Seung-Hyo Lee

Designed Nanocage Displaying Ligand-Specific Peptide Bunches for High Affinity and Biological Activity

Protein-cage nanoparticles are promising multifunctional platforms for targeted delivery of imaging and therapeutic agents owing to their biocompatibility, biodegradability, and low toxicity. The major advantage of protein-cage nanoparticles is the ability to decorate their surfaces with multiple functionalities through genetic and chemical modification to achieve desired properties for therapeutic and/or diagnostic purposes. Specific peptides identified by phage display can be genetically fused onto the surface of cage proteins to promote the association of nanoparticles with a particular cell type or tissue. Upon symmetrical assembly of the cage, peptides are clustered on the surface of the cage protein in bunches. The resulting PBNC (peptide bunches on nanocage) offers the potential of synergistically increasing the avidity of the peptide ligands, thereby enhancing their blocking ability for therapeutic purposes. Here, we demonstrated a proof-of-principle of PBNCs, fusing the interleukin-4 receptor (IL-4R)-targeting peptide, AP-1, identified previously by phage display, with ferritin-L-chain (FTL), which undergoes 24-subunit assembly to form highly stable AP-1-containing nanocage proteins (AP1-PBNCs). AP1-PBNCs bound specifically to the IL-4R-expressing cell line, A549, and their binding and internalization were specifically blocked by anti-IL-4R antibody. AP1-PBNCs exhibited dramatically enhanced binding avidity to IL-4R compared with AP-1 peptide, measured by surface plasmon resonance spectroscopy. Furthermore, treatment with AP1-PBNCs in a murine model of experimental asthma diminished airway hyper-responsiveness and eosinophilic airway inflammation along with decreased mucus hyperproduction. These findings hold great promise for the application of various PBNCs with ligand-specific peptides in therapeutics for different diseases, such as cancer.

TH2 cells and their cytokines regulate formation and function of lymphatic vessels.

Lymphatic vessels (LVs) are critical for immune surveillance and involved in the pathogenesis of diverse diseases. LV density is increased during inflammation; however, little is known about how the resolution of LVs is controlled in different inflammatory conditions. Here we show the negative effects of T helper type 2 (TH2) cells and their cytokines on LV formation. IL-4 and IL-13 downregulate essential transcription factors of lymphatic endothelial cells (LECs) and inhibit tube formation. Co-culture of LECs with TH2 cells also inhibits tube formation, but this effect is fully reversed by interleukin (IL)-4 and/or IL-13 neutralization. Furthermore, the in vivo blockade of IL-4 and/or IL-13 in an asthma model not only increases the density but also enhances the function of lung LVs. These results demonstrate an anti-lymphangiogenic function of TH2 cells and their cytokines, suggesting a potential usefulness of IL-4 and/or IL-13 antagonist as therapeutic agents for allergic asthma through expanding LV mediated-enhanced antigen clearance from the inflammatory sites.

Innate type 2 immunity is associated with eosinophilic pleural effusion in primary spontaneous pneumothorax.

RATIONALE Eosinophilic pleural effusion (EPE) is characterized by greater than 10% eosinophilia and is frequently associated with air and/or blood in the pleural cavity. Primary spontaneous pneumothorax (PSP), defined as the spontaneous presence of air in the pleural space, is one of the most common causes of EPE. Recent studies have shown that type 2 immune responses play important roles in eosinophilic airway inflammation resulting in pleural pathology. OBJECTIVES To determine the predominant immune responses associated with PSP in humans, and to examine whether IL-33, thymic stromal lymphopoietin (TSLP), or type 2 innate lymphoid cell (ILC2)-mediated immune responses are associated factors. METHODS Eosinophil-associated cytokines were measured in the pleural fluid of patients with PSP and control subjects. Th2 cell and ILC2 responses in the pleural cavity and peripheral blood were also evaluated by in vitro restimulation and intracellular cytokine staining of T cells and ILC2s in patients with PSP (n = 62) and control subjects (n = 33). IL-33-mediated IL-5 production by ILC2s was also evaluated. MEASUREMENTS AND MAIN RESULTS Significantly higher concentrations of IL-5 and eotaxin-3 were detected in the pleural fluid of patients with PSP, in addition to significantly higher concentrations of IL-33 and TSLP. Although IL-5 production was induced by IL-33 treatment of ILC2s, other Th2 cell-mediated immune responses were not detected. CONCLUSIONS Our results indicate that innate immune responses characterized by the production of IL-33, TSLP, and IL-5 are associated with the development of EPE in PSP by an ILC2-dependent and Th2-independent mechanism.

Cigarette smoke exacerbates mouse allergic asthma through Smad proteins expressed in mast cells

BackgroundMany studies have found that smoking reduces lung function, but the relationship between cigarette smoke and allergic asthma has not been clearly elucidated, particularly the role of mast cells. This study aimed to investigate the effects of smoke exposure on allergic asthma and its association with mast cells.MethodsBALB/c mice were sensitized and challenged by OVA to induce asthma, and bone marrow-derived mast cells (BMMCs) were stimulated with antigen/antibody reaction. Mice or BMMCs were exposed to cigarette smoke or CSE solution for 1 mo or 6 h, respectively. The recruitment of inflammatory cells into BAL fluid or lung tissues was determined by Diff-Quik or H&E staining, collagen deposition by Sircol assay, penh values by a whole-body plethysmography, co-localization of tryptase and Smad3 by immunohistochemistry, IgE and TGF-β level by ELISA, expressions of Smads proteins, activities of signaling molecules, or TGF-β mRNA by immunoblotting and RT-PCR.ResultsCigarette smoke enhanced OVA-specific IgE levels, penh values, recruitment of inflammatory cells including mast cells, expressions of smad family, TGF-β mRNA and proteins, and cytokines, phosphorylations of Smad2 and 3, and MAP kinases, co-localization of tryptase and Smad3, and collagen deposition more than those of BAL cells and lung tissues of OVA-induced allergic mice. CSE solution pretreatment enhanced expressions of TGF-β, Smad3, activities of MAP kinases, NF-κB/AP-1 or PAI-1 more than those of activated-BMMCs.ConclusionsThe data suggest that smoke exposure enhances antigen-induced mast cell activation via TGF-β/Smad signaling pathways in mouse allergic asthma, and that it exacerbates airway inflammation and remodeling.

Developmental Control of Integrin Expression Regulates Th2 Effector Homing

Integrin CD18, a component of the LFA-1 complex that also includes CD11a, is essential for Th2, but not Th1, cell homing, but the explanation for this phenomenon remains obscure. In this study, we investigate the mechanism by which Th2 effector responses require the LFA-1 complex. CD11a-deficient T cells showed normal in vitro differentiation and function. However, Th2 cell-dependent allergic lung disease was markedly reduced in CD11a null mice and wild-type mice given LFA-1 inhibitors, whereas control of infection with Leishmania major, a Th1-dependent response, was enhanced. In both disease models, recruitment of IL-4-, but not IFN-γ-secreting cells to relevant organs was impaired, as was adhesion of Th2 cells in vitro. These diverse findings were explained by the markedly reduced expression of CD29, an alternate homing integrin, on Th2, but not Th1, cells, which precludes Th2 homing in the absence of CD11a. Thus, murine Th1 and Th2 cells use distinct integrins for homing, suggesting novel opportunities for integrin-based therapeutic intervention in diverse human ailments influenced by Th2 cells.

Role of Th17 Cell and Autoimmunity in Chronic Obstructive Pulmonary Disease

The molecular mechanisms involved in the pathogenesis of chronic obstructive pulmonary disease (COPD) are poorly defined. Accumulating evidences indicate that chronic inflammatory responses and adaptive immunity play important roles in the development and progression of the disease. Recently, it has been shown that IL-17 producing CD4 T cells, named Th17 cells, which have been implicated in the pathogenesis of several inflammatory and autoimmune diseases, are involved in airway inflammation and COPD. In addition, we and others suggest that autoimmunity may play a critical role in the pathogenesis of COPD. Here, we will review the current understanding of roles of Th17 cells and autoimmune responses in COPD.

Interplay between Inflammatory Responses and Lymphatic Vessels

Lymphatic vessels are routes for leukocyte migration and fluid drainage. In addition to their passive roles in migration of leukocytes, increasing evidence indicates their active roles in immune regulation. Tissue inflammation rapidly induces lymphatic endothelial cell proliferation and chemokine production, thereby resulting in lymphangiogenesis. Furthermore, lymphatic endothelial cells induce T cell tolerance through various mechanisms. In this review, we focus on the current knowledge on how inflammatory cytokines affect lymphangiogenesis and the roles of lymphatic vessels in modulating immune responses.

CD53, a suppressor of inflammatory cytokine production, is associated with population asthma risk via the functional promoter polymorphism -1560 C>T.

BACKGROUND In this study, the association of asthma with CD53, a member of the tetraspanin family, was assessed for the first time in a mechanism-based study. METHODS Genetic polymorphisms of CD53 were analyzed in 591 subjects and confirmed in a replication study of 1001 subjects. CD53 mRNA and protein levels were measured in peripheral blood leukocytes, and the effects of the promoter polymorphisms on nuclear factor binding were examined by electrophoretic mobility shift assay. Cellular functional studies were conducted by siRNA transfections. RESULTS Among tagging SNPs of CD53, the -1560 C>T in the promoter region was significantly associated with asthma risk. Compared with the CC genotype, the CT and TT genotypes were associated with a higher asthma risk, with odd ratios of 1.74 (P=0.009) and 2.03 (P=0.004), respectively. These findings were confirmed in the replication study with odd ratios of 1.355 (P=0.047) and 1.495 (P=0.039), respectively. The -1560 C>T promoter SNP had functional effects on nuclear protein binding as well as mRNA and protein expression levels in peripheral blood leukocytes. When CD53 was knocked down by siRNA in THP-1 human monocytic cells stimulated with house dust mite, the production of inflammatory cytokines as well as NFκB activity was significantly over-activated, suggesting that CD53 suppresses over-activation of inflammatory responses. CONCLUSIONS The -1560 C>T SNP is a functional promoter polymorphism that is significantly associated with population asthma risk, and is thought to act by directly modulating nuclear protein binding, thereby altering the expression of CD53, a suppressor of inflammatory cytokine production.

Serum Elastin-Derived Peptides and Anti-Elastin Antibody in Patients with Systemic Sclerosis

The elastin metabolism in systemic sclerosis (SSc) has been known to be abnormal. The authors investigated relationship between the clinical manifestations of systemic sclerosis (SSc) and serum levels of soluble elastin-derived peptide (S-EDP) and anti-elastin antibodies. Serum samples were obtained from 79 patients with SSc and 79 age- and sex-matched healthy controls. Concentrations of serum S-EDP and anti-elastin antibodies were measured by ELISA. The serum concentrations of S-EDP in SSc patients were significantly higher than in healthy controls (median, 144.44 ng/mL vs 79.59 ng/mL, P < 0.001). Serum EDP concentrations were found to be correlated with disease duration in SSc (P = 0.002) and particularly in diffuse cutaneous SSc (P = 0.005). Levels of anti-elastin antibodies were found to be more elevated in SSc patients than in healthy controls (median, 0.222 U vs 0.191 U, P = 0.049), more increased in diffuse cutaneous SSc than limited cutaneous SSc (median, 0.368 U vs 0.204 U, P = 0.031). In addition, levels of anti-elastin antibodies were also found to be negatively associated with presence of anti-centromere antibody (P = 0.023). The S-EDP levels were not found to be correlated with levels of anti-elastin antibodies. The increased S-EDP and anti-elastin antibody levels and association with clinical and laboratory characteristics may reflect the abnormal metabolism in SSc.

Prediction of drug-induced immune-mediated hepatotoxicity using hepatocyte-like cells derived from human embryonic stem cells

Drug-induced liver injury (DILI) is a leading cause of liver disease and a key safety factor during drug development. In addition to the initiation events of drug-specific hepatotoxicity, dysregulated immune responses have been proposed as major pathological events of DILI. Thus, there is a need for a reliable cell culture model with which to assess drug-induced immune reactions to predict hepatotoxicity for drug development. To this end, stem cell-derived hepatocytes have shown great potentials. Here we report that hepatocyte-like cells derived from human embryonic stem cells (hES-HLCs) can be used to evaluate drug-induced hepatotoxic immunological events. Treatment with acetaminophen significantly elevated the levels of inflammatory cytokines by hES-HLCs. Moreover, three human immune cell lines, Jurkat, THP-1, and NK92MI, were activated when cultured in conditioned medium obtained from acetaminophen-treated hES-HLCs. To further validate, we tested thiazolidinedione (TZD) class, antidiabetic drugs, including troglitazone withdrawn from the market because of severe idiosyncratic drug hepatotoxicity. We found that TZD drug treatment to hES-HLCs resulted in the production of pro-inflammatory cytokines and eventually associated immune cell activation. In summary, our study demonstrates for the first time the potential of hES-HLCs as an in vitro model system for assessment of drug-induced as well as immune-mediated hepatotoxicity.