Browsing by Author "Burns, Robert"

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    CXCR5+PD-1+ follicular helper CD8 T cells control B cell tolerance
    (Springer Nature, 2019-09-27) Chen, Yuhong; Yu, Mei; Zheng, Yongwei; Fu, Guoping; Xin, Gang; Zhu, Wen; Luo, Lan; Burns, Robert; Li, Quan-Zhen; Dent, Alexander L.; Zhu, Nan; Cui, Weiguo; Malherbe, Laurent; Wen, Renren; Wang, Demin; Microbiology and Immunology, School of Medicine
    Many autoimmune diseases are characterized by the production of autoantibodies. The current view is that CD4+ T follicular helper (Tfh) cells are the main subset regulating autoreactive B cells. Here we report a CXCR5+PD1+ Tfh subset of CD8+ T cells whose development and function are negatively modulated by Stat5. These CD8+ Tfh cells regulate the germinal center B cell response and control autoantibody production, as deficiency of Stat5 in CD8 T cells leads to an increase of CD8+ Tfh cells, resulting in the breakdown of B cell tolerance and concomitant autoantibody production. CD8+ Tfh cells share similar gene signatures with CD4+ Tfh, and require CD40L/CD40 and TCR/MHCI interactions to deliver help to B cells. Our study thus highlights the diversity of follicular T cell subsets that contribute to the breakdown of B-cell tolerance.
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    Mirc11 Disrupts Inflammatory but Not Cytotoxic Responses of NK Cells
    (AACR, 2019-10) Nanbakhsh, Arash; Srinivasamani, Anupallavi; Holzhauer, Sandra; Riese, Matthew J.; Zheng, Yongwei; Wang, Demin; Burns, Robert; Reimer, Michael H.; Rao, Sridhar; Lemke, Angela; Tsaih, Shirng-Wern; Flister, Michael J.; Lao, Shunhua; Dahl, Richard; Thakar, Monica S.; Malarkannan, Subramaniam; Microbiology and Immunology, School of Medicine
    Natural killer (NK) cells generate proinflammatory cytokines that are required to contain infections and tumor growth. However, the posttranscriptional mechanisms that regulate NK cell functions are not fully understood. Here, we define the role of the microRNA cluster known as Mirc11 (which includes miRNA-23a, miRNA-24a, and miRNA-27a) in NK cell–mediated proinflammatory responses. Absence of Mirc11 did not alter the development or the antitumor cytotoxicity of NK cells. However, loss of Mirc11 reduced generation of proinflammatory factors in vitro and interferon-γ–dependent clearance of Listeria monocytogenes or B16F10 melanoma in vivo by NK cells. These functional changes resulted from Mirc11 silencing ubiquitin modifiers A20, Cbl-b, and Itch, allowing TRAF6-dependent activation of NF-κB and AP-1. Lack of Mirc11 caused increased translation of A20, Cbl-b, and Itch proteins, resulting in deubiquitylation of scaffolding K63 and addition of degradative K48 moieties on TRAF6. Collectively, our results describe a function of Mirc11 that regulates generation of proinflammatory cytokines from effector lymphocytes.