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Phase conversion from the mycelial to yeast of Penicillium marneffei strains. Three day old mycelium of P. marneffei wild type cpeA (WT), cpeA deletion ( ? cpeA ) and revertant ( ? cpeA cpeA ) strains were subjected to the temperature shift at 37 ? C in order to induce the mycelial to yeast phase transition. All strains demonstrate the ability of the hyphae to convert into arthroconidia ( in vitro yeast form of P. marneffei ), magnifi cation 1000 . by guest on November 9, 2016
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Penicillium marneffei is a significant opportunistic fungal pathogen in Southeast Asia and its ability to survive inside the host macrophages is believed to be important in the establishment of infection. Previously, we isolated a gene encoding a catalase- peroxidase (cpeA) from P. marneffei and showed that the cpeA transcript is specifically upreg...
Citations
... In addition to the studies mentioned above, the studies on the identification of antigenic proteins provide further evidence that HMI has a protective impact on fungal infections. Specifically, it is noticeable that many antigenic proteins from medically important fungi (such as H. capsulatum, T. marneffei, and C. neoformans) could react with the antibodies present in the sera of both healthy individuals and people with fungal diseases [59,61,68,99]. These antigenic proteins are often excluded from follow-up studies because they are not diseasespecific molecules. ...
Antibody immunity is now known to play a critical role in combating mycotic infections. The identification of molecules that can elicit an antibody response against fungal pathogens is the first step in developing antibody-based therapeutic strategies. Antigenic proteins are molecules recognized by the immune system that can stimulate antibody production and, therefore, can be a direct target for studying human–fungal pathogen interactions. Advances in recent immunoproteomic approaches have substantially aided in determining the key antigenic proteins on a large scale. In this review, we present a collection of antigenic proteins identified in yeast, dimorphic, and filamentous fungal pathogens to date. The general features of antigenic proteins are summarized and reveal that the proteins could commonly function in antistress responses, protein synthesis, and metabolism. The antigenic proteins listed here could serve as starting materials for developing species-specific or broad-spectrum diagnostic tests, therapeutic antibodies, and even vaccines against fungal infections.
... In response to the host-derived oxidative stress, T. marneffei activates the MAPK signaling pathway and several transcription factors to generate antioxidant proteins, which ultimately are used to neutralize the host-generated ROS/RNS 16 . These antioxidant molecules include superoxide dismutase (sodA), catalase-peroxidase (cpeA), and glutathione peroxidase (gpx1) that are upregulated in the pathogenic yeast form [17][18][19] . The sodA and cpeA were shown to be elevated early at 2 h after being phagocytosed 17,18 . ...
... These antioxidant molecules include superoxide dismutase (sodA), catalase-peroxidase (cpeA), and glutathione peroxidase (gpx1) that are upregulated in the pathogenic yeast form [17][18][19] . The sodA and cpeA were shown to be elevated early at 2 h after being phagocytosed 17,18 . Moreover, the cpeA deletion mutant showed decreased tolerance to hydrogen peroxide, suggesting its antioxidant role in this fungus 18 . ...
Talaromyces marneffei is a human fungal pathogen that causes endemic opportunistic infections, especially in Southeast Asia. The key virulence factors of T. marneffei are the ability to survive host-derived heat and oxidative stress, and the ability to convert morphology from environmental mold to fission yeast forms during infection. Glutathione metabolism plays an essential role in stress response and cellular development in multiple organisms. However, the role of the glutathione system in T. marneffei is elusive. Here, we identified the genes encoding principal enzymes associated with glutathione metabolism in T. marneffei , including glutathione biosynthetic enzymes (Gcs1 and Gcs2), glutathione peroxidase (Gpx1), glutathione reductase (Glr1), and a family of glutathione S-transferase (Gst). Sequence homology search revealed an extended family of the TmGst proteins, consisting of 20 TmGsts that could be divided into several classes. Expression analysis revealed that cells in conidia, mold, and yeast phases exhibited distinct expression profiles of glutathione-related genes. Also, TmGst genes were highly upregulated in response to hydrogen peroxide and xenobiotic exposure. Altogether, our findings suggest that T. marneffei transcriptionally regulates the glutathione genes under stress conditions in a cell-type-specific manner. This study could aid in understanding the role of glutathione in thermal-induced dimorphism and stress response.
... That gene encodes a catalase-peroxidase, an antioxidative bifunctional enzyme, in T. marneffei. (27,28) This pattern of expression could be explained by fact that the yeast growth phase has a unique metabolism which responds to environmental change cultivation. At first, the fungus produces high levels of anti-stress responsive proteins to provide resistance ability. ...
OBJECTIVE Heat shock protein 30 (Hsp30) has been identified as an immunogenic, yeast phase-specific protein in Talaromyces marneffei. The purpose of this study was to investigate how the hsp30 gene and Hsp30 protein are expressed during phase transition and in response to heat and oxidative stress exposure. METHODS Several sequence analysis tools were employed to predict hsp30 control elements and to determine the subcellular localization of Hsp30. In the phase transition experiment, Talaromyces marneffei conidia were cultivated at two different temperatures, 25 °C and 37 °C. Subsequently, stress response tests were conducted by subjecting the yeast cells to heat at 42 °C and by treating them with hydrogen peroxide. The levels of the hsp30 transcript and its protein were measured using real-time RT-PCR and western immunoblot analysis, respectively. RESULTS The sequence analysis revealed the presence of heat response element (HRE), stress responsive element (STRE), and xenobiotic responsive element (XRE), which are typically involved in regulating hsp genes. A web-based tool predicted that Hsp30 protein is localized in cytoplasm, nucleus, and cell membrane. The hsp30 transcript and Hsp30 protein were highly clearly detected in both yeast cells and conidia. Furthermore, the hsp30 transcript in yeast cells was upregulated following heat shock at 42° C and exposure to hydrogen peroxide. These findings indicate that Hsp30 plays a crucial role in assisting the yeast phase of T. marneffei to cope with heat and oxidative stresses. CONCLUSIONS Hsp30 is a protein specific to the conidial and yeast phases of T. marneffei. It likely performs a conserved chaperone function during yeast growth and plays a significant role in stress response by mitigating protein aggregation issues. KEYWORDS Talaromyces marneffei, heat shock protein 30, expression
... However, the progress in the identification of novel antigens in T. marneffei has been hampered by a scarcity of studies focusing on this neglected fungal species. Although certain genes have been characterized and demonstrated to possess immunogenic properties (Pongpom et al., 2005;Vanittanakom et al., 2009;Pongpom and Vanittanakom, 2011;Pongpom et al., 2013), the majority of candidate genes have not been extensively investigated. Infact, more than half of the identified proteins remain unexplored. ...
... The construction of DcpeA and complemented strains were described previously (Pongpom et al., 2013). To generate the Dhsp30 mutant, a similar targeted gene deletion approach was performed. ...
... Three antigenic protein-encoding genes, cpeA, MPLP6, and hsp30 had been previously characterized. They encoded for the catalaseperoxidase (CpeA), MP1-like protein 6 (Mplp6p), and Hsp30 respectively, and they were proven to contain immunogenic properties (Pongpom et al., 2005;Vanittanakom et al., 2009;Pongpom and Vanittanakom, 2011;Pongpom et al., 2013). The remaining fourteen clones in the antigenic protein dataset was subjected to bioinformatic analyses in this current study. ...
Talaromycosis is a fungal infection that generally affects immunocompromised hosts and is one of the most frequent systemic mycoses in HIV patients, especially in endemic areas such as Southeast Asia. Talaromyces marneffei, the causative agent of talaromycosis, grows as a mold in the environment but adapts to the human body and host niches by transitioning from conidia to yeast-like cells. Knowledge of the human host and T. marneffei interaction has a direct impact on the diagnosis, yet studies are still lacking. The morbidity and mortality rates are high in taloromycosis patients if the diagnosis and treatments are delayed. Immunogenic proteins are excellent candidates for developing detection tools. Previously, we identified antigenic proteins that were recognized by antibodies from talaromycosis sera. Three of these identified proteins have been previously characterized in detail, while the others have not been explored. To expedite the progress of antigen discovery, the complete list of antigenic proteins and their features was fully reported in this study. Functional annotation and Gene Ontology examination revealed that these proteins showed a high association with membrane trafficking. Further bioinformatics analyses were performed to search for antigenic protein characteristics, including functional domains, critical residues, subcellular localization, secretory signals, and epitope peptide sequences. Expression profiling of these antigenic encoding genes was investigated using quantitative real-time PCR. The results demonstrated that most genes were expressed at low levels in the mold form, but were highly upregulated in the pathogenic yeast phase, consistent with the antigenic role of these genes during the human-host interaction. Most transcripts accumulated in the conidia, suggesting a role during phase transition. The collection of all antigen-encoding DNA sequences described here is freely accessible at GenBank, which could be useful for the research community to develop into biomarkers, diagnostic tests, research detection tools, and even vaccines.
... H 2 O 2 treatments induced high expression of this gene in both mold and yeast phase. It is therefore proposed that the CpeA of T. marneffei is utilized to protect the conidia and yeast cells from oxidative stress in the host macrophage environment [49]. ...
Talaromyces (Penicillium) marneffei is a thermally dimorphic fungus that causes talaromycosis, and the pathogen is found throughout tropical and subtropical Asia. T. marneffei has specifically emerged as an opportunistic fungal pathogen in individuals with advanced HIV disease and, to a lesser extent, other immunocompromised conditions, but more recently talaromycosis is increasingly described in immunocompetent people. Due to the high mortality rate of up to 50%, understanding T. marneffei interactions with host immune responses and diagnostic modalities is vital to the development of strategies to reduce morbidity and mortality. In this chapter, we describe T. marneffei virulence factors that enhance the fungus’ capacity for survival and growth in the host to lead to disease. We also discuss approaches for early diagnosis, which are essential to reduce the mortality rate in talaromycosis. Talaromycosis remains a neglected disease, but advances in our understanding of host-pathogen dynamics as well as the ongoing development of new diagnostic approaches are poised to enhance our capacity to combat this disease.
... The catalase-peroxidase encoding gene (CpeA) in T. marneffei is associated with the upregulated expression of CpeA transcript both in yeast phase and during macrophage infection [73]. Pongpom et al. (2013) showed that CpeA controls fungal tolerance to H 2 O 2 but not to a heat stress response. H 2 O 2 treatments induced high expression of this gene in both mold and yeast phase. ...
... H 2 O 2 treatments induced high expression of this gene in both mold and yeast phase. It is therefore proposed that the CpeA of T. marneffei is utilized to protect conidia and yeast cells from oxidative stress in the host macrophage environment [74]. In addition to catalase-peroxidase, superoxide dismutase (SOD) is an enzyme that alternately catalyzes the dismutation of the superoxide radical (O 2 − ) into either ordinary molecular oxygen (O 2 ) or hydrogen peroxide (H 2 O 2 ). ...
Talaromycosis (Penicilliosis) is an opportunistic mycosis caused by the thermally dimorphic fungus Talaromyces (Penicillium) marneffei. Similar to other major causes of systemic mycoses, the extent of disease and outcomes are the results of complex interactions between this opportunistic human pathogen and a host’s immune response. This review will highlight the current knowledge regarding the dynamic interaction between T. marneffei and mammalian hosts, particularly highlighting important aspects of virulence factors, intracellular lifestyle and the mechanisms of immune defense as well as the strategies of the pathogen for manipulating and evading host immune cells.
... and Centella asiatica (L.) have been used in treatments due to the ingredients triterpenoid saponin and bacoside that aid in memory in the elderly. Studies in 2013 and 2016 showed that when the elderly (aged 55 and above) consumed 300-450 g daily there was a significant decrease in memory loss without further side effects (Dhanasekaran M, et al., 2007;Pongpom M, et al., 2013;Nuss P, et al., 2009;Hamon A, et al., 2003;Heysieattalab S, et al., 2016;Korpi ER and Sinkkonen ST, 2006). ...
ABSTRACT
Background: Dementia in the elderly has become a
problem in health, medicinal plants, have been used to
cure several human diseases.
Methods: The study used pretest-posttest control
group design research from September 2020 to March
2021 based on phases of before and after herbal treatment. Samples were 361 elderly, randomly selected
using cluster random sampling. Data were collected
based on an Abbreviated Mental Test (AMT) and the
Barthel index of Activities of Daily Living (ADL) which
were then analyzed using Pearson’s product-moment
correlation coefficient, multiple regression, and a paired
t-test.
Results: The results revealed that most samples had
dementia at an abnormal level (40.50%), 91.50% had
no record of a relative with dementia, and had an ADL
score of ‘help themselves and help others. In addition,
age and stress were related to dementia in the elderly, with statistical significance at α =0.01 (r=0.224 and
r=0.636, respectively). Moreover, these factors can
be used to predict dementia with 51.1% (R2=0.511;
p<0.0001) of the total variance of dementia in the elderly. The effectiveness of the bacopa herb was confirmed
by a reduction in the dementia level from 40.50% to
only 24.68% (p<0.0001) and the ADL was increased to
89.24% (p<0.0001).
Conclusion: Age and stress had a major effect on dementia. Therefore, a daily capsule that contains the
herbs Bacopa monnieri and Centella asiatica and germinating rice and turmeric could benefit brain activity,
which were supported by increases in AMT and ADL.
... More than that, with the increased use of immunosuppressants such as anti-IFN-γ in organ transplant rejection reactions and autoimmune diseases, the number of individuals with non-AIDS-related infection caused by TM is on the rise (Chan et al., 2016;Yu et al., 2018). Some specific pathogenic factors have been demonstrated in TM infection so far (Cánovas and Andrianopoulos, 2006;Pongpom et al., 2013;Sapmak et al., 2016;Lau et al., 2018;Feng et al., 2019Feng et al., , 2020. For example, cell wall mannoprotein 1 (MP1p) has been recognized as a key pathogenesis-related protein of TM in the infection process (Sze et al., 2017). ...
Extracellular vesicles (EVs) loaded with proteins, nucleic acids, membrane lipids, and other virulence factors could participate in pathogenic processes in some fungi such as Cryptococcus neoformans and Candida albicans . However, the specific characteristics of EVs derived from Talaromyces marneffei (TM) still have not been figured out yet. In the present study, it has been observed that TM-derived EVs were a heterogeneous group of nanosized membrane vesicles (30–300 nm) under nanoparticle tracking analysis and transmission electron microscopy. The DiI-labeled EVs could be taken up by RAW 264.7 macrophage cells. Incubation of EVs with macrophages would result in increased expression levels of reactive oxygen species, nitric oxide, and some inflammatory factors including interleukin-1β, interleukin-6, interleukin-10, and tumor necrosis factor. Furthermore, the expression of co-stimulatory molecules (CD80, CD86, and MHC-II) was also increased in macrophages stimulated with EVs. The level of inflammatory factors secreted by macrophages showed a significant decrease when EVs were hydrolyzed by protease, while that of DNA and RNA hydrolase treatment remained unchanged. Subsequently, some virulence factors in EVs including heat shock protein, mannoprotein 1, and peroxidase were determined by liquid chromatography–tandem mass spectrometry. Taken together, our results indicated that the TM-derived EVs could mediate inflammatory response and its protein would play a key role in regulating the function of RAW 264.7 macrophage cells.
... It is speculated that the expression of catalase is considered a virulence factor during infection and functions as a protector against environmental ROS [48]. In fact, the catalase/peroxidase protein was reported as immunogenic in fungi for the first time in T. marneffei showing be crucial to this fungus during the oxidative stress response [49]. Facing free radicals may grant a pathogenic potential to S. globosa, despite its low thermotolerance. ...
Sporotrichosis is a subcutaneous mycosis of humans and other mammals, caused by dimorphic species of the genus Sporothrix. In Brazil, human disease is broadly linked to transmission by infected cats and is mainly caused by Sporothrix brasiliensis, Sporothrix schenckii and Sporothrix globosa. In this study, we used a nanoscale liquid chromatography coupled with tandem mass spectrometry approach to provide the yeast proteomic profiles of S. brasiliensis, S. schenckii and S. globosa. From a total of 247 identified proteins, 137 were found as differentially expressed. Functional classification revealed that most are related to carbohydrate and amino acid metabolism as well as stress response. Our data indicate that S. brasiliensis metabolism is distinct of that of S. schenckii and S. globosa, mainly regarding amino acid metabolism and cell wall remodeling, which are induced in the former. Enzymes belonging to glycolytic pathway are, on the other hand, up-regulated in S. schenckii and S. globosa. These findings may explain the previously described more virulent character of S. brasiliensis. Besides complementing genomic comparisons already published, this first comparative proteomic study provided information that indicates new aspects of Sporothrix species metabolism as well as offers information that may be useful in the development of prospective functional studies.
... To test the chronic effects of H 2 O 2 treatment on mycelia and yeast cell growth, 5 µl of conidial suspension (1 × 10 5 −1 × 10 2 conidia/ml) of WT, madsA and CMA strains was spotted on the surface of the SDA plate supplemented with 1.25, 2.5, 5, 10, or 20 mM H 2 O 2 , respectively. Then, the conidia were cultured on SDA plates for 7 d at 25 • C or 37 • C (Pongpom et al., 2013). ...
The opportunistic human pathogen Talaromyces marneffei exhibits a temperature-dependent dimorphic transition, which is closely related with its pathogenicity. This species grows as multinucleate mycelia that produce infectious conidia at 25°C, while undergoes a dimorphic transition to generate uninucleate yeast form cells at 37°C. The mechanisms of phenotype switching are not fully understood. The transcription factor madsA gene is a member of the MADS-box gene family. Previously, it was found that overexpression of madsA gene resulted in mycelial growth instead of yeast form at 37°C. In the current study, the madsA deletion mutant (ΔmadsA) and complemented strain (CMA) were constructed by genetic manipulation. We compared the phenotypes, growth, conidiation, conidial germination and susceptibility to stresses (including osmotic and oxidative) of the ΔmadsA with the wild-type (WT) and CMA strains. The results showed that the ΔmadsA displayed a faster process of the yeast-to-mycelium transition than the WT and CMA. In addition, the deletion of madsA led to a delay in conidia production and conidial germination. The tolerance of ΔmadsA conidia to hydrogen peroxide was better than that of the WT and CMA strains. Then, RNA-seq was performed to identify differences in gene expression between the ΔmadsA mutant and WT strain during the yeast phase, mycelium phase, yeast-to-mycelium transition and mycelium-to-yeast transition, respectively. Gene ontology functional enrichment analyses indicated that some important processes such as transmembrane transport, oxidation-reduction process, protein catabolic process and response to oxidative stress were affected by the madsA deletion. Together, our results suggest that madsA functions as a global regulator involved in the conidiation and germination, especially in the dimorphic transition of T. marneffei. Its roles in the survival, pathogenicity and transmission of T. marneffei require further investigation.
