddard CI, Burke JE, Diedrich JK, Cook S, Shea T, Geinger E, Lintner R, Yates JR, Hajkova P, Narlikar GJ, Cuomo CA, Pritchard JK, Madhani HD. Evolutionary Persistence of DNA Methylation for Millions of Years after Ancient Loss of a De Novo Methyltransferase. Cell 2020; 180:263-277.e20. [PMID: 31955845 PMCID: PMC7197499 DOI: 10.1016/j.cell.2019.12.012] [Citation(s) in RCA: 65] [Impact Index Per Article: 16.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2019] [Revised: 10/09/2019] [Accepted: 12/10/2019] [Indexed: 12/18/2022]
Abstract
Cytosine methylation of DNA is a widespread modification of DNA that plays numerous critical roles. In the yeast Cryptococcus neoformans, CG methylation occurs in transposon-rich repeats and requires the DNA methyltransferase Dnmt5. We show that Dnmt5 displays exquisite maintenance-type specificity in vitro and in vivo and utilizes similar in vivo cofactors as the metazoan maintenance methylase Dnmt1. Remarkably, phylogenetic and functional analysis revealed that the ancestral species lost the gene for a de novo methylase, DnmtX, between 50-150 mya. We examined how methylation has persisted since the ancient loss of DnmtX. Experimental and comparative studies reveal efficient replication of methylation patterns in C. neoformans, rare stochastic methylation loss and gain events, and the action of natural selection. We propose that an epigenome has been propagated for >50 million years through a process analogous to Darwinian evolution of the genome.
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Affiliation(s)
- Sandra Catania
- Department of Biochemistry and Biophysics, University of California, San Francisco, San Francisco, CA 94158, USA
| | - Phillip A Dumesic
- Department of Biochemistry and Biophysics, University of California, San Francisco, San Francisco, CA 94158, USA
| | - Harold Pimentel
- Howard Hughes Medical Institute, Stanford University, Stanford, CA 94305, USA
| | - Ammar Nasif
- MRC London Institute of Medical Sciences (LMS), Reprogramming and Chromatin Group, Du Cane Road, W12 0NN London, UK; Institute of Clinical Sciences, Imperial College Faculty of Medicine, Du Cane Rd, W12 0NN London, UK
| | - Caitlin I Stoddard
- Department of Biochemistry and Biophysics, University of California, San Francisco, San Francisco, CA 94158, USA
| | - Jordan E Burke
- Department of Biochemistry and Biophysics, University of California, San Francisco, San Francisco, CA 94158, USA
| | - Jolene K Diedrich
- Department of Molecular Medicine, The Scripps Research Institute, La Jolla, CA 92037, USA
| | - Sophie Cook
- Department of Biochemistry and Biophysics, University of California, San Francisco, San Francisco, CA 94158, USA
| | - Terrance Shea
- Infectious Disease and Microbiome Program, Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA
| | - Elizabeth Geinger
- Infectious Disease and Microbiome Program, Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA
| | - Robert Lintner
- Infectious Disease and Microbiome Program, Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA
| | - John R Yates
- Department of Molecular Medicine, The Scripps Research Institute, La Jolla, CA 92037, USA
| | - Petra Hajkova
- MRC London Institute of Medical Sciences (LMS), Reprogramming and Chromatin Group, Du Cane Road, W12 0NN London, UK; Institute of Clinical Sciences, Imperial College Faculty of Medicine, Du Cane Rd, W12 0NN London, UK
| | - Geeta J Narlikar
- Department of Biochemistry and Biophysics, University of California, San Francisco, San Francisco, CA 94158, USA
| | - Christina A Cuomo
- Infectious Disease and Microbiome Program, Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA
| | - Jonathan K Pritchard
- Department of Biology, Stanford University, Stanford, CA 94305, USA; Howard Hughes Medical Institute, Stanford University, Stanford, CA 94305, USA
| | - Hiten D Madhani
- Department of Biochemistry and Biophysics, University of California, San Francisco, San Francisco, CA 94158, USA; Chan-Zuckerberg Biohub, San Francisco, CA 94158, USA.
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Chung KY, Brown JCS. Biology and function of exo-polysaccharides from human fungal pathogens. CURRENT CLINICAL MICROBIOLOGY REPORTS 2020; 7:1-11. [PMID: 33042730 DOI: 10.1007/s40588-020-00137-5] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
Purpose of review Environmental fungi such as Cryptococcus neoformans and Aspergillus fumigatus must survive many different and changing environments as they transition from their environmental niches to human lungs and other organs. Fungi alter their cell surfaces and secreted macromolecules to respond to and manipulate their surroundings. Recent findings This review focuses on exo-polysaccharides, chains of sugars that transported out of the cell and spread to the local environment. Major exo-polysaccharides for C. neoformans and A. fumigatus are glucuronylxylomannan (GXM) and galactosaminogalactan (GAG), respectively, which accumulate at high concentrations in growth medium and infected patients. Summary Here we discuss GXM and GAG synthesis and export, their immunomodulatory properties, and their roles in biofilm formation. We also propose areas of future research to address outstanding questions in the field that could facilitate development of new disease treatments.
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Affiliation(s)
- Krystal Y Chung
- Division of Microbiology and Immunology, Pathology Department, University of Utah School of Medicine, Salt Lake City, UT 84112, USA
| | - Jessica C S Brown
- Division of Microbiology and Immunology, Pathology Department, University of Utah School of Medicine, Salt Lake City, UT 84112, USA
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Sun S, Coelho MA, David-Palma M, Priest SJ, Heitman J. The Evolution of Sexual Reproduction and the Mating-Type Locus: Links to Pathogenesis of Cryptococcus Human Pathogenic Fungi. Annu Rev Genet 2019; 53:417-444. [PMID: 31537103 PMCID: PMC7025156 DOI: 10.1146/annurev-genet-120116-024755] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Cryptococcus species utilize a variety of sexual reproduction mechanisms, which generate genetic diversity, purge deleterious mutations, and contribute to their ability to occupy myriad environmental niches and exhibit a range of pathogenic potential. The bisexual and unisexual cycles of pathogenic Cryptococcus species are stimulated by properties associated with their environmental niches and proceed through well-characterized signaling pathways and corresponding morphological changes. Genes governing mating are encoded by the mating-type (MAT) loci and influence pathogenesis, population dynamics, and lineage divergence in Cryptococcus. MAT has undergone significant evolutionary changes within the Cryptococcus genus, including transition from the ancestral tetrapolar state in nonpathogenic species to a bipolar mating system in pathogenic species, as well as several internal reconfigurations. Owing to the variety of established sexual reproduction mechanisms and the robust characterization of the evolution of mating and MAT in this genus, Cryptococcus species provide key insights into the evolution of sexual reproduction.
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Affiliation(s)
- Sheng Sun
- Department of Molecular Genetics and Microbiology, Duke University Medical Center, Durham, North Carolina 27710, USA;
| | - Marco A Coelho
- Department of Molecular Genetics and Microbiology, Duke University Medical Center, Durham, North Carolina 27710, USA;
| | - Márcia David-Palma
- Department of Molecular Genetics and Microbiology, Duke University Medical Center, Durham, North Carolina 27710, USA;
| | - Shelby J Priest
- Department of Molecular Genetics and Microbiology, Duke University Medical Center, Durham, North Carolina 27710, USA;
| | - Joseph Heitman
- Department of Molecular Genetics and Microbiology, Duke University Medical Center, Durham, North Carolina 27710, USA;
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Abstract
Cryptococcus neoformans is a ubiquitous environmental fungus and an opportunistic pathogen that causes fatal cryptococcal meningitis. Advances in genomics, genetics, and cellular and molecular biology of C. neoformans have dramatically improved our understanding of this important pathogen, rendering it a model organism to study eukaryotic biology and microbial pathogenesis. In light of recent progress, we describe in this review the life cycle of C. neoformans with a special emphasis on the regulation of the yeast-to-hypha transition and different modes of sexual reproduction, in addition to the impacts of the life cycle on cryptococcal populations and pathogenesis.
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Affiliation(s)
- Youbao Zhao
- Department of Microbiology, University of Georgia, Athens, Georgia 30602; , , ,
| | - Jianfeng Lin
- Department of Microbiology, University of Georgia, Athens, Georgia 30602; , , ,
| | - Yumeng Fan
- Department of Microbiology, University of Georgia, Athens, Georgia 30602; , , ,
| | - Xiaorong Lin
- Department of Microbiology, University of Georgia, Athens, Georgia 30602; , , ,
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Rojas F, Matthews KR. Quorum sensing in African trypanosomes. Curr Opin Microbiol 2019; 52:124-129. [PMID: 31442903 DOI: 10.1016/j.mib.2019.07.001] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2019] [Revised: 06/28/2019] [Accepted: 07/17/2019] [Indexed: 01/17/2023]
Abstract
Many microbial eukaryotes exhibit cell-cell communication to co-ordinate group behaviours as a strategy to exploit a changed environment, adapt to adverse conditions or regulate developmental responses. Although best characterised in bacteria, eukaryotic microbes have also been revealed to cooperate to optimise their survival or dissemination. An excellent model for these processes are African trypanosomes, protozoa responsible for important human and animal disease in sub Saharan Africa. These unicellular parasites use density sensing in their mammalian host to prepare for transmission. Recently, the signal and signal transduction pathway underlying this activity have been elucidated, revealing that the parasite exploits oligopeptide signals generated by released peptidases to monitor cell density and so generate transmission stages. Here we review the evidence for this elegant quorum sensing mechanism and its parallels with similar mechanisms in other microbial systems. We also discuss its implications for disease spread in the context of coinfections involving different trypanosome species.
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Affiliation(s)
- Federico Rojas
- Institute for Immunology and Infection Research, School of Biological Sciences, University of Edinburgh, Edinburgh EH9 3FL, United Kingdom.
| | - Keith R Matthews
- Institute for Immunology and Infection Research, School of Biological Sciences, University of Edinburgh, Edinburgh EH9 3FL, United Kingdom.
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Hommel B, Sturny-Leclère A, Volant S, Veluppillai N, Duchateau M, Yu CH, Hourdel V, Varet H, Matondo M, Perfect JR, Casadevall A, Dromer F, Alanio A. Cryptococcus neoformans resists to drastic conditions by switching to viable but non-culturable cell phenotype. PLoS Pathog 2019; 15:e1007945. [PMID: 31356623 PMCID: PMC6687208 DOI: 10.1371/journal.ppat.1007945] [Citation(s) in RCA: 31] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2019] [Revised: 08/08/2019] [Accepted: 06/27/2019] [Indexed: 01/22/2023] Open
Abstract
Metabolically quiescent pathogens can persist in a viable non-replicating state for months or even years. For certain infectious diseases, such as tuberculosis, cryptococcosis, histoplasmosis, latent infection is a corollary of this dormant state, which has the risk for reactivation and clinical disease. During murine cryptococcosis and macrophage uptake, stress and host immunity induce Cryptococcus neoformans heterogeneity with the generation of a sub-population of yeasts that manifests a phenotype compatible with dormancy (low stress response, latency of growth). In this subpopulation, mitochondrial transcriptional activity is regulated and this phenotype has been considered as a hallmark of quiescence in stem cells. Based on these findings, we worked to reproduce this phenotype in vitro and then standardize the experimental conditions to consistently generate this dormancy in C. neoformans. We found that incubation of stationary phase yeasts (STAT) in nutriment limited conditions and hypoxia for 8 days (8D-HYPOx) was able to produced cells that mimic the phenotype obtained in vivo. In these conditions, mortality and/or apoptosis occurred in less than 5% of the yeasts compared to 30-40% of apoptotic or dead yeasts upon incubation in normoxia (8D-NORMOx). Yeasts in 8D-HYPOx harbored a lower stress response, delayed growth and less that 1% of culturability on agar plates, suggesting that these yeasts are viable but non culturable cells (VBNC). These VBNC were able to reactivate in the presence of pantothenic acid, a vitamin that is known to be involved in quorum sensing and a precursor of acetyl-CoA. Global metabolism of 8D-HYPOx cells showed some specific requirements and was globally shut down compared to 8D-NORMOx and STAT conditions. Mitochondrial analyses showed that the mitochondrial mass increased with mitochondria mostly depolarized in 8D-HYPOx compared to 8D-NORMox, with increased expression of mitochondrial genes. Proteomic and transcriptomic analyses of 8D-HYPOx revealed that the number of secreted proteins and transcripts detected also decreased compared to 8D-NORMOx and STAT, and the proteome, secretome and transcriptome harbored specific profiles that are engaged as soon as four days of incubation. Importantly, acetyl-CoA and the fatty acid pathway involving mitochondria are required for the generation and viability maintenance of VBNC. Altogether, these data show that we were able to generate for the first time VBNC phenotype in C. neoformans. This VBNC state is associated with a specific metabolism that should be further studied to understand dormancy/quiescence in this yeast.
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Affiliation(s)
- Benjamin Hommel
- Institut Pasteur, CNRS, Molecular Mycology Unit, UMR2000, Paris, France
- Laboratoire de Parasitologie-Mycologie, Hôpital Saint-Louis, Groupe Hospitalier Lariboisière, Saint-Louis, Fernand Widal, Assistance Publique-Hôpitaux de Paris (AP-HP), Paris, France
- Université Paris Diderot, Sorbonne Paris Cité, Paris, France
| | | | - Stevenn Volant
- Institut Pasteur - Bioinformatics and Biostatistics Hub - C3BI, USR 3756 IP CNRS, Paris, France
| | | | - Magalie Duchateau
- Institut Pasteur, Unité de spectrométrie de masse et Protéomique, Paris, France
| | - Chen-Hsin Yu
- Division of Infectious Diseases, Department of Medicine, Duke University Medical Center, Durham, North Carolina, United States of America
| | - Véronique Hourdel
- Institut Pasteur, Unité de spectrométrie de masse et Protéomique, Paris, France
| | - Hugo Varet
- Institut Pasteur - Bioinformatics and Biostatistics Hub - C3BI, USR 3756 IP CNRS, Paris, France
- Institut Pasteur - Transcriptome and Epigenome Platform - Biomics Pole - C2RT, Paris, France
| | - Mariette Matondo
- Institut Pasteur, Unité de spectrométrie de masse et Protéomique, Paris, France
| | - John R. Perfect
- Division of Infectious Diseases, Department of Medicine, Duke University Medical Center, Durham, North Carolina, United States of America
| | - Arturo Casadevall
- Department of Molecular Microbiology and Immunology, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland, United States of America
| | - Françoise Dromer
- Institut Pasteur, CNRS, Molecular Mycology Unit, UMR2000, Paris, France
| | - Alexandre Alanio
- Institut Pasteur, CNRS, Molecular Mycology Unit, UMR2000, Paris, France
- Laboratoire de Parasitologie-Mycologie, Hôpital Saint-Louis, Groupe Hospitalier Lariboisière, Saint-Louis, Fernand Widal, Assistance Publique-Hôpitaux de Paris (AP-HP), Paris, France
- Université Paris Diderot, Sorbonne Paris Cité, Paris, France
- Department of Molecular Microbiology and Immunology, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland, United States of America
- * E-mail:
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Role of Amino Acid Metabolism in the Virulence of Human Pathogenic Fungi. CURRENT CLINICAL MICROBIOLOGY REPORTS 2019. [DOI: 10.1007/s40588-019-00124-5] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
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39
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Pellegrin C, Daguerre Y, Ruytinx J, Guinet F, Kemppainen M, Frey NFD, Puech‐Pagès V, Hecker A, Pardo AG, Martin FM, Veneault‐Fourrey C. Laccaria bicolor
MiSSP8 is a small‐secreted protein decisive for the establishment of the ectomycorrhizal symbiosis. Environ Microbiol 2019; 21:3765-3779. [DOI: 10.1111/1462-2920.14727] [Citation(s) in RCA: 33] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2019] [Revised: 06/18/2019] [Accepted: 06/27/2019] [Indexed: 11/29/2022]
Affiliation(s)
- Clément Pellegrin
- INRA, UMR1136Interactions Arbres/microorganismes Centre Grand‐Est Champenoux France
- UMR 1136, Interactions Arbres/Microorganismes (IAM), Faculté des Sciences et TechnologiesUniversité de Lorraine Vandœuvre lès Nancy France
| | - Yohann Daguerre
- INRA, UMR1136Interactions Arbres/microorganismes Centre Grand‐Est Champenoux France
- UMR 1136, Interactions Arbres/Microorganismes (IAM), Faculté des Sciences et TechnologiesUniversité de Lorraine Vandœuvre lès Nancy France
| | - Joske Ruytinx
- INRA, UMR1136Interactions Arbres/microorganismes Centre Grand‐Est Champenoux France
- UMR 1136, Interactions Arbres/Microorganismes (IAM), Faculté des Sciences et TechnologiesUniversité de Lorraine Vandœuvre lès Nancy France
| | - Frédéric Guinet
- INRA, UMR1136Interactions Arbres/microorganismes Centre Grand‐Est Champenoux France
- UMR 1136, Interactions Arbres/Microorganismes (IAM), Faculté des Sciences et TechnologiesUniversité de Lorraine Vandœuvre lès Nancy France
| | - Minna Kemppainen
- Laboratorio de Micología Molecular, Departamento de Ciencia y TecnologıaUniversidad Nacional de Quilmes and CONICET Roque Sáenz Peña 352 B1876 Bernal Provincia de Buenos Aires Argentina
| | - Nicolas Frei dit Frey
- Laboratoire de Recherche en Sciences VégétalesUniversité de Toulouse, CNRS, UPS 24 chemin de Borde Rouge, Auzeville, BP42617 31326 Castanet Tolosan France
| | - Virginie Puech‐Pagès
- Laboratoire de Recherche en Sciences VégétalesUniversité de Toulouse, CNRS, UPS 24 chemin de Borde Rouge, Auzeville, BP42617 31326 Castanet Tolosan France
| | - Arnaud Hecker
- INRA, UMR1136Interactions Arbres/microorganismes Centre Grand‐Est Champenoux France
- UMR 1136, Interactions Arbres/Microorganismes (IAM), Faculté des Sciences et TechnologiesUniversité de Lorraine Vandœuvre lès Nancy France
| | - Alejandro G. Pardo
- Laboratorio de Micología Molecular, Departamento de Ciencia y TecnologıaUniversidad Nacional de Quilmes and CONICET Roque Sáenz Peña 352 B1876 Bernal Provincia de Buenos Aires Argentina
| | - Francis M. Martin
- INRA, UMR1136Interactions Arbres/microorganismes Centre Grand‐Est Champenoux France
- UMR 1136, Interactions Arbres/Microorganismes (IAM), Faculté des Sciences et TechnologiesUniversité de Lorraine Vandœuvre lès Nancy France
| | - Claire Veneault‐Fourrey
- INRA, UMR1136Interactions Arbres/microorganismes Centre Grand‐Est Champenoux France
- UMR 1136, Interactions Arbres/Microorganismes (IAM), Faculté des Sciences et TechnologiesUniversité de Lorraine Vandœuvre lès Nancy France
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Camacho E, Vij R, Chrissian C, Prados-Rosales R, Gil D, O'Meally RN, Cordero RJB, Cole RN, McCaffery JM, Stark RE, Casadevall A. The structural unit of melanin in the cell wall of the fungal pathogen Cryptococcus neoformans. J Biol Chem 2019; 294:10471-10489. [PMID: 31118223 PMCID: PMC6615676 DOI: 10.1074/jbc.ra119.008684] [Citation(s) in RCA: 59] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2019] [Revised: 05/19/2019] [Indexed: 11/06/2022] Open
Abstract
Melanins are synthesized macromolecules that are found in all biological kingdoms. These pigments have a myriad of roles that range from microbial virulence to key components of the innate immune response in invertebrates. Melanins also exhibit unique properties with potential applications in physics and material sciences, ranging from electrical batteries to novel therapeutics. In the fungi, melanins, such as eumelanins, are components of the cell wall that provide protection against biotic and abiotic elements. Elucidation of the smallest fungal cell wall-associated melanin unit that serves as a building block is critical to understand the architecture of these polymers, its interaction with surrounding components, and their functional versatility. In this study, we used isopycnic gradient sedimentation, NMR, EPR, high-resolution microscopy, and proteomics to analyze the melanin in the cell wall of the human pathogenic fungus Cryptococcus neoformans We observed that melanin is assembled into the cryptococcal cell wall in spherical structures ∼200 nm in diameter, termed melanin granules, which are in turn composed of nanospheres ∼30 nm in diameter, termed fungal melanosomes. We noted that melanin granules are closely associated with proteins that may play critical roles in the fungal melanogenesis and the supramolecular structure of this polymer. Using this structural information, we propose a model for C. neoformans' melanization that is similar to the process used in animal melanization and is consistent with the phylogenetic relatedness of the fungal and animal kingdoms.
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Affiliation(s)
- Emma Camacho
- From the Department of Molecular Microbiology and Immunology, Johns Hopkins Bloomberg School of Public Health, The Johns Hopkins University, Baltimore, Maryland 21205
| | - Raghav Vij
- From the Department of Molecular Microbiology and Immunology, Johns Hopkins Bloomberg School of Public Health, The Johns Hopkins University, Baltimore, Maryland 21205
| | - Christine Chrissian
- the Department of Chemistry and Biochemistry, City College of New York and CUNY Institute for Macromolecular Assemblies, New York, New York 10031, the City University of New York
- Ph.D. Programs in Biochemistry and
| | - Rafael Prados-Rosales
- the Department of Microbiology and Immunology, Albert Einstein College of Medicine, Yeshiva University, Bronx, New York 10461
- the CIC bioGUNE, 48160 Derio, Vizcaya, Spain
- the Department of Preventive Medicine and Public Health and Microbiology, Autonoma University of Madrid, 28049 Madrid, Spain
| | - David Gil
- the CIC bioGUNE, 48160 Derio, Vizcaya, Spain
| | - Robert N O'Meally
- the Johns Hopkins Mass Spectrometry and Proteomic Facility, The Johns Hopkins University, Baltimore, Maryland 21205, and
| | - Radames J B Cordero
- From the Department of Molecular Microbiology and Immunology, Johns Hopkins Bloomberg School of Public Health, The Johns Hopkins University, Baltimore, Maryland 21205
| | - Robert N Cole
- the Johns Hopkins Mass Spectrometry and Proteomic Facility, The Johns Hopkins University, Baltimore, Maryland 21205, and
| | - J Michael McCaffery
- the Integrated Imaging Center, Department of Biology, Engineering in Oncology Center, and Institute for NanoBioTechnology, The Johns Hopkins University, Baltimore, Maryland 21218
| | - Ruth E Stark
- the Department of Chemistry and Biochemistry, City College of New York and CUNY Institute for Macromolecular Assemblies, New York, New York 10031, the City University of New York
- Ph.D. Programs in Biochemistry and
- Chemistry, New York, New York 10016
| | - Arturo Casadevall
- From the Department of Molecular Microbiology and Immunology, Johns Hopkins Bloomberg School of Public Health, The Johns Hopkins University, Baltimore, Maryland 21205,
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Mehmood A, Liu G, Wang X, Meng G, Wang C, Liu Y. Fungal Quorum-Sensing Molecules and Inhibitors with Potential Antifungal Activity: A Review. Molecules 2019; 24:E1950. [PMID: 31117232 PMCID: PMC6571750 DOI: 10.3390/molecules24101950] [Citation(s) in RCA: 42] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2019] [Revised: 05/16/2019] [Accepted: 05/20/2019] [Indexed: 12/16/2022] Open
Abstract
The theory of persisting independent and isolated regarding microorganisms is no longer accepted. To survive and reproduce they have developed several communication platforms within the cells which facilitates them to adapt the surrounding environmental changes. This cell-to-cell communication is termed as quorum sensing; it relies upon the cell density and can stimulate several traits of microbes including biofilm formation, competence, and virulence factors secretion. Initially, this sophisticated mode of communication was discovered in bacteria; later, it was also confirmed in eukaryotes (fungi). As a consequence, many quorum-sensing molecules and inhibitors have been identified and characterized in various fungal species. In this review article, we will primarily focus on fungal quorum-sensing molecules and the production of inhibitors from fungal species with potential applications for combating fungal infections.
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Affiliation(s)
- Arshad Mehmood
- Beijing Advance Innovation Center for Food Nutrition and Human Health, Beijing Engineering and Technology Research Center of Food Additives, Beijing Technology and Business University (BTBU), Beijing 100048, China.
| | - Guorong Liu
- Beijing Advance Innovation Center for Food Nutrition and Human Health, Beijing Engineering and Technology Research Center of Food Additives, Beijing Technology and Business University (BTBU), Beijing 100048, China.
| | - Xin Wang
- Beijing Advance Innovation Center for Food Nutrition and Human Health, Beijing Engineering and Technology Research Center of Food Additives, Beijing Technology and Business University (BTBU), Beijing 100048, China.
| | - Guannan Meng
- Beijing Advance Innovation Center for Food Nutrition and Human Health, Beijing Engineering and Technology Research Center of Food Additives, Beijing Technology and Business University (BTBU), Beijing 100048, China.
| | - Chengtao Wang
- Beijing Advance Innovation Center for Food Nutrition and Human Health, Beijing Engineering and Technology Research Center of Food Additives, Beijing Technology and Business University (BTBU), Beijing 100048, China.
| | - Ya Liu
- R&D Center of China Tobacco Yunnan Industrial Co. Ltd., Kunming 650202, China.
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42
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Horst BG, Stewart EM, Nazarian AA, Marletta MA. Characterization of a Carbon Monoxide-Activated Soluble Guanylate Cyclase from Chlamydomonas reinhardtii. Biochemistry 2019; 58:2250-2259. [DOI: 10.1021/acs.biochem.9b00190] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Benjamin G. Horst
- Department of Chemistry, University of California, Berkeley, Berkeley, California 94720, United States
| | - Edna M. Stewart
- Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, California 94720, United States
| | - Aren A. Nazarian
- Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, California 94720, United States
| | - Michael A. Marletta
- Department of Chemistry, University of California, Berkeley, Berkeley, California 94720, United States
- Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, California 94720, United States
- California Institute for Quantitative Biosciences, University of California, Berkeley, Berkeley, California 94720, United States
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43
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Le Marquer M, San Clemente H, Roux C, Savelli B, Frei Dit Frey N. Identification of new signalling peptides through a genome-wide survey of 250 fungal secretomes. BMC Genomics 2019; 20:64. [PMID: 30658568 PMCID: PMC6339444 DOI: 10.1186/s12864-018-5414-2] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2018] [Accepted: 12/26/2018] [Indexed: 12/21/2022] Open
Abstract
Background Many small peptides regulate eukaryotic cell biology. In fungi, some of these peptides are produced after KEX2 protease activity on proteins displaying repetitions of identical or nearly identical motifs. Following this endoprotease activity, peptides are released in the extracellular space. This type of protein maturation is involved in the production of the α-type sexual pheromone in Ascomycota. In other cases, this processing allows the production of secreted peptides regulating fungal cell wall structure or acting as mycotoxins. In this work, we report for the first time a genome-wide search of KEX2-processed repeat proteins that we call KEPs. We screened the secreted proteins of 250 fungal species to compare their KEP repertoires with regard to their lifestyle, morphology or lineage. Results Our analysis points out that nearly all fungi display putative KEPs, suggesting an ancestral origin common to all opisthokonts. As expected, our pipeline identifies mycotoxins but also α-type sexual pheromones in Ascomycota that have not been explored so far, and unravels KEP-derived secreted peptides of unknown functions. Some species display an expansion of this class of proteins. Interestingly, we identified conserved KEPs in pathogenic fungi, suggesting a role in virulence. We also identified KEPs in Basidiomycota with striking similarities to Ascomycota α-type sexual pheromones, suggesting they may also play alternative roles in unknown signalling processes. Conclusions We identified putative, new, unexpected secreted peptides that fall into different functional categories: mycotoxins, hormones, sexual pheromones, or effectors that promote colonization during host-microbe interactions. This wide survey will open new avenues in the field of small-secreted peptides in fungi that are critical regulators of their intimate biology and modulators of their interaction with the environment. Electronic supplementary material The online version of this article (10.1186/s12864-018-5414-2) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Morgane Le Marquer
- Laboratoire de Recherche en Sciences Végétales, Université de Toulouse, CNRS, UPS, 24 chemin de Borde Rouge, Auzeville, BP42617, 31326, Castanet Tolosan, France
| | - Hélène San Clemente
- Laboratoire de Recherche en Sciences Végétales, Université de Toulouse, CNRS, UPS, 24 chemin de Borde Rouge, Auzeville, BP42617, 31326, Castanet Tolosan, France
| | - Christophe Roux
- Laboratoire de Recherche en Sciences Végétales, Université de Toulouse, CNRS, UPS, 24 chemin de Borde Rouge, Auzeville, BP42617, 31326, Castanet Tolosan, France
| | - Bruno Savelli
- Laboratoire de Recherche en Sciences Végétales, Université de Toulouse, CNRS, UPS, 24 chemin de Borde Rouge, Auzeville, BP42617, 31326, Castanet Tolosan, France
| | - Nicolas Frei Dit Frey
- Laboratoire de Recherche en Sciences Végétales, Université de Toulouse, CNRS, UPS, 24 chemin de Borde Rouge, Auzeville, BP42617, 31326, Castanet Tolosan, France.
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Barriuso J, Hogan DA, Keshavarz T, Martínez MJ. Role of quorum sensing and chemical communication in fungal biotechnology and pathogenesis. FEMS Microbiol Rev 2018; 42:627-638. [PMID: 29788231 DOI: 10.1093/femsre/fuy022] [Citation(s) in RCA: 64] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2017] [Accepted: 05/17/2018] [Indexed: 12/18/2022] Open
Abstract
Microbial cells do not live in isolation in their environment, but rather they communicate with each other using chemical signals. This sophisticated mode of cell-to-cell signalling, known as quorum sensing, was first discovered in bacteria, and coordinates the behaviour of microbial population behaviour in a cell-density-dependent manner. More recently, these mechanisms have been described in eukaryotes, particularly in fungi, where they regulate processes such as pathogenesis, morphological differentiation, secondary metabolite production and biofilm formation. In this manuscript, we review the information available to date on these processes in yeast, dimorphic fungi and filamentous fungi. We analyse the diverse chemical 'languages' used by different groups of fungi, their possible cross-talk and interkingdom interactions with other organisms. We discuss the existence of these mechanisms in multicellular organisms, the ecophysiological role of QS in fungal colonisation and the potential applications of these mechanisms in biotechnology and pathogenesis.
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Affiliation(s)
- Jorge Barriuso
- Centro de Investigaciones Biológicas, Consejo Superior de Investigaciones Científicas, Ramiro de Maeztu 9, 28040 Madrid, Spain
| | - Deborah A Hogan
- Department of Microbiology and Immunology, Geisel School of Medicine at Dartmouth, Hanover, NH 03755, USA
| | - Tajalli Keshavarz
- Department of Life Sciences, Faculty of Science and Technology, University of Westminster, London W1W 6UW, UK
| | - María Jesús Martínez
- Centro de Investigaciones Biológicas, Consejo Superior de Investigaciones Científicas, Ramiro de Maeztu 9, 28040 Madrid, Spain
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Rojas F, Silvester E, Young J, Milne R, Tettey M, Houston DR, Walkinshaw MD, Pérez-Pi I, Auer M, Denton H, Smith TK, Thompson J, Matthews KR. Oligopeptide Signaling through TbGPR89 Drives Trypanosome Quorum Sensing. Cell 2018; 176:306-317.e16. [PMID: 30503212 PMCID: PMC6333907 DOI: 10.1016/j.cell.2018.10.041] [Citation(s) in RCA: 75] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2018] [Revised: 09/13/2018] [Accepted: 10/17/2018] [Indexed: 02/03/2023]
Abstract
Trypanosome parasites control their virulence and spread by using quorum sensing (QS) to generate transmissible “stumpy forms” in their host bloodstream. However, the QS signal “stumpy induction factor” (SIF) and its reception mechanism are unknown. Although trypanosomes lack G protein-coupled receptor signaling, we have identified a surface GPR89-family protein that regulates stumpy formation. TbGPR89 is expressed on bloodstream “slender form” trypanosomes, which receive the SIF signal, and when ectopically expressed, TbGPR89 drives stumpy formation in a SIF-pathway-dependent process. Structural modeling of TbGPR89 predicts unexpected similarity to oligopeptide transporters (POT), and when expressed in bacteria, TbGPR89 transports oligopeptides. Conversely, expression of an E. coli POT in trypanosomes drives parasite differentiation, and oligopeptides promote stumpy formation in vitro. Furthermore, the expression of secreted trypanosome oligopeptidases generates a paracrine signal that accelerates stumpy formation in vivo. Peptidase-generated oligopeptide QS signals being received through TbGPR89 provides a mechanism for both trypanosome SIF production and reception. Trypanosomes use quorum sensing to differentiate to transmissible stumpy forms A GPR89 protein with oligopeptide transport activity drives parasite differentiation Oligopeptide mixtures and synthetic di- and tripeptides promote stumpy formation Released parasite oligopeptidases generate the paracrine quorum sensing signal in vivo
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Affiliation(s)
- Federico Rojas
- Institute for Immunology and Infection Research, School of Biological Sciences, University of Edinburgh, Edinburgh EH9 3FL, UK
| | - Eleanor Silvester
- Institute for Immunology and Infection Research, School of Biological Sciences, University of Edinburgh, Edinburgh EH9 3FL, UK
| | - Julie Young
- Institute for Immunology and Infection Research, School of Biological Sciences, University of Edinburgh, Edinburgh EH9 3FL, UK
| | - Rachel Milne
- Institute for Immunology and Infection Research, School of Biological Sciences, University of Edinburgh, Edinburgh EH9 3FL, UK
| | - Mabel Tettey
- Institute for Immunology and Infection Research, School of Biological Sciences, University of Edinburgh, Edinburgh EH9 3FL, UK
| | - Douglas R Houston
- Institute of Quantitative Biology, Biochemistry and Biotechnology, School of Biological Sciences, University of Edinburgh, Edinburgh EH9 3BF, UK
| | - Malcolm D Walkinshaw
- Institute of Quantitative Biology, Biochemistry and Biotechnology, School of Biological Sciences, University of Edinburgh, Edinburgh EH9 3BF, UK
| | - Irene Pérez-Pi
- Institute of Quantitative Biology, Biochemistry and Biotechnology, School of Biological Sciences, University of Edinburgh, Edinburgh EH9 3BF, UK
| | - Manfred Auer
- Institute of Quantitative Biology, Biochemistry and Biotechnology, School of Biological Sciences, University of Edinburgh, Edinburgh EH9 3BF, UK
| | - Helen Denton
- School of Biology, BSRC, University of St. Andrews, North Haugh, St. Andrews, Fife KY16 9ST, UK
| | - Terry K Smith
- School of Biology, BSRC, University of St. Andrews, North Haugh, St. Andrews, Fife KY16 9ST, UK
| | - Joanne Thompson
- Institute for Immunology and Infection Research, School of Biological Sciences, University of Edinburgh, Edinburgh EH9 3FL, UK.
| | - Keith R Matthews
- Institute for Immunology and Infection Research, School of Biological Sciences, University of Edinburgh, Edinburgh EH9 3FL, UK.
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Paes HC, Derengowski LDS, Peconick LDF, Albuquerque P, Pappas GJ, Nicola AM, Silva FBA, Vallim MA, Alspaugh JA, Felipe MSS, Fernandes L. A Wor1-Like Transcription Factor Is Essential for Virulence of Cryptococcus neoformans. Front Cell Infect Microbiol 2018; 8:369. [PMID: 30483479 PMCID: PMC6243373 DOI: 10.3389/fcimb.2018.00369] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2018] [Accepted: 10/03/2018] [Indexed: 11/29/2022] Open
Abstract
Gti1/Pac2 transcription factors occur exclusively in fungi and their roles vary according to species, including regulating morphological transition and virulence, mating and secondary metabolism. Many of these functions are important for fungal pathogenesis. We therefore hypothesized that one of the two proteins of this family in Cryptococcus neoformans, a major pathogen of humans, would also control virulence-associated cellular processes. Elimination of this protein in C. neoformans results in reduced polysaccharide capsule expression and defective cytokinesis and growth at 37°C. The mutant loses virulence in a mouse model of cryptococcal infection and retains only partial virulence in the Galleria mellonella alternative model at 30°C. We performed RNA-Seq experiments on the mutant and found abolished transcription of genes that, in combination, are known to account for all the observed phenotypes. The protein has been named Required for cytokinesis and virulence 1 (Rcv1).
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Affiliation(s)
- Hugo Costa Paes
- Clinical Medicine Division, University of Brasília Medical School, Brasília, Brazil
| | | | | | | | - Georgios Joannis Pappas
- Department of Cell Biology, Institute of Biological Sciences, University of Brasília, Brasília, Brazil
| | | | | | - Marcelo Afonso Vallim
- Cellular and Molecular Biology Division, Biological Sciences Department, São Paulo Federal University, São Paulo, Brazil
| | - J Andrew Alspaugh
- Department of Medicine, School of Medicine, Duke University, Durham, NC, United States
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Zhou X, Ballou ER. The Cryptococcus neoformans Titan Cell: From In Vivo Phenomenon to In Vitro Model. CURRENT CLINICAL MICROBIOLOGY REPORTS 2018. [DOI: 10.1007/s40588-018-0107-9] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
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48
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Cryptococcus neoformans sexual reproduction is controlled by a quorum sensing peptide. Nat Microbiol 2018; 3:698-707. [PMID: 29784977 DOI: 10.1038/s41564-018-0160-4] [Citation(s) in RCA: 32] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2017] [Accepted: 04/16/2018] [Indexed: 12/13/2022]
Abstract
Bacterial quorum sensing is a well-characterized communication system that governs a large variety of collective behaviours. By comparison, quorum sensing regulation in eukaryotic microbes remains poorly understood, especially its functional role in eukaryote-specific behaviours, such as sexual reproduction. Cryptococcus neoformans is a prevalent fungal pathogen that has two defined sexual cycles (bisexual and unisexual) and is a model organism for studying sexual reproduction in fungi. Here, we show that the quorum sensing peptide Qsp1 serves as an important signalling molecule for both forms of sexual reproduction. Qsp1 orchestrates various differentiation and molecular processes, including meiosis, the hallmark of sexual reproduction. It activates bisexual mating, at least in part through the control of pheromone, a signal necessary for bisexual activation. Notably, Qsp1 also plays a major role in the intercellular regulation of unisexual initiation and coordination, in which pheromone is not strictly required. Through a multi-layered genetic screening approach, we identified the atypical zinc finger regulator Cqs2 as an important component of the Qsp1 signalling cascade during both bisexual and unisexual reproduction. The absence of Cqs2 eliminates the Qsp1-stimulated mating response. Together, these findings extend the range of behaviours governed by quorum sensing to sexual development and meiosis.
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49
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Hommel B, Mukaremera L, Cordero RJB, Coelho C, Desjardins CA, Sturny-Leclère A, Janbon G, Perfect JR, Fraser JA, Casadevall A, Cuomo CA, Dromer F, Nielsen K, Alanio A. Titan cells formation in Cryptococcus neoformans is finely tuned by environmental conditions and modulated by positive and negative genetic regulators. PLoS Pathog 2018; 14:e1006982. [PMID: 29775480 PMCID: PMC5959062 DOI: 10.1371/journal.ppat.1006982] [Citation(s) in RCA: 86] [Impact Index Per Article: 14.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2017] [Accepted: 03/19/2018] [Indexed: 01/06/2023] Open
Abstract
The pathogenic fungus Cryptococcus neoformans exhibits morphological changes in cell size during lung infection, producing both typical size 5 to 7 μm cells and large titan cells (> 10 μm and up to 100 μm). We found and optimized in vitro conditions that produce titan cells in order to identify the ancestry of titan cells, the environmental determinants, and the key gene regulators of titan cell formation. Titan cells generated in vitro harbor the main characteristics of titan cells produced in vivo including their large cell size (>10 μm), polyploidy with a single nucleus, large vacuole, dense capsule, and thick cell wall. Here we show titan cells derived from the enlargement of progenitor cells in the population independent of yeast growth rate. Change in the incubation medium, hypoxia, nutrient starvation and low pH were the main factors that trigger titan cell formation, while quorum sensing factors like the initial inoculum concentration, pantothenic acid, and the quorum sensing peptide Qsp1p also impacted titan cell formation. Inhibition of ergosterol, protein and nucleic acid biosynthesis altered titan cell formation, as did serum, phospholipids and anti-capsular antibodies in our settings. We explored genetic factors important for titan cell formation using three approaches. Using H99-derivative strains with natural genetic differences, we showed that titan cell formation was dependent on LMP1 and SGF29 genes. By screening a gene deletion collection, we also confirmed that GPR4/5-RIM101, and CAC1 genes were required to generate titan cells and that the PKR1, TSP2, USV101 genes negatively regulated titan cell formation. Furthermore, analysis of spontaneous Pkr1 loss-of-function clinical isolates confirmed the important role of the Pkr1 protein as a negative regulator of titan cell formation. Through development of a standardized and robust in vitro assay, our results provide new insights into titan cell biogenesis with the identification of multiple important factors/pathways.
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Affiliation(s)
- Benjamin Hommel
- Institut Pasteur, Molecular Mycology Unit, Département de Mycologie, Paris, France
- CNRS UMR2000, Paris, France
- Laboratoire de Parasitologie-Mycologie, Hôpital Saint-Louis, Groupe Hospitalier Lariboisière, Saint-Louis, Fernand Widal, Assistance Publique-Hôpitaux de Paris (AP-HP), Paris, France
- Université Paris Diderot, Sorbonne Paris Cité, Paris, France
| | - Liliane Mukaremera
- Department of Microbiology and Immunology, University of Minnesota, Minneapolis, Minnesota, United States of America
| | - Radames J. B. Cordero
- Department of Molecular Microbiology and Immunology, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD., United States of America
| | - Carolina Coelho
- Department of Molecular Microbiology and Immunology, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD., United States of America
| | | | - Aude Sturny-Leclère
- Institut Pasteur, Molecular Mycology Unit, Département de Mycologie, Paris, France
- CNRS UMR2000, Paris, France
| | - Guilhem Janbon
- Institut Pasteur, Unité Biologie des ARN des Pathogènes Fongiques, Département de Mycologie, Paris, France
| | - John R. Perfect
- Division of Infectious Diseases, Department of Medicine, Duke University Medical Center, Durham, North Carolina, United States of America
| | - James A. Fraser
- Australian Infectious Diseases Research Centre, The University of Queensland, Brisbane, Queensland, Australia
| | - Arturo Casadevall
- Department of Molecular Microbiology and Immunology, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD., United States of America
| | - Christina A. Cuomo
- Broad Institute of MIT and Harvard, Cambridge, Massachusetts, United States of America
| | - Françoise Dromer
- Institut Pasteur, Molecular Mycology Unit, Département de Mycologie, Paris, France
- CNRS UMR2000, Paris, France
| | - Kirsten Nielsen
- Department of Microbiology and Immunology, University of Minnesota, Minneapolis, Minnesota, United States of America
| | - Alexandre Alanio
- Institut Pasteur, Molecular Mycology Unit, Département de Mycologie, Paris, France
- CNRS UMR2000, Paris, France
- Laboratoire de Parasitologie-Mycologie, Hôpital Saint-Louis, Groupe Hospitalier Lariboisière, Saint-Louis, Fernand Widal, Assistance Publique-Hôpitaux de Paris (AP-HP), Paris, France
- Université Paris Diderot, Sorbonne Paris Cité, Paris, France
- Department of Molecular Microbiology and Immunology, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD., United States of America
- * E-mail:
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Trevijano-Contador N, de Oliveira HC, García-Rodas R, Rossi SA, Llorente I, Zaballos Á, Janbon G, Ariño J, Zaragoza Ó. Cryptococcus neoformans can form titan-like cells in vitro in response to multiple signals. PLoS Pathog 2018; 14:e1007007. [PMID: 29775477 PMCID: PMC5959073 DOI: 10.1371/journal.ppat.1007007] [Citation(s) in RCA: 70] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2017] [Accepted: 04/03/2018] [Indexed: 02/07/2023] Open
Abstract
Cryptococcus neoformans is an encapsulated pathogenic yeast that can change the size of the cells during infection. In particular, this process can occur by enlarging the size of the capsule without modifying the size of the cell body, or by increasing the diameter of the cell body, which is normally accompanied by an increase of the capsule too. This last process leads to the formation of cells of an abnormal enlarged size denominated titan cells. Previous works characterized titan cell formation during pulmonary infection but research on this topic has been hampered due to the difficulty to obtain them in vitro. In this work, we describe in vitro conditions (low nutrient, serum supplemented medium at neutral pH) that promote the transition from regular to titan-like cells. Moreover, addition of azide and static incubation of the cultures in a CO2 enriched atmosphere favored cellular enlargement. This transition occurred at low cell densities, suggesting that the process was regulated by quorum sensing molecules and it was independent of the cryptococcal serotype/species. Transition to titan-like cell was impaired by pharmacological inhibition of PKC signaling pathway. Analysis of the gene expression profile during the transition to titan-like cells showed overexpression of enzymes involved in carbohydrate metabolism, as well as proteins from the coatomer complex, and related to iron metabolism. Indeed, we observed that iron limitation also induced the formation of titan cells. Our gene expression analysis also revealed other elements involved in titan cell formation, such as calnexin, whose absence resulted in appearance of abnormal large cells even in regular rich media. In summary, our work provides a new alternative method to investigate titan cell formation devoid the bioethical problems that involve animal experimentation. Cryptococcus neoformans is a fungal pathogen that has a significant incidence in HIV+ patients in particular, in Sub-saharan Africa, Asia and South America. This yeast poses an excellent model to investigate fungal virulence because it develops many strategies to adapt to the host and evade the immune response. One of the adaptation mechanisms involves the formation of Titan Cells, which are yeast of an abnormal large size. However, research on these cells has been limited to in vivo studies (mainly in mice) because they were not reproducibly found in vitro. In this work, we describe several conditions that induce the appearance of cells that mimic titan cells, and that we denominated as titan-like cells. The main factor that induced titan-like cells was the addition of serum to nutrient limited media. This has allowed to easily performing new approaches to characterize several signaling pathways involved in their development. We found that the formation of these cells is regulated by quorum sensing molecules, and that pathways such as cAMP and PKC regulate the process of cellular enlargement. We have also performed transcriptomic analysis, which led to the identification of new genes that could be involved in the process. This work will open different research lines that will contribute to the elucidation of the role of these cells during infection and on the development of cryptococcal disease.
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Affiliation(s)
- Nuria Trevijano-Contador
- Mycology Reference Laboratory, National Centre for Microbiology, Instituto de Salud Carlos III, Majadahonda, Madrid, Spain
| | - Haroldo Cesar de Oliveira
- Mycology Reference Laboratory, National Centre for Microbiology, Instituto de Salud Carlos III, Majadahonda, Madrid, Spain
- Universidade Estadual Paulista (UNESP), Faculdade de Ciências Farmacêuticas, Câmpus Araraquara, Departamento de Análises Clínicas, Laboratório de Micologia Clínica, Araraquara, São Paulo, Brazil
| | - Rocío García-Rodas
- Mycology Reference Laboratory, National Centre for Microbiology, Instituto de Salud Carlos III, Majadahonda, Madrid, Spain
| | - Suélen Andreia Rossi
- Mycology Reference Laboratory, National Centre for Microbiology, Instituto de Salud Carlos III, Majadahonda, Madrid, Spain
| | - Irene Llorente
- Mycology Reference Laboratory, National Centre for Microbiology, Instituto de Salud Carlos III, Majadahonda, Madrid, Spain
| | - Ángel Zaballos
- Genomics Unit, Core Scientific Services, Instituto de Salud Carlos III, Majadahonda, Madrid, Spain
| | - Guilhem Janbon
- Institut Pasteur, Unité Biologie des ARN des Pathogènes Fongiques, Département de Mycologie, Paris, France
| | - Joaquín Ariño
- Institut de Biotecnologia i Biomedicina and Departament de Bioquímica i Biologia Molecular, Universitat Autònoma de Barcelona, Cerdanyola del Vallès, Spain
| | - Óscar Zaragoza
- Mycology Reference Laboratory, National Centre for Microbiology, Instituto de Salud Carlos III, Majadahonda, Madrid, Spain
- * E-mail:
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