Culture of normal inducer T cell clones with antigen and purified Ek beta:Ek alpha incorporated into planar lipid membranes resulted in specific T cell activation as determined by cell volume increase and IL 3 production. However, in contrast to results obtained with T cell hybridomas, antigen presentation by planar membranes did not induce measurable IL 2 production, and proliferative responses were not detected. Rather, recognition of only Ek beta:Ek alpha and antigen resulted in the specific induction of a long-lived state of proliferative nonresponsiveness to subsequent stimulation by conventional APC and antigen. Induction of nonresponsiveness required protein synthesis, and was not simply due to the absence of IL 2. The antigen-nonresponsive cells could respond to either PMA plus ionomycin or IL 2, and they expressed normal levels of surface antigen-receptor molecules. These results demonstrate that recognition by normal T cell clones of antigen and Ia molecules in the absence of other accessory cell molecules and signals results in a prolonged state of proliferative nonresponsiveness, possibly similar to a state of T cell tolerance in vivo.
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Biotechnol Bioeng
January 2025
Bioprocess Research and Development (BRD), WuXi Biologics, Shanghai, China.
Serving as a dedicated process analytical technology (PAT) tool for biomass monitoring and control, the capacitance probe, or dielectric spectroscopy, is showing great potential in robust pharmaceutical manufacturing, especially with the growing interest in integrated continuous bioprocessing. Despite its potential, challenges still exist in terms of its accuracy and applicability, particularly when it is used to monitor cells during stationary and decline phases. In this study, data pre-processing methods were first evaluated through cross-validation, where the first-order derivative emerged as the most effective method to diminish variability in prediction accuracy across different training datasets.
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January 2025
Johns Hopkins Biomedical Engineering; Johns Hopkins University Department of Molecular Biology and Genetics, Baltimore, Maryland, USA; Johns Hopkins University Department of Medicine, Division of Infectious Disease, Baltimore, Maryland, USA. Electronic address:
Chinese Hamster Ovary (CHO) cells produce monoclonal antibodies and other biotherapeutics at industrial scale. Despite their ubiquitous nature in the biopharmaceutical industry, little is known about the behaviors of individual transfected clonal CHO cells. Most CHO cells are assessed on their stability, their ability to produce the protein of interest over time.
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January 2025
State Key Laboratory of Respiratory Disease, National Clinical Research Center for Respiratory Disease, Guangzhou Institute of Respiratory Health, The First Affiliated Hospital of Guangzhou Medical University, Guangzhou, Guangdong, China.
Coronaviruses (CoVs) pose a significant threat to human health, as demonstrated by the COVID-19 pandemic. The large size of the CoV genome (around 30 kb) represents a major obstacle to the development of reverse genetics systems, which are invaluable for basic research and antiviral drug screening. In this study, we established a rapid and convenient method for generating reverse genetic systems for various CoVs using a bacterial artificial chromosome (BAC) vector and Gibson DNA assembly.
View Article and Find Full Text PDFAdv Exp Med Biol
January 2025
Cancer Biology and Stem Cells Division, The Walter and Eliza Hall Institute of Medical Research, Parkville, VIC, Wurundjeri Country, Melbourne, Australia.
Both intrinsic and extrinsic mechanisms underpin the profound intertumoral heterogeneity in breast cancer. Increasing evidence suggests that the intrinsic characteristics of breast epithelial precursor cells may influence tumour phenotype. These "cells-of-origin" of cancer preside in normal breast tissue and are uniquely susceptible to mutagenesis upon exposure to distinct oncogenic stimuli.
View Article and Find Full Text PDFNat Methods
January 2025
Westlake Laboratory of Life Sciences and Biomedicine, Hangzhou, China.
In vivo lineage tracing holds great potential to reveal fundamental principles of tissue development and homeostasis. However, current lineage tracing in humans relies on extremely rare somatic mutations, which has limited temporal resolution and lineage accuracy. Here, we developed a generic lineage-tracing tool based on frequent epimutations on DNA methylation, enabled by our computational method MethylTree.
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