Bioimmunological activities of Candida glabrata cellular mannan

Candida glabrata is a second most common human opportunistic pathogen which causes superficial but also life-threatening systemic candidiasis. According to the localization of mannans and mannoproteins in the outermost layer of the cell wall, mannan detection could be one of the first steps in the cell recognition of Candida cells by the host innate immune system. Mannans from the cell wall provide important immunomodulatory activities, compromising stimulation of cytokine production, induction of dendritic cells maturation and T-cell immunity. The model of DCs represents a promising tool to study immunomodulatory interventions throughout the vaccine development. Activated DCs induce, activate and polarize T-cell responses by expression of distinct maturation markers and cytokines regulating the adaptive immune responses. In addition, they are uniquely adept at decoding the fungus-associated information and translate it in qualitatively different T helper responses. We find out, that C. glabrata mannan is able to induce proliferation of splenocytes and to increase the production of TNF-α and IL-4. Next, increased the expression of co-stimulatory molecules CD80 and CD86 and the proportion of CD4+CD25+ and CD4+CD28+ T cells during in vitro stimulation of splenocytes

Antioxidant, antimicrobial and anticancer activity of the lichens Cladonia furcata, Lecanora atra and Lecanora muralis

<p>Abstract</p> <p>Background</p> <p>The aim of this study is to investigate in vitro antioxidant, antimicrobial and anticancer activity of the acetone extracts of the lichens <it>Cladonia furcata, Lecanora atra </it>and <it>Lecanora muralis</it>.</p> <p>Methods</p> <p>Antioxidant activity was evaluated by five separate methods: free radical scavenging, superoxide anion radical scavenging, reducing power, determination of total phenolic compounds and determination of total flavonoid content. The antimicrobial activity was estimated by determination of the minimal inhibitory concentration by the broth microdilution method against six species of bacteria and ten species of fungi. Anticancer activity was tested against FemX (human melanoma) and LS174 (human colon carcinoma) cell lines using MTT method.</p> <p>Results</p> <p>Of the lichens tested, <it>Lecanora atra </it>had largest free radical scavenging activity (94.7% inhibition), which was greater than the standard antioxidants. Moreover, the tested extracts had effective reducing power and superoxide anion radical scavenging. The strong relationships between total phenolic and flavonoid contents and the antioxidant effect of tested extracts were observed. Extract of <it>Cladonia furcata </it>was the most active antimicrobial agent with minimum inhibitory concentration values ranging from 0.78 to 25 mg/mL. All extracts were found to be strong anticancer activity toward both cell lines with IC₅₀values ranging from 8.51 to 40.22 μg/mL.</p> <p>Conclusions</p> <p>The present study shows that tested lichen extracts demonstrated a strong antioxidant, antimicrobial and anticancer effects. That suggest that lichens may be used as as possible natural antioxidant, antimicrobial and anticancer agents to control various human, animal and plant diseases.</p

Unraveling the histories of Proterozoic shales through in situ Rb-Sr dating and trace element laser ablation analysis

Published online 20 September 2021. OnlinePublAuthigenic components in marine sediments are important archives for past environment reconstructions. However, defining reliable age constraints and assessing the effects of post-depositional overprints in Precambrian sequences are challenging. We demonstrate a new laser-based analytical approach that has the potential to rapidly and accurately evaluate the depositional and alteration histories of Proterozoic shales. Our study employs a novel application of in situ Rb-Sr dating coupled with simultaneous trace-element analysis using reaction-cell laser ablation–inductively coupled plasma–tandem mass spectrometry (LA-ICPMS/MS). We present results from shales sourced from two wells in the Proterozoic McArthur Basin, northern Australia. These rocks have been widely used by previous studies as a key section for ancient biogeochemical and paleo-redox reconstructions. Shales from well UR5 yielded initial 87Sr/86Sr ratios, Rb-Sr ages, and rare earth element plus yttrium (REEY) patterns similar to those of a dolerite sampled from the same core. We propose that the UR5 samples chronicle hydrothermal alteration instigated by the dolerite intrusion. In contrast, a correlative shale from well UR6 yielded an age consistent with the expected depositional age (1577 ± 56 Ma) with REEY and initial 87Sr/86Sr ratios similar to ca. 1.5 Ga seawater. We suggest that this sample records the minimum depositional age and early marine diagenetic history for this unit. This new technique can date Proterozoic shales quickly, cheaply, and with minimum sample preparation. Importantly, ages are triaged to differentiate between those recording primary marine versus secondary processes. This novel approach provides a potentially powerful tool for dating and fingerprinting the vast array of ancient marine shales for further studies of Earth systems through deep time.Darwinaji Subarkah, Morgan L. Blades, Alan S. Collins, Juraj Farkaš, Sarah Gilbert, Stefan C. Löhr, Ahmad Redaa, Eilidh Cassidy and Thomas Zac

Chromium isotope variations (delta(53)/(52)Cr) in mantle-derived sources and their weathering products: Implications for environmental studies and the evolution of delta(53)/(52)Cr in the Earth's mantle over geologic time

Abstract not availableJuraj Farkaš, Vladislav Chrastný, Martin Novák, Eva Čadkova, Jan Pašava, Ramananda Chakrabarti, Stein B. Jacobsen, Lukáš Ackerman, Thomas D. Bulle

Copper Isotope Fractionation in Archean Hydrothermal Systems: Evidence From the Mesoarchean Carlow Castle Cu‐Co‐Au Deposit

Abstract Copper isotope analysis has emerged as a promising tool for understanding genetic processes in Cu ore deposits. However, applications of this analytical technique to Archean Cu deposits have been extremely limited, even though Archean terranes are among the most economically endowed on Earth. As such, this study presents the first Cu isotope analysis of an Archean Cu deposit, the Mesoarchean Carlow Castle hydrothermal Cu‐Co‐Au deposit. Archean primary Cu sulfide ore samples and Cenozoic supergene Cu ore samples were analyzed. Primary ore samples are isotopically light, with δ65Cu values ranging between −0.80 ± 0.02‰ and 0.00 ± 0.007‰, whilst supergene samples are isotopically heavier and range between −0.50 ± 0.01‰ and 0.62 ± 0.005‰. In primary ore samples, a relationship is observed between the Cu isotope signature, ore grade, and alteration assemblage that records the isotopic and physicochemical evolution of the Carlow Castle deposit's hydrothermal ore‐forming system. A mafic igneous source is suggested as a metal source in the Carlow Castle Cu‐Co‐Au deposit. The limited heavy isotopic fractionation of supergene Cu ore samples in this study is interpreted to reflect limited redox cycling of Cu due to in situ oxidative weathering of vein‐hosted Cu sulfides in the overlying Cenozoic supergene system. This differs from previously studied deposits where significant Cu transport and multiple stages of isotopic enrichment are often evident in supergene Cu enrichment layers. The results of this study suggest that Cu isotope analysis could be valuable in understanding genetic processes in hydrothermal Cu deposits, including Archean ore deposits and terranes

Engineering the acceptor substrate specificity in the xyloglucan endotransglycosylase TmXET6.3 from nasturtium seeds (Tropaeolum majus L.)

Xyloglucan xyloglucosyl transferases (XETs) (EC 2.4.1.207) play a central role in loosening and re-arranging the cellulose-xyloglucan network, which is assumed to be the primary load-bearing structural component of plant cell walls. The full-length sequence of mature TmXET6.3 from Tropaeolum majus (280 residues) was deduced by the nucleotide sequence analysis of near full-length cDNA by Rapid Amplification of cDNA Ends, based on tryptic and chymotryptic peptide sequences. Partly purified TmXET6.3, expressed in Pichia occurred in N-glycosylated and N-deglycosylated forms. The quantification of hetero-transglycosylation activities of TmXET6.3 revealed that (1,3;1,4)-, (1,6)- and (1,4)-β-D-glucooligosaccharides were the preferred acceptor substrates, while (1,4)-β-D-xylooligosaccharides, and arabinoxylo- and glucomanno-oligosaccharides were less preferred. The 3D model of TmXET6.3, and bioinformatics analyses of identified and putative plant xyloglucan endotransglycosylases (XETs)/hydrolases (XEHs) of the GH16 family revealed that H94, A104, Q108, K234 and K237 were the key residues that underpinned the acceptor substrate specificity of TmXET6.3. Compared to the wild-type enzyme, the single Q108R and K237T, and double-K234T/K237T and triple-H94Q/A104D/Q108R variants exhibited enhanced hetero-transglycosylation activities with xyloglucan and (1,4)-β-D-glucooligosaccharides, while those with (1,3;1,4)- and (1,6)-β-D-glucooligosaccharides were suppressed; the incorporation of xyloglucan to (1,4)-β-D-glucooligosaccharides by the H94Q variant was influenced most extensively. Structural and biochemical data of non-specific TmXET6.3 presented here extend the classic XET reaction mechanism by which these enzymes operate in plant cell walls. The evaluations of TmXET6.3 transglycosylation activities and other members of the GH16 family suggested that a broad acceptor substrate specificity in plant XET enzymes could be more widespread than previously anticipated.Barbora Stratilová, Zuzana Firáková, Jaroslav Klaudiny; Sergej Šesták, Stanislav Kozmon, Dana Strouhalová, Soňa Garajová, Fairouz Ait‑Mohand, Ágnes Horváthová, Vladimír Farkaš, Eva Stratilová, Maria Hrmov