745 research outputs found
Differential chlamydospore development by the analyzed <i>Candida</i> strains in Staib liquid medium.
No full text<p><i>C. dubliniensis</i> wild type Wü284 and the <i>C. albicans nrg1</i>Δ mutant MMC3 form chlamydospores, in contrast to the <i>C. albicans</i> wild type SC5314. The fungal strains were grown for 28 h in Staib medium at 25°C and inspected by microscopy (scale bar: 10 µm).</p
DRL6 induces chlamydospores in Staib agar.
No full text(A) Abundant chlamydospore formation by C. dubliniensis Wü284. (B) Poor filamentation and no detectable chlamydospores by C. albicans SC5314. (C) Occasionally visible chlamydospore formation by DRL6 (Δisw2/Δisw2) strain in Staib agar as indicated by the black arrow heads. Plates were grown at room temperature in the dark for up to 7 days, and representative pictures are from at least 3 independent experiments.</p
Proteins encoded by <i>cdCSP1</i> and <i>cdCSP2</i> are specifically expressed and located in chlamydospores.
No full text<p><i>C. dubliniensis</i> wild type Wü284 (A) and the <i>C. dubliniensis</i> GFP reporter strains Cd30750G1A/B (cdCsp1-GFP) (B) and Cd40770G1A/B (cdCsp2-GFP) (C) were grown in YPD and Staib liquid medium for 28 h at 25°C, and on rice-extract agar for 3 d at 25°C, respectively, and inspected by phase contrast and fluorescence microscopy. Fluorescence microscopy demonstrated that the genes of interest are specifically induced during growth in Staib medium and that the encoded proteins exclusively localize to chlamydospores. The two independently constructed A/B-GFP reporter strains behaved identically and only one of them is shown (scale bar: 10 µm).</p
Identification of chlamydospore specific genes in <i>Candida</i>.
No full text<p>Venn diagram of genes which were ≥ two fold up- (A) and downregulated (B) in both the <i>C. albicans nrg1</i>Δ mutant and the <i>C. dubliniensis</i> wild type during growth in Staib medium.</p
Global transcriptome sequencing identifies chlamydospore specific markers in Candida albicans and Candida dubliniensis
No full textArt.e61940Candida albicans and Candida dubliniensis are pathogenic fungi that are highly related but differ in virulence and in some phenotypic traits. During in vitro growth on certain nutrient-poor media, C. albicans and C. dubliniensis are the only yeast species which are able to produce chlamydospores, large thick-walled cells of unknown function. Interestingly, only C. dubliniensis forms pseudohyphae with abundant chlamydospores when grown on Staib medium, while C. albicans grows exclusively as a budding yeast. In order to further our understanding of chlamydospore development and assembly, we compared the global transcriptional profile of both species during growth in liquid Staib medium by RNA sequencing. We also included a C. albicans mutant in our study which lacks the morphogenetic transcriptional repressor Nrg1. This strain, which is characterized by its constitutive pseudohyphal growth, specifically produces masses of chlamydospores in Staib medium, similar to C. dubliniensis. This comparative approach identified a set of putatively chlamydospore-related genes. Two of the homologous C. albicans and C. dubliniensis genes (CSP1 and CSP2) which were most strongly upregulated during chlamydospore development were analysed in more detail. By use of the green fluorescent protein as a reporter, the encoded putative cell wall related proteins were found to exclusively localize to C. albicans and C. dubliniensis chlamydospores. Our findings uncover the first chlamydospore specific markers in Candida species and provide novel insights in the complex morphogenetic development of these important fungal pathogens.8Nr.
Induced expression levels of genes <i>CSP1</i> and <i>CSP2</i> during chlamydospore formation.
No full text<p><i>C. dubliniensis</i> Wü284, <i>C. albicans</i> SC5314 and the <i>C. albicans nrg1</i>Δ mutant were grown for 28 h in Staib medium and YPD medium, respectively, before total RNA was isolated. (A) qRT-PCR measurements detected a strong upregulation of <i>cdCSP1</i> and <i>cdCSP2</i> gene expression levels in <i>C. dubliniensis</i> during growth in Staib versus YPD medium. (B) Similarly, the <i>C. albicans</i> homologues <i>caCSP1</i> and <i>caCSP2</i> were found to be upregulated in the chlamydospore producing <i>C. albicans nrg1</i>Δ mutant stronger than in <i>C. albicans</i> wild-type yeast cells. The results are the means ±SD from three biological replicates, ‘*’ indicates that the detected differences were significant (<i>P</i><0.05).</p
Global Transcriptome Sequencing Identifies Chlamydospore Specific Markers in Candida albicans and Candida dubliniensis
No full textCandida albicans and Candida dubliniensis are pathogenic fungi that are highly related but differ in virulence and in some phenotypic traits. During in vitro growth on certain nutrient-poor media, C. albicans and C. dubliniensis are the only yeast species which are able to produce chlamydospores, large thick-walled cells of unknown function. Interestingly, only C. dubliniensis forms pseudohyphae with abundant chlamydospores when grown on Staib medium, while C. albicans grows exclusively as a budding yeast. In order to further our understanding of chlamydospore development and assembly, we compared the global transcriptional profile of both species during growth in liquid Staib medium by RNA sequencing. We also included a C. albicans mutant in our study which lacks the morphogenetic transcriptional repressor Nrg1. This strain, which is characterized by its constitutive pseudohyphal growth, specifically produces masses of chlamydospores in Staib medium, similar to C. dubliniensis. This comparative approach identified a set of putatively chlamydospore-related genes. Two of the homologous C. albicans and C. dubliniensis genes (CSP1 and CSP2) which were most strongly upregulated during chlamydospore development were analysed in more detail. By use of the green fluorescent protein as a reporter, the encoded putative cell wall related proteins were found to exclusively localize to C. albicans and C. dubliniensis chlamydospores. Our findings uncover the first chlamydospore specific markers in Candida species and provide novel insights in the complex morphogenetic development of these important fungal pathogens
IL-4-Induced Arginase 1 Suppresses Alloreactive T Cells in Tumor-Bearing Mice
No full textWe previously demonstrated that a specialized subset of immature myeloid cells migrate to lymphoid organs as a result of tumor growth or immune stress, where they suppress B and T cell responses to Ags. Although NO was required for suppression of mitogen activation of T cells by myeloid suppressor cells (MSC), it was not required for suppression of allogenic responses. In this study, we describe a novel mechanism used by MSC to block T cell proliferation and CTL generation in response to alloantigen, which is mediated by the enzyme arginase 1 (Arg1). We show that Arg1 increases superoxide production in myeloid cells through a pathway that likely utilizes the reductase domain of inducible NO synthase (iNOS), and that superoxide is required for Arg1-dependent suppression of T cell function. Arg1 is induced by IL-4 in freshly isolated MSC or cloned MSC lines, and is therefore up-regulated by activated Th2, but not Th1, cells. In contrast, iNOS is induced by IFN-gamma and Th1 cells. Because Arg1 and iNOS share L-arginine as a common substrate, our results indicate that L-arginine metabolism in myeloid cells is a potential target for selective intervention in reversing myeloid-induced dysfunction in tumor-bearing hosts
Çevresel örneklerde cryptococcus neoformans taramaları için patlıcan (Solanum melongena) agarın yeni bir besiyeri olarak değerlendirilmesi
No full textCryptococcus neofomans, özellikle bağışıklık sistemi baskılanmış kişilerde hayatı tehdit eden enfeksiyonlara neden olabilen kapsüllü bir maya mantarıdır. Enfeksiyonların, çevresel ortamdan solunum havasına bulaşması ile oluştuğu kabul edilmektedir. Bilinen çevresel odaklar kanatlı çıkartıları, ağaçlarda çürüyen kovuklar ve topraktır. Öncül maddeleri içeren besiyeri ortamında kahverengi pigmentli maya oluşumu, C.neoformans’ın hızlı tanımlanmasında önemli bir basamaktır. Bu besiyerlerinin yapımında, kolay ulaşılabilir ve ekonomik olmaları nedeniyle bitki tohumları tercih edilmektedir. Guizotia abysinicca (Nijer tohumu, kuşyemi) ile Staib agar, Helianthus annus (Ayçiçeği) ile Pal besiyeri, Brassica nigra (Hardal) tohumu agar, tütün agar, Mucuna pruriens (Kadife fasulye) tohumu agar, Perilla frutescens (Çin fesleğeni) tohumu agar, Rubus fruticosus (Böğürtlen) agar ve öğütülmüş kırmızıbiber agar C.neoformans’ın pigment yapımına dayalı olarak ayırımını sağlayan seçici besiyerleridir. Bu çalışmanın amacı, ülkemizde yaygın olarak bulunan patlıcandan (Solanum melongena) elde edilen yeni bir besiyerinde C.neoformans’ın pigment yapımının araştırılması ve kolonize olduğu çevresel ortamlardan izolasyonunda Staib, Pal ve tütün agarla performanslarının karşılaştırılmasıdır. Araştırmaya 3 farklı patlıcandan (S.melongena Melanzaza viserba, S.melongena Pinstripe F1 ve S.ovigerum Ivory F1) hazırlanan besiyerleri alınmıştır. Ülkemizde sürekli kolo- nizasyonun bulunduğu Gökova-Akyaka bölgesindeki 19 Eucalyptus camaldulensis ağacının kovuklarından sürüntü tekniği ile alınan örnekler, patlıcan besiyeri ile Staib, Pal ve tütün agar besiyerlerine ekilmiştir. Araştırmaya alınan türlerden S.melongena Melanzaza viserba ve S.melongena Pinstripe F1 ile yapılan besiyerlerinde C.neoformans pigment oluştururken, S.ovigerum Ivory F1’den yapılan besiyerinde pigment oluşumu gözlenmemiştir. Kolonizasyon bölgesindeki 19 E.camaldulensis ağacının 11 (%57.9)’inden basit Staib agar, basit Pal agar ve patlıcan agar ile izolasyon yapılabilirken, tütün agar ile 10 (%52.6) örnekten izolasyon yapılabilmiştir. Benzer şekilde C.neoformans üremesi, basit Staib, basit Pal ve patlıcan agar besiyerlerinde sırasıyla 51, 57 ve 48 koloni oluşturan ünite (cfu)/petri plağı (ortanca değer) olarak saptanırken, tütün agarda daha az sayıda (33 cfu/petri) koloni üremesi saptanmıştır. Patlıcan agar besiyerinin C.neoformans’ı çevresel ortamlardan ayırabilme yeteneği, basit Staib ve Pal agar besiyerlerinden farklı bulunmamıştır (p= 0.71). Sonuç olarak çevresel izolasyon taramalarında yaygın olarak kullanılan Staib agar ve Pal agar besiyeri ile birlikte patlıcan agar besiyeri de kolaylıkla hazırlanarak kullanılabilmektedir
- …
