The role of glycogen synthase kinase 3-beta in interferon beta biology.

Interferon;Glycogen synthase kinase 3;Toll-like receptors;IL-10

Huizhi Wang, 1975-

University:University of Louisville

Department:Microbiology and Immunology

关键词: Interferon;    Glycogen synthase kinase 3;    Toll-like receptors;    IL-10;   

Others  :  https://ir.library.louisville.edu/cgi/viewcontent.cgi?article=2515&context=etd

美国|英语

来源: The Universite of Louisville's Institutional Repository

【 摘 要 】

It has been shown that GSK3 ß plays a critical role in the inflammation response by differentially regulating MyD88-dependent pro- and anti-inflammatory cytokines production in TLR4-stimulated innate immune cells. The work included in this dissertation demonstrates that (I) GSK3ß negatively regulates the production of the TLR4 dependent and MyD88-independent cytokine, IFN ß, by controlling the levels of total c-Jun and thereby modulating the amount of c-Jun /ATF2 complexes, and (II) that IFN ß induces IL-10 in dendritic cells by regulating GSK3 ß activity. Part I: TLR4 stimulation of macrophages has been shown to induce the production of interferon-ß (IFN-ß) via the MyD88-independent pathway. Here we demonstrate that glycogen synthase kinase 3-ß (GSK3-ß) plays a fundamental role in this process. Suppression of GSK3-ß activity by pharmacological inhibition, siRNA-mediated gene silencing, or ectopic expression of a kinase-dead GSK3-ß mutant, augmented IFN-ß production by TLR4-stimulated macrophages. Conversely, ectopic expression of a constitutively active GSK3-ß mutant severely attenuated IFN-ß production. GSK3-ß was found to negatively control the cellular levels of the transcription factor c-Jun and its nuclear association with ATF-2. siRNA-mediated knockdown of c-Jun levels abrogated the ability of GSK3-ß inhibition to augment IFN-ß production by TLR4 stimulated macrophages. Inhibition of GSK3 in vivo resulted in potently augmenting the systemic levels of IFN-ß in mice that were administered LPS. These findings identified a novel regulatory pathway controlling IFN-ß production by TLR4-stimulated innate immune cells. Part II: IFN-ß is known to induce the production of IL-10 by innate immune cells, yet the underlying cellular mechanisms responsible for this effect are unknown. Here, we demonstrate that the constitutively active serine/threonine kinase, GSK3-ß, controls the IFN-ß-mediated production of IL-10 by human dendritic cells. Stimulation of cells with IFN-ß induced the activation of the phosphatidylinositol 3-kinase (PI3K) pathway and blockade of PI3K activity inhibited the ability of IFN-ß to induce IL-10 production. Assessment of downstream kinases within the PI3K pathway demonstrated that IFN-ß induced the phosphorylation and subsequent suppression of GSK3ß activity. Direct inhibition of GSK3 activity via pharmacological inhibition, siRNA-mediated knockdown of GSK3-ß, or ectopic expression of a kinase dead GSK3-ß potently augmented the levels of IL-10 produced by type I IFN-stimulated dendritic cells, whereas no affect on the production of pro-inflammatory cytokines was observed. In contrast, ectopic expression of a constitutively active GSK3-ß mutant severely attenuated the levels of IL-10 produced by IFN-ß-stimulated cells. Analysis of transcription factors involved in the regulation of IL-10 showed that