Biology subjects

Tsai, H.-C.

Publications and source records attributed to Tsai, H.-C..

5 recordsLinked to original sources

bioRxiv2021

INPP5E regulates CD3ζ enrichment at the immune synapse by phosphoinositide distribution control

The immune synapse, a specialized interface formed between T lymphocytes and antigen-presenting cells (APCs) after antigen recognition, is essential for T cell activation and the adaptive immune response. It has been shown that this interface shares similarities with the primary cilium, a sensory organelle in eukaryotic cells, although roles of ciliary proteins on the immune synapse remain elusive. In this study, we find that inositol polyphosphate-5-phosphatase E (INPP5E), a cilium-enriched protein responsible for regulating phosphoinositide localization, accumulated at the immune synapse during antigen-specific conjugation or antibody capping, and formed a complex with CD3{zeta}, ZAP-70, and Lck. Silencing INPP5E in T-cells impaired polarized distribution of CD3{zeta} at the immune synapse, and correlated with a failure of PI(4,5)P2 clearance at the center of the synapse. Moreover, INPP5E silencing decreased proximal TCR signaling, including phosphorylation of CD3{zeta} and ZAP-70, and finally, attenuated IL-2 secretion. Our results suggest that INPP5E is a new player in phosphoinositide manipulation at the synapse, controlling the TCR signaling cascade.

cell biology↗

bioRxiv2020

Epigenetic therapy remodels the immune synaptic cytoskeleton to potentiate cancer susceptibility to γδ T cells

{gamma}{delta} T cells are a distinct subgroup of T cells that bridge the innate and adaptive immune systems and can attack cancer or virus-infected cells in an MHC-unrestricted manner. Despite its antitumor ability in both autologous and allogeneic settings, earlier trials of adoptive {gamma}{delta} T cell transfer in solid tumors had limited success due to limitations in cell expansion and the lack of a strategy to modulate tumor lytic interactions between {gamma}{delta} T and cancer cells. Here, we show through quantitative surface proteomics and gene enrichment analyses that DNA methyltransferase inhibitors (DNMTis) upregulate multiple surface molecules related to {gamma}{delta} T cell activation in cancer cells. DNMTi treatment of human lung cancer potentiates tumor lysis by ex vivo-expanded {gamma}{delta} T cells using a clinical-grade expansion protocol developed by our team to enrich for the V{delta}1 subset while preserving their antitumor effector functions. Mechanistically, DNMTis enhance immune synapse formation and stabilize the synaptic cleft to facilitate {gamma}{delta} T-mediated tumor lysis. Through integrated analysis of RNA-seq, DNA methylation, and ATAC-seq, we demonstrate that depletion of DNMTs induces coordinated pattern alterations of immune synaptic-cytoskeletal networks at the cancer side of the immune synapse. In addition, single-cell mass cytometry reveals enrichment of polyfunctional {gamma}{delta} T subsets by DNMTis. Combined DNMTi and adoptive {gamma}{delta} T transfer in a mouse lung cancer model offers a significant survival benefit. Consistently, the DNMTi-associated cytoskeleton signature identifies a subset of lung cancer patients with improved survival. Our results demonstrate that epigenetic mechanisms are crucial for cytoskeletal remodeling in cancer to potentiate immune attack and support a combinatorial strategy of DNMTis and {gamma}{delta} T cell-based immunotherapy in lung cancer management. One Sentence SummaryDNA methyltransferase inhibitors potentiate the killing of lung cancer by {gamma}{delta} T cells through remodeling cytoskeletal-immune synaptic networks.

cancer biology↗

bioRxiv2019

Fucosyltransferase 4 shapes oncogenic glycoproteome to drive metastasis of lung adenocarcinoma

Aberrant fucosylation plays a critical role in lung cancer progression. Identification of the key fucosyltransferase as a therapeutic target may refine lung cancer management. Here, we identified a terminal 1,3-fucosyltransferase, FUT4, as the key prognostic predictor for lung adenocarcinoma through transcriptomic screens in lung cancer cohorts. Overexpression of FUT4 promotes lung cancer invasion, migration and cell adhesion in vitro and provokes distant metastases in mouse xenograft models. RNA-seq and glycoproteomics analyses revealed that FUT4 mediates aberrant fucosylation of intracellular transport and signal transduction proteins, which facilitates concurrent transcriptional activation of multiple cellular processes, including membrane trafficking, cell cycle, and major oncogenic signaling pathways. Notably, knockdown of FUT4 markedly curtailed lung colonization and distant metastases of lung cancer cells in mouse xenograft models. In addition, the metastatic phenotype provoked by FUT4-mediated fucosylproteomic networks can be diminished by targeted pathway inhibitors. Collectively, FUT4 represents a promising therapeutic target in lung cancer metastasis. Our data highlight the potentials for integration of glycomics into precision medicine-based therapeutics.

cancer biology↗

bioRxiv2019

Pericytes regulate vascular immune homeostasis in the CNS

Brain endothelium possesses several organ-specific features collectively known as the blood-brain barrier (BBB). In addition, trafficking of immune cells in the healthy central nervous system (CNS) is tightly regulated by CNS vasculature. In CNS autoimmune diseases such as multiple sclerosis (MS), these homeostatic mechanisms are overcome by autoreactive lymphocyte entry into the CNS causing inflammatory demyelinating immunopathology. Previous studies have shown that pericytes regulate the development of organ-specific characteristics of brain vasculature such as the BBB and astrocytic end-feet. Whether pericytes are involved in the control of leukocyte trafficking remains elusive. Using adult, pericyte-deficient mice (Pdgfbret/ret), we show here that brain vasculature devoid of pericytes shows increased expression of VCAM-1 and ICAM-1, which is accompanied by increased leukocyte infiltration of dendritic cells, monocytes and T cells into the brain, but not spinal cord parenchyma. Regional differences enabling leukocyte trafficking into the brain as opposed to the spinal cord inversely correlate with the pericyte coverage of blood vessels. Upon induction of experimental autoimmune encephalitomyelitis (EAE), pericyte-deficient mice succumb to severe neurological impairment. Treatment with first line MS therapy - fingolimod significantly reverses EAE, indicating that the observed phenotype is due to the massive influx of immune cells into the brain. Furthermore, pericyte-deficiency in mice that express myelin oligodendrocyte glycoprotein peptide (MOG35-55) specific T cell receptor (Pdgfbret/ret; 2D2Tg) leads to the development of spontaneous neurological symptoms paralleled by massive influx of leukocytes into the brain, suggesting altered brain vascular immune quiescence as a prime cause of exaggerated neuroinflammation. Thus, we show that pericytes indirectly restrict immune cell transmigration into the CNS under homeostatic conditions and during autoimmune-driven neuroinflammation by inducing immune quiescence of brain endothelial cells.

neuroscience↗

bioRxiv2018

Naa10p promotes metastasis by stabilizing matrix metalloproteinase-2 protein in human osteosarcomas

N--Acetyltransferase 10 protein (Naa10p) mediates N-terminal acetylation of nascent proteins. Oncogenic or tumor suppressive roles of Naa10p were reported in cancers. Here, we report an oncogenic role of Naa10p in promoting metastasis of osteosarcomas. Higher NAA10 transcripts were observed in metastatic osteosarcoma tissues compared to non-metastatic tissues and were also correlated with a worse prognosis of patients. Knockdown and overexpression of Naa10p in osteosarcoma cells respectively led to decreased and increased cell migratory/invasive abilities. Re-expression of Naa10p, but not an enzymatically inactive mutant, relieved suppression of the invasive ability in vitro and metastasis in vivo imposed by Naa10p-knockdown. According to protease array screening, we identified that matrix metalloproteinase (MMP)-2 was responsible for the Naa10p-induced invasive phenotype. Naa10p was directly associated with MMP-2 protein through its acetyltransferase domain and maintained MMP-2 protein stability via NatA complex activity. MMP-2 expression levels were also significantly correlated with Naa10p levels in osteosarcoma tissues. These results reveal a novel function of Naa10p in the regulation of cell invasiveness by preventing MMP-2 protein degradation that is crucial during osteosarcoma metastasis.

cancer biology↗