Publications by authors named "Hyuncheol Lee"

Manufacturing sufficient adeno-associated virus (AAV) to meet current and projected clinical needs is a significant hurdle to the growing gene therapy industry. The recently discovered membrane-associated accessory protein (MAAP) is encoded by an alternative open reading frame in the AAV cap gene that is found in all presently reported natural serotypes. Recent evidence has emerged supporting a functional role of MAAP in AAV egress, although the underlying mechanisms of MAAP function remain unknown.

View Article and Find Full Text PDF

Short-time Fourier transforms with short segment lengths are typically used to analyze single ion charge detection mass spectrometry (CDMS) data either to overcome effects of frequency shifts that may occur during the trapping period or to more precisely determine the time at which an ion changes mass or charge, or enters an unstable orbit. The short segment lengths can lead to scalloping loss unless a large number of zero-fills are used, making computational time a significant factor in real-time analysis of data. Apodization specific fitting leads to a 9-fold reduction in computation time compared to zero-filling to a similar extent of accuracy.

View Article and Find Full Text PDF

Instrumental resolution of Fourier transform-charge detection mass spectrometry instruments with electrostatic ion trap detection of individual ions depends on the precision with which ion energy is determined. Energy can be selected using ion optic filters or from harmonic amplitude ratios (HARs) that provide Fellgett's advantage and eliminate the necessity of ion transmission loss to improve resolution. Unlike the ion energy-filtering method, the resolution of the HAR method increases with charge (improved /) and thus with mass.

View Article and Find Full Text PDF

3C protease (3C), a chymotrypsin-like cysteine protease encoded by the foot-and-mouth disease virus (FMDV), plays an essential role in processing the FMDV P1 polyprotein into individual viral capsid proteins in FMDV replication. Previously, it has been shown that 3C is involved in the blockage of the host type-I interferon (IFN) responses by FMDV. However, the underlying mechanisms are poorly understood.

View Article and Find Full Text PDF

We describe a genome-wide screening strategy to identify target genes whose modulation increases the capacity of a cell to produce recombinant adeno-associated viral (AAV) vector. Specifically, a single-guide RNA (sgRNA) library for a CRISPR-based genome-wide transcriptional activation screen was inserted into an AAV vector, and iterative rounds of viral infection and rescue in HEK293 producer cells enabled the enrichment of sgRNAs targeting genes whose upregulation increased AAV production. Numerous gain-of-function targets were identified, including spindle and kinetochore associated complex subunit 2 (SKA2) and inositol 1, 4, 5-trisphosphate receptor interacting protein (ITPRIP).

View Article and Find Full Text PDF

VP1, a pivotal capsid protein encoded by the foot-and-mouth disease virus (FMDV), plays an important role in receptor-mediated attachment and humoral immune responses. Previous studies show that amino acid changes in the VP1 protein of cell culture-adapted strains of FMDV alter the properties of the virus. In addition, FMDV VP1 modulates host IFN signal transduction.

View Article and Find Full Text PDF
Article Synopsis
  • Tacrolimus combined with low-dose steroids is as effective as high-dose steroids for achieving remission in adults with minimal change nephrotic syndrome, based on a 24-week study with 144 participants.
  • The study found that 79.1% of the tacrolimus group and 76.8% of the high-dose steroid group achieved complete remission within 8 weeks, indicating noninferiority.
  • However, patients on the maintenance treatment of tacrolimus plus tapered steroids experienced significantly lower relapse rates compared to those on tapered high-dose steroids alone.
View Article and Find Full Text PDF

NF-κB essential modulator (NEMO) is a key regulatory protein that functions during NF-κB- and interferon-mediated signaling in response to extracellular stimuli and pathogen infections. Tight regulation of NEMO is essential for host innate immune responses and for maintenance of homeostasis. Here, we report that the E3 ligase MARCH2 is a novel negative regulator of NEMO-mediated signaling upon bacterial or viral infection.

View Article and Find Full Text PDF

Efforts to identify mutations that underlie inherited genetic diseases combined with strides in the development of gene therapy vectors over the last three decades have culminated in the approval of several adeno-associated virus (AAV)-based gene therapies. Genetic diseases that manifest in the lung such as cystic fibrosis (CF) and surfactant deficiencies, however, have so far proven to be elusive targets. Early clinical trials in CF using AAV serotype 2 (AAV2) achieved safety, but not efficacy endpoints; however, importantly, these studies provided critical information on barriers that need to be surmounted to translate AAV lung gene therapy toward clinical success.

View Article and Find Full Text PDF

During viral infection, virus-derived cytosolic nucleic acids are recognized by host intracellular specific sensors. The efficacy of this recognition system is crucial for triggering innate host defenses, which then stimulate more specific adaptive immune responses against the virus. Recent studies show that signal transduction pathways activated by sensing proteins are positively or negatively regulated by many modulators to maintain host immune homeostasis.

View Article and Find Full Text PDF

Fas-associated factor 1 is a death-promoting protein that induces apoptosis by interacting with the Fas receptor. Until now, FAF1 was reported to interact potentially with diverse proteins and to function as a negative and/or positive regulator of several cellular possesses. However, the role of FAF1 in defense against bacterial infection remains unclear.

View Article and Find Full Text PDF

The herbs and have been commonly used for centuries in indigenous and folk medicine in tropical and subtropical regions of the world. In this study, we show that extracts from these herbs have antiviral effects against the respiratory syncytial virus (RSV) in vitro cell cultures and an in vivo mouse model. Treatment of HEp2 cells and A549 cells with a non-cytotoxic concentration of or extract significantly reduced RSV replication, RSV-induced cell death, RSV gene transcription, RSV protein synthesis, and also blocked syncytia formation.

View Article and Find Full Text PDF

Small heterodimer partner (SHP) is an orphan nuclear receptor that acts as a transcriptional co-repressor by interacting with nuclear receptors and transcription factors. Although SHP plays a negative regulatory function in various signaling pathways, its role in virus infection has not been studied. Here, we report that SHP is a potent negative regulator of the virus-mediated type I IFN signaling that maintains homeostasis within the antiviral innate immune system.

View Article and Find Full Text PDF

Tryptophanyl-tRNA synthetase (WRS) is one of the aminoacyl-tRNA synthetases (ARSs) that possesses noncanonical functions. Full-length WRS is released during bacterial infection and primes the Toll-like receptor 4 (TLR4)-myeloid differentiation factor 2 (MD2) complex to elicit innate immune responses. However, the role of WRS in viral infection remains unknown.

View Article and Find Full Text PDF

Purpose: Lower urinary tract symptoms (LUTS) can be distressing and socially isolating, and the economic impact can be substantial. Further data to characterize the epidemiology and effects of LUTS in South Korea would be beneficial.

Materials And Methods: In an international, internet-based survey, the prevalence and impact of LUTS was evaluated in adults aged ≥40 years.

View Article and Find Full Text PDF

Enterovirus 71 (EV71) is the major causative agent of hand-foot-and-mouth disease (HFMD) and many neurological manifestations. Recently, this virus has become a serious concern because of consecutive epidemics in the Asia-Pacific region. However, no effective vaccine for EV71 has been discovered except two EV71 vaccines which are being used in local communities of China.

View Article and Find Full Text PDF

Dense granule protein-7 (GRA-7) is an excretory protein of Toxoplasma gondii. It is a potential serodiagnostic marker and vaccine candidate for toxoplasmosis. Previous reports demonstrated that GRA-7 induces innate immune responses in macrophages by interacting with TRAF6 via the MyD88-dependent pathway.

View Article and Find Full Text PDF

The antiviral activities of synthesized Kα2-helix peptide, which was derived from the viral FLICE-like inhibitor protein (vFLIP) of Kaposi's sarcoma-associated herpesvirus (KSHV), against influenza A virus (IAV) were investigated in vitro and in vivo, and mechanisms of action were suggested. In addition to the robust autophagy activity of the Kα2-helix peptide, the present study showed that treatment with the Kα2 peptide fused with the TAT peptide significantly inhibited IAV replication and transmission. Moreover, TAT-Kα2 peptide protected the mice, that were challenged with lethal doses of highly pathogenic influenza A H5N1 or H1N1 viruses.

View Article and Find Full Text PDF

FAS-associated factor-1 (FAF1) is a component of the death-inducing signaling complex involved in Fas-mediated apoptosis. It regulates NF-κB activity, ubiquitination, and proteasomal degradation. Here, we found that FAF1 positively regulates the type I interferon pathway.

View Article and Find Full Text PDF

Rubicon is part of a Beclin-1-Vps34-containing autophagy complex. Rubicon induces antimicrobial responses upon Toll-like receptor (TLR) stimulation and functions as a feedback inhibitor to prevent unbalanced proinflammatory responses depending on dectin-1 signaling. However, the role played by Rubicon during antiviral immune responses, particularly the type I interferon (IFN) responses, remains largely unknown.

View Article and Find Full Text PDF

Bee venom (BV) from honey bee (Apis Melifera L.) contains at least 18 pharmacologically active components including melittin (MLT), phospholipase A (PLA), and apamin etc. BV is safe for human treatments dose dependently and proven to possess different healing properties including antibacterial and antiparasitidal properties.

View Article and Find Full Text PDF

The mammalian cytoplasmic multi-tRNA synthetase complex (MSC) is a depot system that regulates non-translational cellular functions. Here we found that the MSC component glutamyl-prolyl-tRNA synthetase (EPRS) switched its function following viral infection and exhibited potent antiviral activity. Infection-specific phosphorylation of EPRS at Ser990 induced its dissociation from the MSC, after which it was guided to the antiviral signaling pathway, where it interacted with PCBP2, a negative regulator of mitochondrial antiviral signaling protein (MAVS) that is critical for antiviral immunity.

View Article and Find Full Text PDF

RIG-I is a key cytosolic sensor that detects RNA viruses through its C-terminal region and activates the production of antiviral interferons (IFNs) and proinflammatory cytokines. While posttranslational modification has been demonstrated to regulate RIG-I signaling activity, its significance for the sensing of viral RNAs remains unclear. Here, we first show that the RIG-I C-terminal region undergoes deacetylation to regulate its viral RNA-sensing activity and that the HDAC6-mediated deacetylation of RIG-I is critical for viral RNA detection.

View Article and Find Full Text PDF