Publications by authors named "In-Hak Choi"

35 Publications

Association between allergic rhinitis-related factors and sleep duration in adolescents: Korea National Health and Nutrition Examination Survey V (2010-2012).

Int J Pediatr Otorhinolaryngol 2021 Mar 4;142:110613. Epub 2021 Jan 4.

Department of Otorhinolaryngology-Head & Neck Surgery, College of Medicine, Korea University, Seoul, 02841, Republic of Korea. Electronic address:

Objectives: Previous studies have shown that sleep and allergic rhinitis (AR) is closely associated, bidirectionally affecting each other. Adolescence is a period that adequate sleep is essential, and the burden of AR increases, both of which greatly affect the quality of life. The aim of the present study was to investigate the correlation between inappropriate sleep duration and each AR-related subjective/objective factor in Korean adolescents.

Methods: We analyzed the data of 1936 adolescents aged between 12 and 18 years who participated in the Korea National Health and Nutrition Examination Survey from 2010 to 2012. Data on sleep duration, physician-diagnosed AR, and presence of rhinitis symptoms were collected using a self-administered questionnaire. Nasal endoscopic findings, including watery rhinorrhea and pale inferior turbinate mucosa, and aeroallergen sensitization based on serum specific immunoglobulin E levels were examined.

Results: There was a higher prevalence of AR (23.68%) in the inappropriate sleep duration group than in the control group (16.56%; odds ratio = 1.56, p = 0.0024). The presence of endoscopic findings of AR showed a positive association with inappropriate sleep duration in males (odds ratio = 1.52, p = 0.008). In addition, in all three indoor allergens investigated, aeroallergen sensitization was not associated with inappropriate sleep duration.

Conclusion: Inappropriate sleep duration was associated with increased prevalence of AR in Korean adolescents. Especially, this association was relevant in nasal endoscopic findings in male.
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http://dx.doi.org/10.1016/j.ijporl.2021.110613DOI Listing
March 2021

The clinical significance of HERV-H LTR -associating 2 expression in cervical adenocarcinoma.

Medicine (Baltimore) 2021 Jan;100(1):e23691

Department of Obstetrics and Gynecology, Inje University, College of Medicine, Busan Paik Hospital.

Abstract: HERV-H LTR -associating 2 (HHLA2) is a recently discovered member of the B7-family of immune checkpoint molecules that is overexpressed in several types of cancer. The aim of the present study was to investigate the expression of HHLA2 in cervical adenocarcinoma (AC) and the relationship between its expression and clinicopathological factors to assess its use as a potential marker for AC prognosis.This study included 76 patients diagnosed with cervical AC. Their resected specimens were obtained and a tissue microarray was constructed. Expression of HHLA2 was detected by the immunohistochemistry. Based on the follow-up data, correlation of HHLA2 expression and clinicopathological features, including overall survival (OS) and disease-free survival, was evaluated. Furthermore, we investigated the correlation between the expression of HHLA2 and programmed death ligand 1 (PD-L1).A total of 76 cases of invasive cervical AC were evaluated. High HHLA2 expression was detected in 62 cases (81.6%) and low HHLA2 expression was presented in 14 cases (18.4%). HHLA2 expression showed a significant negative correlation with lymph node metastasis (P = .011). Disease free survival was 75.0% and 49.0% in high-expression and the low expression group, respectively (P = .057). Although there was no statistical significance, an improved OS was observed in the high expression group (83.1% vs 64.9%, P = .479). Further, the expression of HHLA2 and PD-L1 correlated positively (P = .005). Thus, an improved OS was observed in the PD-L1 expression group (90.7% vs 66.2%, P = .037).High expression of HHLA2 is related to tumor progression and prognosis in patients with cervical AC. Therefore, HHLA2 may be a potential biomarker for predicting prognosis of cervical AC.
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http://dx.doi.org/10.1097/MD.0000000000023691DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7793359PMC
January 2021

Association of Cotinine-Verified Cigarette Exposure with Chronic Rhinosinusitis in Korean Adults.

Int J Environ Res Public Health 2020 11 9;17(21). Epub 2020 Nov 9.

Department of Otorhinolaryngology-Head & Neck Surgery, College of Medicine, Korea University, Seoul 02841, Korea.

Chronic rhinosinusitis is known to be influenced by cigarette exposure; however, this relationship is based on the presence of nasal polyps, and objective measurements of cigarette exposure in chronic rhinosinusitis are not well established. This study aimed to estimate the association between chronic rhinosinusitis and smoking status based on self-reported questionnaires and urinary cotinine levels according to the presence of nasal polyps. We analyzed a total of 23,621 participants who participated from the fifth Korea National Health and Nutrition Examination Survey (2010-2012). Serum total and specific IgE level were measured. Higher prevalence of chronic rhinosinusitis with nasal polyps was associated with current smoking status (OR = 1.43, 95% CI = 1.00-2.03). This association was prevalent in participants aged ≤ 50 years (OR = 1.76, 95% CI = 1.01-3.05), and higher urinary cotinine level showed correlation with higher prevalence of chronic rhinosinusitis with nasal polyps in this age group (OR = 1.04, 95% CI = 1.00-1.08). In addition, positive correlation between serum total IgE and urinary cotinine levels was greater in patients with chronic rhinosinusitis (β = 0.493, 95% CI = 0.071-0.916) than in controls (β = 0.062, 95% CI = 0.021-0.103). Aggressive smoking interventions should be performed in patients with chronic rhinosinusitis with nasal polyp, especially in cases of young adults or high serum IgE levels.
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http://dx.doi.org/10.3390/ijerph17218291DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7665152PMC
November 2020

Association between subjective olfactory dysfunction and female hormone-related factors in South Korea.

Sci Rep 2019 12 27;9(1):20007. Epub 2019 Dec 27.

Department of Otorhinolaryngology-Head & Neck Surgery, College of Medicine, Korea University, Seoul, Korea.

An association between olfactory dysfunction and female hormone level has been reported; however, no previous studies have investigated the correlation with life-long female hormone exposure. The aim of this study was to estimate the association between subjective olfactory dysfunction and various endogenous and exogenous female hormone-related factors including age at menarche and menopause, number of pregnancies and deliveries, age at first and last delivery, duration of breastfeeding, use of oral contraceptives, and use of hormone therapy. The study analysed a total of 3863 female participants using data from the Korean National Health and Nutrition Examination Survey V (2010-2012). The prevalence of olfactory dysfunction was 3.5% for premenopausal participants and 6.2% for postmenopausal women. Among premenopausal women (compared to women breastfed less than 12 months), the 12-24-month group (OR = 4.690, 95% CI = 1.431-15.369) and the 25-48-month group (OR = 6.548, 95% CI = 1.758-24.394) had higher rates of olfactory dysfunction. In postmenopausal women, starting menopause at a younger age was positively associated with olfactory dysfunction (OR = 0.939, 95% CI = 0.887-0.993). These data suggest that a longer duration of endogenous oestrogen deprivation is associated with subjective olfactory dysfunction.
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http://dx.doi.org/10.1038/s41598-019-56565-xDOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6934502PMC
December 2019

Psychiatric Distress as a Common Risk Factor for Tinnitus and Joint Pain: A National Population-Based Survey.

Clin Exp Otorhinolaryngol 2020 Aug 18;13(3):234-240. Epub 2019 Dec 18.

Department of Otolaryngology-Head and Neck Surgery, Korea University College of Medicine, Seoul, Korea.

Objectives: This study aimed to investigate the relationship between tinnitus and joint pain from representative samples of Koreans.

Methods: The demographics and the responses to a questionnaire about tinnitus and joint pain severity and mental health status of adults aged ≥50 years in the 2010-2012 Korean National Health and Nutrition Examination Survey were analyzed.

Results: Among 9,032 individuals, 26.7% reported experiencing tinnitus within the past year. Participants with tinnitus were more frequently older, hearing loss, and had lower education levels, income, and body weight. Participants with regular exercise and sleep had a lower tinnitus prevalence. The incidences of stress, depressed mood, and suicidal ideation were significantly higher in the tinnitus group and participants with joint pain. The rates of participants with tinnitus according to the number of joint pain sites (zero, one, two, and three) was 22.1%, 31.4%, 33.3%, and 44.2%, and those of participants with severely annoying tinnitus according to the number of joint pain sites (zero, one, two, and three) were 3.3%, 6.8%, 7.9%, and 10.7%, respectively.

Conclusion: Tinnitus prevalence and severity were significantly related to joint pain, and both conditions were related to psychiatric distress. Thus, the authors suggest that psychiatric distress as a common risk factor for tinnitus and joint pain should be considered when deciding treatment strategies and in guiding public health policy.
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http://dx.doi.org/10.21053/ceo.2019.00563DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7435435PMC
August 2020

The optimal and safe intensity for facial nerve stimulation during intraoperative neuromonitoring in middle ear surgery.

PLoS One 2019 29;14(8):e0221748. Epub 2019 Aug 29.

Department of Otolaryngology-Head and Neck Surgery, Korea University College of Medicine, Seoul, Republic of Korea.

Objective: This study aimed to investigate the optimal and safe intensity for facial nerve stimulation during middle ear surgery.

Methods: Thirty-seven patients who had their facial nerve exposed prior to surgery were prospectively enrolled in this study, and electromyography (EMG) recordings were obtained from the orbicularis oculi and orbicularis oris muscles. Four pigs were also enrolled in an animal study, and continuous stimulation was performed on the facial nerves of the pigs for 10 minutes. The EMG responses were measured and the pathologic outcomes of the facial nerve after stimulation were determined.

Results: In the human study, the mean intensity of the minimal electrical stimulation threshold was 0.21 mA (range: 0.1-0.3 mA). A linear correlation was observed between stimulus intensity and response amplitude for intensities below 0.4 mA. Response amplitudes reached a plateau between 0.4 mA and 1.0 mA. The minimal stimulus intensity that could generate a maximal response was 0.4 mA in the orbicularis oculi (244 μV) and orbicularis oris (545 μV). In the animal study, there were no observed changes in EMG or nerve damage incidence after the continuous stimulation of 3.0 mA.

Conclusions: 0.4 mA is considered to be the optimal intensity of facial nerve stimulation during middle ear surgery, and it was estimated through the animal study that a stimulation of 3.0 mA is safe from facial nerve damage.
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http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0221748PLOS
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6715191PMC
March 2020

Decreased expression of type I (IFN-β) and type III (IFN-λ) interferons and interferon-stimulated genes in patients with chronic rhinosinusitis with and without nasal polyps.

J Allergy Clin Immunol 2019 12 23;144(6):1551-1565.e2. Epub 2019 Aug 23.

Department of Otorhinolaryngology-Head & Neck Surgery, College of Medicine, Korea University, Seoul, Korea. Electronic address:

Background: Little is known about antiviral responses in the sinonasal mucosal tissue of patients with chronic rhinosinusitis (CRS).

Objective: we investigated the presence of virus and the expression of Toll-like receptor (TLR) 3, TLR7, and interferon and interferon-stimulated genes (ISGs) in healthy mucosal tissue of control subjects and the inflammatory sinus mucosal tissue of CRS patients, and evaluated whether levels of interferons and ISGs might be affected by CRS-related cytokines and by treatment with macrolides, dexamethasone, or TLR3 and TLR7 agonists.

Methods: The presence of virus in the sinonasal mucosa was evaluated with real-time PCR. The expression of interferons and ISGs in the sinonasal mucosa and in cultured epithelial cells treated with T1 and T2 cytokines, macrolides, dexamethasone, or TLR3 and TLR7 agonists were evaluated with real-time PCR and Western blotting. The expression of TLR3 and TLR7 in the sinonasal mucosa were evaluated with immunohistochemistry.

Results: Respiratory viruses were detected in 15% of samples. Interferons and ISGs are expressed in normal mucosa, but their levels were decreased in patients with CRS. Interferon and ISG levels were upregulated in cells treated with macrolides, dexamethasone, or TLR3 agonist, but some were decreased in cytokine-treated cells. TLR3 and TLR7 levels showed no significant difference between normal and inflammatory sinus mucosal tissue.

Conclusion: These results suggest that decreased levels of interferons and ISGs in patients with CRS might contribute to impairment of the antiviral innate response in inflammatory sinonasal epithelial cells. Macrolides and glucocorticoids might provide positive effects on the treatment of CRS by upregulating interferon and ISG expression.
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http://dx.doi.org/10.1016/j.jaci.2019.08.010DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7111475PMC
December 2019

Increased expression of interleukin 36 in chronic rhinosinusitis and its contribution to chemokine secretion and increased epithelial permeability.

Cytokine 2020 01 17;125:154798. Epub 2019 Aug 17.

Department of Otorhinolaryngology-Head & Neck Surgery, College of Medicine, Korea University, Seoul, South Korea. Electronic address:

Background: IL-36 family, a recently reported member of the IL-1 cytokine family, plays an essential role in nonspecific innate immune response to infection. This study aims at investigating the expression of IL-36 family members (α, β, and γ) in normal and inflammatory sinus mucosa of patients with chronic rhinosinusitis (CRS), their effects on chemokine secretion and on the barrier function of epithelial and endothelial cells, and the effect of Toll-like receptors on the expression of IL-36 in epithelial cells.

Material And Methods: The expression of IL-36 family in normal and inflammatory sinus mucosa, the production of chemokines or the expression levels of IL-36 family in epithelial cells treated with IL-36 family members or stimulated with TLR3, TLR4, TLR5, or TLR7/8 agonists were measured with real time PCR, ELISA, immunohistochemistry, or Western blot. The epithelial and endothelial permeability, and transendothelial leukocyte migration were investigated using cultured epithelial and endothelial cells.

Results: IL-36α, IL-36β, and IL-36γ were localized in epithelial cells of sinonasal mucosa. Their levels increased in inflammatory mucosa of CRS patients and are up-regulated by TLR3, TLR4, or TLR5 agonists. IL-36α, or IL-36γ induced CXCL1, CXCL2, and CXCL3 production. Epithelial and endothelial permeability, transendothelial leukocyte migration were increased in cells treated with IL-36α, IL-36β, or IL-36γ.

Conclusions: These results suggest that IL-36α, IL-36β, and IL-36γ localized in superficial epithelium may act as a responder to microbial and nonmicrobial elements through TLR and subsequently produce CXC chemokines, playing an interplay between innate and adaptive immune response.
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http://dx.doi.org/10.1016/j.cyto.2019.154798DOI Listing
January 2020

Association of Sinonasal Factors With Chronic Laryngitis in Korean Adults.

JAMA Otolaryngol Head Neck Surg 2019 Aug 15. Epub 2019 Aug 15.

Department of Otorhinolaryngology-Head & Neck Surgery, College of Medicine, Korea University, Seoul, Korea.

Importance: Allergic laryngitis is underdiagnosed owing to overlapping clinical manifestations that arise from other causes of laryngitis. Sinonasal conditions associated with chronic laryngitis, including allergic laryngitis, have not been reported using population-based epidemiologic data.

Objective: To estimate the association of the prevalence of chronic laryngitis with various sinonasal symptoms and endoscopic findings, and to identify which of the sinonasal factors are particularly associated with allergic cause of chronic laryngitis.

Design, Setting, And Participants: This cross-sectional, population-based study of 11 283 participants 18 years and older who had undergone laryngoscopic and nasal endoscopic examination used data from 2010 through 2012 in the fifth edition of the Korea National Health and Nutrition Examination Survey, a nationwide survey of South Korea. Participants were extracted by stratified, multistage, clustered sampling to comprise a nationally representative sample. Data were analyzed in September 2017.

Exposures: Sociodemographic characteristics, smoking status, alcohol use, questionnaires for voice change and sinonasal symptoms, and nasal endoscopic examinations before and after shrinkage of the nasal mucosa.

Main Outcomes And Measures: Chronic laryngitis diagnosed by laryngoscopic examination, and allergic cause of laryngitis determined by specific serum immunoglobulin E tests.

Results: Of the 11 283 participants included in the study, the mean (SD) age was 50.1 (16.6) years, and 6365 (56.4%) were women. In total, 343 participants (3.0%) were diagnosed with chronic laryngitis through results of laryngoscopic examination. Chronic laryngitis was associated with a higher rate of rhinitis symptoms (odds ratio [OR], 1.54; 95% CI, 1.21-1.96), anterior/posterior nasal drip (OR, 2.03; 95% CI, 1.38-2.98), nasal congestion (OR, 1.49; 95% CI, 0.99-2.25), endoscopic findings of pale mucosa (OR, 1.74; 95% CI, 1.33-2.28), mucous or puslike discharge (OR, 1.53; 95% CI, 1.08-2.18), and puslike discharge in the middle meatus (OR, 1.85; 95% CI, 1.19-2.88), especially in female participants and participants older than 50 years. Subgroup analysis revealed that all participants with allergic laryngitis showed sensitization to Dermatophagoides farinae, and the allergic laryngitis group (n = 9) had a higher presence of rhinitis symptoms (n = 5; 56%) than did the nonallergic laryngitis group (n = 1 of 12; 8%) among participants younger than 50 years (risk difference, 47%; 95% CI, 4%-78%).

Conclusions And Relevance: The association of various sinonasal factors with chronic laryngitis were prominent in female participants, as well as those 50 years and older. Nevertheless, the presence of rhinitis symptoms in patients with chronic laryngitis was associated with allergic cause of laryngitis solely in participants younger than 50 years. In young adults, presence of rhinitis symptoms might aid in considering allergic laryngitis.
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http://dx.doi.org/10.1001/jamaoto.2019.2134DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6696733PMC
August 2019

Clinical Analysis of Pediatric Thyroid Cancer: A Single Medical Institution Experience of 18 Years.

Ann Otol Rhinol Laryngol 2019 Dec 2;128(12):1152-1157. Epub 2019 Aug 2.

Department of Otorhinolaryngology-Head and Neck Surgery, Korea University College of Medicine, Seoul, Republic of Korea.

Objective: The incidence of pediatric thyroid cancer is relatively low compared to the disease in adults. This study aims to present the data in our institution on pediatric thyroid cancer patients, with particular emphasis on the risk factors of recurrence together with treatment outcomes.

Subjects And Methods: Between January 2000 and July 2018, patients <20 years who were diagnosed with thyroid carcinoma and primarily treated with surgery at a major large-volume tertiary medical center specializing in thyroid cancer were enrolled. A total of 83 patients were eligible for this study.

Results: The majority of the studied patients were girls and adolescents (age ≥13 years). Papillary thyroid carcinoma (PTC) was the most common pathology (n = 74). PTC tumors >1 cm showed higher rate of lymph node metastasis and extrathyroidal extension than tumors ≤1 cm. All patients survived with nine PTC patients who displayed treatment failure. Age, tumor size, multifocality, lateral lymph node metastasis, and postoperative thyroglobulin levels were significant prognosticators for disease recurrence.

Conclusion: Pediatric thyroid cancer is relatively rare and should be considered a specific disease entity with respect to the thyroid cancer in adults, since there are several distinctive characteristics.
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http://dx.doi.org/10.1177/0003489419868251DOI Listing
December 2019

Neutrophil extracellular traps in nasal secretions of patients with stable and exacerbated chronic rhinosinusitis and their contribution to induce chemokine secretion and strengthen the epithelial barrier.

Clin Exp Allergy 2019 10 12;49(10):1306-1320. Epub 2019 Jul 12.

Department of Otorhinolaryngology-Head & Neck Surgery, College of Medicine, Korea University, Seoul, South Korea.

Background: Neutrophil extracellular traps (NETs) participate in innate immunity by trapping microorganisms. Their pathophysiological implications have not been defined in chronic rhinosinusitis (CRS).

Objective: We investigated the presence of NETs in nasal secretion of patients with stable or exacerbated CRS and evaluated whether NETs participate in the secretion of chemokines in sinonasal epithelial cells, the epithelial permeability, and transendothelial leucocyte migration, and elucidate whether NETs are released by macrolides and dexamethasone.

Methods: The presence of NETs in nasal secretion and the release of NETs from neutrophils stimulated with macrolides or dexamethasone were evaluated by dsDNA Assay kit and fluorescence microscope. The chemokine secretion, epithelial permeability, and transendothelial leucocyte migration were measured in cultured cells incubated with NETs, the supernatant of unstimulated neutrophils (unstim), NETs inhibitor (DPI), or H3Cit, where the expression of junctional complex proteins and ICAM-1 was evaluated by real-time PCR, Western blots, and confocal microscope.

Results: The amount of NETs and NETs-forming neutrophils in nasal secretion increased in exacerbated CRS. Epithelial cells treated with NETs or H3Cit secreted chemokines and showed decreased permeability associated with up-regulated junctional complex proteins. Increased transendothelial leucocyte migration associated with up-regulated ICAM-1 was noted in endothelial cells treated with NETs or H3Cit. These findings were not found in cells treated with unstim, or DPI. NETs were released by macrolides, but not by dexamethasone.

Conclusions And Clinical Relevance: NETs formation increased in exacerbated CRS, inducing chemokine secretion, strengthening the epithelial barrier, and promoting the neutrophils infiltration. Therefore, the release of NETs in CRS might be beneficial or detrimental to CRS patients.
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http://dx.doi.org/10.1111/cea.13448DOI Listing
October 2019

The Significance of VSIG4 Expression in Ovarian Cancer.

Int J Gynecol Cancer 2017 06;27(5):872-878

*Department of Obstetrics and Gynecology, †Paik Institute for Clinical Research, ‡Department of Microbiology and Immunology, §Advanced Research Center for Multiple Myeloma, and ∥Department of Pathology, Busan Paik Hospital, Inje University College of Medicine, Busan, Republic of Korea.

Objectives: The protein V-set and Ig domain-containing 4 (VSIG4), a novel B7 family-related macrophage protein with the capacity to inhibit T-cell activation, has a potential role in cancer. Here we suggest its possibility as a therapeutic target and prognostic biomarker of ovarian cancer.

Methods: Between January 2011 and June 2015, tumor tissues and peripheral blood samples were obtained during surgery from 10 patients with benign ovarian tumors and 22 patients with ovarian cancers. Messenger RNA and protein expression levels of VSIG4 in benign tumor and cancer tissues were examined by the reverse transcription polymerase chain reaction and Western blot, respectively. Soluble VSIG4 concentrations were measured by an enzyme-linked immunosorbent assay. The correlation between VSIG4 expression and the prognosis of ovarian cancer was analyzed according to the patients' clinicopathologic characteristics.

Results: VSIG4 messenger RNA and protein expression levels in ovarian cancer tissues were higher than those in benign ovarian tumors (P = 0.0013 and 0.0001, respectively). Soluble VSIG4 concentrations were increased in patients with ovarian cancer compared with that in patients with benign ovarian tumors (P = 0.0452). Moreover, soluble VSIG4 levels were significantly increased in advanced-stage and recurrent ovarian cancer (P = 0.0244 and 0.0288, respectively). High VSIG4 expression of cancer tissue and low VSIG4 expression of plasma (soluble VSIG4) were associated with a longer disease-free interval (P = 0.0246 and 0.0398, respectively).

Conclusions: VSIG4 is overexpressed in ovarian cancers compared with that in benign tumors. This finding supports VSIG4 being used as a potential therapeutic target for ovarian cancer. Furthermore, soluble VSIG4 levels are associated with the progression and recurrence of ovarian cancer, indicating that soluble VSIG4 may be used as a potential biomarker for predicting tumor prognosis.
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http://dx.doi.org/10.1097/IGC.0000000000000979DOI Listing
June 2017

Pre-stimulation of CD81 expression by resting B cells increases proliferation following EBV infection, but the overexpression of CD81 induces the apoptosis of EBV-transformed B cells.

Int J Mol Med 2015 Dec 13;36(6):1464-78. Epub 2015 Oct 13.

Department of Anatomy and Research Center for Tumor Immunology, Inje University College of Medicine, Busan 614-735, Republic of Korea.

Hepatitis C virus (HCV) E2 protein binds to CD81, which is a component of the B cell co-stimulatory complex. The E2-CD81 interaction leads to B cell proliferation, protein tyrosine phosphorylation and to the hypermutation of immunoglobulin genes. Epidemiological studies have reported a high prevalence of B cell non-Hodgkin lymphoma (NHL) in HCV-positive patients, suggesting a potential association between HCV and Epstein-Barr virus (EBV) in the genesis of B lymphocyte proliferative disorders. In the present study, in order to investigate the association between EBV and HCV in B cells, we created an in vitro EBV-induced B cell transformation model. CD81 was gradually overexpressed during transformation by EBV. B cells isolated from HCV-positive patients grew more rapidly and clumped together earlier than B cells isolated from healthy donors following EBV infection. Pre-stimulation of CD81 expressed by resting B cells with anti-CD81 monoclonal antibody (mAb) or HCV E2 accelerated the generation of lymphoblastoid cell lines (LCLs) by EBV infection. These cells proliferated prominently through the early expression of interleukin-10 and intracellular latent membrane protein (LMP)-l. By contrast, the overexpression of CD81 on EBV-transformed B cells by anti-CD81 mAb or HCV E2 protein induced apoptosis through reactive oxygen species (ROS)-mediated mitochondrial dysfunction. These results suggest that the engagement of CD81 expressed by B cells has differential effects on B cell fate (proliferation or apoptosis) according to EBV infection and the expression level of CD81.
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http://dx.doi.org/10.3892/ijmm.2015.2372DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4678167PMC
December 2015

Circulating tumor cell microseparator based on lateral magnetophoresis and immunomagnetic nanobeads.

Anal Chem 2013 Mar 19;85(5):2779-86. Epub 2013 Feb 19.

Department of Nano Engineering, Center for Nano Manufacturing, Inje University, Gimhae 621-749, Republic of Korea.

This paper presents a circulating tumor cell (CTC) microseparator for isolation of CTCs from human peripheral blood using immunomagnetic nanobeads with bound antiepithelial cell adhesive molecule (EpCAM) antibodies that specifically bind to epithelial cancer cells. The isolation is performed through lateral magnetophoresis, which is induced by high-gradient magnetic separation technology, involving a ferromagnetic wire array inlaid in the bottom substrate of a microchannel. Experimental results showed that the CTC microseparator isolates about 90% of spiked CTCs in human peripheral blood at a flow rate of up to 5 mL/h and purifies to approximately 97%. The overall isolation procedure was completed within 15 min for 200 μL of peripheral blood. CTCs from peripheral blood of patients with breast and lung cancers were isolated with the CTC microseparator, and the results were compared with those of healthy donors. Using a fluorescence-based viability assay, the viability of CTCs isolated from peripheral blood of patients with cancer was observed. In addition, the usefulness of the CTC microseparator for subsequent genetic assay was confirmed by reverse-transcriptase polymerase chain reaction (RT-PCR) amplification of cancer-specific genes using CTCs isolated from patients with cancer.
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http://dx.doi.org/10.1021/ac303284uDOI Listing
March 2013

A high-speed, high-performance on-chip integrated reverse transcription (RT)-microchip.

Biomed Microdevices 2013 Feb;15(1):9-15

Department of Nano Engineering, Center for Nano Manufacturing, Inje University, 607 Obang-dong, Gimhae, GyongNam, 621-749, Republic of Korea.

This report introduces an on-chip integrated reverse transcription (RT)-microchip, which includes two genetic functionalities of RNA extraction and cDNA synthesis. In the RNA extraction compartment, RNA is extracted from peripheral blood lysate within 1 min, by lateral magnetophoresis using magnetic oligo-dT beads. The extracted RNA is then collected and used directly to produce cDNA in the cDNA synthesis microchamber, which is monolithically integrated with the RNA extraction compartment. To verify the superiority of the proposed RT-microchip, RT-PCR amplification was performed using cDNA harvested from the RT-microchip, and the results were compared with those obtained using typical RNA extraction methods such as a silica matrix column and magnetic oligo-dT beads. The RT-PCR amplification results using 100 μl of blood showed that the intensity of the bands in gel electrophoresis of the RT-microchip was 2-fold stronger than that of the silica matrix column and 2.65-fold stronger than that of the magnetic oligo-dT beads. The results demonstrate that the RT-microchip technique is the most sensitive of the tested methods.
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http://dx.doi.org/10.1007/s10544-012-9682-3DOI Listing
February 2013

PD-1 on dendritic cells impedes innate immunity against bacterial infection.

Blood 2009 Jun 1;113(23):5811-8. Epub 2009 Apr 1.

Department of Oncology and Institute for Cell Engineering, Johns Hopkins University School of Medicine, Baltimore, MD, USA.

Programmed death one (PD-1) is an inducible molecule belonging to the immunoglobulin superfamily. It is expressed on activated T and B lymphocytes and plays pivotal roles in the negative regulation of adaptive immune responses. We report here an unexpected finding: that PD-1 could also be induced on splenic dendritic cells (DCs) by various inflammatory stimuli. Adoptive transfer of PD-1-deficient DCs demonstrates their superior capacity to wild-type DCs in innate protection of mice against lethal infection by Listeria monocytogenes. Furthermore, PD-1-deficient mice are also more resistant to the infection than wild-type controls, even in the absence of T and B cells, accompanied by elevated production of DC-derived interleukin-12 and tumor necrosis factor-alpha. Our results reveal a novel role of PD-1 in the negative regulation of DC function during innate immune response.
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http://dx.doi.org/10.1182/blood-2009-02-203141DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2700320PMC
June 2009

Tetra-arsenic oxide (Tetras) enhances radiation sensitivity of solid tumors by anti-vascular effect.

Cancer Lett 2009 May 19;277(2):212-7. Epub 2009 Jan 19.

Department of Microbiology, Busanpaik Hospital, Inje University College of Medicine, 633-165 Gaegum-Dong, Jin-Gu, Busan, Republic of Korea.

Tetras (tetra-arsenic oxide, As(4)O(6)) is a derivative of arsenic used in Korean traditional medicine for the treatment of cancer, but its mechanism remains largely undefined. Recently, a similar arsenic derivative, diarsenic trioxide (As(2)O(3), ATO), has been shown to mediate anti-tumor activity, therefore reigniting interest in the therapeutic effect of arsenic compounds. Here we report that Tetras can effectively mediate an anti-vascular effect on tumors, leading to delay in tumor growth and increased survival. Our study demonstrates for the first time the potential use of Tetras as a radiation therapy enhancement agent for solid tumors. These findings reveal an unappreciated role of Tetras in cancer therapy and its potential application to radiotherapy in achieving local tumor control.
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http://dx.doi.org/10.1016/j.canlet.2008.12.012DOI Listing
May 2009

Cross-linking of B7-H1 on EBV-transformed B cells induces apoptosis through reactive oxygen species production, JNK signaling activation, and fasL expression.

J Immunol 2008 Nov;181(9):6158-69

Department of Anatomy and Research Center for Tumor Immunology, Inje University College of Medicine, Busan, Republic of Korea.

B7-H1 is a newly identified member of the B7 family with important regulatory functions in cell-mediated immune responses, and it is expressed in human immune cells and several tumors. We first observed that expression of surface B7-H1 on B cells was increased during the immortalization process by EBV, which is strongly related to both inflammation and tumorigenesis. Cross-linking of B7-H1 on EBV-transformed B cells using anti-B7-H1 Ab (clone 130002) induced reactive oxygen species (ROS) generation, mitochondrial disruption, release of apoptotic proteins from mitochondria, and subsequent apoptosis. Inhibition of caspases and ROS generation recovered B7-H1-mediated apoptosis and proteolytic activities of caspase-8, -9, and -3. We observed that B7-H1 stimulation induced both transcription and translation of fasL. ZB4, an antagonistic anti-fas Ab, and NOK-1, an antagonistic anti-fasL Ab, effectively blocked apoptosis without exerting any influence on ROS generation. N-acetylcysteine (NAC) completely blocked the induction of fasL mRNA and protein. We found that B7-H1 stimulation activated the phosphorylation of JNK and c-jun and down-regulated ERK1/2 and p-Akt. NAC blocked the activation of JNK and down-regulation of ERK, but both z-VAD-fmk (N-benzyloxycarbonyl-Val-Ala-Asp-fluoromethylketone) and ZB4 did not inhibit JNK activation of B7-H1 stimulation. SP600125 blocked fasL induction and apoptosis but did not affect ROS generation after B7-H1 stimulation. Taken together, we concluded that B7-H1-mediated apoptosis on EBV-transformed B cells may be involved in the induction of fasL, which is evoked by ROS generation and JNK activation after cross-linking of B7-H1. These results provide a new concept for understanding reverse signaling through B7-H1 and another mechanism of tumor immunotherapy using anti-B7-H1.
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http://dx.doi.org/10.4049/jimmunol.181.9.6158DOI Listing
November 2008

B7-H4 reverse signaling induces the apoptosis of EBV-transformed B cells through Fas ligand up-regulation.

Cancer Lett 2008 Aug 15;266(2):227-37. Epub 2008 Apr 15.

Department of Anatomy and Tumor Immunology, Inje University College of Medicine, 633-165 Kaekum-2-dong, Jin-gu, Busan 614-735, Republic of Korea.

B7-H4 has an inhibitory effect on immune responses via the down-regulation of T cell-mediated immunity, but how the engagement of B7-H4 molecules by counter molecules affects the signaling mechanism of the B7-H4-expressing cells is poorly defined. In this study, we found that B7-H4 expression was enhanced on B cells infected with Epstein-Barr virus (EBV) and that triggering of these molecules induced apoptosis of EBV-transformed B cells. Engagement of B7-H4 initially increased intracellular level of ROS, which then induced the expression of FasL. Engagement of B7-H4 subsequently provoked Fas-mediated and caspase-dependent apoptosis in association with cytochrome c and AIF, and EndoG was released from the mitochondria on EBV-transformed B cells. These results suggest that B7-H4 may be a potential therapeutic target for EBV involved malignancy diseases.
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http://dx.doi.org/10.1016/j.canlet.2008.02.067DOI Listing
August 2008

12-O-tetradecanoyl phorbol 13-acetate induces the expression of B7-DC, -H1, -H2, and -H3 in K562 cells.

Int J Oncol 2007 Dec;31(6):1439-47

Chronic Disease Research Center and Institute for Medical Science, Keimyung University School of Medicine, Daegu, Korea.

Induction of the B7 family molecules by 12-O-tetradecanoyl phorbol 13-acetate (TPA) has been reported, however, the mechanism by which TPA up-regulates these molecules remains poorly understood. In this study, the expression of B7-DC, -H1, -H2, and -H3 in response to TPA was markedly induced in K562 cells. TPA also induced activation of ERK, p38 mitogen-activated protein kinase (MAPK), JNK, phosphatidylinositol-3-kinase (PI-3K), or nuclear factor (NF)-kappaB. Pre-treatments with protein kinase C (PKC) inhibitors significantly inhibited TPA-induced expression of B7-DC, -H1, -H2, and -H3 mRNA as well as TPA-induced phosphorylation of ERK, p38 MAPK, JNK, and PI-3K. TPA-induced expression of B7-DC, -H1, -H2, and -H3 mRNA was abrogated by pre-treatments with inhibitors of ERK and p38 MAPK. However, inhibition of PI-3K and JNK only caused decrease of TPA-induced B7-DC mRNA and B7-H3 mRNA, respectively. TPA-induced degradation of IkappaB-alpha was markedly abrogated by treatments with PKC inhibitors, but not by treatments with inhibitors of ERK, p38 MAPK, JNK, or PI-3K. NF-kappaB inhibitors significantly attenuated the expression of B7-DC, -H1, -H2, and -H3 mRNA in response to TPA. These results suggest that TPA induces the expression of B7-DC, -H1, -H2, and -H3 mRNA in K562 cells via activation of PKC, ERK, p38 MAPK, and NF-kappaB. Distinctly, the expression of B7-DC mRNA and -H3 mRNA in response to TPA is also PI-3K- and JNK-dependent, respectively.
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December 2007

Single-chain antibody fragment specific for Plasmodium vivax Duffy binding protein.

Clin Vaccine Immunol 2007 Jun 25;14(6):726-31. Epub 2007 Apr 25.

Department of Malariology, Paik Institute for Clinical Research, College of Medicine, Inje University, 633-165 Gaegum-dong, Jin-gu, Busan 614-735, South Korea.

Phage display of single-chain variable fragment (scFv) antibodies is a powerful tool for selecting important, useful, and specific human antibodies. We constructed a library from three patients infected with Plasmodium vivax. Panning on recombinant PvRII enriched a population of scFvs that recognized region II of the P. vivax Duffy binding protein (DBP). Three clones of scFvs that reacted with PvRII were selected, and their biological functions were analyzed. These scFvs inhibited erythrocyte binding to DBP. Clone SFDBII92 had the greatest affinity (dissociation constant = 3.62 x 10(-8) M) and the greatest inhibition activity (50% inhibitory concentration approximately 2.9 microg/ml) to DBP. Thus, we demonstrated that human neutralizing antibody could be made from malaria patients using phage display and that these neutralizing scFvs should prove valuable for developing both passive and active immunization strategies based on DBP.
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http://dx.doi.org/10.1128/CVI.00456-06DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1951088PMC
June 2007

Triptolide suppresses interleukin-1beta-induced human beta-defensin-2 mRNA expression through inhibition of transcriptional activation of NF-kappaB in A549 cells.

Int J Mol Med 2007 May;19(5):757-63

Chronic Disease Research Center and Institute for Medical Science, Keimyung University School of Medicine, Daegu, Korea.

The immunosuppressive effect of triptolide has been associated with suppression of T-cell activation. However, the immunosuppressive effects of triptolide on innate immunity in the epithelial barrier remain to be elucidated. Human beta-defensin (HBD)-2 is an inducible antimicrobial peptide and plays an important role in the innate immunity. We have previously demonstrated that IL-1beta induced HBD-2 mRNA expression in A549 cells through activation of nuclear factor-kappaB (NF-kappaB) transcriptional factor as well as p38 mitogen-activated protein kinase (MAPK), c-Jun N-terminal kinase (JNK), or phosphatidylinositol-3-kinase (PI3K). In this study, we investigated effects of triptolide on IL-1beta-induced HBD-2 mRNA expression in A549 cells. Triptolide inhibited IL-1beta-induced HBD-2 mRNA expression in a dose-dependent manner. Addition of triptolide did not suppress activation of p38 MAPK, JNK, or PI3K in response to IL-1beta. Triptolide inhibited IL-1beta-induced MAPK phosphatase-1 expression at the transcriptional level and resulted in sustained phosphorylation of JNK or p38 MAPK, explaining the little effect of triptolide on IL-1beta-induced phosphorylation of these kinases. Although triptolide partially suppressed IL-1beta-mediated degradation of IkappaB-alpha and nuclear translocation of p65 NF-kappaB, triptolide potently inhibited NF-kappaB promoter-driven luciferase activity in A549 cells. These results collectively suggest that the inhibitory effect of triptolide on IL-1beta-induced HBD-2 mRNA expression in A549 cells seems to be at least in part mediated through nuclear inhibition of NF-kappaB transcriptional activity, but not inhibition of p38 MAPK, JNK, or PI3K. This inhibition may explain the ability of triptolide to diminish innate immune response.
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May 2007

Mast cells play a key role in the development of late airway hyperresponsiveness through TNF-alpha in a murine model of asthma.

Eur J Immunol 2007 Apr;37(4):1107-15

Department of Immunology, Chonbuk National University Medical School, Chonju, Republic of Korea.

We have investigated the role of TNF-alpha in mast cell-mediated late airway hyperresponsiveness (AHR) using mast cell-deficient WBB6F1-W/W(v) (W/W(v)) mice in a murine model of asthma, which exhibits a biphasic increase in AHR. TNF-alpha levels in the airway and magnitude of late AHR in response to airway allergen challenge were severely impaired in W/W(v) mice compared to their littermates. In addition to TNF-alpha, cytosolic phospholipase A(2) (cPLA(2)) phosphorylation and enzymatic activity in the lungs were also impaired in W/W(v) mice. Either anti-TNF-alpha antibody or an inhibitor of cPLA(2) abolished late AHR in congeneic +/+ mice. Intratracheal administration of TNF-alpha resulted in increases in late AHR, cPLA(2 )phosphorylation, cPLA(2 )activity, and phosphorylation of mitogen-activated protein kinases. Mast cell replacement restored airway TNF-alpha level, cPLA(2 )phosphorylation and enzymatic activity in the lungs as well as late AHR in W/W(v) mice. These data indicate that mast cells play a key role in the development of late AHR through liberation of TNF-alpha.
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http://dx.doi.org/10.1002/eji.200636612DOI Listing
April 2007

[Human monoclonal antibody inhibiting reverse transcriptase activity of hepatitis B virus polymerase protein].

Korean J Gastroenterol 2007 Feb;49(2):85-92

Department of Internal Medicine, Inje University College of Medicine, Busanjin-Gu, Busan, Korea.

Background/aims: To develop a novel treatment method for hepatitis B virus (HBV) infection, we aimed to make a human monoclonal antibody inhibiting reverse transcriptase (RT) activity of P protein which was important in HBV replication by using phage display technique. Therefore, we analysed the usability of human monoclonal antibody as a protein based gene therapy.

Methods: Reverse transcriptase/polymerase (RT/POL) functional motif of P protein of HBV was cloned in pMAL-c vector and expressed as maltose binding fusion protein form. The RT/POL recombinant protein (pMRT/POL) was purified by amylose resin column. Using human single chain Fv phage antibody library with 1.1 x 10(10), human antibody against pMRT/POL was selected with BIAcore panning. Selected antibody fragments were analyzed for the activity of RT inhibition. Finally, they were analyzed for the affinity with BIAcore and the complementarity determining regions with nucleotide sequencing.

Results: pMRT/POL recombinant protein expressed in E. coli showed RT activity, 1 micro g of recombinant protein had an activity equivalent to 5 unit of MMLV RT. By BIAcore panning, we could select 3 clones; POL-A5, POL-B8 and POL-B12. Each clone's RT inhibiting activity were 52-82%, affinity against antigen were 8.15 x 10(-8) M to 1.75 x 10(-6) M.

Conclusions: Human monoclonal antibodies produced in this study showed low affinity, but efficiently inhibited the activity of RT in vitro. If POL-A5, POL-B8, and POL-B12 can be converted to intracellular antibody form, it can be used for protein-based gene therapy by inhibiting the replication through the neutralization of polymerase protein of HBV.
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February 2007

Leptomycin B, a metabolite of Streptomyces, inhibits the expression of inducible nitric oxide synthase in BV2 microglial cells.

Int J Oncol 2006 Dec;29(6):1509-15

Chronic Disease Research Center and Institute for Medical Science, Keimyung University School of Medicine, Jung-Gu, Daegu 700-712, South Korea.

Overexpression of inducible nitric oxide synthase (iNOS) and the resultant overproduction of NO has been implicated in neuronal inflammatory diseases. Leptomycin B (LMB), a metabolite of Streptomyces, has been identified as a specific inhibitor of CRM1 nuclear export receptor. In this study, we evaluated the effect of LMB on lipopolysaccharide (LPS)-induced iNOS expression in BV2 cells, a murine microglial cells and the associated mechanisms. LMB strongly inhibited LPS-induced iNOS protein and mRNA expressions in BV2 cells in which 10 ng/ml of LMB (18 nM) was sufficient to greatly down-regulate iNOS by LPS, suggesting the potency of LMB to inhibit iNOS. The data of iNOS promoter-driven luciferase assay further suggested that the LMB inhibitory effect was in part due to inhibition of iNOS transcription. However, LPS-induced activation of various intracellular signaling proteins, such as nuclear factor-kappaB (NF-kappaB), extracellular signal-regulated kinases (ERKs), p38s, and c-Jun N-terminal kinases (JNKs), whose activations are known to be important for iNOS expression by LPS in BV2 cells, were not affected in the presence of LMB. Together, these results suggest that LMB inhibits iNOS expression in response to LPS in BV2 microglia, and the inhibition seems to be associated with blockage of CRM1-mediated iNOS mRNA nuclear export and also in part transcriptional down-regulation of iNOS, but not through modulation of NF-kappaB and the mitogen-activated protein kinase signaling pathways.
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December 2006

Silibinin polarizes Th1/Th2 immune responses through the inhibition of immunostimulatory function of dendritic cells.

J Cell Physiol 2007 Feb;210(2):385-97

College of Pharmacy, Pusan National University, Busan, Korea.

Silibinin is the primary active compound in silymarin. It has been demonstrated to exert anti-carcinogenic effects and hepato-protective effects. However, the effects of silibinin on the maturation and immunostimulatory activities exhibited by dendritic cells (DCs) remain, for the most part, unknown. In this study, we have attempted to determine whether silibinin can influence surface molecule expression, dextran uptake, cytokine production, capacity to induce T-cell differentiation, and the signaling pathways underlying these phenomena in murine bone marrow-derived DCs. Silibinin was shown to significantly suppress the expression of CD80, CD86, MHC class I, and MHC class II in the DCs, and was also associated with impairments of LPS-induced IL-12 expression in the DCs. Silibinin-treated DCs proved highly efficient with regard to Ag capture via mannose receptor-mediated endocytosis. Silibinin also inhibited the LPS-induced activation of MAPKs and the nuclear translocation of the NF-kappaB p65 subunit. Additionally, silibinin-treated DCs evidenced an impaired induction of Th1 response, and a normal cell-mediated immune response. These findings provide new insight into the immunopharmacological functions of silibinin, especially with regard to their impact on the DCs. These findings expand our current understanding of the immunopharmacological functions of silibinin, and may prove useful in the development of therapeutic adjuvants for acute and chronic DC-associated diseases.
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http://dx.doi.org/10.1002/jcp.20852DOI Listing
February 2007

Essential role of TNF family molecule LIGHT as a cytokine in the pathogenesis of hepatitis.

J Clin Invest 2006 Apr 23;116(4):1045-51. Epub 2006 Mar 23.

Immunology Graduate Program, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA.

LIGHT is an important costimulatory molecule for T cell immunity. Recent studies have further implicated its role in innate immunity and inflammatory diseases, but its cellular and molecular mechanisms remain elusive. We report here that LIGHT is upregulated and functions as a proinflammatory cytokine in 2 independent experimental hepatitis models, induced by concanavalin A and Listeria monocytogenes. Molecular mutagenesis studies suggest that soluble LIGHT protein produced by cleavage from the cell membrane plays an important role in this effect through the interaction with the lymphotoxin-beta receptor (LTbetaR) but not herpes virus entry mediator. NK1.1+ T cells contribute to the production, but not the cleavage or effector functions, of soluble LIGHT. Importantly, treatment with a mAb that specifically interferes with the LIGHT-LTbetaR interaction protects mice from lethal hepatitis. Our studies thus identify a what we believe to be a novel function of soluble LIGHT in vivo and offer a potential target for therapeutic interventions in hepatic inflammatory diseases.
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http://dx.doi.org/10.1172/JCI27083DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1409742PMC
April 2006

Improvement of neutralizing activity of human scFv antibodies against hepatitis B virus binding using CDR3 V(H) mutant library.

Viral Immunol 2006 ;19(1):115-23

Department of Microbiology, College of Medicine and Center for Viral Disease Research, Inje University, Pusan, Republic of Korea.

CDR3 of the heavy-chain variable region of immunoglobulin is a region in which somatic mutation occurs heavily after secondary antibody response, resulting in an affinity maturation of antibodies in vivo. The aim of this study was to improve the affinity of a human single-chain variable fragment (scFv) specific for pre-S1 of hepatitis B virus (HBV) by introducing random mutagenesis in CDR3 variable region of heavy chain (V(H)) of the parental scFv clone 1E4. By using a BIAcore for panning and screening, we have selected three clones (A9, B2, and B9) with lower highest affinity (K(D)) than 1E4. Affinities of selected clones ranged from 1.7 x 10(7) mol/L to 6.3 x 10(8) mol/L, which were increased by factors of 1.4 to 4.0, respectively, compared to the parental clone. Binding inhibition assay using flow cytometry and polymerase chain reaction revealed that B2 (6.4 x 10(8) mol/L) had a higher neutralizing activity against pre-S1 or HBV virion binding to liver cell line. This anti-pre-S1 scFv can be considered as a potential therapeutic tool for a passive immunotherapy for HBV infection.
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http://dx.doi.org/10.1089/vim.2006.19.115DOI Listing
July 2006

Interferon regulatory factor-1 is prerequisite to the constitutive expression and IFN-gamma-induced upregulation of B7-H1 (CD274).

FEBS Lett 2006 Feb 9;580(3):755-62. Epub 2006 Jan 9.

Department of Microbiology, Inje University College of Medicine, Busan 614-735, Republic of Korea.

Majority of cancer cells upregulate co-inhibitory molecule B7-H1 which confers resistance to anti-tumor immunity, allowing cancers to escape from host immune surveillance. We addressed the molecular mechanism underlying the regulation of cancer-associated B7-H1 expression in response to interferon-gamma (IFN-gamma). Using promoter constructs in luciferase assay, the region between 202 and 320 bp from the translational start site is responsible for B7-H1 expression. Electrophoretic mobility shift assay, site-directed mutagenesis and knockdown experiment using siRNA revealed that interferon regulatory factor-1 (IRF-1) is primarily responsible for the constitutive B7-H1 expression as well as for the IFN-gamma-mediated B7-H1 upregulation in a human lung cancer cell line A549. Additionally, AG490, a Janus activated kinase/signal transducer and activator of transcription inhibitor, greatly abolished the responsiveness of A549 cells to IFN-gamma by reducing the IRF-1 transcription. Our findings support a critical role of IRF-1 in the regulation of constitutive and IFN-gamma-induced expression of B7-H1 in cancer cells.
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http://dx.doi.org/10.1016/j.febslet.2005.12.093DOI Listing
February 2006

Hepatitis B virus-neutralizing anti-pre-S1 human antibody fragments from large naïve antibody phage library.

Antiviral Res 2005 Dec 9;68(3):109-15. Epub 2005 Aug 9.

Department of Microbiology, College of Medicine and Center for Viral Disease Research, Inje University, Jin-Gu, Busan 614-735, Republic of Korea.

We report the construction of a large nonimmunized human phage antibody library in single-chain variable region fragment (scFv) format, which allowed the selection of antibodies that neutralize hepatitis B virus (HBV) in vitro. We generated 1.1 x 10(10) independent scFv clones using the cDNA of functional variable (V) gene segments of heavy and light chains purified from the peripheral blood mononuclear cells of 50 nonimmunized human donors. Using BIAcore, we selected two clones that recognized pre-S1 and neutralized pre-S1 and HBV binding to Chang liver cells. Clone G10 had the highest affinity (K(D)=1.69 x 10(-7)M), which was higher than that of clone 1E4 that was generated previously from a heavy chain-shuffled immune library. The off-rates of clones were within 10(-3)s(-1) as determined by BIAcore and were comparable to those of antibodies derived from a normal secondary immune response. In the inhibition assays of pre-S1 and virus binding to Chang liver cells using flow cytometry and the polymerase chain reaction, G10 had better neutralizing activity than 1E4. The new phage library may be a valuable source of antibodies with reasonable affinities to different targets, and the anti-pre-S1 G10 may be a good candidate for immunoprophylaxis against HBV infection.
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http://dx.doi.org/10.1016/j.antiviral.2005.06.012DOI Listing
December 2005