Browsing by Author "Son, Young Min"

Now showing 1 - 8 of 8
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    BCL6 represses antiviral resistance in follicular T helper cells
    (Wiley, 2017-08) Amet, Tohti; Son, Young Min; Jiang, Li; Cheon, In Su; Huang, Su; Gupta, Samir K.; Dent, Alexander L.; Montaner, Luis J.; Yu, Qigui; Sun, Jie; Microbiology and Immunology, School of Medicine
    Follicular Th (Tfh) cells are a distinct subset of Th cells that help B cells produce class-switched antibodies. Studies have demonstrated that Tfh cells are highly prone to HIV infection and replication. However, the molecular mechanisms underlying this phenomenon are largely unclear. Here, we show that murine and human Tfh cells have diminished constitutive expression of IFN-stimulated genes (ISGs) inclusive of antiviral resistance factor MX dynamin-like GTPase 2 (MX2) and IFN-induced transmembrane 3 (IFITM3) compared with non-Tfh cells. A lower antiviral resistance in Tfh was consistent with a higher susceptibility to retroviral infections. Mechanistically, we found that BCL6, a master regulator of Tfh cell development, binds to ISG loci and inhibits the expression of MX2 and IFITM3 in Tfh cells. We demonstrate further that inhibition of the BCL6 BR-C, ttk, and bab (BTB) domain function increases the expression of ISGs and suppresses HIV infection and replication in Tfh cells. Our data reveal a regulatory role of BCL6 in inhibiting antiviral resistance factors in Tfh cells, thereby promoting the susceptibility Tfh cells to viral infections. Our results indicate that the modulation of BCL6 function in Tfh cells could be a potential strategy to enhance Tfh cell resistance to retroviral infections and potentially decrease cellular reservoirs of HIV infection.
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    Inhibition of stearoyl-CoA desaturases suppresses follicular help T- and germinal center B- cell responses
    (Wiley, 2020-07) Son, Young Min; Cheon, In Su; Goplen, Nick P.; Dent, Alexander L.; Sun, Jie; Microbiology and Immunology, School of Medicine
    Stearoyl-CoA desaturases (SCD) are endoplasmic reticulum (ER)-associated enzymes that catalyze the synthesis of the monounsaturated fatty acids (MUFAs). As such, SCD play important roles in maintaining the intracellular balance between saturated fatty acid (SFAs) and MUFAs. The roles of SCD in CD4+ T-helper cell responses are currently unexplored. Here, we have found that murine and human follicular helper T (TFH ) cells express higher levels of SCD compared to non-TFH cells. Further, the expression of SCD in TFH cells is dependent on the TFH lineage-specification transcription factor BCL6. We found that the inhibition of SCD impaired TFH cell maintenance and shifted the balance between TFH and follicular regulatory T (TFR ) cells in the spleen. Consequently, SCD inhibition dampened germinal center B-cell responses following influenza immunization. Mechanistically, we found that SCD inhibition led to increased ER stress and enhanced TFH cell apoptosis in vitro and in vivo. These results reveal a possible link between fatty acid metabolism and cellular and humoral responses induced by immunization or potentially, autoimmunity.
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    Neonatal hyperoxia promotes asthma-like features through IL-33–dependent ILC2 responses
    (Elsevier, 2017) Cheon, In Su; Son, Young Min; Jiang, Li; Goplen, Nicholas P.; Kaplan, Mark H.; Limper, Andrew H.; Kita, Hirohito; Paczesny, Sophie; Prakash, Y. S.; Tepper, Robert; Ahlfeld, Shawn K.; Sun, Jie; Pediatrics, School of Medicine
    Background Premature infants often require oxygen supplementation and, therefore, are exposed to oxidative stress. Following oxygen exposure, preterm infants frequently develop chronic lung disease and have a significantly increased risk of asthma. Objective We sought to identify the underlying mechanisms by which neonatal hyperoxia promotes asthma development. Methods Mice were exposed to neonatal hyperoxia followed by a period of room air recovery. A group of mice was also intranasally exposed to house dust mite antigen. Assessments were performed at various time points for evaluation of airway hyperresponsiveness, eosinophilia, mucus production, inflammatory gene expression, and TH and group 2 innate lymphoid cell (ILC2) responses. Sera from term- and preterm-born infants were also collected and levels of IL-33 and type 2 cytokines were measured. Results Neonatal hyperoxia induced asthma-like features including airway hyperresponsiveness, mucus hyperplasia, airway eosinophilia, and type 2 pulmonary inflammation. In addition, neonatal hyperoxia promoted allergic TH responses to house dust mite exposure. Elevated IL-33 levels and ILC2 responses were observed in the lungs most likely due to oxidative stress caused by neonatal hyperoxia. IL-33 receptor signaling and ILC2s were vital for the induction of asthma-like features following neonatal hyperoxia. Serum IL-33 levels correlated significantly with serum levels of IL-5 and IL-13 but not IL-4 in preterm infants. Conclusions These data demonstrate that an axis involving IL-33 and ILC2s is important for the development of asthma-like features following neonatal hyperoxia and suggest therapeutic potential for targeting IL-33, ILC2s, and oxidative stress to prevent and/or treat asthma development related to prematurity.
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    Respiratory mucosal immunity against SARS-CoV-2 after mRNA vaccination
    (American Association for the Advancement of Science, 2022) Tang, Jinyi; Zeng, Cong; Cox, Thomas M.; Li, Chaofan; Son, Young Min; Cheon, In Su; Wu, Yue; Behl, Supriya; Taylor, Justin J.; Chakraborty, Rana; Johnson, Aaron J.; Schiavo, Dante N.; Utz, James P.; Reisenauer, Janani S.; Midthun, David E.; Mullon, John J.; Edell, Eric S.; Alameh, Mohamad G.; Borish, Larry; Teague, William G.; Kaplan, Mark H.; Weissman, Drew; Kern, Ryan; Hu, Haitao; Vassallo, Robert; Liu, Shan-Lu; Sun, Jie; Microbiology and Immunology, School of Medicine
    SARS-CoV-2 mRNA vaccination induces robust humoral and cellular immunity in the circulation; however, it is currently unknown whether it elicits effective immune responses in the respiratory tract, particularly against variants of concern (VOCs), including Omicron. We compared the SARS-CoV-2 S-specific total and neutralizing antibody responses, and B and T cell immunity, in the bronchoalveolar lavage fluid (BAL) and blood of COVID-19-vaccinated individuals and hospitalized patients. Vaccinated individuals had significantly lower levels of neutralizing antibody against D614G, Delta (B.1.617.2), and Omicron BA.1.1 in the BAL compared with COVID-19 convalescents despite robust S-specific antibody responses in the blood. Furthermore, mRNA vaccination induced circulating S-specific B and T cell immunity, but in contrast to COVID-19 convalescents, these responses were absent in the BAL of vaccinated individuals. Using a mouse immunization model, we demonstrated that systemic mRNA vaccination alone induced weak respiratory mucosal neutralizing antibody responses, especially against SARS-CoV-2 Omicron BA.1.1 in mice; however, a combination of systemic mRNA vaccination plus mucosal adenovirus-S immunization induced strong neutralizing antibody responses not only against the ancestral virus but also the Omicron BA.1.1 variant. Together, our study supports the contention that the current COVID-19 vaccines are highly effective against severe disease development, likely through recruiting circulating B and T cell responses during reinfection, but offer limited protection against breakthrough infection, especially by the Omicron sublineage. Hence, mucosal booster vaccination is needed to establish robust sterilizing immunity in the respiratory tract against SARS-CoV-2, including infection by the Omicron sublineage and future VOCs.
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    Tissue-resident CD4+ T helper cells assist the development of protective respiratory B and CD8+ T cell memory responses
    (American Association for the Advancement of Science, 2021) Son, Young Min; Cheon, In Su; Wu, Yue; Li, Chaofan; Wang, Zheng; Gao, Xiaochen; Chen, Yao; Takahashi, Yoshimasa; Fu, Yang-Xin; Dent, Alexander L.; Kaplan, Mark H.; Taylor, Justin J.; Cui, Weiguo; Sun, Jie; Microbiology and Immunology, School of Medicine
    Much remains unknown about the roles of CD4+ T helper cells in shaping localized memory B cell and CD8+ T cell immunity in the mucosal tissues. Here, we report that lung T helper cells provide local assistance for the optimal development of tissue-resident memory B and CD8+ T cells after the resolution of primary influenza virus infection. We have identified a population of T cells in the lung that exhibit characteristics of both follicular T helper and TRM cells, and we have termed these cells as resident helper T (TRH) cells. Optimal TRH cell formation was dependent on transcription factors involved in T follicular helper and resident memory T cell development including BCL6 and Bhlhe40. We show that TRH cells deliver local help to CD8+ T cells through IL-21-dependent mechanisms. Our data have uncovered the presence of a tissue-resident helper T cell population in the lung that plays a critical role in promoting the development of protective B cell and CD8+ T cell responses.
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    Topical Prostaglandin E Analog Restores Defective Dendritic Cell–Mediated Th17 Host Defense Against Methicillin-Resistant Staphylococcus Aureus in the Skin of Diabetic Mice
    (American Diabetes Association, 2016-12) Dejani, Naiara N.; Brandt, Stephanie L.; Piñeros, Annie; Glosson-Byers, Nicole L.; Wang, Sue; Son, Young Min; Medeiros, Alexandra I.; Serezani, C. Henrique; Microbiology and Immunology, School of Medicine
    People with diabetes are more prone to Staphylococcus aureus skin infection than healthy individuals. Control of S. aureus infection depends on dendritic cell (DC)–induced T-helper 17 (Th17)–mediated neutrophil recruitment and bacterial clearance. DC ingestion of infected apoptotic cells (IACs) drive prostaglandin E2 (PGE2) secretion to generate Th17 cells. We speculated that hyperglycemia inhibits skin DC migration to the lymph nodes and impairs the Th17 differentiation that accounts for poor skin host defense in diabetic mice. Diabetic mice showed increased skin lesion size and bacterial load and decreased PGE2 secretion and Th17 cells compared with nondiabetic mice after methicillin-resistant S. aureus (MRSA) infection. Bone marrow–derived DCs (BMDCs) cultured in high glucose (25 mmol/L) exhibited decreased Ptges mRNA expression, PGE2 production, lower CCR7-dependent DC migration, and diminished maturation after recognition of MRSA-IACs than BMDCs cultured in low glucose (5 mmol/L). Similar events were observed in DCs from diabetic mice infected with MRSA. Topical treatment of diabetic mice with the PGE analog misoprostol improved host defense against MRSA skin infection by restoring DC migration to draining lymph nodes, Th17 differentiation, and increased antimicrobial peptide expression. These findings identify a novel mechanism involved in poor skin host defense in diabetes and propose a targeted strategy to restore skin host defense in diabetes.
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    The Transcription Factor Bhlhe40 Programs Mitochondrial Regulation of Resident CD8+ T Cell Fitness and Functionality
    (Elsevier, 2019-09-17) Li, Chaofan; Zhu, Bibo; Son, Young Min; Wang, Zheng; Jiang, Li; Xiang, Min; Ye, Zhenqing; Beckermann, Kathryn E.; Wu, Yue; Jenkins, James W.; Siska, Peter J.; Vincent, Benjamin G.; Prakash, Y. S.; Peikert, Tobias; Edelson, Brian T.; Taneja, Reshma; Kaplan, Mark H.; Rathmell, Jeffrey C.; Dong, Haidong; Hitosugi, Taro; Sun, Jie; Microbiology and Immunology, School of Medicine
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    Uncoupling of macrophage inflammation from self-renewal modulates host recovery from respiratory viral infection
    (Cell Press, 2021) Zhu, Bibo; Wu, Yue; Huang, Su; Zhang, Ruixuan; Son, Young Min; Li, Chaofan; Cheon, In Su; Gao, Xiaochen; Wang, Min; Chen, Yao; Zhou, Xian; Nguyen, Quynh; Phan, Anthony T.; Behl, Supriya; Taketo, M. Mark; Mack, Matthias; Shapiro, Virginia S.; Zeng, Hu; Ebihara, Hideki; Mullon, John J.; Edell, Eric S.; Reisenauer, Janani S.; Demirel, Nadir; Kern, Ryan M.; Chakraborty, Rana; Cui, Weiguo; Kaplan, Mark H.; Zhou, Xiaobo; Goldrath, Ananda W.; Sun, Jie; Microbiology and Immunology, School of Medicine
    Tissue macrophages self-renew during homeostasis and produce inflammatory mediators upon microbial infection. We examined the relationship between proliferative and inflammatory properties of tissue macrophages by defining the impact of the Wnt/β-catenin pathway, a central regulator of self-renewal, in alveolar macrophages (AMs). Activation of β-catenin by Wnt ligand inhibited AM proliferation and stemness, but promoted inflammatory activity. In a murine influenza viral pneumonia model, β-catenin-mediated AM inflammatory activity promoted acute host morbidity; in contrast, AM proliferation enabled repopulation of reparative AMs and tissue recovery following viral clearance. Mechanistically, Wnt treatment promoted β-catenin-HIF-1α interaction and glycolysis-dependent inflammation while suppressing mitochondrial metabolism and thereby, AM proliferation. Differential HIF-1α activities distinguished proliferative and inflammatory AMs in vivo. This β-catenin-HIF-1α axis was conserved in human AMs and enhanced HIF-1α expression associated with macrophage inflammation in COVID-19 patients. Thus, inflammatory and reparative activities of lung macrophages are regulated by β-catenin-HIF-1α signaling, with implications for the treatment of severe respiratory diseases.