技术资料

Objective: To develop a rapid functional assay to validate variants of uncertain significance (VUS) in the MEFV gene. Methods: Overactivity of the pyrin inflammasome pathway and ASC speck oligomerisation in response to stimulation with low concentrations of Clostridium difficile toxin A was directly visualised by immunofluorescence microscopy. A semi‐automated algorithm was developed to count cells and ASC specks. Results: The semi‐automated ASC speck assay is able to discriminate between healthy controls and patients with familial Mediterranean fever (FMF) and pyrin inflammasome overactivity with high sensitivity. It is also able to discriminate pyrin inflammasome overactivity from other autoinflammatory disease controls with high specificity. Conclusion: The semi‐automated ASC speck assay may be a useful test to functionally validate VUS in the MEFV gene and screen for pyrin inflammasome overactivity. A semi‐automated ASC speck assay using machine learning is able to discriminate between healthy controls and patients with familial Mediterranean fever (FMF) with high sensitivity. It is also able to discriminate FMF from other autoinflammatory diseases with high specificity. View Publication

In stem cell biology,a long-held structure–function relationship is the domed colony morphology and naïve pluripotency for mouse or human pluripotent stem cells. This link has provided a convenient way to recognize bona fide naïve pluripotent cells during derivation,passaging and characterization. However,the molecular basis of this link remains poorly understood. Results: We show that a loss of domed morphology may not impact the overall genetic architecture of naïve pluripotency in mouse embryonic stem cells (mESCs). We first generated stable mESC lines by knocking out Myh9 that encodes non-muscle myosin heavy chain IIA,resulting in colonies deprived of the typical domed morphology,but competent to differentiate into the three germ layers and chimeric mice. Modulating cell morphologies with inhibitors against kinases known to regulate myosin pathway also phenocopy the knockout in wild type mESCs. Conclusions: These results provide evidence that the domed morphology and potency can be uncoupled and suggest that domed structure is not a pre-requisite for acquiring and maintaining naïve pluripotency. View Publication

Chimeric antigen receptor (CAR) T cell therapy has transformed the treatment landscape of hematologic cancers by engineering T cells to specifically target and destroy cancer cells. Monitoring CAR T cell activity and function is essential for optimizing therapeutic outcomes,but existing tools for CAR detection are often limited in specificity and functional assessment capability. Methods: We developed dextran multimers by conjugating multiple CAR-specific antigens to a dextran backbone. The multimers were compared to previously reported antigen tetramers for their ability to stain and detect CAR T cells. Because these multimers incorporate the CAR target antigen,they uniquely enable assessment of CAR T cell functionality. We tested the staining and functional properties of the multimers across a range of CAR constructs with different affinities,using flow cytometry and microscopy. Results: The dextran multimers demonstrated high specificity and sensitivity in staining CAR T cells,with adjustable antigen density to optimize binding. Dextran multimers also enabled effective clustering and subsequent activation of CARs,showing their utility as both a staining and functional assessment tool. The multimers revealed that CARs with different affinities and clustering tendencies displayed varied binding and activation in response to different antigen densities. Conclusions: Dextran multimers offer a dual advantage as versatile reagents for both staining and functional analysis of CAR T cells. Their capacity to engage CARs with the specific antigen provides a valuable platform for evaluating CAR functionality,informing CAR design improvements,and enhancing therapeutic precision. View Publication

MEF2C encodes a transcription factor that is critical in nervous system development. Here,to examine disease-associated functions of MEF2C in human microglia,we profiled microglia differentiated from isogenic MEF2C-haploinsufficient and MEF2C-knockout induced pluripotent stem cell lines. Complementary transcriptomic and functional analyses revealed that loss of MEF2C led to a hyperinflammatory phenotype with broad phagocytic impairment,lipid accumulation,lysosomal dysfunction and elevated basal inflammatory cytokine secretion. Genome-wide profiling of MEF2C-bound sites coupled with the active regulatory landscape enabled inference of its transcriptional functions and potential mechanisms for MEF2C-associated cellular functions. Transcriptomic and epigenetic approaches identified substantial overlap with idiopathic autism datasets,suggesting a broader role of human microglial MEF2C dysregulation in idiopathic autism. In a mouse xenotransplantation model,loss of MEF2C led to morphological,lysosomal and lipid abnormalities in human microglia in vivo. Together,these studies reveal mechanisms by which reduced microglial MEF2C could contribute to the development of neurological diseases. Coufal and colleagues generated microglia from human iPS cells to examine mechanistic roles of the transcription factor MEF2C and how these roles might relate to the autism phenotype seen following the loss of MEF2C in human microglia. View Publication