AUTHOR=Kogut Michael H. , Swaggerty Christina L. , Chiang Hsin-I , Genovese Kenneth J. , He Haiqi , Zhou Huaijun , Arsenault Ryan J. 

TITLE=Critical Role of Glycogen Synthase Kinase-3β in Regulating the Avian Heterophil Response to Salmonella enterica Serovar Enteritidis

JOURNAL=Frontiers in Veterinary Science

VOLUME=1

YEAR=2014

URL=https://www.frontiersin.org/journals/veterinary-science/articles/10.3389/fvets.2014.00010

DOI=10.3389/fvets.2014.00010

ISSN=2297-1769

ABSTRACT=<p>A microarray-assisted gene expression screen of chicken heterophils revealed glycogen synthase kinase-3β (GSK-3β), a multifunctional Ser/Thr kinase, to be consistently upregulated 30–180 min following stimulation with <italic>Salmonella enterica</italic> serovar Enteritidis (<italic>S</italic>. Enteritidis). The present study was designed to delineate the role of GSK-3β in regulating the innate function of chicken heterophils in response to <italic>S</italic>. Enteritidis exposure. Using a specific GSK-3β ELISA assay, 30 min after infection with <italic>S</italic>. Enteritidis, heterophils had a significant decrease (<italic>p</italic> ≤ 0.05) in total GSK-3β, but a significant increase (<italic>p</italic> ≤ 0.05) in phosphorylated GSK-3β (Ser9). By 60 min post-infection, there was no difference in the amount of phosphorylated GSK-3β (Ser9) in either the uninfected and infected heterophils. <italic>S</italic>. Enteritidis interaction with heterophils alters GSK-3β activity by stimulating phosphorylation at Ser9 and that peaks by 30 min post-infection. Further, inhibition of GSK3β with lithium chloride resulted in a significant decrease (<italic>p</italic> ≤ 0.05) in NF-κB activation and expression of IL-6, but induces a significant increase (<italic>p</italic> ≤ 0.05) in the expression of the anti-inflammatory cytokine, IL-10. Using a phospho-specific antibody array confirmed the phosphorylation of GSK-3β (Ser9) as well as the phosphorylation of the downstream cytokine-activated intracellular signaling pathway involved in stimulating immune responses, IκB, the IκB subunit IKK-β, and the NF-κB subunits p105, p65, and c-Rel. Our data revealed that the phosphorylation of GSK-3β (Ser9) is responsible for inducing and controlling an innate response to the bacteria. Our findings suggest that the repression of GSK-3 activity is beneficial to the host cell and may act as a target for treatment in controlling intestinal colonization in chickens. Further experiments will define the <italic>in vivo</italic> modulation of GSK-3 as a potential alternative to antibiotics in salmonella and other intestinal bacterial infections.</p>