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Yong, T.

Publications and source records attributed to Yong, T..

6 recordsLinked to original sources

Parthenolide boosts megakaryocyte maturation and restores platelet responses in Wiskott Aldrich syndrome

Wiskott-Aldrich syndrome (WAS) is an inborn error of immunity with a broad disease spectrum, classified into class I (late onset) or II (early onset) variants. Thrombocytopenia and small platelets are the most consistent findings among patients, difficult to treat and related to development of autoimmunity. To identify new treatment options for thrombocytopenia in WAS, we developed a FACS-based screening for drug repurposing. We identified parthenolide as a lead small molecule that increased WASp abundance in cells with residual WASp expression. Using the megakaryocytic MEG-01 cells, gene edited to express WAS class I and II genetic variants, parthenolide induced megakaryocyte maturation as evident by upregulation of CD61, increased cell size and complexity, increased phosphorylation of ERK1/2, and higher DNA ploidy. We generated a new mouse model harboring a WAS class I missense variant WASp-R88C, corresponding to human WASp-R86C, with reduced expression of WASp. WASp-R88C mice had lower numbers of platelets compared to WT mice. Bone marrow-derived WASp-R88C and WASp-KO megakaryocytes, differentiated in the presence of parthenolide derivative, DMAPT, showed increased ploidy and upregulation of the maturation markers CD61, CD41 and CD42d, resulting in improved platelet production in vitro. Treatment with parthenolide derivative, DMAPT, led to increased platelet numbers in vivo in WASp-R88C mice and dampened the hyperactivation of WAS patient platelets by reducing thrombin-induced CD62P exposure after activation. The identification of parthenolide offers a promising therapeutic approach for WAS patients who are unresponsive or unsuitable for definitive therapies.

cell biology↗

Single cell analysis reveals molecular traits of pediatric lymphoma resistant subclones

The cause of refractory/relapse (R/R) in pediatric lymphoma is unclear. We hypothesized that a stem-like, chemoresistance lymphoma subclone may contribute to R/R. Combining single cell RNA sequencing (scRNA-seq) and immune receptor sequencing (scVDJ-seq) on freshly acquired pediatric non-Hodgkin lymphoma (pNHL n=10), Hodgkin lymphoma (pHL n=5), and 10 reactive lymph nodes from adults or children (a/pReLy), we discovered pediatric-specific progenitor-like lymphocytes, whose cellular program was enriched in pNHL subclones emerging late during clonal evolution, accompanied by loss of immune receptor expression. R-CHOP target gene expression indicated that these subclones may escape first-line treatment, and suggested MSI2, an RNA binding protein, as a potential target. In pHL, the progenitor-like program was found in the tumor microenvironment (TME) but not Hodgkin cells which, during relapse, were myeloid-like and accompanied by CD74highCCL5+ CD8 T cells. In summary, we discovered R/R associated lymphoma subclones in pediatric lymphoma and potential ways to eradicate them. Key messagesO_LIProgenitor-like lymphocytes are uniquely found in pediatric reactive lymph nodes, but not in adults. C_LIO_LIResistant subclones from pNHL acquire progenitor-like program and share MSI2 expression. C_LIO_LIRelapsed Hodgkin cells are monocyte-like and recruit CD74highCCL5+ CD8 T cells. C_LI

cancer biology↗

AID facilitates TET2 demethylation of Irf4 for plasma cell fate in germinal center B cells

Activation-induced cytidine deaminase (AID) is essential for B cell affinity maturation. We investigated why AID deficiency gives rise to giant germinal centers (GC) using the AIDR112H mouse model that is devoid of AID activity. The increased GC response was associated with accumulation of GC B cells in the light zone in immunized AIDR112H mice. AIDR112H GC B cells had reduced capacity to up-regulate IRF4 to initiate plasma cell differentiation, leading to accumulation of a transitional GC population with reduced GL7 expression. Genetic introduction of a high affinity B cell receptor (BCR) was unable to restore plasma cell differentiation of AIDR112H B cells while ectopic expression of catalytic active AID rescued plasma cell generation. AIDR112H impaired recruitment of AID to the Irf4 promoter/enhancer and disrupted the interaction with Ten-eleven Translocation 2 (TET2). Consequently, DNA demethylation at the Irf4 promoter/enhancer was reduced in AIDR112H GC B cells and impeded high Irf4 expression for transition into plasma cells. This data reveals a B cell-intrinsic mechanism that governs the plasma cell fate decision through epigenetic remodeling mediated by AID in cooperation with TET2. Key messagesO_LIAID deficiency leads to accumulation of a transitional (t)GC population of B cells with low expression of GL7 and failure to up-regulate IRF4 C_LIO_LIAID deamination activity is needed to promote up-regulation of IRF4 for plasma cell differentiation. C_LIO_LICo-operation between TET2 and AID facilitates demethylation of the Irf4 enhancer/promoter. C_LI

immunology↗

Screening, Identification and Growth Promotion Ability of Phosphate Solubilizing Bacteria from Soybean Rhizosphere under Maize-Soybean Intercropping Systems

The solubilization and mineralization of phosphorus by phosphate-solubilizing bacteria (PSB) is one of the most important bacterial physiological characteristics in the soil biogeochemical cycle. Through the isolation and screening of microorganisms in the rhizosphere soil of intercropped soybean in Yaan, Renshou and Chongzhou, 9 PSBs with high phosphorus solubilizing ability were identified. It mainly belongs to Bacillus and Pseudomonas. The phosphate solubility of Bacillus aryabhattai B8W22 is as high as 388.62 {micro}g{middle dot}mL-1. The physiological and biochemical characteristics of each strain showed that it can secrete organic acids such as formic acid, acetic acid lactic acid and pyruvic acid. In addition, all strains can produce indole acetic acid and siderophores that promote plant growth. Seed germination experiments also showed that the phosphorus solubilizing bacteria isolated in this research have a certain ability to promote plant growth. IMPRTANCEBacillus aryabhattai from rhizosphere soil of intercropped soybean has high phosphate-solubilizing ability, could produce indole acetic acid and siderophores that promote plant growth, and are of great significance in reducing the application of chemical phosphate fertilizers and promoting sustainable agricultural development.

microbiology↗

Learning to count: determining the stoichiometry of bio-molecular complexes using fluorescence microscopy and statistical modelling

Cellular biology occurs through myriad interactions between diverse molecular components, many of which assemble in to specific complexes. Various techniques can provide a qualitative survey of which components are found in a given complex. However, quantitative analysis of the absolute number of molecules within a complex (known as stoichiometry) remains challenging. Here we provide a novel method that combines fluorescence microscopy and statistical modelling to derive accurate molecular counts. We have devised a system in which a given biomolecule is differentially labelled with spectrally distinct fluorescent dyes (label A or B), which are then mixed such that B-labelled molecules are vastly outnumbered by those with label A. Complexes, containing this component, are then simply scored as either being positive or negative for label B. The frequency of positive complexes is directly related to the stoichiometry of interaction and molecular counts can be inferred by statistical modelling. We demonstrate this method using complexes of Adenovirus particles and monoclonal antibodies, achieving counts that are in excellent agreement with previous estimates. Beyond virology, this approach is readily transferable to other experimental systems and, therefore, provides a powerful tool for quantitative molecular biology. The statistical models used in our analysis are available here: https://github.com/sophiamersmann/molecular-counting, the raw data used for molecular counting can be found here: 10.5281/zenodo.3955142.

bioinformatics↗

Big data reveals deep associations in physical examination indicators and can help predict overall underlying health status

Because of lacking of the systematic investigation of correlations between the physical examination indicators (PEIs), currently most of them are independently used for disease warning. This results in very limited diagnostic values of general physical examination. Here, we first systematically analyzed the correlations between 221 PEIs in healthy and in 34 unhealthy states in 803,614 peoples in China. We revealed rich relevant between PEIs in healthy physical status (7,662 significant correlations, 31.5% of all). However, in disease conditions, the PEI correlations changed. We further focused on the difference of these PEIs between healthy and 35 unhealthy physical status, 1,239 significant PEI difference were discovered suggesting as candidate disease markers. Finally, we established machine learning algorithms to predict the health status by using 15%-16% PEIs by feature extraction, which reached 66%-99% precision predictions depending on the physical state. This new encyclopedia of PEI correlation provides rich information to chronic disease diagnosis. Our developed machine learning algorithms will have fundamental impact in practice of general physical examination.

pathology↗