Viral interleukin-10 gene transfer prevents liver ischemia-reperfusion injury: Toll-like receptor-4 and heme oxygenase-1 signaling in innate and adaptive immunity.
Ischemia-reperfusion injury (IRI) contributes to early and late dysfunction of liver transplants. We have shown that sentinel Toll-like receptor-4 (TLR4) plays a key role in the activation of T cell immune responses during hepatic IRI. We have also documented that overexpression of heme oxygenase-1 (HO-1) exerts potent cytoprotective effects. This study analyzes how adenovirus (Ad)-based viral interleukin-10 (vIL-10) gene transfer affects TLR4 and HO-1 signaling in host innate and adaptive immunity during liver IRI. Using a partial lobar warm IRI model, groups of wild-type and HO-1(+/-) knockout (KO) mice were assessed for severity of hepatocellular damage after 90 min of warm ischemia followed by 6 hr of reperfusion. Both wild-type and HO-1 (+/-) KO mice treated with Ad-vIL-10 have shown improved hepatic function (serum glutamic-oxaloacetic transaminase levels), ameliorated histological signs of IRI (Suzuki's score), decreased neutrophil accumulation (myeloperoxidase activity), and depressed tumor necrosis factor-alpha/IL-1beta, IL-2/interferon-gamma, E-selectin, and macrophage inflammatory protein-2 expression. These effects were IL-10 dependent as treatment with neutralizing antibody re-created liver IRI. In contrast, untreated wild-type and HO-1 (+/-) KO mice, as well as wild-type and HO-1 (+/-) KO mice treated with Ad-beta-Gal, showed severe hepatocellular damage due to IRI. Unlike in controls, wild-type and HO-1 (+/-) KO mice treated with Ad-vIL-10 revealed markedly depressed TLR4 and NF-kappaB expression, along with increased HO-1 and Bcl-2/Bcl-x(L) expression, as compared with respective controls. Thus, vIL-10 gene transfer prevents hepatic IRI in association with depressed expression of innate TLR4, and adaptive Th1 cytokine/chemokine programs. The induction of antioxidant HO-1 and anti-apoptotic Bcl-2/Bcl-x(L) by vIL-10 exerts synergistic cytoprotective function against antigen-independent hepatic inflammatory response triggered by IRI.
Ke
Bibo
B
Dumont-UCLA Transplant Center, Department of Surgery, David Geffen School of Medicine at UCLA, University of California, Los Angeles, Los Angeles, CA 90095, USA.
Shen
Xiu-Da
XD
Tsuchihashi
Sei-Ichiro
S
Gao
Feng
F
Araujo
Jesus A
JA
Busuttil
Ronald W
RW
Ritter
Thomas
T
Kupiec-Weglinski
Jerzy W
JW
D000818:Animals; D016207:Cytokines / Q000378:metabolism; D019610:Cytoprotection / Q000235:genetics / Q000276:immunology; D015536:Down-Regulation; D019040:E-Selectin / Q000378:metabolism; D018014:Gene Transfer Techniques; D015316:Genetic Therapy; D051547:Heme Oxygenase-1 / Q000235:genetics / Q000502:physiology*; D007113:Immunity, Innate / Q000235:genetics; D016753:Interleukin-10 / Q000032:analysis / Q000235:genetics*; D008099:Liver / Q000098:blood supply* / Q000276:immunology / Q000473:pathology; D051379:Mice; D018345:Mice, Knockout; D016328:NF-kappa B / Q000378:metabolism; D015427:Reperfusion Injury / Q000276:immunology / Q000473:pathology / Q000517:prevention & control*; D015398:Signal Transduction; D051197:Toll-Like Receptor 4 / Q000378:metabolism*
D016207:Cytokines; D019040:E-Selectin; D016328:NF-kappa B; D051197:Toll-Like Receptor 4; D016753:Interleukin-10; D051547:Heme Oxygenase-1