• IMMUNE NETWORK
• /
• v.21 no.1
• /
• pp.3.1-3.16
• /
• 2021

Coronavirus disease 2019 caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has been spreading worldwide since its outbreak in December 2019, and World Health Organization declared it as a pandemic on March 11, 2020. SARS-CoV-2 is highly contagious and is transmitted through airway epithelial cells as the first gateway. SARS-CoV-2 is detected by nasopharyngeal or oropharyngeal swab samples, and the viral load is significantly high in the upper respiratory tract. The host cellular receptors in airway epithelial cells, including angiotensin-converting enzyme 2 and transmembrane serine protease 2, have been identified by single-cell RNA sequencing or immunostaining. The expression levels of these molecules vary by type, function, and location of airway epithelial cells, such as ciliated cells, secretory cells, olfactory epithelial cells, and alveolar epithelial cells, as well as differ from host to host depending on age, sex, or comorbid diseases. Infected airway epithelial cells by SARS-CoV-2 in ex vivo experiments produce chemokines and cytokines to recruit inflammatory cells to target organs. Same as other viral infections, IFN signaling is a critical pathway for host defense. Various studies are underway to confirm the pathophysiological mechanisms of SARS-CoV-2 infection. Herein, we review cellular entry, host-viral interactions, immune responses to SARS-CoV-2 in airway epithelial cells. We also discuss therapeutic options related to epithelial immune reactions to SARS-CoV-2.

• Journal of Microbiology and Biotechnology
• /
• v.14 no.4
• /
• pp.836-843
• /
• 2004

Nontypeable H. influenzae (NTHi), a Gram-negative obligate human pathogen, causes pneumonia, chronic bronchitis, and otitis media, and the respiratory epithelium is the first line of defense that copes with the pathogen. In an effort to identify transcriptional responses of human respiratory epithelial cells to infection with NTHi, we examined its differential gene expression using high density cDNA microarrays. BEAS-2B human bronchial epithelial cells were exposed to NTHi for 3 hand 24 h, and the alteration of mRNA expression was analyzed using microarrays consisting of 8,170 human cDNA clones. The results indicated that approximately 2.6% of the genes present on the microarrays increased in expression over 2-fold and 3.8% of the genes decreased during the 24-h infection period. Upregulated genes included cytokines (granulocyte-macrophage colony stimulating factor 2, granulocyte chemotactic protein 2, IL-6, IL-10, IL-8), transcription factors (Kruppel-like factor 7, CCAAT/enhancer binding protein $\beta$, E2F-1, NF-$\kappa$B, cell surface molecules (CD74, ICAM-1, ICAM-2, HLA class I), as well as those involved in signal transduction and cellular transport. Selected genes were further confirmed by reverse-transcription-PCR. These data expand our knowledge of host cellular responses during NTHi infection and should provide a molecular basis for the study of host-NTHi interaction.

• Advances in Traditional Medicine
• /
• v.7 no.5
• /
• pp.518-526
• /
• 2008

Recently a major goal in asthma therapy is to reduce or prevent the inflammatory response of airway. Eosinophilic accumulation in the tissue is a prominent feature of allergic diseases including asthma. Production of chemokines by bronchial epithelial cells may contribute to the allergic inflammation by recruiting eosinophils. In this study we evaluated the inhibitory effect of Gamichungsangbohatang (GMCSBHT), used traditionally in treating asthma, on secretion of chemokines for eosinophils in human A549 epithelial cells. Chemokines such as eotaxin, RANTES, IL-8 were inhibited in a dose-dependent manner, but IL-16 showed no inhibition by GMCSBHT. These findings indicate that GMCSBHT might be a therapeutic value in treating asthma by suppression of chemokines secretion associated with local accumulation of eosinophils.

• The Journal of Internal Korean Medicine
• /
• v.27 no.1
• /
• pp.208-220
• /
• 2006

Objective: Eosinophils are typically characterized by a bilobar nucleus with highly condensed chromatin and cytoplasm containing two major types of granules, specific and primary granules, and lipid bodies. The role of inflammation in asthma and other allergic diseases of the airways is widely appreciated, and airway inflammation is now included as a defining feature of asthma. The importance of the presence of eosinophils in the airways of patients with fetal asthma has long been recognized, but the mechanism by which these cells are recruited and retained in the lungs are only now being elucidated. Eotaxin is a potent and specific eosinophil chemoattractant that is mobilized in the respiratory epithelium after allergic stimulation. Methods : Water extracts of Armeniacae Amarum Semen(AAS) and pulmonary epithelial cell lines A549(alveolar typeII epithelial cells) and human eosinophils were used. Cytotoxic effects of AAS and MIS assay were estimated, as well as the effects of AAS on chemokines from prestimulated A549 cells by sandwich ELISA and RI-PCR. Chemotaxis assay was conducted on prestimulated eosinophils treated with AAS. Results : In this study it is demonstrated that $TGF-{\alpha}$, IL-4 and $IL-1{\beta}$ induced the accumulation of chemokine mRNAs in the alveolar epithelial cell lines A549 in dose-dependent manner. Eotaxin and IL-8 were inhibited by AAS in dose-dependent manner(p<0.05). Eosinophil migration was inhibited at high concentrations of AAS(p<0.05). Conculusions : These findings are indicative of suppression of eotaxin and IL-8, and suggest that this is accomplished through AAS treatment. This raises the possibility that AAS is of therapeutic value in diseases such as asthma.

• The Journal of Korean Oriental Chronic Disease
• /
• v.10 no.1
• /
• pp.1-20
• /
• 2005

Background and Objective: The importance of the presence of eosinophils in the airways of patients with fetal asthma has long been recognized, but the mechanism by which these cells are recruited and retained in the lung are only now being elucidated. Eotaxin is a potent and specific eosinophil chemoattractant that is mobilized in the respiratory epithelium after allergic stimulation. Material and Methods: We used water extracts of Liripois Tuber and pulmonary epithelial cell lines A549(human typeII-like epithelial cells) and human eosinophils. We estimated cytotoxic effects of Liripois Tuber via MTS assay, and estimated the effects of Liripois Tuber on chemokines from prestimulated A549 cells by sandwich ELISA and RT-PCR. We conducted chemotaxis assay on prestimulated eosinophils treated with Liripois Tuber. Result: In this study we demonstrated that $TNF-{\alpha}$, IL-4 and $IL-1{\beta}$ induced the accumulation of chemokines mRNA in the pulmonary epithelial cell lines A549 in dose-dependent manner. Chemokines were inhibited by Liripois Tuber in dose-dependent manner. The eosinophil migration was inhibited at high concentration of Liripois Tuber. Conculusion: These findings indicate that the supression of the expression of chemokines can be accomplished by Liripois Tuber treatment, raising the possibility that Liripois Tuber might be of therapeutic value in diseases such as asthma.

• Tuberculosis and Respiratory Diseases
• /
• v.70 no.6
• /
• pp.462-473
• /
• 2011

Background: Smoking is a risk factor for idiopathic pulmonary fibrosis (IPF), but the mechanism of the association remains obscure. There is evidence demonstrating that plasminogen activator inhibitor-1 (PAI-1) is involved in the progression of pulmonary fibrosis. This study was to determine whether the administration of small interfering RNA (siRNA) targeting PAI-1 or PAI-1 inhibitor to the cigarette smoking extract (CSE)-exposed rat alveolar type II epithelial cells (ATII cells) limits the epithelial-mesenchymal transition (EMT). Methods: ATII cells were isolated from lung of SD-rat using percoll gradient method and cultured with 5% CSE. The EMT was determined from the ATII cells by measuring the real-time RT PCR and western blotting after the PAI-1 siRNA transfection to the cells and after administration of tiplaxtinin, an inhibitor of PAI-1. The effect of PAI-1 inhibitor was also evaluated in the bleomycin-induced rats. Results: PAI-1 was overexpressed in the smoking exposed ATII cells and was directly associated with EMT. The EMT from the ATII cells was suppressed by PAI-1 siRNA transfection or administration of tiplaxtinin. Signaling pathways for EMT by smoking extract were through the phosphorylation of SMAD2 and ERK1/2, and finally Snail expression. Tiplaxtinin also suppressed the pulmonary fibrosis and PAI-1 expression in the bleomycin-induced rats. Conclusion: Our data shows that CSE induces rat ATII cells to undergo EMT by PAI-1 via SMAD2-ERK1/2-Snail activation. This suppression of EMT by PAI-1 siRNA transfection or PAI-1 inhibitor in primary type II alveolar epithelial cells might be involved in the attenuation of bleomycin-induced pulmonary fibrosis in rats.

• Korean Journal of Veterinary Research
• /
• v.33 no.4
• /
• pp.693-699
• /
• 1993

In 1990, a retrospective examination of histologic data determined that 23 histology accessions at the Miwon Institute of Animal Science had a diagnosis of crytosporidiosis. These cases presented 10% of the 230 histologic examinations of broiler chicks of 23 cases, 18 cases were respiratory infection and 5 cases were bursal infection. The histologic findings of respiratory cryptosporidiosis were hyperplasia of mucosa epithelial cell, slightly swelling of epithelial cells, deciliation of tracheal epithelium, distribution of cryptosporidium organisms in epithelial surface of trachea and infiltration of plasma cells and lymphocytes in mucosa propria layer in trachea.

• Tuberculosis and Respiratory Diseases
• /
• v.42 no.4
• /
• pp.447-454
• /
• 1995

Cytokine release from alveolar macrophages and subsequent interaction of these cytokines with the bronchial epithelium can induce epithelial cells to release inflammatory mediators. Nitric oxide(NO), a highly reactive gas formed from arginine by nitric oxide synthase(NOS), is known to be involved in inflammation and edema formation, and the inducible form of NOS(iNOS) can be increased by cytokines. In this context, we hypothesized that lung epithelial cells could be stimulated by cytokines released by alveolar macrophages to express iNOS. To test this hypothesis, the murine lung epithelial cell line, LA-4, or the human lung epithelial cell line, A549, were stimulated with culture supernatant fluids from alveolar macrophages. NO production was assessed by evaluating the culture supernatant fluids for nitrite and nitrate, the stable end products of NO. Both murine and human cell culture supernatant fluids demonstrated an increase in nitrite and nitrate which were time- and dose-dependent and attenuated by $TNF{\alpha}$ and IL-$1{\beta}$ antibodies(p<0.05, all comparisons). Consistent with these observations, cytomix a combination of $TNF{\alpha}$, IL-$1{\beta}$, and $\gamma$-interferon, stimulated the lung epithelial cell lines as well as primary cultures of human bronchial epithelial cells to increase their NO production as evidenced by an increase in nitrite and nitrate in their culture supernatant fluids, an increase in the iNOS staining by immunocytochemistry, and an increase in iNOS mRNA by Northern blottin(p<0.05, all comparisons). The cytokine effects on iNOS were all attenuated by dexamethasone. To determine if these in vitro observations are reflected in vivo, exhaled NO was measured and found to be increased in asthmatics not receiving corticosteroids. These data demonstrate that alveolar macrophage derived cytokines increase iNOS expression in lung epithelial cells and that these in vitro observations are mirrored by increased exhaled NO levels in asthmatics. Increased NO in the lung may contribute to edema formation and airway narrowing.

• The Journal of Internal Korean Medicine
• /
• v.26 no.1
• /
• pp.199-212
• /
• 2005

Objective : Airway inflammation is now regarded as a defining feature of asthma. The importance of eosinophits in the airway inflammation of asthma patients is widely recognized, and eosinophils mobilization in the respiratory epithelium is activated by chemoattractants and cytokines. This study was designed to examine the extent of the ability of Moutan Cortex Radicis to inhibit eosinophil chemotaxis of pulmonary epithelium after allergic stimulation. Material and Methods : Water extracts of Moutan Cortex Radicis and pulmonary epithelial cell lines A549(human type II-like epithelial cells) and human eosinophils were used. Cytotoxic effects of Moutan Cortex Radicis were estimated via MTS assay, and the effects of Moutan Cortex Radicis on chemokines from prestimulated A549 cells were estimated by sandwich ELISA and RT-PCR. Chemotaxis assay on prestimulated eosinophils treated with Moutan Cortex Radicis. was conducted Result : In this study we demonstrated that $TNF-{\alpha}$ and IL-4, $IL-1{\beta}$ induced the accumulation of chemokines' mRNA in the pulmonary epithelial cell lines A549 in a dose-dependent manner. Chemokines of eotaxin, ICAM-1, YCAM-1, IL-8, IL-16 were inhibited by Moutan Cortex Radicis in a dose dependent manner, but RANTES showed no inhibition due to Moutan Cortex Radicis. Eosinophil migration was inhibited at high concentrations of Moutan Cortex Radicis. Conculusion : These findings are indicative of supression of chemokines accomplished by Moutan Cortex Radicis treatment, demonstrating the potential therapeutic value of Moutan Cortex Radicis for treating diseases such as asthma.

• The Journal of Internal Korean Medicine
• /
• v.29 no.2
• /
• pp.318-333
• /
• 2008

Objectives : In this study, the author tried to examine whether Cheogjogupye-tang (淸燥救肺湯, CGPT) and Yieum-jeon (理陰煎, YEJ) significantly affect in vitro and in vivo mucin secretion, MUC5AC gene expression in airway epithelial cells and contractility of isolated tracheal smooth muscle of rabbit. Materials and Methods : For in vitro experiment, confluent hamster tracheal surface epithelial (HTSE) cells were chased for 30 minutes in the presence of CGPT and YEJ to assess the effects of the agents on mucin secretion by enzyme-linked immunosorbent assay (ELISA), with removal of oriental herbal medicine extract from each agent-treated sample by centrifuge microfilter. Also, the effects of the agents on TNF-alpha or EGF-induced MUC5AC gene expression in human airway epithelial cells (NCI-H292) were investigated. Possible cytotoxicities of the agent were assessed by examining both LDH release from HTSE cells and the rate of survival and proliferation of NCI-H292 cells. For in vivo experiment, hypersecretion of airway mucin and goblet cell hyperplasia was induced by exposure of rats to $SO_2$ over 3 weeks. Effects of CGPT and YEJ orally administered for 1 week on in vivo mucin secretion from tracheal goblet cells of rats and hyperplasia of goblet cells were assessed using ELISA and histological analysis after staining the epithelial tissue with alcian blue, respectively. Also, the effects of CGPT and YEJ on contractility of isolated tracheal smooth muscle were investigated. Results : (1) CGPT significantly inhibited in vitro mucin secretion from cultured HTSE cells. However, YEJ did not affect in vitro mucin secretion; (2) CGPT and YEJ did not affect hypersecretion of in vivo mucin and hyperplasia of tracheal goblet cells; (3) CGPT and YEJ slightly increased the expression levels of TNF-alpha or EGF-induced MUC5AC gene in NCI-H292 cells; (4) CGPT and YEJ inhibited acetylcholine-induced contraction of isolated tracheal smooth muscle of rabbit; (5) CGPT and YEJ did not affect LDH release from HTSE cells and the survival and proliferation of NCI-H292 cells. Conclusion : The results from the present study suggest that CGPT and YEJ mainly affect the expression of mucin gene rather than secretion of mucin and do not show remarkable cytotoxicity to respiratory epithelial cells.