Biology subjects

Kang, H. J.

Publications and source records attributed to Kang, H. J..

11 recordsLinked to original sources

bioRxiv2026

Dual-targeted nanoparticles enable the ex vivo generation of cytotoxic and phagocytic CAR effector cells

Chimeric antigen receptor (CAR)-T cells and CAR-macrophages (or CAR-monocytes) offer complementary antitumor functions. CAR-T cells exert potent cytotoxicity against cancer cells, whereas CAR-macrophages can infiltrate solid tumors, phagocytose cancer cells and promote antigen spreading. Antibody-conjugated lipid nanoparticles (LNPs) have emerged as non-viral mRNA delivery platforms for generating CAR-immune cells. However, these systems have generally been optimized to target a single immune-cell type. Here, to enable the ex vivo generation of CAR-T cells and CAR-monocytes, we developed CLCM08, an anti-CD222 antibody, and co-displayed it with an anti-CD5 antibody on LNPs. CD222 is predominantly expressed by monocytes, macrophages and T cells, and facilitates the internalization of CD222-binding molecules. CD5 is primarily expressed by T cells and has previously been used to enable LNP-mediated mRNA delivery to these cells. Delivery of CAR mRNA by dual CD222/CD5 antibody-conjugated LNPs to primary monocytes and T cells substantially enhanced the ex vivo generation of CAR-monocytes and CAR-T cells compared with non-conjugated LNPs. Moreover, CD19 CAR-T cells and CAR-monocytes generated using dual CD222/CD5 antibody-conjugated LNPs showed enhanced cytotoxic and phagocytic activity, respectively, relative to cells generated using non-conjugated LNPs, with anti-CD222 LNPs producing the largest phagocytic gain in monocytes. These findings establish an adaptable antibody-conjugated LNP-mRNA platform for the ex vivo generation of CAR-T cells and CAR-monocytes.

biochemistry↗

bioRxiv2025

Systematic Growth Factor Profiling Platform for 3D Tumor Models Reveals Estradiol-Responsive Cellular Mechanisms of Immunotherapy Resistance

Current organoid culture systems face critical limitations: standardized growth factor formulations fail to capture patient-specific signaling requirements, and single-cell-type approaches overlook tumor-stromal interactions essential for understanding immunotherapy resistance. To address these challenges, we developed an innovative biofabrication platform that systematically integrates patient-derived three-dimensional (3D) cultures with comprehensive growth factor profiling across 128 combinations. Through systematic screening of 23 ovarian cancer patient samples and single-cell RNA sequencing, we identified two estradiol-responsive cellular populations that coordinate immunosuppression: a malignant cell fraction (MAL.PDCD5) and a cancer-associated fibroblast (CAF) fraction (FB.TNFSF10). MAL.PDCD5 cells suppress immune infiltration by downregulating antigen presentation, while FB.TNFSF10 cells promote immunosuppression through enhanced TGF-{beta} signaling. Spatial transcriptomic analysis revealed striking mutual exclusivity between FB.TNFSF10 cells and T/NK cells, providing evidence of active immune cell exclusion. Most significantly, FB.TNFSF10 abundance emerged as a robust predictor of immune checkpoint inhibitor therapy resistance across multiple cancer cohorts, independent of conventional biomarkers. This biofabrication platform provides a scalable framework for drug screening and biomarker discovery, with immediate applications in precision medicine for patient stratification and combination therapy development.

cancer biology↗

bioRxiv2025

Synaptic and intrinsic membrane defects disrupt early neural network dynamics in Down syndrome

Down syndrome, caused by trisomy 21, affects around six million people worldwide and features learning, memory and language deficits. However, the mechanisms underlying trisomy 21 neurophenotypes involving human cortical circuitry are unknown. By characterising developing neural network dynamics and single cell excitability profiles, with synaptic and voltage-dependent ion channel behaviour, using an isogenic induced pluripotent stem cell- derived neuronal model, we show that trisomy 21 impairs the activity and development of cortical circuitry. This is caused by deficient glutamatergic synaptic connectivity and by aberrant intrinsic membrane properties involving K+ and Na+ channels culminating in spike firing defects that weaken neural network activity and disrupt the synchrony of developing neurons. We also identify transiently activated A-type K+ channels, specifically Kv4.3 channels, as a key orchestrator for Down syndrome during neurodevelopment. Overall, these excitability changes will significantly contribute towards the aberrant neurophenotypes observed later on in life.

neuroscience↗

bioRxiv2023

An RXLR effector targets ER-Golgi interface to induce ER stress and necrotic cell death

To achieve successful colonization, the pathogen secretes hundreds of effectors into host cells to manipulate the hosts immune response. Despite numerous studies, the molecular mechanisms underlying effector-induced necrotic cell death remain elusive. In this study, we identified a novel virulent RXLR effector named Pc12 from P. capsici. Pc12 induces necrosis by triggering a distinct ER stress response through its interaction with Rab13-2. Unlike conventional hypersensitive response cell death associated with effector-triggered immunity, Pc12-induced cell death does not coincide with defense gene expression. Instead, it induces the aggregation of ER-resident proteins and confines secretory proteins within the ER. Pc12 interacts with Rab13-2, exhibiting a specific affinity for the active form of Rab13-2. Thus, the complex of Pc12 and Rab13-2 mimics the conformation of the inactive state of Rab13-2, subsequently recruiting the Rab-escort protein (REP). This process results in disruptions in vesicle formation within the ER-Golgi trafficking pathway. Furthermore, the substitution of a single amino acid of Rab13-2 structurally predicted to be crucial for the Pc12 interaction decreased the interaction with Pc12 while maintaining the interaction with REP1. These findings offer valuable insights into the ER stress-mediated cell death as well as a potential strategy for enhancing resistance against pathogens.

plant biology↗

bioRxiv2023

Structure-Based Discovery of a NPFF1R Antagonist with Analgesic Activity

While opioid drugs remain among the most effective analgesics for pain management, adverse effects limit their use. Molecules that synergize with opioids, increasing analgesia without increasing side effects, could prove beneficial. A potential way to do so is via the RF-amide receptor system, as NPFFR1 agonists reduce {micro}- opioid receptor ({micro}OR)-based analgesia while antagonists increase it. These inferences are, however, clouded by the lack of selectivity of most NPFF1R ligands. Seeking selective antagonists of the NPFF1R, we screened a large virtual library against a homology model of NPFF1R. From 26 high-ranking molecules that were synthesized and tested, one antagonized NPFF1R with a Ki of 319 nM. Structure-based optimization led to a 22 nM antagonist of NPFF1R, compound 56, with selectivity against a large panel of GPCRs. When administered alone, 56 has no activity in mouse tail-flick nociception assays. However, coadministration of compound 56 and morphine produced significantly greater antinociception than did morphine alone, consistent with the notion that NPFF1R nociceptive activity occurs via modulation of {micro}OR signaling. Surprisingly, in the hot-plate assays 56 was analgesic by itself, suggesting that NPFF1R alone can also confer analgesia. At equi-analgesic doses, combinations of 56 with morphine reduced the common constipation side effect of morphine versus using morphine alone. The high selectivity of 56 and its activity in cooperation with morphine supports further analgesic development against NPFF1R and against the RF-amide family of receptors more generally.

pharmacology and toxicology↗

bioRxiv2023

Oomycete effector AVRblb2 targets cyclic nucleotide-gated channels through calcium sensors to suppress pattern-triggered immunity

Transient, rapid increase of cytosolic Ca2+ upon pathogen infection is essential for plant pathogen-associated molecular pattern (PAMP)-triggered immunity (PTI). Several cyclic nucleotide-gated channels (CNGCs) have been implicated; however, their regulatory mechanisms remain elusive. Here, the Phytophthora infestans RXLR effector AVRblb2 family targeted NbCNGC18-20 at the plasma membrane, inhibiting Ca2+ influx and PTI. AVRblb2 required calmodulin (CaM) and calmodulin-like (CML) proteins as co-factors to interact with N. benthamiana CNGCs (NbCNGCs), forming the AVRblb2-CaM/CML-NbCNGCs complex. After recognizing PAMPs, NbCNGC18 formed active heteromeric channels with other CNGCs, potentially providing selectivity for diverse signals to fine-tune cytosolic Ca2+ levels and responses. AVRblb2 suppressed the Ca2+ influx and oxidative burst induced by NbCNGC18 heteromeric complexes. Silencing CNGC18, CNGC20, and CNGC25 compromised the effect of AVRblb2 on P. infestans virulence, confirming that AVRblb2 contributed to virulence by targeting CNGCs. Our findings delineated the regulatory mechanism and role of effector-targeted Ca2+ channels in plant innate immunity.

plant biology↗

bioRxiv2022

Neurotensin receptor allosterism revealed in complex with a biased allosteric modulator

The NTSR1 neurotensin receptor (NTSR1) is a G protein coupled receptor (GPCR) found in the brain and peripheral tissues with neurotensin (NTS) being its endogenous peptide ligand. In the brain, NTS modulates dopamine neuronal activity, induces opioid-independent analgesia, and regulates food intake. Recent studies indicate that biasing NTSR1 toward {beta}-Arrestin signaling can attenuate the actions of psychostimulants and other drugs of abuse. Here we provide the cryoEM structures of NTSR1 ternary complexes with heterotrimeric Gq and Go with and without the brain penetrant small molecule SBI-553. In functional studies, we discovered that SBI-553 displays complex allosteric actions exemplified by negative allosteric modulation for G proteins that are G subunit selective and positive allosteric modulation and agonism for {beta}-Arrestin translocation at NTSR1. Detailed structural analysis of the allosteric binding site illuminated the structural determinants for biased allosteric modulation of SBI-553 on NTSR1. These insights promise to both accelerate the structure-guided design of more effective NTSR1 therapeutics and provide insights into the complexities of GPCR allosteric modulation.

biophysics↗

bioRxiv2021

Design, synthesis, and characterization of mG2P026 as a high contrast PET imaging ligand for metabotropic glutamate receptor 2

An array of triazolopyridines based on JNJ-46356479 (6) were synthesized as potential PET imaging ligands for metabotropic glutamate receptor 2 (mGluR2) in the brain. The selected candidates 8-11 featured an enhanced positive allosteric modulator (PAM) activity (37-fold max.) and an apparent mGluR2 agonist activity (25-fold max.) compared to compound 6. Radiolabeling of compounds 8 and 9 (also named mG2P026) was achieved via the Cu(I)-mediated radiofluorination in the automated TRACERLabTM FXF-N platform. Both [18F]8 and [18F]9 were obtained with satisfactory radiochemical yields (> 5%, non-decay corrected), high molar activity (> 180 GBq/mol), and excellent chemical and radiochemical purities (> 98%). Preliminary characterization of [18F]8 and [18F]9 in rats confirmed their excellent brain permeability with [18F]9 showing better brain heterogeneity and favorable binding kinetics. Pretreatment with different classes of PAMs enhanced the radioactivity uptake for both [18F]8 and [18F]9 at the regions of interest by 20.3-40.9% and 16.7-81.6%, respectively, due to their pharmacological effects. Further evaluation of [18F]9 in a nonhuman primate confirmed its superior brain heterogeneity in mapping mGlu2 receptors and its higher specific binding than [18F]6. Pretreatment with 0.5 mg/kg BINA led (2) to an enhanced brain uptake of [18F]9 by 3% in high tracer uptake regions that was consistent with the rat studies. Therefore, [18F]9 has the potential to be translated for human studies.

neuroscience↗

bioRxiv2021

A Promising Chemical Series of Positive Allosteric Modulators of the μ-Opioid Receptor that Enhance the Antinociceptive Efficacy of Opioids but not their Adverse Effects

Positive allosteric modulators (PAMs) of the {micro}-opioid receptor (MOR) have been proposed to exhibit therapeutic potential by maximizing the analgesic properties of clinically used opioid drugs while limiting their adverse effects or risk of overdose as a result of using lower drug doses. We herein report in vitro and in vivo characterization of two small molecules from a chemical series of MOR PAMs that exhibit: (i) MOR PAM activity and receptor subtype selectivity in vitro, (ii) a differential potentiation of the antinociceptive effect of oxycodone, morphine, and methadone in mouse models of pain that roughly correlates with in vitro activity, and (iii) a lack of potentiation of adverse effects associated with opioid administration, such as somatic withdrawal, respiratory depression, and analgesic tolerance. This series of MOR PAMs holds promise for the development of adjuncts to opioid therapy to mitigate against overdose and opioid use disorders.

neuroscience↗

bioRxiv2018

Somatic uniparental disomy with a rare EFL1 variant causes Shwachman-Diamond syndrome through dysregulating ribosomal protein synthesis

Shwachman-Diamond syndrome (SDS; OMIM: #260400) is caused by variants in SBDS (Shwachman-Bodian-Diamond syndrome gene), which encodes a protein that plays an important role in ribosome assembly. Recent reports suggest that recessive variants in EFL1 are also responsible for SDS. However, the precise genetic mechanism that leads to EFL1-induced SDS remains incompletely understood. Here we present three unrelated Korean SDS patients that carry biallelic pathogenic variants in EFL1 with biased allele frequencies, resulting from a bone marrow-specific somatic uniparental disomy (UPD) in chromosome 15. The recombination events generated cells that were homozygous for the relatively milder variant, allowing for the evasion of catastrophic physiological consequences. Still, the milder EFL1 variant was solely able to impair 80S ribosome assembly and induce SDS features in cell line, zebrafish, and mouse models. The loss of EFL1 resulted in a pronounced inhibition of terminal oligo-pyrimidine element-containing ribosomal protein transcript 80S assembly. Therefore, we propose a more accurate pathogenesis mechanism of EFL1 dysfunction that eventually leads to aberrant translational control and ribosomopathy.

genetics↗

bioRxiv2018

Human CtIP forms a tetrameric dumbbell-shaped particle which binds and bridges complex DNA end structures for double-strand break repair

CtIP is involved in the resection of double-stranded DNA breaks during the S and G2 phases of the cell cycle for repair by homologous recombination. Acting in concert with the MRN complex, it plays a particularly important role in handling complex DNA end structures by localised nucleolytic processing of DNA termini in preparation for longer range resection. Here we show that human CtIP is a tetrameric protein adopting a dumbbell architecture in which DNA binding domains are connected by long coiled-coils. The protein complex binds two short DNA duplexes with high affinity and bridges DNA molecules in trans. DNA binding is potentiated by dephosphorylation and is not specific for DNA end structures per se. However, the affinity for linear DNA molecules is increased if the DNA terminates with more complex structures including forked ssDNA overhangs and model nucleoprotein conjugates. This work provides a biochemical and structural basis for the function of CtIP at complex DNA breaks.

biochemistry↗