Browsing by Author "Zhou, Baohua"

Now showing 1 - 10 of 26
  • Thumbnail Image
    Item
    An IL-9-pulmonary macrophage axis defines the allergic lung inflammatory environment
    (American Association for the Advancement of Science, 2022) Fu, Yongyao; Wang, Jocelyn; Zhou, Baohua; Pajulas, Abigail; Gao, Hongyu; Ramdas, Baskar; Koh, Byunghee; Ulrich, Benjamin J.; Yang, Shuangshuang; Kapur, Reuben; Renauld, Jean-Christophe; Paczesny, Sophie; Liu, Yunlong; Tighe, Robert M.; Licona-Limón, Paula; Flavell, Richard A.; Takatsuka, Shogo; Kitamura, Daisuke; Tepper, Robert S.; Sun, Jie; Kaplan, Mark H.; Microbiology and Immunology, School of Medicine
    Despite IL-9 functioning as a pleiotropic cytokine in mucosal environments, the IL-9-responsive cell repertoire is still not well defined. Here, we found that IL-9 mediates proallergic activities in the lungs by targeting lung macrophages. IL-9 inhibits alveolar macrophage expansion and promotes recruitment of monocytes that develop into CD11c+ and CD11c- interstitial macrophage populations. Interstitial macrophages were required for IL-9-dependent allergic responses. Mechanistically, IL-9 affected the function of lung macrophages by inducing Arg1 activity. Compared with Arg1-deficient lung macrophages, Arg1-expressing macrophages expressed greater amounts of CCL5. Adoptive transfer of Arg1+ lung macrophages but not Arg1- lung macrophages promoted allergic inflammation that Il9r-/- mice were protected against. In parallel, the elevated expression of IL-9, IL-9R, Arg1, and CCL5 was correlated with disease in patients with asthma. Thus, our study uncovers an IL-9/macrophage/Arg1 axis as a potential therapeutic target for allergic airway inflammation.
  • Thumbnail Image
    Item
    Characterization of Allergen-Specific Immunoglubulin E Development in a Food Allergy Model and Its Regulation by T Follicular Helper and T Follicular Regulatory Cells
    (2023-05) Chen, Qiang; Dent, Alexander; Kaplan, Mark; Brutkiewicz, Randy; Zhou, Baohua
    Food allergy is a highly prevalent and serious disease regulated by immunoglobin E (IgE) antibodies specific for food allergens.The development of IgE is regulated by T follicular helper cells (TFH) and T follicular regulatorycells (TFR) in the germinal center (GC). We aimed to understandthe regulation of IgEin the GC by TFH and TFR cellsusinga mouse food allergy model. We found that the dosage and timingof allergen delivery into thegut is criticalfor allergen-specific IgE development, in part because the timing of allergen delivery affected the expression of regulatory factors by TFH and TFR cells. We studied FGL2, an inhibitory factor, and found that down-regulation of FGL2 in TFH cells was important for the allergic IgEresponse. Apart from inhibitory factors, TFH cell-derived IL-4 is required for IgE responses. We unexpectedlyfound that TFR cells in food allergy produce comparable amountsof IL-4 to TFH cellsand IL-4–expressing TFR cells promoteallergen-specific IgEin food allergy. The IgE response is highly sensitive to IL-4 levels, suggesting the need for extra IL-4 from TFR cells. However,TFR cells have distinct functionsdepending on the immune environment, since TFR cells repress IgEinanairway inflammation model. We found that TFR cells in airway inflammation have a different gene expression profile from TFR cells in food allergy, whichmay explain their distinct functions. Lastly, previous studies showed that high-affinity IgE driving anaphylactic reactions is produced via IgG1-switchedintermediate B cells. We challenged this paradigm by showing that high-affinity IgE develops in the absence ofIgG1-switchedB cellsin our food allergy model.Overall, our studies reveal that IgE is regulated by novel pathways in food allergy. We hope to exploit these new pathways to develop new specific therapies for food allergy.
  • Thumbnail Image
    Item
    DC-derived TSLP promotes Th2 polarization in LPS-primed allergic airway inflammation
    (Wiley, 2012) Zhang, Yanlu; Zhou, Xueping; Zhou, Baohua; Pediatrics, School of Medicine
    Thymic stromal lymphopoietin (TSLP) plays important roles in the pathogenesis of allergic diseases. Whether and how TSLP is involved in the initial priming of T helper type-2 (Th2) differentiation against harmless antigen remains unclear. Using an intranasal sensitization protocol with OVA and LPS, we showed that TSLP signaling is required for low-dose LPS-induced Th2 inflammation, but not for high-dose LPS-induced Th1 immunity. We further demonstrated that low-dose LPS-activated bone marrow-derived dendritic cells expressed relatively high Tslp but low Il12a, and were able to prime naïve DO11.10 T cells to differentiate into Th2 cells in a TSLP-dependent manner. After transfer into wild-type recipient mice, the low-dose LPS-activated OVA-loaded dendritic cells (DCs) induced airway eosinophilia, but primed neutrophil-dominated airway inflammation when TSLP-deficient DCs were used. These studies demonstrate that TSLP released by DCs in response to a low concentration of LPS plays a role in priming Th2 differentiation and thus may serve as a polarizing third signal, in addition to antigen/MHC class II and co-stimulatory factors, from antigen-presenting DCs to direct effector T-cell differentiation.
  • Thumbnail Image
    Item
    FOXP3 exon 2 controls Treg stability and autoimmunity
    (American Association for the Advancement of Science, 2022) Du, Jianguang; Wang, Qun; Yang, Shuangshuang; Chen, Si; Fu, Yongyao; Spath, Sabine; Domeier, Phillip; Hagin, David; Anover-Sombke, Stephanie; Haouili, Maya; Liu, Sheng; Wan, Jun; Han, Lei; Liu, Juli; Yang, Lei; Sangani, Neel; Li, Yujing; Lu, Xiongbin; Janga, Sarath Chandra; Kaplan, Mark H.; Torgerson, Troy R.; Ziegler, Steven F.; Zhou, Baohua; Pediatrics, School of Medicine
    Differing from the mouse Foxp3 gene that encodes only one protein product, human FOXP3 encodes two major isoforms through alternative splicing-a longer isoform (FOXP3 FL) containing all the coding exons and a shorter isoform lacking the amino acids encoded by exon 2 (FOXP3 ΔE2). The two isoforms are naturally expressed in humans, yet their differences in controlling regulatory T cell phenotype and functionality remain unclear. In this study, we show that patients expressing only the shorter isoform fail to maintain self-tolerance and develop immunodeficiency, polyendocrinopathy, and enteropathy X-linked (IPEX) syndrome. Mice with Foxp3 exon 2 deletion have excessive follicular helper T (TFH) and germinal center B (GC B) cell responses, and develop systemic autoimmune disease with anti-dsDNA and antinuclear autoantibody production, as well as immune complex glomerulonephritis. Despite having normal suppressive function in in vitro assays, regulatory T cells expressing FOXP3 ΔE2 are unstable and sufficient to induce autoimmunity when transferred into Tcrb-deficient mice. Mechanistically, the FOXP3 ΔE2 isoform allows increased expression of selected cytokines, but decreased expression of a set of positive regulators of Foxp3 without altered binding to these gene loci. These findings uncover indispensable functions of the FOXP3 exon 2 region, highlighting a role in regulating a transcriptional program that maintains Treg stability and immune homeostasis.
  • Thumbnail Image
    Item
    FOXP3 interacts with hnRNPF to modulate pre-mRNA alternative splicing
    (American Society for Biochemistry and Molecular Biology, 2018-06-29) Du, Jianguang; Wang, Qun; Ziegler, Steven F.; Zhou, Baohua; Microbiology and Immunology, School of Medicine
    FOXP3 promotes the development and function of regulatory T cells mainly through regulating the transcription of target genes. RNA alternative splicing has been implicated in a wide range of physiological and pathophysiological processes. We report here that FOXP3 associates with heterogeneous nuclear ribonucleoprotein (hnRNP) F through the exon 2-encoded region of FOXP3 and the second quasi-RNA recognition motif (qRRM) of hnRNPF. FOXP3 represses the ability of hnRNPF to bind to its target pre-mRNA and thus modulates RNA alternative splicing. Furthermore, overexpression of mouse hnRNPF in in vitro-differentiated regulatory T cells (Tregs) reduced their suppressive function. Thus, our studies identify a novel mechanism by which FOXP3 regulates mRNA alternative splicing to modulate the function of regulatory T cells.
  • Thumbnail Image
    Item
    Functions of Thymic Stromal Lymphopoietin in Immunity and Disease
    (Springer, 2012) Zhang, Yanlu; Zhou, Baohua; Pediatrics, School of Medicine
    Thymic stromal lymphopoietin (TSLP) is an interleukin 7-like cytokine expressed mainly by epithelial cells. Current studies provide compelling evidence that TSLP is capable of activating dendritic cells to promote T helper (Th) 2 immune responses. TSLP has also been shown to directly promote Th2 differentiation of naïve CD4(+) T cell and activate natural killer T cells, basophils and other innate immune cells at the initial stage of inflammation. In addition, TSLP affects B cell maturation and activation and can also influence regulatory T (Treg) cell differentiation and development. TSLP-induced Th2 responses are associated with the pathogenesis of allergic inflammatory diseases, including atopic dermatitis, asthma, and rhinitis. Based on recent findings in humans and mouse models, TSLP might also be involved in the pathogenesis of inflammatory bowel disease and progression of cancer. In this review, we will summarize our current understanding of the biology of TSLP and highlight the important issues for future investigations.
  • Thumbnail Image
    Item
    IL-33 promotes the egress of group 2 innate lymphoid cells from the bone marrow
    (Rockefeller University Press, 2018-01-02) Stier, Matthew T.; Zhang, Jian; Goleniewska, Kasia; Cephus, Jacqueline Y.; Rusznak, Mark; Wu, Lan; Kaer, Luc Van; Zhou, Baohua; Newcomb, Dawn C.; Peebles, R. Stokes, Jr.; Pediatrics, School of Medicine
    Group 2 innate lymphoid cells (ILC2s) are effector cells within the mucosa and key participants in type 2 immune responses in the context of allergic inflammation and infection. ILC2s develop in the bone marrow from common lymphoid progenitor cells, but little is known about how ILC2s egress from the bone marrow for hematogenous trafficking. In this study, we identified a critical role for IL-33, a hallmark peripheral ILC2-activating cytokine, in promoting the egress of ILC2 lineage cells from the bone marrow. Mice lacking IL-33 signaling had normal development of ILC2s but retained significantly more ILC2 progenitors in the bone marrow via augmented expression of CXCR4. Intravenous injection of IL-33 or pulmonary fungal allergen challenge mobilized ILC2 progenitors to exit the bone marrow. Finally, IL-33 enhanced ILC2 trafficking to the lungs in a parabiosis mouse model of tissue disruption and repopulation. Collectively, these data demonstrate that IL-33 plays a critical role in promoting ILC2 egress from the bone marrow.
  • Thumbnail Image
    Item
    IL-9 by INFERence
    (Elsevier, 2013-10-17) Zhou, Baohua; Kaplan, Mark H.; Department of Pediatrics, IU School of Medicine
    Despite discovery of the cytokine over 20 years ago, the relevant biological sources of IL-9 have remained a mystery. In this issue of Immunity, Licona-Limón et al. (2013) use a newly generated reporter mouse to demonstrate a role for IL-9-secreting T cells in helminthic parasite immunity.
  • Thumbnail Image
    Item
    Interleukin-9 is Required for Allergic Airway Inflammation Mediated by the Cytokine Thymic Stromal Lymphopoietin
    (Elsevier, 2013) Yao, Weiguo; Zhang, Yanlu; Jabeen, Rukhsana; Nguyen, Evelyn T.; Wilkes, David S.; Tepper, Robert S.; Kaplan, Mark H.; Zhou, Baohua; Pediatrics, School of Medicine
    Thymic stromal lymphopoietin (TSLP) is an epithelial cell-derived cytokine important for the initiation and development of T helper (Th2) cell-mediated allergic inflammation. In this study, we identified a positive association between interleukin-9 (IL-9) and TSLP concentration in the serum of infants with atopic dermatitis. In primary cell cultures, the addition of TSLP led to an increase in IL-9 production from human and mouse Th9 cells, and induced an increase in signal transducer and activator of transcription 5 (STAT5) activation and binding to the Il9 promoter. In vivo, use of an adoptive transfer model demonstrated that TSLP promoted IL-9-dependent, Th9 cell-induced allergic inflammation by acting directly on T cells. Moreover, transgenic expression of TSLP in the lung stimulated IL-9 production in vivo, and anti-IL-9 treatment attenuated TSLP-induced airway inflammation. Together, our results demonstrate that TSLP promotes Th9 cell differentiation and function and define a requirement for IL-9 in TSLP-induced allergic inflammation.
  • Thumbnail Image
    Item
    Interleukin-9 promotes mast cell progenitor proliferation and CCR2-dependent mast cell migration in allergic airway inflammation
    (Elsevier, 2023) Pajulas, Abigail; Fu, Yongyao; Cheung, Cherry C. L.; Chu, Michelle; Cannon, Anthony; Alakhras, Nada; Zhang, Jilu; Ulrich, Benjamin J.; Nelson, Andrew S.; Zhou, Baohua; Kaplan, Mark H.; Microbiology and Immunology, School of Medicine
    Allergic asthma is a chronic lung disease characterized by airway hyperresponsiveness and cellular infiltration that is exacerbated by immunoglobulin E-dependent mast cell (MC) activation. Interleukin-9 (IL-9) promotes MC expansion during allergic inflammation but precisely how IL-9 expands tissue MCs and promotes MC function is unclear. In this report, using multiple models of allergic airway inflammation, we show that both mature MCs (mMCs) and MC progenitors (MCp) express IL-9R and respond to IL-9 during allergic inflammation. IL-9 acts on MCp in the bone marrow and lungs to enhance proliferative capacity. Furthermore, IL-9 in the lung stimulates the mobilization of CCR2+ mMC from the bone marrow and recruitment to the allergic lung. Mixed bone marrow chimeras demonstrate that these are intrinsic effects in the MCp and mMC populations. IL-9-producing T cells are both necessary and sufficient to increase MC numbers in the lung in the context of allergic inflammation. Importantly, T cell IL-9-mediated MC expansion is required for the development of antigen-induced and MC-dependent airway hyperreactivity. Collectively, these data demonstrate that T cell IL-9 induces lung MC expansion and migration by direct effects on the proliferation of MCp and the migration of mMC to mediate airway hyperreactivity.