Yong Woo Jung

Background: Tuberculosis (TB), caused by Mycobacterium tuberculosis ( M.tb ), remains a major public health problem worldwide. The development of effective drugs and vaccines remains crucial but the prolonged culture period of M.tb hampers this process. This limitation has been addressed by developing a bioluminescent M.tb strain that can be used to measure bacterial burden in live animals non-invasively and in real time. We investigated whether bioluminescence real-time imaging technologies could be used to monitor the infection process in live mice, with the aim of facilitating TB research. Methods: In this study, we constructed bioluminescence-expressing M.tb strains. We compared the growth of these recombinant reporter and wild-type (WT) strains to confirm their stability in vitro. BALB/c mice were infected via intranasal or intravenous routes and monitored using an In Vivo Imaging System. The efficacy of isoniazid treatment was assessed using bioluminescence imaging and confirmed using colony-forming unit (CFU) assays. In a separate experiment, BCG-vaccinated and naïve control mice were infected with M.tb L5-Lux, a recombinant strain that expresses luxCDABE under the L5 promoter derived from the L5 mycobacteriophage. Vaccine efficacy was assessed by comparing bioluminescence and CFU counts. Results: The M.tb L5-Lux strain showed stable growth and a strong bioluminescent signal comparable to the WT strain. In both infection models, bioluminescence intensity strongly correlated with bacterial load. Isoniazid treatment led to a significant reduction in luminescence and CFU. In the vaccine study, BCG-vaccinated mice exhibited lower in vivo and ex vivo bioluminescence and approximately 0.5 log₁₀ lower CFU counts than naïve controls, demonstrating the utility of the M.tb L5-Lux strain for vaccine efficacy assessment. Conclusions: The M.tb L5-Lux bioluminescent reporter strain provides a sensitive and efficient tool for monitoring M.tb infection and evaluating anti-TB drug and vaccine efficacy in real time. This imaging-based platform facilitates faster and more ethical preclinical testing by reducing the number of animals and experimental duration.

Background/Objectives: Tuberculosis (TB) remains a major global health challenge, and the Bacillus Calmette–Guérin (BCG) vaccine has limited efficacy against adult pulmonary disease. Protein subunit vaccines are a promising alternative but require strong adjuvants to induce cell-mediated immunity. Synthetic agonists targeting toll-like receptor 4 (TLR4) and stimulators of interferon genes (STINGs) have emerged as effective immunostimulants. Therefore, we aimed to evaluate the immunogenicity and protective efficacy of Ag85B-based subunit vaccines formulated with synthetic TLR4 and STING agonists in a BCG-boosted mouse model. Methods: Three synthetic adjuvants—QTP709-1, QTP709-3, and QTP701—were formulated as oil-in-water emulsions containing distinct surfactant and immunostimulant components. The potential of vaccine formulations to activate dendritic cells (DCs) and elicit Ag85B-specific immune responses, including IgG subclass levels, interferon-γ (IFN-γ) enzyme-linked immunosorbent spots, and polyfunctional T-cell responses, was assessed by flow cytometry. Protective efficacy was evaluated based on pulmonary bacterial burden and histopathology following Mycobacterium tuberculosis (M. tb) Erdman challenge. Results: All formulations promoted DC maturation and enhanced antigen-specific immune responses. Each adjuvant elicited strong Ag85B-specific humoral immunity, increased IFN-γ secretion, and polyfunctional CD4⁺ and CD8⁺ T cells co-producing IFN-γ, TNF-α, and interleukin-2. Among them, QTP709-1 was associated with increased levels of chemokine receptor 5-associated chemokines and showed a trend toward reduced lung bacterial burden and histopathological inflammation following M. tb challenge. Conclusions: Synthetic TLR4 and STING agonists were associated with enhanced immunogenicity of TB subunit vaccines and showed evidence of protective potential, with TLR4-based formulations exhibiting more pronounced immunological responses. QTP709-1 exhibited strong immunostimulatory and protective effects, supporting its potential as a candidate adjuvant for next-generation TB vaccines.

GATA-3 serves as a key transcription factor driving Th2 cell differentiation and allergic cytokine production. Identifying the natural modulators of GATA-3 could provide therapeutic opportunities for the regulation of allergic responses. This study aimed to identify Vitis amurensis-derived natural products with strong GATA-3 inhibition and to elucidate their binding modes and mechanisms of action. The DNA-binding domain 2 (DBD2) of human GATA-3 was analyzed by using NMR spectroscopy, including backbone assignment. Isolated natural compounds were screened for binding activity, followed by reporter gene assays to evaluate the transcriptional inhibition potential. Two-dimensional NMR and docking studies were conducted to characterize binding interactions and identify binding sites. Stilbenoids from V. amurensis showed specific binding to the DNA-binding domain of GATA-3, as detected by 2D NMR. Reporter gene assays revealed dose-dependent transcriptional inhibition by these compounds. One of the hit compounds, KUP149, exhibited two binding modes on DBD2 based on NMR data, both of which can disrupt GATA-3-DNA interactions. These findings suggest stilbene-based natural products as potential inhibitors of allergic immune responses via GATA-3 modulation.

Choi H, et al. Immune Netw. 2023 Feb;23(1):e10. https://doi.org/10.4110/in.2023.23.e10

Jung YW, et al. Immune Netw. 2023 Feb;23(1):e1. https://doi.org/10.4110/in.2023.23.e1

Memory T cells, which are generated after the primary immune response to cognate antigens, possess unique features compared to naïve or effector T cells. These memory T cells are maintained for a long period of time and robustly reactivate in lymphoid or peripheral tissues where they re-encounter antigens. Environments surrounding memory T cells are importantly involved in the process of the maintenance and reactivation of these T cells. Although memory T cells are generally believed to be formed in response to acute infections, the pathogenesis and persistence of chronic inflammatory diseases, including allergic diseases, are also related to the effector functions of memory CD4 T cells. Thus, the factors involved in the homeostasis of allergen-specific memory CD4 T cells need to be understood to surmount these diseases. Here, we review the characteristics of allergen-specific memory CD4 T cells in allergic diseases and the importance of extrinsic factors for the homeostasis and reactivation of these T cells in the view of mediating persistence, recurrence, and aggravation of allergic diseases. Overall, this review provides a better understanding of memory CD4 T cells to devise effective therapeutic strategies for refractory chronic inflammatory diseases.

Introduction: Asthma is a chronic disease, characterized by reversible airway obstruction, hypersensitivity reactions, and inflammation. Oral corticosteroids are an important treatment option for patients with severe or steroid-resistant asthma. Biologics for asthma are recommended in patients with severe asthma, owing to their steroid-sparing effect as well as their ability to reduce the severity and aggravation of uncontrolled asthma. Most clinical trials of omalizumab in patients with asthma have suggested its tolerability and safety. However, some studies reported eosinophilic comorbidities in the ear, nose, and throat during omalizumab treatment, particularly eosinophilic otitis media. This study examined the relationship between ear disorders and omalizumab compared with that of other biologics for asthma using a large real-world database. Materials and Methods: Individual case safety reports from the Uppsala Monitoring Centre Vigibase of biologics for asthma (omalizumab, mepolizumab, reslizumab, benralizumab, and dupilumab) up to 29 December 2019, were used. A disproportionality analysis was performed using the proportional reporting ratio (PRR), reporting odds ratio (ROR), and information components (IC). A hierarchy analysis used the Medical Dictionary for Regulatory Activities Terminology. A tree map was generated using R studio version 4.2. Results: In 32,618 omalizumab reports, 714 adverse events (AEs) were detected as signals. Among the 714 signals, seventeen AEs were detected as signals of omalizumab-related ear and labyrinth disorders in 394 reports. Only three AEs (ear pain, ear disorder, and ear discomfort) were detected from mepolizumab. No signal was detected from reslizumab, benralizumab, and dupilumab. Conclusions: Careful monitoring of ear disorders is recommended when omalizumab treatment is started, with decreased oral corticosteroid use in patients with severe asthma. Further studies are necessary to confirm the omalizumab-related signals.

Kyong Hoon Kim, Aryeong Choi, Sang Hoon Kim, Heonju Song, Seohoon Jin, Kyungim Kim, Jaebong Jang, Hanbyeul Choi, and Yong Woo Jung. Mol. Cells 2021;44:795-804. https://doi.org/10.14348/molcells.2021.0137

Baicalein (5,6,7-trihydroxy-2-phenyl-4H-1-benzopyran-4-one), a flavonoid analog from Scutellaria baicalensis, possesses several pharmacological activities including antioxidant, antiproliferative, and anti-inflammatory activities. We previously reported that baicalein inhibits the thymic stromal lymphopoietin (TSLP)/TSLP receptor (TSLPR) signaling pathways and can be used as an active ingredient in the treatment of asthma and atopic dermatitis. However, baicalein is rapidly metabolized to baicalin and baicalein-6-O-glucuronide in vivo, which limits its preclinical and clinical use. In this study, we designed, synthesized, and evaluated baicalein prodrugs that protect the OH group at the 7-position of the A ring in baicalein with the amino acid carbamate functional group. Comprehensive in vitro and in vivo studies identified compound 2 as a baicalein prodrug candidate that improved the plasma exposure of baicalein in mouse animal studies. Our results demonstrated that this prodrug approach could be further adopted to discover oral baicalein prodrugs.