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1.
JMIR Cancer ; 9: e48786, 2023 Aug 02.
Article in English | MEDLINE | ID: mdl-37531163

ABSTRACT

BACKGROUND: Twitter has become a popular platform for individuals to broadcast their daily experiences and opinions on a wide range of topics and emotions. Tweets from patients with cancer could offer insights into their needs. However, limited research has been conducted using Twitter data to understand the needs of patients with cancer despite the substantial amount of health-related data posted on the platform daily. OBJECTIVE: This study aimed to uncover the potential of using Twitter data to understand the perspectives and experiences of patients with thyroid cancer at a global level. METHODS:  This retrospective descriptive study collected tweets relevant to thyroid cancer in 2020 using the Twitter scraping tool. Only English-language tweets were included, and data preprocessing was performed to remove irrelevant tweets, duplicates, and retweets. Both tweets and Twitter users were manually classified into various groups based on the content. Each tweet underwent sentiment analysis and was classified as either positive, neutral, or negative. RESULTS: A total of 13,135 tweets related to thyroid cancer were analyzed. The authors of the tweets included patients with thyroid cancer (3225 tweets, 24.6%), patient's families and friends (2449 tweets, 18.6%), medical journals and media (1733 tweets, 13.2%), health care professionals (1093 tweets, 8.3%), and medical health organizations (940 tweets, 7.2%), respectively. The most discussed topics related to living with cancer (3650 tweets, 27.8%), treatment (2891 tweets, 22%), diagnosis (1613 tweets, 12.3%), risk factors and prevention (1137 tweets, 8.7%), and research (953 tweets, 7.3%). An average of 36 tweets pertaining to thyroid cancer were posted daily. Notably, the release of a film addressing thyroid cancer and the public disclosure of a news reporter's personal diagnosis of thyroid cancer resulted in a significant escalation in the volume of tweets. From the sentiment analysis, 53.5% (7025/13,135) of tweets were classified as neutral statements and 32.7% (4299/13,135) of tweets expressed negative emotions. Tweets from patients with thyroid cancer had the highest proportion of negative emotion (1385/3225 tweets, 42.9%), particularly when discussing symptoms. CONCLUSIONS:  This study provides new insights on using Twitter data as a valuable data source to understand the experiences of patients with thyroid cancer. Twitter may provide an opportunity to improve patient and physician engagement or apply as a potential research data source.

2.
Healthc Inform Res ; 29(3): 269-279, 2023 Jul.
Article in English | MEDLINE | ID: mdl-37591682

ABSTRACT

OBJECTIVES: Twitter has been used to express a diverse range of public opinions about cannabis legalization in Thailand. The purpose of this study was to observe changes in sentiments after cannabis legalization and to investigate health-related topics discussed on Twitter. METHODS: Tweets in Thai and English related to cannabis were scraped from Twitter between May 1 and June 13, 2022, during cannabis legalization in Thailand. Sentiment and topic-modeling analyses were used to compare the content of tweets before and after legalization. Health-related topics were manually grouped into categories by their content and rated according to the number of corresponding tweets. RESULTS: We collected 21,242 and 6,493 tweets, respectively, for Thai and English search terms. A sharp increase in the number of tweets related to cannabis legalization was detected at the time of its public announcement. Sentiment analysis in the Thai search group showed a significant change (p < 0.0001) in sentiment distribution after legalization, with increased negative and decreased positive sentiments. A significant change was not found in the English search group (p = 0.4437). Regarding cannabis-containing food as a leading issue, topic-modeling analysis revealed public concerns after legalization in the Thai search group, but not the English one. Topics related to cannabis tourism surfaced only in the English search group. CONCLUSIONS: Since cannabis legalization, the primary health-related concern has been cannabis-containing food. Education and clear regulations on cannabis use are required to strengthen oversight of cannabis in the Thai population, as well as among medical tourists.

3.
Glob Chall ; 7(3): 2200213, 2023 Mar.
Article in English | MEDLINE | ID: mdl-36910465

ABSTRACT

Anticancer peptides (ACPs) are rising as a new strategy for cancer therapy. However, traditional laboratory screening to find and identify novel ACPs from hundreds to thousands of peptides is costly and time consuming. Here, a sequential procedure is applied to identify candidate ACPs from a computer-generated peptide library inspired by alpha-lactalbumin, a milk protein with known anticancer properties. A total of 2688 distinct peptides, 5-25 amino acids in length, are generated from alpha-lactalbumin. In silico ACP screening using the physicochemical and structural filters and three machine learning models lead to the top candidate peptides ALA-A1 and ALA-A2. In vitro screening against five human cancer cell lines supports ALA-A2 as the positive hit. ALA-A2 selectively kills A549 lung cancer cells in a dose-dependent manner, with no hemolytic side effects, and acts as a cell penetrating peptide without membranolytic effects. Sequential window acquisition of all theorical fragment ions-proteomics and functional validation reveal that ALA-A2 induces autophagy to mediate lung cancer cell death. This approach to identify ALA-A2 is time and cost-effective. Further investigations are warranted to elucidate the exact intracellular targets of ALA-A2. Moreover, these findings support the use of larger computational peptide libraries built upon multiple proteins to further advance ACP research and development.

4.
EXCLI J ; 22: 84-107, 2023.
Article in English | MEDLINE | ID: mdl-36814851

ABSTRACT

Cancer is the leading cause of death worldwide, resulting in the mortality of more than 10 million people in 2020, according to Global Cancer Statistics 2020. A potential cancer therapy involves targeting the DNA repair process by inhibiting PARP-1. In this study, classification models were constructed using a non-redundant set of 2018 PARP-1 inhibitors. Briefly, compounds were described by 12 fingerprint types and built using the random forest algorithm concomitant with various sampling approaches. Results indicated that PubChem with an oversampling approach yielded the best performance, with a Matthews correlation coefficient > 0.7 while also affording interpretable molecular features. Moreover, feature importance, as determined from the Gini index, revealed that the aromatic/cyclic/heterocyclic moiety, nitrogen-containing fingerprints, and the ether/aldehyde/alcohol moiety were important for PARP-1 inhibition. Finally, our predictive model was deployed as a web application called PARP1pred and is publicly available at https://parp1pred.streamlitapp.com, allowing users to predict the biological activity of query compounds using their SMILES notation as the input. It is anticipated that the model described herein will aid in the discovery of effective PARP-1 inhibitors.

5.
Biomed Res Int ; 2023: 7891753, 2023.
Article in English | MEDLINE | ID: mdl-36794257

ABSTRACT

The inhibition of poly(ADP-ribose) polymerases (PARPs) and ataxia telangiectasia and Rad3-related (ATR) would be an alternative approach for cancer treatments. The aim of this study is to investigate the synergy of the different combinations of PARP inhibitors (olaparib, talazoparib, or veliparib) and ATR inhibitor AZD6738. A drug combinational synergy screen that combines olaparib, talazoparib, or veliparib with AZD6738 was performed to identify the synergistic interaction, and the combination index was calculated to verify synergy. TK6 isogenic cell lines with defects in different DNA repair genes were used as a model. Cell cycle analysis, micronucleus induction, and focus formation assays of serine-139 phosphorylation of the histone variant H2AX demonstrated that AZD6738 diminished G2/M checkpoint activation induced by PARP inhibitors and allowed DNA damage-containing cells to continue dividing, leading to greater increases in micronuclei as well as double-strand DNA breaks in mitotic cells. We also found that AZD6738 was likely to potentiate cytotoxicity of PARP inhibitors in homologous recombination repair deficiency cell lines. AZD6738 sensitized more genotypes of DNA repair-deficient cell lines to talazoparib than to olaparib and veliparib, respectively. The combinational approach of PARP and ATR inhibition to enhance response to PARP inhibitors could expand the utility of PARP inhibitors to cancer patients without BRCA1/2 mutations.


Subject(s)
Antineoplastic Agents , Poly(ADP-ribose) Polymerase Inhibitors , Humans , Poly(ADP-ribose) Polymerase Inhibitors/pharmacology , Cell Line, Tumor , Recombinational DNA Repair , Antineoplastic Agents/pharmacology , Poly(ADP-ribose) Polymerases/genetics , Homologous Recombination , Phthalazines/pharmacology , Ataxia Telangiectasia Mutated Proteins/genetics , Ataxia Telangiectasia Mutated Proteins/metabolism
6.
Biomedicines ; 9(8)2021 Aug 09.
Article in English | MEDLINE | ID: mdl-34440185

ABSTRACT

Chemotherapy in childhood leukemia is associated with late morbidity in leukemic survivors, while certain patient subsets are relatively resistant to standard chemotherapy. It is therefore important to identify new agents with sensitivity and selectivity towards leukemic cells, while having less systemic toxicity. Peptide-based therapeutics has gained a great deal of attention during the last few years. Here, we used an integrative workflow combining mass spectrometric peptide library construction, in silico anticancer peptide screening, and in vitro leukemic cell studies to discover a novel anti-leukemic peptide having 3+ charges and an alpha helical structure, namely HMP-S7, from human breast milk. HMP-S7 showed cytotoxic activity against four distinct leukemic cell lines in a dose-dependent manner but had no effect on solid malignancies or representative normal cells. HMP-S7 induced leukemic cell death by penetrating the plasma membrane to enter the cytoplasm and cause the leakage of lactate dehydrogenase, thus acting in a membranolytic manner. Importantly, HMP-S7 exhibited anti-leukemic effects against patient-derived leukemic cells ex vivo. In conclusion, HMP-S7 is a selective anti-leukemic peptide with promise, which requires further validation in preclinical and clinical studies.

7.
BMC Pediatr ; 21(1): 22, 2021 01 07.
Article in English | MEDLINE | ID: mdl-33407268

ABSTRACT

BACKGROUND: Sandhoff disease (SD) is an autosomal recessive lysosomal storage disorder, resulting in accumulation of GM2 ganglioside, particular in neuronal cells. The disorder is caused by deficiency of ß-hexosaminidase B (HEX-B), due to pathogenic variant of human HEXB gene. METHOD: This study describes clinical features, biochemical, and genetic defects among Thai patients with infantile SD during 2008-2019. RESULTS: Five unrelated Thai patients presenting with developmental regression, axial hypotonia, seizures, exaggerated startle response to noise, and macular cherry red spot were confirmed to have infantile SD based on deficient HEX enzyme activities and biallelic variants of the HEXB gene. In addition, an uncommon presenting feature, cardiac defect, was observed in one patient. All the patients died in their early childhood. Plasma total HEX and HEX-B activities were severely deficient. Sequencing analysis of HEXB gene identified two variants including c.1652G>A (p.Cys551Tyr) and a novel variant of c.761T>C (p.Leu254Ser), in 90 and 10% of the mutant alleles found, respectively. The results from in silico analysis using multiple bioinformatics tools were in agreement that the p.Cys551Tyr and the p.Leu254Ser are likely pathogenic variants. Molecular modelling suggested that the Cys551Tyr disrupt disulfide bond, leading to protein destabilization while the Leu254Ser resulted in change of secondary structure from helix to coil and disturbing conformation of the active site of the enzyme. Genome-wide SNP array analysis showed no significant relatedness between the five affected individuals. These two variants were not present in control individuals. The prevalence of infantile SD in Thai population is estimated 1 in 1,458,521 and carrier frequency at 1 in 604. CONCLUSION: The study suggests that SD likely represents the most common subtype of rare infantile GM2 gangliosidosis identified among Thai patients. We firstly described a potential common variant in HEXB in Thai patients with infantile onset SD. The data can aid a rapid molecular confirmation of infantile SD starting with the hotspot variant and the use of expanded carrier testing.


Subject(s)
Sandhoff Disease , beta-Hexosaminidase beta Chain , Child, Preschool , Hexosaminidase B/genetics , Humans , Mutation , Sandhoff Disease/diagnosis , Sandhoff Disease/genetics , Thailand
8.
3 Biotech ; 11(1): 2, 2021 Jan.
Article in English | MEDLINE | ID: mdl-33269186

ABSTRACT

The goal of this study was to identify and biochemically characterize a novel hyperthermostable keratinase from microorganisms for feather waste degradation. Here, a hyperthermophilic Geoglobus acetivorans keratinase (GacK) gene was chosen based on a search of a sequence database. The selected GacK gene was synthesized, cloned, and successfully expressed without a signal peptide in the E. coli system. A monomer of approximately 58 kDa was obtained in a soluble form and purified. The recombinant GacK displayed the highest activity at an optimum temperature of 100 °C and a pH of 10. The hyperthermostable GacK enzymatic performance remained high even after incubation in nonionic surfactants and the chelating agent EDTA. The residual and keratinolytic activities of GacK, as determined with azocasein and keratin azure used as substrates, remained significantly greater than 80% at 130 °C for 7 h. The kinetic parameters Km and Vmax for azure keratin were 0.41 mg/ml and 875.14 unit/mg, respectively, while those for azocasein were 1.51 mg/ml and 505.32 unit/mg, respectively. The results suggest that the enzyme is among the most hyperthermostable keratinases. Because of its enzymatic characteristics to degrade keratin azure at high temperatures, GacK may potentially be utilized in future industrial applications.

9.
Biomolecules ; 10(12)2020 12 16.
Article in English | MEDLINE | ID: mdl-33339185

ABSTRACT

Recent developments in chemotherapy focus on target-specific mechanisms, which occur only in cancer cells and minimize the effects on normal cells. DNA damage and repair pathways are a promising target in the treatment of cancer. In order to identify novel compounds targeting DNA repair pathways, two key proteins, 53BP1 and RAD54L, were tagged with fluorescent proteins as indicators for two major double strand break (DSB) repair pathways: non-homologous end-joining (NHEJ) and homologous recombination (HR). The engineered biosensor cells exhibited the same DNA repair properties as the wild type. The biosensor cells were further used to investigate the DNA repair activities of natural biological compounds. An extract from Phyllosticta sp., the endophyte isolated from the medicinal plant Garcinia cowa Roxb. ex Choisy, was tested. The results showed that the crude extract induced DSB, as demonstrated by the increase in the DNA DSB marker γH2AX. The damaged DNA appeared to be repaired through NHEJ, as the 53BP1 focus formation in the treated fraction was higher than in the control group. In conclusion, DNA repair-based biosensors are useful for the preliminary screening of crude extracts and biological compounds for the identification of potential targeted therapeutic drugs.


Subject(s)
Biosensing Techniques , DNA Damage , DNA Repair , Endophytes/chemistry , Garcinia/microbiology , Plant Extracts/pharmacology , Animals , Cell Line , Cell Survival , Chickens , DNA Breaks, Double-Stranded , DNA End-Joining Repair , DNA Helicases/metabolism , DNA-Binding Proteins/metabolism , Fermentation , Fungi/metabolism , Garcinia/metabolism , Histones/metabolism , Homologous Recombination , Plants, Medicinal , Seeds/metabolism , Tumor Suppressor p53-Binding Protein 1/metabolism
10.
FEBS Open Bio ; 10(10): 2055-2071, 2020 10.
Article in English | MEDLINE | ID: mdl-33017104

ABSTRACT

Tripartite motif-containing protein 29 (TRIM29) is involved in DNA double-strand break (DSB) repair. However, the specific roles of TRIM29 in DNA repair are not clearly understood. To investigate the involvement of TRIM29 in DNA DSB repair, we disrupted TRIM29 in DT40 cells by gene targeting with homologous recombination (HR). The roles of TRIM29 were investigated by clonogenic survival assays and immunofluorescence analyses. TRIM29 triallelic knockout (TRIM29-/-/-/+) cells were sensitive to etoposide, but resistant to camptothecin. Foci formation assays to assess DNA repair activities showed that the dissociation of etoposide-induced phosphorylated H2A histone family member X (É£-H2AX) foci was retained in TRIM29-/-/-/+ cells, and the formation of etoposide-induced tumor suppressor p53-binding protein 1 (53BP1) foci in TRIM29-/-/-/+ cells was slower compared with wild-type (WT) cells. Interestingly, the kinetics of camptothecin-induced RAD51 foci formation of TRIM29-/-/-/+ cells was higher than that of WT cells. These results indicate that TRIM29 is required for efficient recruitment of 53BP1 to facilitate the nonhomologous end-joining (NHEJ) pathway and thereby suppress the HR pathway in response to DNA DSBs. TRIM29 regulates the choice of DNA DSB repair pathway by facilitating 53BP1 accumulation to promote NHEJ and may have potential for development into a therapeutic target to sensitize refractory cancers or as biomarker of personalized therapies.


Subject(s)
DNA Repair/genetics , DNA-Binding Proteins/metabolism , Transcription Factors/metabolism , Tumor Suppressor p53-Binding Protein 1/genetics , Animals , Cell Line , DNA/genetics , DNA Breaks, Double-Stranded , DNA End-Joining Repair/genetics , DNA End-Joining Repair/physiology , DNA Repair/physiology , DNA-Binding Proteins/physiology , Humans , Transcription Factors/physiology , Tumor Suppressor p53-Binding Protein 1/metabolism , Tumor Suppressor p53-Binding Protein 1/physiology , Vertebrates/genetics
11.
Genes Cells ; 25(11): 718-729, 2020 Nov.
Article in English | MEDLINE | ID: mdl-32939879

ABSTRACT

Ring finger protein 43 (RNF43) is an E3 ubiquitin ligase which is well-known for its role in negative regulation of the Wnt-signaling pathway. However, the function in DNA double-strand break repairs has not been investigated. In this study, we used a lymphoblast cell line, DT40, and mouse embryonic fibroblast as cellular models to study DNA double-strand break (DSB) repairs. For this purpose, we created RNF43 knockout, RNF43-/- DT40 cell line to investigate DSB repairs. We found that deletion of RNF43 does not interfere with cell proliferation. However, after exposure to various types of DNA-damaging agents, RNF43-/- cells become more sensitive to topoisomerase II inhibitors, etoposide, and ICRF193, than wild type cells. Our results also showed that depletion of RNF43 results in apoptosis upon etoposide-mediated DNA damage. The delay in resolution of γH2AX and 53BP1 foci formation after etoposide treatment, as well as epistasis analysis with DNAPKcs, suggested that RNF43 might participate in DNA repair of etoposide-induced DSB via non-homologous end joining. Disturbed γH2AX foci formation in MEFs following pulse etoposide treatment supported the notion that RNF43 also functions DNA repair in mammalian cells. These findings propose two possible functions of RNF43, either participating in NHEJ or removing the blockage of 5' topo II adducts from DSB ends.


Subject(s)
DNA Repair/physiology , Ubiquitin-Protein Ligases/metabolism , Animals , Cell Line , DNA Breaks, Double-Stranded/drug effects , DNA Damage/drug effects , DNA Repair/drug effects , DNA Repair/genetics , DNA Topoisomerases, Type II/drug effects , DNA Topoisomerases, Type II/metabolism , DNA-Binding Proteins/metabolism , Etoposide/adverse effects , Etoposide/pharmacology , Gene Knockout Techniques/methods , Mice , Oncogene Proteins/genetics , Recombination, Genetic/drug effects , Topoisomerase II Inhibitors/pharmacology , Ubiquitin-Protein Ligases/genetics , Ubiquitin-Protein Ligases/physiology
12.
Article in English | MEDLINE | ID: mdl-28115356

ABSTRACT

Pythiosis is a life-threatening infectious disease caused by the oomycete Pythium insidiosum Direct exposure to Py. insidiosum zoospores can initiate infections of the eye, limb, gastrointestinal tract, or skin/subcutaneous tissue. Treatments for pythiosis have mostly relied on surgery. Antifungal drugs are generally ineffective against Py. insidiosum However, one patient with an invasive Py. insidiosum infection recovered completely following treatment with terbinafine and itraconazole. Additionally, the drug target sterol biosynthetic enzymes have been identified in the oomycete Aphanomyces euteiches It remains an open question whether Py. insidiosum is susceptible to the antifungal drugs and harbors any of the known drug target enzymes. Here, we determined the in vitro susceptibilities of terbinafine and itraconazole against 30 isolates of Py. insidiosum We also analyzed endogenous sterols and searched for genes encoding the sterol biosynthetic enzymes in the genomes of Py. insidiosum and related oomycetes. The susceptibility assay showed that the growth of each of the Py. insidiosum isolates was inhibited by the antifungal agents, but only at difficult-to-achieve concentrations, which explains the clinical resistance of the drugs in the treatment of pythiosis patients. Genome searches of Py. insidiosum and related oomycetes demonstrated that these organisms contained an incomplete set of sterol biosynthetic enzymes. Gas chromatographic mass spectrometry did not detect any sterol end products in Py. insidiosum In conclusion, Py. insidiosum possesses an incomplete sterol biosynthetic pathway. Resistance to antifungal drugs targeting enzymes in the ergosterol biosynthetic pathway in Py. insidiosum was due to modifications or losses of some of the genes encoding the drug target enzymes.


Subject(s)
Antifungal Agents/pharmacology , Drug Resistance, Fungal , Pythium/drug effects , Pythium/metabolism , Sterols/biosynthesis , Gas Chromatography-Mass Spectrometry , Itraconazole/pharmacology , Microbial Sensitivity Tests , Naphthalenes/pharmacology , Phylogeny , Pythiosis/microbiology , Pythium/classification , Pythium/genetics , Terbinafine
13.
PLoS Pathog ; 12(8): e1005787, 2016 08.
Article in English | MEDLINE | ID: mdl-27542117

ABSTRACT

Soaring rates of systemic fungal infections worldwide underscore the need for vaccine prevention. An understanding of the elements that promote vaccine immunity is essential. We previously reported that Th17 cells are required for vaccine immunity to the systemic dimorphic fungi of North America, and that Card9 and MyD88 signaling are required for the development of protective Th17 cells. Herein, we investigated where, when and how MyD88 regulates T cell development. We uncovered a novel mechanism in which MyD88 extrinsically regulates the survival of activated T cells during the contraction phase and in the absence of inflammation, but is dispensable for the expansion and differentiation of the cells. The poor survival of activated T cells in Myd88-/- mice is linked to increased caspase3-mediated apoptosis, but not to Fas- or Bim-dependent apoptotic pathways, nor to reduced expression of the anti-apoptotic molecules Bcl-2 or Bcl-xL. Moreover, TLR3, 7, and/or 9, but not TLR2 or 4, also were required extrinsically for MyD88-dependent Th17 cell responses and vaccine immunity. Similar MyD88 requirements governed the survival of virus primed T cells. Our data identify unappreciated new requirements for eliciting adaptive immunity and have implications for designing vaccines.


Subject(s)
Fungal Vaccines/immunology , Lymphocyte Activation , Mycoses/immunology , Myeloid Differentiation Factor 88/immunology , Th17 Cells/immunology , Animals , Bcl-2-Like Protein 11/genetics , Bcl-2-Like Protein 11/immunology , CARD Signaling Adaptor Proteins/genetics , CARD Signaling Adaptor Proteins/immunology , Cell Differentiation/genetics , Cell Differentiation/immunology , Cell Survival/genetics , Cell Survival/immunology , Mice , Mice, Knockout , Mycoses/genetics , Mycoses/prevention & control , Myeloid Differentiation Factor 88/genetics , Proto-Oncogene Proteins c-bcl-2/genetics , Proto-Oncogene Proteins c-bcl-2/immunology , Toll-Like Receptors/genetics , Toll-Like Receptors/immunology , bcl-X Protein/genetics , bcl-X Protein/immunology , fas Receptor/genetics , fas Receptor/immunology
14.
J Infect Dis ; 213(11): 1762-6, 2016 06 01.
Article in English | MEDLINE | ID: mdl-26931447

ABSTRACT

We investigated how innate sensing by the mannose receptor (MR) influences the development of antifungal immunity. We demonstrate that MR senses mannan on the surface of attenuated Blastomyces dermatitidis vaccine yeast and that MR(-/-) mice demonstrate impaired vaccine immunity against lethal experimental blastomycosis, compared with wild-type control mice. Using naive Blastomyces-specific transgenic CD4(+) T cells, we found that MR regulates differentiation of naive T cells into T-helper type 17 (Th17) effector cells, which are essential in vaccine immunity against systemic dimorphic fungi. Thus, MR regulates differentiation of Th17 cells and is required to induce vaccine immunity against lethal pulmonary blastomycosis.


Subject(s)
Blastomyces/immunology , Blastomycosis/immunology , Fungal Vaccines/immunology , Lectins, C-Type/metabolism , Mannose-Binding Lectins/metabolism , Receptors, Cell Surface/metabolism , Th17 Cells/immunology , Animals , Cell Wall/immunology , Disease Resistance , Female , Immunogenicity, Vaccine , Interleukin-17/metabolism , Lymphopoiesis , Male , Mannans/metabolism , Mannose Receptor , Mice, Inbred C57BL , Th17 Cells/cytology
15.
J Clin Microbiol ; 54(1): 43-8, 2016 Jan.
Article in English | MEDLINE | ID: mdl-26719582

ABSTRACT

Pythiosis is an emerging and life-threatening infectious disease of humans and animals living in tropical and subtropical countries and is caused by the fungus-like organism Pythium insidiosum. Antifungals are ineffective against this pathogen. Most patients undergo surgical removal of the infected organ, and many die from advanced infections. Early and accurate diagnosis leads to prompt management and promotes better prognosis for affected patients. Immunohistochemical assays (IHCs) have been developed using rabbit antibodies raised against P. insidiosum crude extract, i.e., culture filtrate antigen (CFA), for the histodiagnosis of pythiosis, but cross-reactivity with pathogenic fungi compromises the diagnostic performance of the IHC. Therefore, there is a need to improve detection specificity. Recently, the elicitin protein, ELI025, was identified in P. insidiosum, but it was not identified in other human pathogens, including true fungi. The ELI025-encoding gene was successfully cloned and expressed as a recombinant protein in Escherichia coli. This study aims to develop a new IHC using the rabbit anti-ELI025 antibody (anti-ELI) and to compare its performance with the previously reported anti-CFA-based IHC. Thirty-eight P. insidiosum histological sections stained positive by anti-ELI-based and anti-CFA-based IHCs indicating 100% detection sensitivity for the two assays. The anti-ELI antibody stained negative for all 49 negative-control sections indicating 100% detection specificity. In contrast, the anti-CFA antibody stained positive for one of the 49 negative controls (a slide prepared from Fusarium-infected tissue) indicating 98% detection specificity. In conclusion, the anti-ELI based IHC is sensitive and specific for the histodiagnosis of pythiosis and is an improvement over the anti-CFA-based assay.


Subject(s)
Antibodies/immunology , Immunohistochemistry/methods , Pythiosis/diagnosis , Pythium/immunology , Pythium/isolation & purification , Animals , Humans , Sensitivity and Specificity
16.
Infect Immun ; 84(3): 635-42, 2015 Dec 14.
Article in English | MEDLINE | ID: mdl-26667836

ABSTRACT

C-type lectin receptors (CLRs) are essential in shaping the immune response to fungal pathogens. Vaccine-induced resistance requires Dectin-2 to promote differentiation of antifungal Th1 and Th17 cells. Since Dectin-2 and MCL heterodimerize and both CLRs use FcRγ as the signaling adaptor, we investigated the role of MCL in vaccine immunity to the fungal pathogen Blastomyces dermatitidis. MCL(-/-) mice showed impaired vaccine resistance against B. dermatitidis infection compared to that of wild-type animals. The lack of resistance correlated with the reduced recruitment of Th17 cells to the lung upon recall following experimental challenge and impaired interleukin-17 (IL-17) production by vaccine antigen-stimulated splenocytes in vitro. Soluble MCL fusion protein recognized and bound a water-soluble ligand from the cell wall of vaccine yeast, but the addition of soluble Dectin-2 fusion protein did not augment ligand recognition by MCL. Taken together, our data indicate that MCL regulates the development of vaccine-induced Th17 cells and protective immunity against lethal experimental infection with B. dermatitidis.


Subject(s)
Blastomyces/immunology , Blastomycosis/immunology , Fungal Vaccines/immunology , Lectins, C-Type/immunology , Receptors, Immunologic/immunology , Animals , Blastomyces/genetics , Blastomycosis/genetics , Blastomycosis/microbiology , Fungal Vaccines/administration & dosage , Fungal Vaccines/genetics , Humans , Interleukin-17/immunology , Lectins, C-Type/genetics , Mice , Mice, Inbred C57BL , Receptors, Immunologic/genetics , Th17 Cells/immunology
17.
Infect Genet Evol ; 35: 127-33, 2015 Oct.
Article in English | MEDLINE | ID: mdl-26254563

ABSTRACT

Oomycetes are fungus-like in appearance, but form a distinct clade within the eukaryotes. While most pathogenic oomycetes infect plants, the understudied oomycete Pythium insidiosum infects humans and animals, and causes a life-threatening infectious disease, called pythiosis. Phylogenetic analyses divide P. insidiosum into 3 groups, according to geographic origins: Clade-I (Americas), Clade-II (Asia and Australia), and Clade-III (Thailand). Surgical removal of the infected organ is the inevitable treatment for patients with pythiosis, but it is often too late or unsuccessful, and many patients die from advanced infection. Understanding P. insidiosum's basic biology could lead to improved infection control. Elicitins, a unique group of proteins found only in oomycetes, are involved in sterol acquisition and stimulation of host responses. Recently, we identified glycosylated and non-glycosylated forms of the elicitin-like protein, ELI025, which is secreted by P. insidiosum, and detected during P. insidiosum infection. In this study, we investigated geographic variation of ELI025 in 24 P. insidiosum strains isolated from humans, animals, and the environment. Genotypes of ELI025, based on 2 sets of PCR primers, correlated well with rDNA-based phylogenetic grouping. Unlike strains in Clade-I and -II, Clade-III strains secreted no glycosylated ELI025. Sera from 17 pythiosis patients yielded a broad range of antibody responses against ELI025, and ∼30% lacked reactivity against the protein. Selective production or secretion of glycosylated ELI025 by different P. insidiosum strains might contribute to the variable host antibody responses. In conclusion, ELI025 was secreted by all P. insidiosum strains isolated from different hosts and geographic origins, but the protein had different biochemical, and immunological characteristics. These finding contribute to the better understanding of the biology and evolution of P. insidiosum, and could lead to appropriate clinical application of the ELI025 protein for diagnosis or treatment of pythiosis.


Subject(s)
Glycoproteins/metabolism , Pythiosis/parasitology , Pythium/isolation & purification , Pythium/metabolism , Animals , DNA, Ribosomal/analysis , Glycoproteins/genetics , Glycoproteins/immunology , Glycosylation , Humans , Phylogeny , Phylogeography , Pythiosis/immunology , Pythiosis/metabolism , Pythium/classification , Pythium/genetics , Sequence Analysis, DNA
18.
Eur J Immunol ; 45(9): 2542-52, 2015 Sep.
Article in English | MEDLINE | ID: mdl-26140582

ABSTRACT

Chromoblastomycosis is a chronic skin infection caused by the pigmented saprophytic mould Fonsecaea pedrosoi. Chronicity of infection can be broken by a coordinated innate recognition of the spores by pattern recognition receptors. While Mincle signaling via the Syk/Card9 pathway is required for fungal recognition by host cells, it is not sufficient for host control. Exogenously applied TLR agonists are necessary to promote the induction of proinflammatory cytokines and clearance of infection in vivo. Here, we investigated whether costimulation by TLR agonists fosters the development of adaptive immune responses, by examining the development of fungus-specific T cells. Subcutaneous infection of mice with F. pedrosoi spores induced the activation, expansion, and differentiation of Ag-specific CD4(+) T cells but TLR costimulation did not further augment these T-cell responses. The Dectin-2/FcRγ/Card9 signaling pathway promoted the differentiation of fungus-specific CD4(+) T cells into Th17 cells, whereas Mincle inhibited the development of this T-helper subset in infected mice. These results indicate differential roles for Dectin-2 and Mincle in the generation of adaptive immune responses to F. pedrosoi infection.


Subject(s)
Chromoblastomycosis/immunology , Lectins, C-Type/immunology , Membrane Proteins/immunology , Saccharomycetales/immunology , Skin/immunology , Th17 Cells/immunology , Adaptive Immunity , Animals , CARD Signaling Adaptor Proteins/genetics , CARD Signaling Adaptor Proteins/immunology , Cell Differentiation , Chromoblastomycosis/microbiology , Chromoblastomycosis/pathology , Gene Expression Regulation , Host-Pathogen Interactions , Injections, Subcutaneous , Intracellular Signaling Peptides and Proteins/genetics , Intracellular Signaling Peptides and Proteins/immunology , Lectins, C-Type/genetics , Membrane Proteins/genetics , Mice , Mice, Transgenic , Protein-Tyrosine Kinases/genetics , Protein-Tyrosine Kinases/immunology , Receptors, IgG/genetics , Receptors, IgG/immunology , Saccharomycetales/pathogenicity , Signal Transduction , Skin/microbiology , Skin/pathology , Spores, Fungal/immunology , Spores, Fungal/pathogenicity , Syk Kinase , Th17 Cells/microbiology , Th17 Cells/pathology
19.
Genome Announc ; 3(3)2015 Jun 18.
Article in English | MEDLINE | ID: mdl-26089407

ABSTRACT

Pythium insidiosum is an oomycete that causes a life-threatening infectious disease called pythiosis in humans and animals living in tropical and subtropical countries. Here, we report the first draft genome sequence of P. insidiosum. The genome of P. insidiosum is 53.2 Mb and contains 14,962 open reading frames.

20.
Cell Host Microbe ; 17(4): 452-65, 2015 Apr 08.
Article in English | MEDLINE | ID: mdl-25800545

ABSTRACT

Fungal infections remain a threat due to the lack of broad-spectrum fungal vaccines and protective antigens. Recent studies showed that attenuated Blastomyces dermatitidis confers protection via T cell recognition of an unknown but conserved antigen. Using transgenic CD4(+) T cells recognizing this antigen, we identify an amino acid determinant within the chaperone calnexin that is conserved across diverse fungal ascomycetes. Calnexin, typically an ER protein, also localizes to the surface of yeast, hyphae, and spores. T cell epitope mapping unveiled a 13-residue sequence conserved across Ascomycota. Infection with divergent ascomycetes, including dimorphic fungi, opportunistic molds, and the agent causing white nose syndrome in bats, induces expansion of calnexin-specific CD4(+) T cells. Vaccine delivery of calnexin in glucan particles induces fungal antigen-specific CD4(+) T cell expansion and resistance to lethal challenge with multiple fungal pathogens. Thus, the immunogenicity and conservation of calnexin make this fungal protein a promising vaccine target.


Subject(s)
Antigens, Fungal/immunology , Ascomycota/immunology , CD4-Positive T-Lymphocytes/drug effects , CD4-Positive T-Lymphocytes/immunology , Calnexin/immunology , Cell Proliferation/drug effects , Epitopes/immunology , Animals , Mice
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