Biology subjects

Kao, Y.-H.

Publications and source records attributed to Kao, Y.-H..

7 recordsLinked to original sources

bioRxiv2023

Self-Healable Spider Dragline Silk Materials

Developing materials with structural flexibility that permits self-repair in response to external disturbances remains challenging. Spider silk, which combines an exceptional blend of strength and pliability in nature, serves as an ideal dynamic model for adaptive performance design. In this work, a novel self-healing material is generated using spider silk. Dragline silk from spider Nephila pilipes is demonstrated with extraordinary in situ self-repair property through a constructed thin film format, surpassing that of two other silks from spider Cyrtophora moluccensis and silkworm Bombyx mori. Subsequently, R2, a key spidroin associated with self-healing, is biosynthesized, with validated cohesiveness. R2 is further programmed with tunable healability (permanent and reversible) and conductivity (graphene doping; R2G) for electronics applications. In the first demonstration, film strips from R2 and R2G are woven manually into multidimensional (1D-3D) conductive fabrics for creating repairable logic gate circuits. In the second example, a reversibly-healable R2/R2G strip is fabricated as a re-configurable wearable ring probe to fit fingertips of varying widths while retaining its detecting capabilities. Such prototype displays a unique conformable wearable technology. Last, the remarkable finding of self-healing in spider silk could offer a new material paradigm for developing future adaptive biomaterials with tailored performance and environmental sustainability.

bioengineering↗

bioRxiv2022

Quantum CART (qCART), a piggyBac-based system for development and production of virus-free multiplex CAR-T cell therapy

Chimeric antigen receptor T (CAR-T) cell therapy has the potential to transform cancer treatment. However, CAR-T therapy application is currently limited to certain types of relapsed/refractory B cell lymphomas. To unlock the full potential of CAR-T therapy, technologic breakthroughs will be needed in multiple areas, including optimization of autologous CAR-T development, shortening the innovation cycle, and further manufacturing advancement of next-generation CAR-T therapies. Here, we established a simple and robust virus-free multiplex Quantum CART system that seamlessly and synergistically integrates four platforms: 1. GTailor for rapid identification of lead CAR construct design, 2. Quantum Nufect for effective but gentle electroporation-based gene delivery, 3. Quantum pBac, featuring a virus-free transposon-based vector with large payload capacity and integration profile similar to retrovirus, and 4. iCellar for robust and high-quality CAR+ T memory stem cell expansion. This robust, virus-free multiplex Quantum CART system is expected to unleash the full potential of CAR-T therapy for treating diseases.

cancer biology↗

bioRxiv2022

Manufacturing highly potent CD20/CD19-targeted iCasp9 regulatable CAR-T cells using the Quantum pBac-based CAR-T (qCART) system for clinical application

BackgroundCD19-targeted chimeric antigen receptor therapies (CAR19) have driven a paradigm shift in the treatment of relapsed/refractory B-cell malignancies. However, >50% of CAR19-treated patients experienced progressive disease mainly due to antigen escape and low persistence. Clinical prognosis is heavily influenced by CAR-T cell function and systemic cytokine toxicities. Furthermore, it remains a challenge to efficiently, cost-effectively, and consistently manufacture clinically relevant number of virally engineered CAR-T cells. MethodsUsing a highly efficient piggyBac transposon-based vector, Quantum pBac, we developed a virus-free cell engineering system, Quantum CART (qCART), for development and production of multiplex CAR-T therapies. ResultsHere, we demonstrated in vitro and in vivo that consistent, robust, and functional CD20/CD19 dual-targeted CAR-T stem cell memory (TSCM) cells can be efficiently manufactured using the qCART system for clinical application. qCART-manufactured CAR-T cells from cancer patients expanded efficiently, rapidly eradicated tumors, and can be safely controlled via an iCasp9 suicide gene-inducing drug. ConclusionsThe qCART system is an elegant system for the manufacturing of CAR-T products having all the desired CAR-T therapy attributes. We believe that the simplicity of manufacturing multiplex CAR-T cells using the qCART system will not only significantly enhance the accessibility of CAR-T therapy but also unlock the full potential of armored CAR-T therapy for the treatment of solid tumors in the future. What is already known on this topicDespite the considerable success which has been achieved with CD19-targeted chimeric antigen receptor therapies (CAR19), >50% of CAR19-treated patients still experienced progressive disease. Therefore, there is a need to further improve CAR19 therapies. Current CAR19 therapies commonly utilize virus-based cell engineering methods. CAR-T production using these methods face multiple hurdles, including difficulties to efficiently, cost-effectively, and consistently manufacture clinically relevant number of CAR-T cells. We have previously used a highly efficient piggyBac transposon-based vector, Quantum pBac, to establish Quantum CART (qCART) which is a virus-free cell engineering system for development and production of multiplex CAR-T therapies. What this study addsIn this report, we further demonstrate in vitro and in vivo that consistent, robust, and functional iCasp9-regulatable, CD20/CD19 dual-targeted CAR-T stem cell memory (TSCM) cells can be efficiently manufactured using the qCART system for clinical application. These cells possess all the desired attributes for ensuring therapeutic efficacy in CAR-T therapy, including high CAR-TSCM, balanced CD8/CD4 ratio, low exhaustion and senescence marker expressions, and high ex vivo and in vivo expansion capacity. Importantly, we show that qCART-manufactured CAR-T cells from hematological cancer patients expanded efficiently, effectively eradicated tumors, and can be safely controlled via an iCasp9 suicide gene-inducing drug. We believe that the simplicity of manufacturing multiplex CAR-T cells using the qCART system will not only significantly enhance the accessibility of CAR-T therapy but also unlock the full potential of armored CAR-T therapy for the treatment of solid tumors in the future. How this study might affect research, practice or policyOur findings demonstrate that qCART is a virus-free CAR-T engineering system for manufacturing CAR-TSCM cells from either healthy donors or hematological cancer patients, that possess all the desired attributes for a successful CAR-T therapy. These cells expanded efficiently, rapidly eradicated tumors, and can be safely controlled via activation of iCasp9. We expect that this simple yet robust system for manufacturing multiplex CAR-T cells will advance the CAR-T field.

cancer biology↗

bioRxiv2021

Dependable Algorithm for Visualizing Snoring Duration through Acoustic Analysis

BackgroundSnoring is a nuisance for the bed partners of people who snore and is also associated with chronic diseases. Estimating the snoring duration from a whole-night-sleep period is challenging. The authors present a dependable algorithm for visualizing snoring durations through acoustic analysis. MethodBoth instruments (Sony digital recorder and smartphones SnoreClock app) were placed within 30 cm from the examinees head during the sleep period. Subsequently, spectrograms were plotted based on audio files recorded from Sony recorders. The authors developed an algorithm to validate snoring durations through visualization of typical snoring segments. ResultsIn total, 37 snoring recordings obtained from six individuals were analyzed. The mean age of the participants was 44.6 {+/-} 9.9 years. A 3-s segment demonstrated the typical dominant frequency bands and amplitude waves of two snores. Every recorded file was tailored to a regular 600-s segment and plotted. Visualization revealed that the typical features of the clustered snores in the amplitude domains were near-isometric spikes (most had an ascending-descending trend). The recorded snores exhibited one or more visibly fixed frequency bands. Intervals were noted between the snoring clusters and were incorporated into the whole-night snoring calculation. The correlative coefficients of snoring rates of digitally recorded files examined by Examiners A and B were higher (0.865, p < 0.001) than those with SnoreClock app (0.757, p < 0.001; 0.787, p < 0.001, respectively). ConclusionA dependable algorithm with high reproducibility was developed for visualizing snoring durations.

physiology↗

bioRxiv2020

ZmMTOPVIB is essential for double-strand break formation and bipolar spindle assembly in maize meiosis

The programmed formation of DNA double-strand breaks (DSBs) during early meiosis is catalyzed by SPO11, a conserved ortholog to the A subunit of an archaeal topoisomerase VI (TopoVI) which functions as a hetero-tetramer comprising two A and two B subunits. An essential role of the meiotic TopoVI B subunit (TopVIB) in DSB formation has been reported in mouse, Arabidopsis and rice. Very recently, rice MTopVIB was revealed to have an unexpected role in meiotic bipolar spindle assembly, highlighting multiple functions of MTopVIB during rice meiosis. In this work, the meiotic TopVIB in maize (ZmMTOPVIB) was characterized. The ZmmtopVIB mutant plants exhibited normal vegetative growth but male and female sterility. DSB formation is abolished in mutant meiocytes. Despite normal assembly of axial elements, synapsis was severely affected and homologous pairing was disrupted in mutants. Importantly, we showed that bipolar spindle assembly was also affected in ZmmtopVIB, resulting in triad and polyad formation. Overall, our results demonstrate that ZmMTOPVIB plays critical roles in DSB formation and homologous recombination. In addition, the newly-discovered function of MTOPVIB in bipolar spindle assembly is likely conserved across different monocots. One-sentence summaryThe dual roles of MTOPVIB in regulating meiotic DSB formation and bipolar spindle assembly are evolutionarily conserved in monocot plants.

cell biology↗

bioRxiv2018

The dynamic association of SPO11-1 with conformational changes of meiotic axial elements in maize

Meiotic double-strand breaks (DSBs) are generated by the evolutionarily conserved SPO11 complex in the context of chromatin loops that are organized along axial elements (AEs) of chromosomes. However, how DSBs are formed with respect to chromosome axes and the SPO11 complex remains unclear in plants. Here, we confirm that DSB and bivalent formation are defective in maize spo11-1 mutants. Super-resolution microscopy demonstrates dynamic localization of SPO11-1 during recombination initiation, with variable numbers of SPO11-1 foci being distributed in nuclei but similar numbers of SPO11-1 foci being found on AEs. Notably, cytological analysis of spo11-1 meiocytes revealed an aberrant AE structure. At leptotene, AEs of wild-type and spo11-1 meiocytes were similarly curly and discontinuous. However, during early zygotene, wild-type AEs become uniform and exhibit shortened axes, whereas the elongated and curly AEs persisted in spo11-1 mutants, suggesting that loss of SPO11-1 compromised AE structural maturation. Our results reveal an interesting relationship between SPO11-1 loading onto AEs and the conformational remodeling of AEs during recombination initiation. Author SummaryMeiosis is essential during sexual reproduction to produce haploid gametes. Recombination is the most crucial step during meiotic prophase I. It enables pairing of homologous chromosomes prior to their reductional division and generates new combinations of genetic alleles for transmission to the next generation. Meiotic recombination is initiated by generating DNA double-strand breaks (DSBs) via SPO11, a topoisomerase-related enzyme. The activity, timing and location of this DSB machinery must be controlled precisely, but how this is achieved remains obscure. Here, we show dynamic localization of SPO11-1 on chromatin during meiotic initiation in maize, yet a similar number of SPO11-1 is able to load onto axial elements (AEs), which accompanies a structural change of the AEs of wild-type meiotic chromosomes. Interestingly, loss of SPO11-1 not only affects DSB formation but also impairs structural alterations of AEs, resulting in abnormally long and curly AEs during early meiosis. Our study provides new insights into SPO11-1 localization during recombination initiation and suggests an intimate relationship between DSB formation and AE structural changes.

molecular biology↗

bioRxiv2017

Practical unidentifiability of a simple vector-borne disease model: implications for parameter estimation and intervention assessment

BackgroundMathematical modeling has an extensive history in vector-borne disease epidemiology, and is increasingly used for prediction, intervention design, and understanding mechanisms. Many of these studies rely on parameter estimation to link models and data, and to tailor predictions and counterfactuals to specific settings. However, few studies have formally evaluated whether vector-borne disease models can properly estimate the parameters of interest given the constraints of a particular dataset.\n\nMethodology/Principle FindingsIdentifiability methods allow us to examine whether model parameters can be estimated uniquely--a lack of consideration of such issues can result in misleading or incorrect parameter estimates and model predictions. Here, we evaluate both structural (theoretical) and practical identifiability of a commonly used compartmental model of mosquitoborne disease, using 2010 dengue epidemic in Taiwan as a case study. We show that while the model is structurally identifiable, it is practically unidentifiable under a range of human and mosquito time series measurement scenarios. In particular, the transmission parameters form a practically identifiable combination and thus cannot be estimated separately, which can lead to incorrect predictions of the effects of interventions. However, in spite of unidentifiability of the individual parameters, the basic reproduction number was successfully estimated across the unidentifiable parameter ranges. These identifiability issues can be resolved by directly measuring several additional human and mosquito life-cycle parameters both experimentally and in the field.\n\nConclusionsWhile we only consider the simplest case for the model, without explicit environmental drivers, we show that a commonly used model of vector-borne disease is unidentifiable from human and mosquito incidence data, making it difficult or impossible to estimate parameters or assess intervention strategies. This work illustrates the importance of examining identifiability when linking models with data to make predictions, and particularly highlights the importance of combining experimental, field, and case data if we are to successfully estimate epidemiological and ecological parameters using models.\n\nAuthor SummaryMathematical models have seen increasing use in understanding transmission processes, developing interventions, and predicting disease incidence and prevalence. Vector-borne diseases in particular present both a challenge and an opportunity for modeling, due to the complex interactions between host and vector species. A key step in many of these studies is connecting transmission models with data to infer parameters and make useful predictions, which requires careful consideration of identifiability and uncertainty of the model parameters. Whether due to intrinsic limitations of the model structure, or practical limitations of the data collected, is common that many different parameter values may yield the same or very similar fits to the data, making it impossible to successfully estimate the parameters. This issue of parameter unidentifiability can have broad implications for our ability to draw conclusions from mechanistic models--in some cases making it difficult or impossible to generate specific predictions, forecasts, or parameter estimates from a given model and data. Here, we evaluate these questions for a commonly-used model of vectorborne disease, examining how parameter uncertainty and unidentifiability can affect intervention predictions, estimation of the basic reproduction number, and other public health conclusions drawn from the model.

epidemiology↗