51
|
Peptide-Like Nylon-3 Polymers with Activity against Phylogenetically Diverse, Intrinsically Drug-Resistant Pathogenic Fungi. mSphere 2018; 3:3/3/e00223-18. [PMID: 29794056 PMCID: PMC5967195 DOI: 10.1128/msphere.00223-18] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2018] [Accepted: 05/01/2018] [Indexed: 11/20/2022] Open
Abstract
Understanding the dimensions of fungal diversity has major implications for the control of diseases in humans, plants, and animals and in the overall health of ecosystems on the planet. One ancient evolutionary strategy organisms use to manage interactions with microbes, including fungi, is to produce host defense peptides (HDPs). HDPs and their synthetic analogs have been subjects of interest as potential therapeutic agents. Due to increases in fungal disease worldwide, there is great interest in developing novel antifungal agents. Here we describe activity of polymeric HDP analogs against fungi from 18 pathogenic genera composed of 41 species and 72 isolates. The synthetic polymers are members of the nylon-3 family (poly-β-amino acid materials). Three different nylon-3 polymers show high efficacy against surprisingly diverse fungi. Across the phylogenetic spectrum (with the exception of Aspergillus species), yeasts, dermatophytes, dimorphic fungi, and molds were all sensitive to the effects of these polymers. Even fungi intrinsically resistant to current antifungal drugs, such as the causative agents of mucormycosis (Rhizopus spp.) and those with acquired resistance to azole drugs, showed nylon-3 polymer sensitivity. In addition, the emerging pathogens Pseudogymnoascus destructans (cause of white nose syndrome in bats) and Candida auris (cause of nosocomial infections of humans) were also sensitive. The three nylon-3 polymers exhibited relatively low toxicity toward mammalian cells. These findings raise the possibility that nylon-3 polymers could be useful against fungi for which there are only limited and/or no antifungal agents available at present.IMPORTANCE Fungi reside in all ecosystems on earth and impart both positive and negative effects on human, plant, and animal health. Fungal disease is on the rise worldwide, and there is a critical need for more effective and less toxic antifungal agents. Nylon-3 polymers are short, sequence random, poly-β-amino acid materials that can be designed to manifest antimicrobial properties. Here, we describe three nylon-3 polymers with potent activity against the most phylogenetically diverse set of fungi evaluated thus far in a single study. In contrast to traditional peptides, nylon-3 polymers are highly stable to proteolytic degradation and can be produced efficiently in large quantities at low cost. The ability to modify nylon-3 polymer composition easily creates an opportunity to tailor efficacy and toxicity, which makes these materials attractive as potential broad-spectrum antifungal therapeutics.
Collapse
|
52
|
Plant Homeodomain Genes Play Important Roles in Cryptococcal Yeast-Hypha Transition. Appl Environ Microbiol 2018; 84:AEM.01732-17. [PMID: 29500261 DOI: 10.1128/aem.01732-17] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2017] [Accepted: 02/19/2018] [Indexed: 11/20/2022] Open
Abstract
Cryptococcus neoformans is a major opportunistic fungal pathogen. Like many dimorphic fungal pathogens, C. neoformans can undergo morphological transition from the yeast form to the hypha form, and its morphotype is tightly linked to its virulence. Although some genetic factors controlling morphogenesis have been identified, little is known about the epigenetic regulation in this process. Proteins with the plant homeodomain (PHD) finger, a structurally conserved domain in eukaryotes, were first identified in plants and are known to be involved in reading and effecting chromatin modification. Here, we investigated the role of the PHD finger family genes in Cryptococcus mating and yeast-hypha transition. We found 16 PHD finger domains distributed among 15 genes in the Cryptococcus genome, with two genes, ZNF1α and RUM1α, located in the mating type locus. We deleted these 15 PHD genes and examined the impact of their disruption on cryptococcal morphogenesis. The deletion of five PHD finger genes dramatically affected filamentation. The rum1αΔ and znf1αΔ mutants showed enhanced ability to initiate filamentation but impaired ability to maintain filamentous growth. The bye1Δ and the phd11Δ mutants exhibited enhanced filamentation, while the set302Δ mutants displayed reduced filamentation. Ectopic overexpression of these five genes in the corresponding null mutants partially or completely restored the defect in filamentation. Furthermore, we demonstrated that Phd11, a suppressor of filamentation, regulates the yeast-hypha transition through the known master regulator Znf2. The findings indicate the importance of epigenetic regulation in controlling dimorphic transition in C. neoformansIMPORTANCE Morphotype is known to have a profound impact on cryptococcal interaction with various hosts, including mammalian hosts. The yeast form of Cryptococcus neoformans is considered the virulent form, while its hyphal form is attenuated in mammalian models of cryptococcosis. Although some genetic regulators critical for cryptococcal morphogenesis have been identified, little is known about epigenetic regulation in this process. Given that plant homeodomain (PHD) finger proteins are involved in reading and effecting chromatin modification and their functions are unexplored in C. neoformans, we investigated the roles of the 15 PHD finger genes in Cryptococcus mating and yeast-hypha transition. Five of them profoundly affect filamentation as either a suppressor or an activator. Phd11, a suppressor of filamentation, regulates this process via Znf2, a known master regulator of morphogenesis. Thus, epigenetic regulation, coupled with genetic regulation, controls this yeast-hypha transition event.
Collapse
|
53
|
Abstract
Dimorphic fungal pathogens cause a significant human disease burden and unlike most fungal pathogens affect immunocompetent hosts. To examine the origin of virulence of these fungal pathogens, we compared genomes of classic systemic, opportunistic, and non-pathogenic species, including Emmonsia and two basal branching, non-pathogenic species in the Ajellomycetaceae, Helicocarpus griseus and Polytolypa hystricis. We found that gene families related to plant degradation, secondary metabolites synthesis, and amino acid and lipid metabolism are retained in H. griseus and P. hystricis. While genes involved in the virulence of dimorphic pathogenic fungi are conserved in saprophytes, changes in the copy number of proteases, kinases and transcription factors in systemic dimorphic relative to non-dimorphic species may have aided the evolution of specialized gene regulatory programs to rapidly adapt to higher temperatures and new nutritional environments. Notably, both of the basal branching, non-pathogenic species appear homothallic, with both mating type locus idiomorphs fused at a single locus, whereas all related pathogenic species are heterothallic. These differences revealed that independent changes in nutrient acquisition capacity have occurred in the Onygenaceae and Ajellomycetaceae, and underlie how the dimorphic pathogens have adapted to the human host and decreased their capacity for growth in environmental niches.
Collapse
|
54
|
Emergomyces: a New Genus of Dimorphic Fungal Pathogens Causing Disseminated Disease among Immunocompromised Persons Globally. CURRENT FUNGAL INFECTION REPORTS 2018. [DOI: 10.1007/s12281-018-0308-y] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
|
55
|
Kirkland TN, Fierer J. Coccidioides immitis and posadasii; A review of their biology, genomics, pathogenesis, and host immunity. Virulence 2018; 9:1426-1435. [PMID: 30179067 PMCID: PMC6141143 DOI: 10.1080/21505594.2018.1509667] [Citation(s) in RCA: 47] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2018] [Accepted: 07/31/2018] [Indexed: 11/24/2022] Open
Abstract
Coccidioides immitis and C. posadasii are two highly pathogenic dimorphic fungal species that are endemic in the arid areas of the new world, including the region from west Texas to southern and central California in the USA that cause coccidioidomycosis (also known as Valley Fever). In highly endemic regions such as southern Arizona, up to 50% of long term residents have been infected. New information about fungal population genetics, ecology, epidemiology, and host-pathogen interactions is becoming available. However, our understanding of some aspects of coccidioidomycosis is still incomplete, including the extent of genetic variability of the fungus, the genes involved in virulence, and how the changes in gene expression during the organism's dimorphic life cycle are related to the transformation from a free-living mold to a parasitic spherule. Unfortunately, efforts to develop an effective subunit vaccine have not yet been productive, although two potential live fungus vaccines have been developed.
Collapse
Affiliation(s)
- Theo N. Kirkland
- Division of Infectious Diseases, Department of Medicine, University of California San Diego School of Medicine, San Diego, CA, USA
| | - Joshua Fierer
- Division of Infectious Diseases, Department of Medicine, University of California San Diego School of Medicine, San Diego, CA, USA
- VA Healthcare San Diego, San Diego, CA, USA
| |
Collapse
|
56
|
Schwartz IS, McLoud JD, Berman D, Botha A, Lerm B, Colebunders R, Levetin E, Kenyon C. Molecular detection of airborne Emergomyces africanus, a thermally dimorphic fungal pathogen, in Cape Town, South Africa. PLoS Negl Trop Dis 2018; 12:e0006174. [PMID: 29357352 PMCID: PMC5800596 DOI: 10.1371/journal.pntd.0006174] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2017] [Revised: 02/06/2018] [Accepted: 12/18/2017] [Indexed: 12/28/2022] Open
Abstract
Emergomyces africanus is a thermally dimorphic fungus that causes a systemic mycosis in immunocompromised persons in South Africa. Infection is presumed to follow inhalation of airborne propagules. We developed a quantitative PCR protocol able to detect as few as 5 Es. africanus propagules per day. Samples were collected in Cape Town, South Africa over 50 weeks by a Burkard spore trap with an alternate orifice. We detected Es. africanus in air samples from 34 days (10%) distributed over 11 weeks. These results suggest environmental exposure to airborne Es. africanus propagules occurs more commonly in endemic areas than previously appreciated.
Collapse
Affiliation(s)
- Ilan S. Schwartz
- Max Rady College of Medicine, University of Manitoba, Winnipeg, Manitoba, Canada
- Global Health Institute, University of Antwerp, Antwerp, Belgium
| | - Josh D. McLoud
- Biological Sciences, University of Tulsa, Tulsa, Oklahoma, United States of America
| | - Dilys Berman
- University of Cape Town, Cape Town, Western Cape, South Africa
| | - Alfred Botha
- Department of Microbiology, Stellenbosch University, Stellenbosch, Western Cape, South Africa
| | - Barbra Lerm
- Department of Microbiology, Stellenbosch University, Stellenbosch, Western Cape, South Africa
| | | | - Estelle Levetin
- Biological Sciences, University of Tulsa, Tulsa, Oklahoma, United States of America
| | - Chris Kenyon
- Department of Clinical Sciences, Institute of Tropical Medicine, Antwerp, Belgium
| |
Collapse
|
57
|
de S Araújo GR, Souza WD, Frases S. The hidden pathogenic potential of environmental fungi. Future Microbiol 2017; 12:1533-1540. [PMID: 29168657 DOI: 10.2217/fmb-2017-0124] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Invasive fungal infections are a growing threat to immunocompromised patients, highlighting the importance of monitoring fungal pathogens. Global warming (including climatic oscillations) may select for environmental species that have acquired thermotolerance, a key step toward pathogenesis to humans. Also, important virulence factors have developed in environmental fungi, because they are essential for yeast survival in the environment. Thus, fungi traditionally regarded as nonpathogenic to humans have virulence factors similar to those of their pathogenic relatives. Here, we highlight the emergence of saprophytic environmental fungi - including species of Cryptococcus, Aspergillus, Penicillium, Candida and Scedosporium - as new human pathogens. Emerging pathogens are, in some cases, resistant to the available antifungals, potentiating the threat of novel fungal diseases.
Collapse
Affiliation(s)
- Glauber R de S Araújo
- Laboratório de Ultraestrutura Celular Hertha Meyer, Instituto de Biofísica Carlos Chagas Filho, Federal University of Rio de Janeiro, Rio de Janeiro, RJ, Brazil
| | - Wanderley de Souza
- Laboratório de Ultraestrutura Celular Hertha Meyer, Instituto de Biofísica Carlos Chagas Filho, Federal University of Rio de Janeiro, Rio de Janeiro, RJ, Brazil
| | - Susana Frases
- Laboratório de Ultraestrutura Celular Hertha Meyer, Instituto de Biofísica Carlos Chagas Filho, Federal University of Rio de Janeiro, Rio de Janeiro, RJ, Brazil
| |
Collapse
|
58
|
Idnurm A, Bailey AM, Cairns TC, Elliott CE, Foster GD, Ianiri G, Jeon J. A silver bullet in a golden age of functional genomics: the impact of Agrobacterium-mediated transformation of fungi. Fungal Biol Biotechnol 2017; 4:6. [PMID: 28955474 PMCID: PMC5615635 DOI: 10.1186/s40694-017-0035-0] [Citation(s) in RCA: 49] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2017] [Accepted: 09/18/2017] [Indexed: 11/10/2022] Open
Abstract
The implementation of Agrobacterium tumefaciens as a transformation tool revolutionized approaches to discover and understand gene functions in a large number of fungal species. A. tumefaciens mediated transformation (AtMT) is one of the most transformative technologies for research on fungi developed in the last 20 years, a development arguably only surpassed by the impact of genomics. AtMT has been widely applied in forward genetics, whereby generation of strain libraries using random T-DNA insertional mutagenesis, combined with phenotypic screening, has enabled the genetic basis of many processes to be elucidated. Alternatively, AtMT has been fundamental for reverse genetics, where mutant isolates are generated with targeted gene deletions or disruptions, enabling gene functional roles to be determined. When combined with concomitant advances in genomics, both forward and reverse approaches using AtMT have enabled complex fungal phenotypes to be dissected at the molecular and genetic level. Additionally, in several cases AtMT has paved the way for the development of new species to act as models for specific areas of fungal biology, particularly in plant pathogenic ascomycetes and in a number of basidiomycete species. Despite its impact, the implementation of AtMT has been uneven in the fungi. This review provides insight into the dynamics of expansion of new research tools into a large research community and across multiple organisms. As such, AtMT in the fungi, beyond the demonstrated and continuing power for gene discovery and as a facile transformation tool, provides a model to understand how other technologies that are just being pioneered, e.g. CRISPR/Cas, may play roles in fungi and other eukaryotic species.
Collapse
Affiliation(s)
- Alexander Idnurm
- School of BioSciences, University of Melbourne, Melbourne, VIC 3010 Australia
| | - Andy M. Bailey
- School of Biological Sciences, University of Bristol, Bristol, UK
| | - Timothy C. Cairns
- Department of Applied and Molecular Microbiology, Technische Universität Berlin, Berlin, Germany
| | - Candace E. Elliott
- School of BioSciences, University of Melbourne, Melbourne, VIC 3010 Australia
| | - Gary D. Foster
- School of Biological Sciences, University of Bristol, Bristol, UK
| | - Giuseppe Ianiri
- Department of Molecular Genetics and Microbiology, Duke University Medical Center, Durham, USA
| | - Junhyun Jeon
- College of Life and Applied Sciences, Yeungnam University, Gyeongsan, South Korea
| |
Collapse
|
59
|
Xu X, Lin J, Zhao Y, Kirkman E, So YS, Bahn YS, Lin X. Glucosamine stimulates pheromone-independent dimorphic transition in Cryptococcus neoformans by promoting Crz1 nuclear translocation. PLoS Genet 2017; 13:e1006982. [PMID: 28898238 PMCID: PMC5595294 DOI: 10.1371/journal.pgen.1006982] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2017] [Accepted: 08/17/2017] [Indexed: 02/06/2023] Open
Abstract
Morphotype switch is a cellular response to external and internal cues. The Cryptococcus neoformans species complex can undergo morphological transitions between the yeast and the hypha form, and such morphological changes profoundly affect cryptococcal interaction with various hosts. Filamentation in Cryptococcus was historically considered a mating response towards pheromone. Recent studies indicate the existence of pheromone-independent signaling pathways but their identity or the effectors remain unknown. Here, we demonstrated that glucosamine stimulated the C. neoformans species complex to undergo self-filamentation. Glucosamine-stimulated filamentation was independent of the key components of the pheromone pathway, which is distinct from pheromone-elicited filamentation. Glucosamine stimulated self-filamentation in H99, a highly virulent serotype A clinical isolate and a widely used reference strain. Through a genetic screen of the deletion sets made in the H99 background, we found that Crz1, a transcription factor downstream of calcineurin, was essential for glucosamine-stimulated filamentation despite its dispensability for pheromone-mediated filamentation. Glucosamine promoted Crz1 translocation from the cytoplasm to the nucleus. Interestingly, multiple components of the high osmolality glycerol response (HOG) pathway, consisting of the phosphorelay system and some of the Hog1 MAPK module, acted as repressors of glucosamine-elicited filamentation through their calcineurin-opposing effect on Crz1’s nuclear translocation. Surprisingly, glucosamine-stimulated filamentation did not require Hog1 itself and was distinct from the conventional general stress response. The results demonstrate that Cryptococcus can resort to multiple genetic pathways for morphological transition in response to different stimuli. Given that the filamentous form attenuates cryptococcal virulence and is immune-stimulatory in mammalian models, the findings suggest that morphogenesis is a fertile ground for future investigation into novel means to compromise cryptococcal pathogenesis. Cryptococcal meningitis claims half a million lives each year. There is no clinically available vaccine and the current antifungal therapies have serious limitations. Thus identifying cryptococcal specific programs that can be targeted for antifungal or vaccine development is of great value. We have shown previously that switching from the yeast to the hypha form drastically attenuates/abolishes cryptococcal virulence. Cryptococcal cells in the filamentous form also trigger host immune responses that can protect the host from a subsequent lethal challenge. However, self-filamentation is rarely observed in serotype A isolates that are responsible for the vast majority of cryptococcosis cases. In this study, we found that glucosamine stimulated self-filamentation in genetically distinct strains of the Cryptococcus species complex, including the most commonly used serotype A reference strain H99. We demonstrated that filamentation elicited by glucosamine did not depend on the pheromone pathway, but it requires the calcineurin transcription factor Crz1. Glucosamine promotes nuclear translocation of Crz1, which is positively controlled by the phosphatase calcineurin and is suppressed by the HOG pathway. These findings raise the possibility of manipulating genetic pathways controlling fungal morphogenesis against diseases caused by the Cryptococcus species complex.
Collapse
Affiliation(s)
- Xinping Xu
- Center for Experimental Medicine, The First Affiliated Hospital of Nanchang University, Nanchang, Jiangxi, China
- Department of Biology, Texas A&M University, College Station, Texas, United States of America
- * E-mail: (XL); (XX)
| | - Jianfeng Lin
- Department of Biology, Texas A&M University, College Station, Texas, United States of America
- Department of Microbiology, University of Georgia, Athens, Georgia, United States of America
| | - Youbao Zhao
- Department of Biology, Texas A&M University, College Station, Texas, United States of America
- Department of Microbiology, University of Georgia, Athens, Georgia, United States of America
| | - Elyssa Kirkman
- Department of Biology, Texas A&M University, College Station, Texas, United States of America
| | - Yee-Seul So
- Department of Biotechnology, Yonsei University, Seoul, Korea
| | - Yong-Sun Bahn
- Department of Biotechnology, Yonsei University, Seoul, Korea
| | - Xiaorong Lin
- Department of Biology, Texas A&M University, College Station, Texas, United States of America
- Department of Microbiology, University of Georgia, Athens, Georgia, United States of America
- * E-mail: (XL); (XX)
| |
Collapse
|
60
|
Lee PP, Lau YL. Cellular and Molecular Defects Underlying Invasive Fungal Infections-Revelations from Endemic Mycoses. Front Immunol 2017; 8:735. [PMID: 28702025 PMCID: PMC5487386 DOI: 10.3389/fimmu.2017.00735] [Citation(s) in RCA: 44] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2017] [Accepted: 06/09/2017] [Indexed: 01/29/2023] Open
Abstract
The global burden of fungal diseases has been increasing, as a result of the expanding number of susceptible individuals including people living with human immunodeficiency virus (HIV), hematopoietic stem cell or organ transplant recipients, patients with malignancies or immunological conditions receiving immunosuppressive treatment, premature neonates, and the elderly. Opportunistic fungal pathogens such as Aspergillus, Candida, Cryptococcus, Rhizopus, and Pneumocystis jiroveci are distributed worldwide and constitute the majority of invasive fungal infections (IFIs). Dimorphic fungi such as Histoplasma capsulatum, Coccidioides spp., Paracoccidioides spp., Blastomyces dermatiditis, Sporothrix schenckii, Talaromyces (Penicillium) marneffei, and Emmonsia spp. are geographically restricted to their respective habitats and cause endemic mycoses. Disseminated histoplasmosis, coccidioidomycosis, and T. marneffei infection are recognized as acquired immunodeficiency syndrome (AIDS)-defining conditions, while the rest also cause high rate of morbidities and mortalities in patients with HIV infection and other immunocompromised conditions. In the past decade, a growing number of monogenic immunodeficiency disorders causing increased susceptibility to fungal infections have been discovered. In particular, defects of the IL-12/IFN-γ pathway and T-helper 17-mediated response are associated with increased susceptibility to endemic mycoses. In this review, we put together the various forms of endemic mycoses on the map and take a journey around the world to examine how cellular and molecular defects of the immune system predispose to invasive endemic fungal infections, including primary immunodeficiencies, individuals with autoantibodies against interferon-γ, and those receiving biologic response modifiers. Though rare, these conditions provide importance insights to host defense mechanisms against endemic fungi, which can only be appreciated in unique climatic and geographical regions.
Collapse
Affiliation(s)
- Pamela P Lee
- LKS Faculty of Medicine, Department of Paediatrics and Adolescent Medicine, Queen Mary Hospital, The University of Hong Kong, Hong Kong, China
| | - Yu-Lung Lau
- LKS Faculty of Medicine, Department of Paediatrics and Adolescent Medicine, Queen Mary Hospital, The University of Hong Kong, Hong Kong, China.,Shenzhen Primary Immunodeficiencies Diagnostic and Therapeutic Laboratory, The University of Hong Kong-Shenzhen Hospital (HKU-SZH), Shenzhen, China
| |
Collapse
|
61
|
Souza ACO, Amaral AC. Antifungal Therapy for Systemic Mycosis and the Nanobiotechnology Era: Improving Efficacy, Biodistribution and Toxicity. Front Microbiol 2017; 8:336. [PMID: 28326065 PMCID: PMC5340099 DOI: 10.3389/fmicb.2017.00336] [Citation(s) in RCA: 42] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2016] [Accepted: 02/17/2017] [Indexed: 01/11/2023] Open
Abstract
Fungal diseases have been emerging as an important public health problem worldwide with the increase in host predisposition factors due to immunological dysregulations, immunosuppressive and/or anticancer therapy. Antifungal therapy for systemic mycosis is limited, most of times expensive and causes important toxic effects. Nanotechnology has become an interesting strategy to improve efficacy of traditional antifungal drugs, which allows lower toxicity, better biodistribution, and drug targeting, with promising results in vitro and in vivo. In this review, we provide a discussion about conventional antifungal and nanoantifungal therapies for systemic mycosis.
Collapse
Affiliation(s)
- Ana C. O. Souza
- Laboratory of Pathogenic Dimorphic Fungi, Institute of Biomedical Sciences, University of São PauloSão Paulo, Brazil
| | - Andre C. Amaral
- Laboratory of Nano and Biotechnology, Institute of Tropical Pathology and Public Health, Federal University of GoiásGoiânia, Brazil
| |
Collapse
|
62
|
Sapmak A, Kaewmalakul J, Nosanchuk JD, Vanittanakom N, Andrianopoulos A, Pruksaphon K, Youngchim S. Talaromyces marneffei laccase modifies THP-1 macrophage responses. Virulence 2016; 7:702-17. [PMID: 27224737 DOI: 10.1080/21505594.2016.1193275] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Talaromyces (Penicillium) marneffei is an emerging opportunistic pathogen associated with HIV infection, particularly in Southeast Asia and southern China. The rapid uptake and killing of T. marneffei conidia by phagocytic cells along with the effective induction of an inflammatory response by the host is essential for disease control. T. marneffei produces a number of different laccases linked to fungal virulence. To understand the role of the various laccases in T. marneffei, laccase-encoding genes were investigated. Targeted single, double and triple gene deletions of laccases encoding lacA, lacB, and lacC showed no significant phenotypic effects suggesting redundancy of function. When a fourth laccase-encoding gene, pbrB, was deleted in the ΔlacA ΔlacB ΔlacC background, the quadruple mutant displayed delayed conidiation and the conidia were more sensitive to H2O2, sodium dodecyl sulfate (SDS), and antifungal agents than wild-type and other transformants. Conidia of the quadruple mutant showed marked differences in their interaction with the human monocyte cell line, THP-1 such that phagocytosis was significantly higher when compared with the wild-type at one and 2 hours of incubation while the phagocytic index was significantly different from 15 to 120 minutes. In addition, killing of the quadruple mutant by THP-1 cells was more efficient at 2 and 4 hours of incubation. The levels of the proinflammatory cytokines TNF-α, IL-1β and IL-6 from THP-1 cells infected with the quadruple mutant were also significantly increased in comparison with wild-type. The results demonstrate that production of laccases by T. marneffei actually promotes the pathogen's resistance to innate host defenses.
Collapse
Affiliation(s)
- Ariya Sapmak
- a Department of Microbiology , Faculty of Medicine, Chiang Mai University , Chiang Mai , Thailand.,b Faculty of Medical Technology, Nakhon Ratchasima College , Nakhon Ratchasima , Thailand
| | - Jutikul Kaewmalakul
- a Department of Microbiology , Faculty of Medicine, Chiang Mai University , Chiang Mai , Thailand
| | - Joshua D Nosanchuk
- c Department of Medicine, Division of Infectious Diseases, and Department of Microbiology and Immunology , Albert Einstein College of Medicine , Bronx , NY , USA
| | - Nongnuch Vanittanakom
- a Department of Microbiology , Faculty of Medicine, Chiang Mai University , Chiang Mai , Thailand
| | - Alex Andrianopoulos
- d Genetics, Genomics and Development, School of BioSciences, The University of Melbourne , Victoria , Australia
| | - Kritsada Pruksaphon
- a Department of Microbiology , Faculty of Medicine, Chiang Mai University , Chiang Mai , Thailand
| | - Sirida Youngchim
- a Department of Microbiology , Faculty of Medicine, Chiang Mai University , Chiang Mai , Thailand
| |
Collapse
|
63
|
Kirkland TN. A few shared up-regulated genes may influence conidia to yeast transformation in dimorphic fungal pathogens. Med Mycol 2016; 54:648-53. [PMID: 27118798 DOI: 10.1093/mmy/myw019] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2016] [Accepted: 03/10/2016] [Indexed: 01/13/2023] Open
Abstract
The small number of fungi that commonly cause disease in normal people share the capacity to grow as mycelia in the soil at 25°C and as yeast (or spherules) in mammals at 37°C. This remarkable conversion has long been a topic of interest in medical mycology. The conidia to yeast conversion has been studied by transcription profiling in several fungal species, including Histoplasma capsulatum, Paracoccidioides brasiliensis, Coccidioides spp., Blastomyces dermatitidis, and Talaromyces marneffei One limitation of transcriptional profiling is determining which genes are involved in the process of conversion to yeast as opposed to a result of conversion to yeast. If there are genes that are up-regulated in the yeast phase of more than one dimorphic, pathogenic fungus they might be required for conversion to yeast (or spherules). To address this issue, 24 up-regulated genes common to Coccidioides spp spherules and H. capsulatum yeasts were identified. Four homologs of these genes were also found in P. brasiliensis, B. dermatitidis or T. marneffei genes that were up-regulated in yeast. 4-hydroxyphenylpurvate dioxygenase, a gene involved in tyrosine metabolism and melanin synthesis that has been shown to be required for yeast conversion, is conserved and up-regulated in yeast in all five species. Another up-regulated gene that is conserved in all five species is a MFS sugar porter. These results suggest that a minority of up-regulated yeast (or spherule) genes are conserved across species and raises the possibility that conserved up-regulated genes may be of special interest for differentiation of mycelium into yeast.
Collapse
|
64
|
Revisiting old friends: Developments in understanding Histoplasma capsulatum pathogenesis. J Microbiol 2016; 54:265-76. [DOI: 10.1007/s12275-016-6044-5] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2016] [Accepted: 02/02/2016] [Indexed: 12/27/2022]
|
65
|
Chacko N, Zhao Y, Yang E, Wang L, Cai JJ, Lin X. The lncRNA RZE1 Controls Cryptococcal Morphological Transition. PLoS Genet 2015; 11:e1005692. [PMID: 26588844 PMCID: PMC4654512 DOI: 10.1371/journal.pgen.1005692] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2015] [Accepted: 10/30/2015] [Indexed: 02/01/2023] Open
Abstract
In the fungal pathogen Cryptococcus neoformans, the switch from yeast to hypha is an important morphological process preceding the meiotic events during sexual development. Morphotype is also known to be associated with cryptococcal virulence potential. Previous studies identified the regulator Znf2 as a key decision maker for hypha formation and as an anti-virulence factor. By a forward genetic screen, we discovered that a long non-coding RNA (lncRNA) RZE1 functions upstream of ZNF2 in regulating yeast-to-hypha transition. We demonstrate that RZE1 functions primarily in cis and less effectively in trans. Interestingly, RZE1's function is restricted to its native nucleus. Accordingly, RZE1 does not appear to directly affect Znf2 translation or the subcellular localization of Znf2 protein. Transcriptome analysis indicates that the loss of RZE1 reduces the transcript level of ZNF2 and Znf2's prominent downstream targets. In addition, microscopic examination using single molecule fluorescent in situ hybridization (smFISH) indicates that the loss of RZE1 increases the ratio of ZNF2 transcripts in the nucleus versus those in the cytoplasm. Taken together, this lncRNA controls Cryptococcus yeast-to-hypha transition through regulating the key morphogenesis regulator Znf2. This is the first functional characterization of a lncRNA in a human fungal pathogen. Given the potential large number of lncRNAs in the genomes of Cryptococcus and other fungal pathogens, the findings implicate lncRNAs as an additional layer of genetic regulation during fungal development that may well contribute to the complexity in these "simple" eukaryotes.
Collapse
Affiliation(s)
- Nadia Chacko
- Department of Biology, Texas A&M University, College Station, Texas, United States of America
| | - Youbao Zhao
- Department of Biology, Texas A&M University, College Station, Texas, United States of America
| | - Ence Yang
- Department of Veterinary Integrative Biosciences, Texas A&M University, College Station, Texas, United States of America
| | - Linqi Wang
- Department of Biology, Texas A&M University, College Station, Texas, United States of America
| | - James J. Cai
- Department of Veterinary Integrative Biosciences, Texas A&M University, College Station, Texas, United States of America
| | - Xiaorong Lin
- Department of Biology, Texas A&M University, College Station, Texas, United States of America
- * E-mail:
| |
Collapse
|
66
|
Boyce KJ, Andrianopoulos A. Fungal dimorphism: the switch from hyphae to yeast is a specialized morphogenetic adaptation allowing colonization of a host. FEMS Microbiol Rev 2015; 39:797-811. [DOI: 10.1093/femsre/fuv035] [Citation(s) in RCA: 131] [Impact Index Per Article: 14.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/02/2015] [Indexed: 01/19/2023] Open
|
67
|
Lin J, Idnurm A, Lin X. Morphology and its underlying genetic regulation impact the interaction between Cryptococcus neoformans and its hosts. Med Mycol 2015; 53:493-504. [PMID: 25841056 DOI: 10.1093/mmy/myv012] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2014] [Accepted: 02/09/2015] [Indexed: 11/12/2022] Open
Abstract
Cryptococcus neoformans is a fungus that causes the majority of fatal cryptococcal meningitis cases worldwide. This pathogen is capable of assuming different morphotypes: yeast, pseudohypha, and hypha. The yeast form is the most common cell type observed clinically. The hyphal and pseudohyphal forms are rarely observed in the clinical setting and are considered attenuated in virulence. However, as a ubiquitous environmental pathogen, Cryptococcus interacts with various organisms, and it is known to be parasitic to different hosts. Capitalizing on recent discoveries, morphogenesis regulators were manipulated to examine the impact of cell shape on the cryptococcal interaction with three different host systems: the soil amoeba Acanthamoeba castellanii (a protist), the greater wax moth Galleria mellonella (an insect), and the murine macrophage cell line J774A.1 (mammalian cells). The regulation of Ace2 and morphogenesis (RAM) pathway is a highly conserved pathway among eukaryotes that regulates cytokinesis. Disruption of any of five RAM components in Cryptococcus renders cells constitutively in the pseudohyphal form. The transcription factor Znf2 is the master activator of the yeast to hyphal transition. Deletion of ZNF2 locks cells in the yeast form, while overexpression of this regulator drives hyphal growth. Genetic epistasis analyses indicate that the RAM and the Znf2 pathways regulate distinct aspects of cryptococcal morphogenesis and independently of each other. These investigations using the Cryptococcus RAM and ZNF2 mutants indicate that cell shape, cell size, and likely cell surface properties weigh differently on the outcome of cryptococcal interactions with different hosts. Thus, certain traits evolved in Cryptococcus that are beneficial within one host might be detrimental when a different host is encountered.
Collapse
Affiliation(s)
- Jianfeng Lin
- Department of Biology, Texas A&M University, College Station, Texas, USA School of Biological Sciences, University of Missouri-Kansas City, Missouri, USA
| | - Alexander Idnurm
- School of Biological Sciences, University of Missouri-Kansas City, Missouri, USA School of BioSciences, University of Melbourne, Melbourne, Victoria, Australia
| | - Xiaorong Lin
- Department of Biology, Texas A&M University, College Station, Texas, USA
| |
Collapse
|
68
|
Abstract
Morphogenesis in fungi is often induced by extracellular factors and executed by fungal genetic factors. Cell surface changes and alterations of the microenvironment often accompany morphogenetic changes in fungi. In this review, we will first discuss the general traits of yeast and hyphal morphotypes and how morphogenesis affects development and adaptation by fungi to their native niches, including host niches. Then we will focus on the molecular machinery responsible for the two most fundamental growth forms, yeast and hyphae. Last, we will describe how fungi incorporate exogenous environmental and host signals together with genetic factors to determine their morphotype and how morphogenesis, in turn, shapes the fungal microenvironment.
Collapse
Affiliation(s)
- Xiaorong Lin
- Department of Biology, Texas A&M University, College Station, Texas 77843-3258
| | - J Andrew Alspaugh
- Department of Medicine, Division of Infectious Diseases, Duke University Medical Center, Durham, North Carolina 27710
| | - Haoping Liu
- Department of Biological Chemistry, University of California, Irvine, California 92697
| | - Steven Harris
- Center for Plant Science Innovation, University of Nebraska-Lincoln, Lincoln, Nebraska 68588
| |
Collapse
|