Downregulation of cytokine-induced neutrophil chemoattractant and prolongation of rat liver allograft survival by interleukin-10

Effect of β-Nicotinamide Adenine Dinucleotide on Acute Allograft Rejection After Rat Lung Transplantation

Acute rejection is still a major limitation for a successful outcome in lung transplantation. Since β-nicotinamide adenine dinucleotide (NAD+) has been shown to have various immunomodulatory properties on the innate and adaptive immune system, we evaluate here a potential protective effect of NAD+ against acute lung rejection.

Methods

Rat single-lung transplantation was performed in 2 groups (n = 8 per group), using Brown-Norway donors and major histocompatibility complex-mismatched Lewis recipients. Recipients of the NAD+ group received 1000 mg/kg NAD+ intraperitoneally before transplantation and daily thereafter until euthanasia, whereas the control group received saline solution. At autopsy on day 5, blood samples were analyzed and the lung allograft was assessed by bronchioalveolar lavage, histology, and immunochemistry.

Results

The NAD+ group maintained an intact compliant lung tissue, a strong trend of lower acute cellular rejection (A3 versus A3-A4) and significantly less lymphocytic bronchiolitis (B0-B2R versus B1R-Bx). In addition, a trend of fewer alveolar CD68+ macrophages and significantly fewer interstitial CD163+ macrophages was observed. Bronchoalveolar lavage in the NAD+ group showed significantly fewer proinflammatory cytokines interleukin (IL)-6, IL-13, TNFα, and a protective IL-6/IL-10-ratio. In blood samples, we observed significantly fewer neutrophils, and proinflammatory GRO/KC in the NAD+ group.

Conclusions

NAD+ might be a promising substance in prevention of acute allograft rejection in lung transplantation.

Inhibition of γδ-TcR or IL17a Reduces T-Cell and Neutrophil Infiltration after Ischemia/Reperfusion Injury in Mouse Liver

Neutrophil and T-cell recruitment contribute to hepatic ischemia/reperfusion injury. The initial inflammatory response is orchestrated by Kupffer cells and liver sinusoid endothelial cells. However, other cell types, including γδ-Τ cells, seem to be key mediators in further inflammatory cell recruitment and proinflammatory cytokine release, including IL17a. In this study, we used an in vivo model of partial hepatic ischemia/reperfusion injury (IRI) to investigate the role of the γδ-Τ-cell receptor (γδTcR) and the role of IL17a in the pathogenesis of liver injury. Forty C57BL6 mice were subjected to 60 min of ischemia followed by 6 h of reperfusion (RN 6339/2/2016). Pretreatment with either anti-γδΤcR antibodies or anti-IL17a antibodies resulted in a reduction in histological and biochemical markers of liver injury as well as neutrophil and T-cell infiltration, inflammatory cytokine production and the downregulation of c-Jun and NF-κΒ. Overall, neutralizing either γδTcR or IL17a seems to have a protective role in liver IRI.

Donor Preconditioning with Inhaled Sevoflurane Mitigates the Effects of Ischemia-Reperfusion Injury in a Swine Model of Lung Transplantation

Primary graft dysfunction (PGD) and ischemia-reperfusion injury (IRI) occur in up to 30% of patients undergoing lung transplantation and may impact on the clinical outcome. Several strategies for the prevention and treatment of PGD have been proposed, but with limited use in clinical practice. In this study, we investigate the potential application of sevoflurane (SEV) preconditioning to mitigate IRI after lung transplantation. The study included two groups of swines (preconditioned and not preconditioned with SEV) undergoing left lung transplantation after 24-hour of cold ischemia. Recipients' data was collected for 6 hours after reperfusion. Outcome analysis included assessment of ventilatory, hemodynamic, and hemogasanalytic parameters, evaluation of cellularity and cytokines in BAL samples, and histological analysis of tissue samples. Hemogasanalytic, hemodynamic, and respiratory parameters were significantly favorable, and the histological score showed less inflammatory and fibrotic injury in animals receiving SEV treatment. BAL cellular and cytokine profiling showed an anti-inflammatory pattern in animals receiving SEV compared to controls. In a swine model of lung transplantation after prolonged cold ischemia, SEV showed to mitigate the adverse effects of ischemia/reperfusion and to improve animal survival. Given the low cost and easy applicability, the administration of SEV in lung donors may be more extensively explored in clinical practice.

Bone marrow stem cells modified with human interleukin 10 attenuate acute rejection in rat lung allotransplantation

OBJECTIVES

The aim of this study was to investigate new therapeutic options to attenuate acute rejection in a rat lung allograft model. Cell-based gene therapies have recently been reported as a novel curative option in acute and chronic diseases for which conventional treatments are not available. We studied the effect of human interleukin 10 (hIL-10) on expressing bone marrow-derived mesenchymal stem cells (BMSCs) in combination with cyclosporine A (CsA) on acute rejection of lung allografts in the rat.

METHODS

Lung allotransplantation was performed from male Brown Norway donor to male Fisher (F344) rats. Rat BMSCs were transfected with hIL-10 in vitro and introduced in the graft prior to implantation. Group A (n = 5) received CsA intraperitoneally (2.5 mg/kg body weight) for 5 days post-transplant; Group B (n = 5) received BMSC and CsA and Group C (n = 5) received hIL-10-BMSC before implantation and CsA. Graft function was assessed by blood gas levels only from the graft on day 5; tissue was sampled for histological grading of rejection and measurement of the wet-to-dry ratio.

RESULTS

All Group A control animals showed severe signs of rejection. On Day 5, all grafts in Group C showed improved gas exchange (mean arterial partial pressure of oxygen 222.2 ± 40.38 mmHg vs 92.36 ± 20.92 mmHg in Group B and 42.72 ± 18.07 mmHg in Group A). Histological examination revealed moderate-to-severe rejection in all animals in Group A [International Society for Heart and Lung Transplantation Level III B (ISHLT)] in contrast to low-to-moderate rejection in Group B (II-IIIA) and much improved histological grade in Group C (I-IIA). Moreover, the wet-to-dry ratio was also reduced in Group C (4.8 ± 1.19 compared with 4.78 ± 0.62 in Group B and 9.36 ± 0.90 in Group A).

CONCLUSIONS

The hIL-10 BMSC represent a promising novel method for localized cell-based gene therapy for acute rejection in a rat lung allograft model.

Plasma and bronchoalveolar lavage samples in acute lung allograft rejection: the potential role of cytokines as diagnostic markers

The role of differential cytology patterns in peripheral blood and bronchoalveolar lavage samples is increasingly investigated as a potential adjunct to diagnose acute and chronic allograft dysfunction after lung transplantation. While these profiles might facilitate the diagnosis of acute cellular rejection, low sensitivity and specificity of these patterns limit direct translation in a clinical setting. In this context, the identification of other biomarkers is needed. This review article gives an overview of cytokine profiles of plasma and bronchoalveolar lavage samples during acute cellular rejection. The value of these cytokines in supporting the diagnosis of acute cellular rejection is discussed. Current findings on the topic are highlighted and experimental settings for future research projects are identified.

Interleukin-10 Gene Transfer: Prevention of Multiple Organ Injury in a Murine Cecal Ligation and Puncture Model of Sepsis

INTRODUCTION

The aim of this study was to determine the effect of immunoregulatory cytokine interleukin-10 (IL-10) gene therapy on multiple organ injury (MOI) induced by a cecal ligation and puncture (CLP) model of sepsis in mice.

METHODS

Male Balb/c mice subjected to CLP were treated with either an hIL-10-carrying vector or an empty control vector. We assessed the degree of lung, liver, and kidney tissue destruction biochemically by measuring myeloperoxidase (MPO) and malondialdehyde (MDA) activity. Histologic assessments were based on neutrophil infiltration in lung and liver tissue. IL-10 protein expression was examined immunohistochemically, and ultrastructural changes in the liver were studied by transmission electron microscopy. We analyzed the expression of tumor necrosis factor-alpha (TNFalpha) mRNA by reverse transcription polymerase chain reaction 3, 8, and 24 hours after CLP in all organs.

RESULTS

Organ damage was significantly reduced by hIL-10 gene transfer, which was associated at the tissue level with reduced MPO activity in the liver, lung, and kidney and decreased leukocyte sequestration and MDA formation in the lung. The liver MDA was not significantly higher in the hIL-10 gene therapy group than in the controls and seemed not to be affected by hIL-10 gene transfer. The reduced portal tract neutrophilic infiltration and preserved ultrastructure of the hepatocytes also showed that tissue function was not impaired. The lung and kidney TNFalpha mRNA expression was suppressed markedly in the hIL-10 gene therapy group, but liver TNFalpha mRNA expression varied over time.

CONCLUSIONS

These findings showed that IL-10 gene therapy significantly attenuated sepsis-induced MOI.

Clone culture of human interleukin-10 gene modified L02 hepatocytes and selection of cell strain with most interleukin-10 expression

AIM: To clone and culture human interleukin-10 (IL-10) gene modified L02 hepatocytes and select the cell strain highly expressing IL-10.

METHODS: With preparation of previously constructed and purified eukaryotic expression plasmid vector pchIL-10, L02 hepatocytes were transfected and then the positive clones were selected with the help of G418 pressure. Enzyme-linked immunosorbent assay (ELISA) was used to detect the expression of human IL-10 in the cells strain.

RESULTS: Sequencing and restriction endonuclease digestion confirmed that eukaryotic expression plasmid vector pchIL-10 was constructed successfully, and electrophoresis show a band of 540 bp. hIL-10 gene was highly expressed in L02 hepatocytes and the highest expression level was 69.875 ng/10⁶ cell per hour.

CONCLUSION: Human interleukin-10 (IL-10) gene modified L02 hepatocytes can highly expresses hIl-10, which may be used in the antifibrotic or cirrhotic treatment.

Interleukin-10 and chronic liver disease

Interleukin (IL)-10 is an important immunoregulatory cytokine produced by many cell populations. Numerous investigations suggest that IL-10 plays a major role in chronic liver diseases. IL-10 gene polymorphisms are possibly associated with liver disease susceptibility or severity. Recombinant human IL-10 has been produced and is currently tested in clinical trials. These trials may give new insights into the immunobiology of IL-10 and suggest that the IL-10/IL-10 receptor system may become a new therapeutic target.

Kupffer cell-dependent TNF-alpha signaling mediates injury in the arterialized small-for-size liver transplantation in the mouse

Implantation of small liver grafts causes liver injury and defective regeneration leading to graft failure. We investigated whether Kupffer cell-dependent TNF-alpha signaling contributes to this poor outcome. Partial 30% liver transplantation was performed in C57BL/6 wild-type mice (control group), and in three groups with down-regulation of the TNF-alpha pathway: (i) TNF receptor 1 knockout [TNFR-1(-/-)] mice, and mice pretreated with (ii) gadolinium chloride or (iii) pentoxifylline (PTX). Fifty-percent partial liver transplantation, a model associated with full recovery, and transplantation in IL-6 knockout [IL-6(-/-)] mice were performed in some experiments. Graft injury, regeneration, portal flow, liver microcirculation, leukocyte adhesion, and animal survival were assessed. Animal survival rates were 14% in the control group vs. 43% in the gadolinium chloride group, 57% for the TNFR-1(-/-) group, and 86% in the PTX group (P < 0.001). Markers of liver injury were reduced in all treated groups when compared with controls. Each treated group disclosed better portal flow and sinusoid perfusion, decreased leukocyte adherence, particularly in the PTX group. Liver regeneration occurred only in the treated groups. IL-6 and IL-10 levels were dramatically up-regulated (50x) in the PTX group, and at lower levels in other experimental groups. The protective effect of PTX was lost in IL-6(-/-) mice and protection was restored by a single dose of r-IL-6. In conclusion, interruption of TNF-alpha signaling or depletion of Kupffer cells improves survival after 30% liver transplantation, reduces liver injury, and enhances regeneration. The superior effects of PTX are mediated by IL-6.

The multifaceted relationship between IL-10 and adaptive immunity: putting together the pieces of a puzzle

Interleukin-10 (IL-10) is a pleiotropic cytokine that modulates the function of several adaptive immunity-related cells. Although generally considered an immunosuppressive molecule, IL-10 possesses immunostimulatory properties in several in vitro and in vivo models. These very different outcomes are believed to depend upon experimental conditions, the dominant immune effector mediating a given immune response, the timing of IL-10 production/administration, and IL-10 dose and/or location of expression. In the present work, we review the current knowledge regarding IL-10 activity on adaptive immunity related cells, emphasize new insights on IL-10 molecular/cellular targets, and summarize the available data on the relationship between IL-10 and some pathological conditions (e.g. infectious diseases, autoimmunity, allergy, cancer and transplantation) involving adaptive immunity.

The effects of endogenous interleukin-10 on gray matter damage and the development of pain behaviors following excitotoxic spinal cord injury in the mouse

Interleukin-10 (IL-10) has been utilized as a neuroprotective agent in experimental models of spinal cord injury because of its potent anti-inflammatory properties. Previous studies have delivered a single dose (5 microg) of IL-10 following experimental spinal cord injury in the rat, and demonstrated various degrees of neuroprotection. However, the role of endogenous production of IL-10 has not been considered. Therefore, the purpose of the current study was to establish the role of endogenous IL-10 and demonstrate the true potential of exogenous IL-10 administration through the use of IL-10((-/-)) mice. Using the quisqualic acid model of spinal cord injury, we examined the extent of gray matter damage and onset of injury-induced pain behaviors at various time points following injury in wild-type vs. IL-10((-/-)) mice. Additionally, IL-10 was reconstituted in IL-10 deficient mice by the intraperitoneal administration of 50 ng recombinant murine (rm) IL-10 30 min following quisqualic acid injection. Animals were observed daily following injury for the onset of pain-behaviors. At days 1, 7, and 14 following injection, lesion analysis revealed a greater extent of damage at early time points (1 day, 7 days) following injury in the IL-10((-/-)) animals as compared with wild-type animals. However, by 14 days post-experimental spinal cord injury, the extent of damage between the two groups was not significant. IL-10((-/-)) animals that received the single (50 ng) rmIL-10 injection following injury displayed gray matter damage patterns similar to wild-type animals. The pronounced early damage noted in the IL-10((-/-)) animals was associated with an approximately two-fold increase in peripheral neutrophils, an index of an innate immune response to injury, compared with wild-type mice. In addition, wild type and IL-10((-/-)) animals receiving rmIL-10 demonstrated a delay in the onset of injury-induced pain behaviors. However, by 14 days post-experimental spinal cord injury the overall incidence of pain behaviors was similar between all treatment groups. Therefore, the absence of IL-10 expression accelerates the kinetics of lesion expansion, the onset of pain behaviors, and the peripheral immune response to spinal cord injury. Endogenous IL-10 and low doses of exogenous IL-10 are neuroprotective at 1 and 7 days following injury. Therefore, the results of the current study suggest that low dose IL-10 administration acutely following spinal cord injury has potential as a therapeutic agent for limiting tissue loss following injury.

Preconditioning of donors with interleukin-10 reduces hepatic ischemia-reperfusion injury after liver transplantation in pigs

BACKGROUND

Graft ischemia-reperfusion injury (IRI) resulting from postreperfusion inflammatory reaction remains a major cause of complications after liver transplantation. In this article, the authors investigated the effect of anti-inflammatory cytokine interleukin (IL)-10 on IRI, in a preclinical model of liver transplantation in pigs.

METHODS

Donor pigs received IL-10 or saline at the start of liver graft harvesting. After 5 hr of cold ischemia, liver grafts were transplanted into untreated recipient pigs. IRI severity was measured in recipients by transaminase release and by cellular infiltration and necrosis on liver biopsy specimens.

RESULTS

Donor IL-10 administration attenuated IRI, as indicated by significant reduction of mean peak of transaminase in recipients of grafts from IL-10-treated donors. In contrast, no significant differences in cell infiltration or amount of necrosis were observed on liver biopsy specimens between groups.

CONCLUSIONS

Donor preconditioning with IL-10 may constitute an interesting pharmacologic approach to reduce IRI severity after liver transplantation.

Molecular mechanisms of hepatic ischemia-reperfusion injury and preconditioning

Ischemia-reperfusion injury is, at least in part, responsible for the morbidity associated with liver surgery under total vascular exclusion or after liver transplantation. The pathophysiology of hepatic ischemia-reperfusion includes a number of mechanisms that contribute to various degrees in the overall injury. Some of the topics discussed in this review include cellular mechanisms of injury, formation of pro- and anti-inflammatory mediators, expression of adhesion molecules, and the role of oxidant stress during the inflammatory response. Furthermore, the roles of nitric oxide in preventing microcirculatory disturbances and as a substrate for peroxynitrite formation are reviewed. In addition, emerging mechanisms of protection by ischemic preconditioning are discussed. On the basis of current knowledge, preconditioning or pharmacological interventions that mimic these effects have the greatest potential to improve clinical outcome in liver surgery involving ischemic stress and reperfusion.

Investigation of promoter polymorphisms in the tumor necrosis factor-alpha and interleukin-10 genes in liver transplant patients

BACKGROUND

Cytokines such as tumor necrosis factor (TNF)-alpha and interleukin (IL)-10 play significant roles in the inflammatory and immune responses that mediate allograft rejection. The presence of a G-->A polymorphism at position -308 in the promoter region of the TNF-alpha gene increased its transcription 6- to 7-fold. A similar polymorphism at position -1082 of the IL-10 promoter results in decreased production of IL-10 protein. In this study we have determined whether the single nucleotide polymorphisms in the promoter regions of the TNF-alpha and IL-10 genes can predict the outcome of the allograft in liver recipients.

METHODS

DNA was extracted from whole blood of liver recipients. The genotype of the patients was determined by polymerase chain reaction using sequence-specific primers. The level of TNF-alpha and IL-10 protein was measured by ELISA after stimulation of peripheral blood mononuclear cells with concanavalin A.

RESULTS

There was significant correlation between acute cellular rejection and the presence of the -308A polymorphism (P<0.001), with 8 of 13 patients with the TNF-alpha polymorphism having evidence of acute rejection. Cell stimulation studies revealed that the level of TNF-alpha protein produced by patients with liver rejection was significantly higher than for patients without rejection (P=0.001). There were no strong associations between the presence of the IL-10 polymorphisms and rejection (P=0.71).

CONCLUSIONS

This study adds to the understanding of the role of cytokine polymorphisms in liver transplants. The data suggest that cytokine promoter polymorphisms may be a risk factor associated with allograft rejection in the liver.

The role of interleukin-10 in lung transplantation

Interleukin-10 (IL-10) is a pleiotropic cytokine and its main function is to limit and terminate inflammatory responses. Lung transplantation is a relatively young clinical field compared to the transplantation of other solid organs and long-term survival is still limited. Complications after lung transplantation include ischemia-reperfusion injury immediately after transplantation, acute rejection and infection within the first year after transplantation and chronic allograft dysfunction in form of bronchiolitis obliterans thereafter. In the setting of lung transplantation two key functions of IL-10 might be of interest: (1) the inhibition of inflammatory immune responses; and (2) the inhibition of T-cell mediated immune responses. In animal models, it has been shown that exogenous IL-10 is able to prevent posttransplant ischemia-reperfusion injury as well as to decrease acute rejection. It was also effective in preventing airway obliteration in an animal model of posttransplant bronchiolitis obliterans. Beneficial effects of IL-10 may be found early and late after lung transplantation. Location of IL-10 expression as well as the timing of administration seems to be important for the desired effects.

Interleukin-10 and the interleukin-10 receptor

Interleukin-10 (IL-10), first recognized for its ability to inhibit activation and effector function of T cells, monocytes, and macrophages, is a multifunctional cytokine with diverse effects on most hemopoietic cell types. The principal routine function of IL-10 appears to be to limit and ultimately terminate inflammatory responses. In addition to these activities, IL-10 regulates growth and/or differentiation of B cells, NK cells, cytotoxic and helper T cells, mast cells, granulocytes, dendritic cells, keratinocytes, and endothelial cells. IL-10 plays a key role in differentiation and function of a newly appreciated type of T cell, the T regulatory cell, which may figure prominently in control of immune responses and tolerance in vivo. Uniquely among hemopoietic cytokines, IL-10 has closely related homologs in several virus genomes, which testify to its crucial role in regulating immune and inflammatory responses. This review highlights findings that have advanced our understanding of IL-10 and its receptor, as well as its in vivo function in health and disease.

Prolongation of sheep corneal allograft survival by ex vivo transfer of the gene encoding interleukin-10

BACKGROUND

Modification of a donor cornea by gene therapy ex vivo has potential to modulate irreversible rejection, the major cause of corneal graft failure. Our aim was to transfer the gene encoding mammalian IL-10 to ovine donor corneas and to determine subsequent orthotopic corneal allograft survival in an outbred sheep model.

METHODS

The replicative capacity of ovine corneal endothelium was determined by autoradiography after deliberate injury. A replication-defective adenovirus was used to deliver the lacZ reporter gene to ovine corneas and transfected corneas were organ-cultured in vitro to allow transfection efficiency, duration of reporter gene expression, and toxicity attributable to the vector to be determined. A cDNA encoding full-length ovine IL-10 was cloned into an adenoviral vector that was used to transfect donor corneas ex vivo before transplantation. Orthotopic penetrating corneal transplantation was performed in outbred sheep.

RESULTS

Sheep corneal endothelium was found to be essentially amitotic. Transfection of > 70% corneal endothelial cells was achieved with the viral vector and expression was maintained for 28 days in vitro. IL-10 mRNA was detectable in transfected, organ-cultured corneas for 21 days in vitro. Donor corneas transfected with cDNA encoding IL-10 showed significantly prolonged survival after penetrating keratoplasty (median 55 days, range 19 > or =300 days) compared with control corneas (median 20.5 days, range 18-32 days, P=0.011).

CONCLUSION

Local gene therapy-mediated expression of the immunomodulatory cytokine IL-10 has the potential to reduce the incidence of corneal graft rejection and to prolong corneal allograft survival.

Interleukin-10 and the Interleukin-10 Receptor

Interleukin-10 (IL-10), first recognized for its ability to inhibit activation and effector function of T cells, monocytes, and macrophages, is a multifunctional cytokine with diverse effects on most hemopoietic cell types. The principal routine function of IL-10 appears to be to limit and ultimately terminate inflammatory responses. In addition to these activities, IL-10 regulates growth and/or differentiation of B cells, NK cells, cytotoxic and helper T cells, mast cells, granulocytes, dendritic cells, keratinocytes, and endothelial cells. IL-10 plays a key role in differentiation and function of a newly appreciated type of T cell, the T regulatory cell, which may figure prominently in control of immune responses and tolerance in vivo. Uniquely among hemopoietic cytokines, IL-10 has closely related homologs in several virus genomes, which testify to its crucial role in regulating immune and inflammatory responses. This review highlights findings that have advanced our understanding of IL-10 and its receptor, as well as its in vivo function in health and disease.

Interleukin-10 inhibits pulmonary NF-kappaB activation and lung injury induced by hepatic ischemia-reperfusion

Hepatic ischemia and reperfusion cause local and remote organ injury. This injury culminates from an integrated cascade of proinflammatory cytokines, chemokines, and adhesion molecules, many of which are regulated by the transcription factor nuclear factor-kappaB (NF-kappaB). The anti-inflammatory cytokine interleukin-10 (IL-10) has been shown to have inhibitory effects on NF-kappaB. The objective of the current study was to determine whether IL-10 could suppress pulmonary NF-kappaB activation and ensuing lung injury induced by hepatic ischemia-reperfusion. C57BL/6 mice underwent partial hepatic ischemia with or without intravenous administration of IL-10. Hepatic ischemia-reperfusion resulted in pulmonary NF-kappaB activation, increased mRNA expression of tumor necrosis factor-alpha (TNF-alpha), and macrophage inflammatory protein-2 (MIP-2), as well as increased pulmonary neutrophil accumulation and lung edema. Administration of IL-10 suppressed lung NF-kappaB activation, reduced TNF-alpha and MIP-2 mRNA expression, and decreased pulmonary neutrophil recruitment and lung injury. The data suggest that IL-10 protects against hepatic ischemia and reperfusion-induced lung injury by inhibiting lung NF-kappaB activation and the resulting pulmonary production of proinflammatory mediators.

Interleukin-10 suppresses hepatic ischemia/reperfusion injury in mice: implications of a central role for nuclear factor kappaB

Ischemia/reperfusion injury of the liver requires the participation of proinflammatory cytokines, chemokines, and adhesion molecules, many of which are regulated by the transcription factor nuclear factor kappaB (NFkappaB). The anti-inflammatory cytokine, interleukin-10 (IL-10) affects inflammatory reactions, at least in part, through inhibitory effects on the transcription factor, NFkappaB. The objective of the current study was to determine whether IL-10 could suppress hepatic ischemia/reperfusion-induced NFkappaB activation and the ensuing inflammatory liver injury. C57BL/6 mice underwent partial hepatic ischemia and reperfusion with or without intravenous injections of recombinant murine IL-10. Hepatic NFkappaB activation was induced in a time-dependent fashion. IL-10 suppressed NFkappaB activation as well as messenger RNA expression of tumor necrosis factor-alpha (TNF-alpha) and macrophage inflammatory protein-2 (MIP-2). In addition, IL-10 reduced serum levels of TNF-alpha and MIP-2. Hepatic neutrophil recruitment, liver edema, and hepatocellular injury were all significantly reduced by IL-10. The data suggest that IL-10 protects against hepatic ischemia/reperfusion injury by suppressing NFkappaB activation and subsequent expression of proinflammatory mediators.