BACKGROUND: The interaction between killer immunoglobulin-like receptors (KIRs) and HLA class I regulates natural killer (NK) cell cytotoxicity and function. The impact of NK cell alloreactivity through KIR in liver transplantation remains unelucidated. Since the frequency of HLA-C and KIR genotypes show ethnic differences, we assessed the impact of HLA-C, KIR genotype, or KIR-ligand mismatch on the allograft outcome of Korean liver allografts. METHODS: One hundred eighty-two living donor liver transplant patients were studied. Thirty-five patients (19.2%) had biopsy-confirmed acute rejection (AR), and eighteen (9.9%) had graft failure. The HLA-C compatibility, KIR genotypes, ligand-ligand, and KIR-ligand matching was retrospectively investigated for association with allograft outcomes. RESULTS: Homozygous C1 ligands were predominant in both patients and donors, and frequency of the HLA-C2 allele in Koreans was lower than that in other ethnic groups. Despite the significantly lower frequency of the HLA-C2 genotype in Koreans, donors with at least one HLA-C2 allele showed higher rates of AR than donors with no HLA-C2 alleles (29.2% vs 15.7%, P=0.0423). Although KIR genotypes also showed ethnic differences, KIR genotypes and the number of activating KIR/inhibitory KIR were not associated with the allograft outcome. KIR-ligand mismatch was expected in 31.6% of Korean liver transplants and had no impact on AR or graft survival. CONCLUSIONS: This study could not confirm the clinical impact of KIR genotypes and KIR-ligand mismatch. However, we demonstrated that the presence of HLA-C2 allele in the donor influenced AR of Korean liver allografts.
Adult ; Alleles ; Asian Continental Ancestry Group/*genetics ; Female ; Genotype ; Graft Rejection ; Graft Survival ; HLA-C Antigens/*genetics ; Homozygote ; Humans ; Killer Cells, Natural/cytology/immunology ; Ligands ; *Liver Transplantation ; Male ; Middle Aged ; Proportional Hazards Models ; Receptors, KIR/chemistry/*genetics/metabolism ; Republic of Korea ; Tissue Donors ; Transplantation, Homologous

OBJECTIVETo investigate the effects of inhibiting TIM-4 function in Kupffer cells (KCs) on liver graft rejection in mice and explore the underlying mechanism.

METHODSMouse models of orthotopic liver transplantation were treated with a control mAb group and TIM-4 mAb. The activated KCs were assayed with immunohistochemistry after operation. The expression of TIM-4 in KCs were assayed with Western blotting and RT-PCR and the levels of AST, ALT, TBIL, TNF-α, IFN-γ and CCL2 were assayed detected. The expression of TIM-4 in KCs was observed with laser confocal microscopy. HE staining was used to observe the microstructure of the liver tissues, and the number of CD25Foxp3T cells was determined using with flow cytometry; the proteins levels of p-P65and p-P38 were assayed with Western blotting. The donor mice were treated with clodronate liposomes to destroy the KCs in the liver before transplantation, and the liver grafts were examined for graft rejection.

RESULTSThe number of activated KCs in the liver graft increased progressively over time. Compared with the sham-operated group, the liver graft showed significantly increased TIM-4 protein and mRNA levels at 1, 3, and 7 days after transplantation (P<0.05) and increased levels of AST, ALT, TBIL, TNF-α, IFN-γ and CCL2 at 7 days (P<0.05). The graft in TIM-4 mAb group showed mild pathological changes with a mean RAI score of 2.67∓0.75, which was significantly lower than that in control mAb group (P<0.05). The mean survival time of the recipient mice was 53.8∓6.4 days in TIM-4 mAb group, significantly longer than that in the control mAB group (14.5∓2.9 days, P<0.05). Donor treatment with clodronate liposomes resulted in comparable RAI scores in TIM-4 mAb and control mAb groups (8.01∓0.64 vs 7.93∓0.56, P>0.05). The protein levels of p-P65 and p-P38 in TIM-4 mAb group were significantly lower than those in control mAb group (P<0.05), and CD25Foxp3T cells in the liver graft increased significantly in TIM-4 mAb group.

CONCLUSIONInhibition of TIM-4 function in KCs reduces the production of inflammatory factors after liver transplantation possibly by inhibiting the NF-κB and MAPK signaling pathways and promoting the proliferation of Foxp3Treg cells to induce allograft tolerance.

Animals ; Antibodies, Monoclonal ; pharmacology ; Graft Rejection ; Immunohistochemistry ; Kupffer Cells ; drug effects ; metabolism ; Liver ; surgery ; Liver Transplantation ; Male ; Membrane Proteins ; antagonists & inhibitors ; Mice ; NF-kappa B ; metabolism ; T-Lymphocytes, Regulatory ; immunology

OBJECTIVETo compare the serum miR-663 levels in renal transplant patients with and without acute rejection (AR) and explore the role of miR-663 acute renal graft rejection.

METHODSReal time-PCR was used to determine serum miR-663 levels in renal transplant recipients with and without AR. MTT assay and Annexin V-FITC assay were employed to examine the viability and apoptosis of human renal glomerular endothelial cells (HRGEC) treated with a miR-663 mimic or a miR-663 inhibitor, and ELISA was performed to detect the expression of inflammation-related cytokines including IL-6, IFN-γ, CCL-2 and TNF-α in the cells. Transwell assay was used to examine the effect of miR-663 mimic and miR-663 inhibitor on the chemotactic capability of macrophages.

RESULTSSerum miR-663 level was significantly higher in renal transplant recipients with AR than in those without AR. The miR-663 mimic significantly inhibited the viability of HRGECs and increase the cell apoptosis rate, while miR-663 inhibitor suppressed the cell apoptosis. The miR-663 mimic increased the expression levels of inflammation-related cytokines and enhanced the chemotactic capability of macrophages.

CONCLUSIONmiR-663 might play important roles in acute renal graft rejection and may become a therapeutic target for treating AR.

Apoptosis ; Cells, Cultured ; Cytokines ; metabolism ; Endothelial Cells ; cytology ; Graft Rejection ; blood ; Humans ; Kidney Glomerulus ; cytology ; Kidney Transplantation ; Macrophages ; cytology ; drug effects ; MicroRNAs ; blood

In allogeneic transplantation, including the B6 anti-BALB.B settings, H60 and H4 are two representative dominant minor histocompatibility antigens that induce strong CD8 T-cell responses. With different distribution patterns, H60 expression is restricted to hematopoietic cells, whereas H4 is ubiquitously expressed. H60-specific CD8 T-cell response has been known to be dominant in most cases of B6 anti-BALB.B allo-responses, except in the case of skin transplantation. To understand the mechanism underlying the subdominance of H60 during allogeneic skin transplantation, we investigated the dynamics of the H60-specific CD8 T cells in B6 mice transplanted with allogeneic BALB.B tail skin. Unexpectedly, longitudinal bioluminescence imaging and flow cytometric analyses revealed that H60-specific CD8 T cells were not always subdominant to H4-specific cells but instead showed a brief dominance before the H4 response became predominant. H60-specific CD8 T cells could expand in the draining lymph node and migrate to the BALB.B allografts, indicating their active participation in the anti-BALB.B allo-response. Enhancing the frequencies of H60-reactive CD8 T cells prior to skin transplantation reversed the immune hierarchy between H60 and H4. Additionally, H60 became predominant when antigen presentation was limited to the direct pathway. However, when antigen presentation was restricted to the indirect pathway, the expansion of H60-specific CD8 T cells was limited, whereas H4-specific CD8 T cells expanded significantly, suggesting that the temporary immunodominance and eventual subdominance of H60 could be due to their reliance on the direct antigen presentation pathway. These results enhance our understanding of the immunodominance phenomenon following allogeneic tissue transplantation.
Animals ; Antigen Presentation ; Antigen-Presenting Cells/immunology/metabolism ; CD8-Positive T-Lymphocytes/*immunology ; Epitopes, T-Lymphocyte/*immunology ; Female ; Graft Rejection/*immunology ; Interferon-gamma ; Lymphocyte Activation/immunology ; Lymphocyte Count ; Mice ; Minor Histocompatibility Antigens/*immunology/metabolism ; *Skin Transplantation ; Transplantation, Homologous

OBJECTIVETo determine whether the miRNA expression profile in peripheral blood mononuclear cells (PBMCs) differs between liver transplant recipients with long-term stable survival and those with acute rejection.

METHODSTwenty-nine liver transplant recipients with long-term stable survival (STA) group, 10 recipients with acute rejection (RJ group), and 17 healthy subjects (control group) were recruited for genome-wide microarray analysis of miRNA expressions in the PBMCs. The differentially expressed miRNAs among the 3 groups were validated by real-time PCR, and the targets of these miRNAs were predicted.

RESULTSCompared with the RJ group, the STA group showed down-regulation of 13 miRNAs in the PBMCs. Of these down-regulated miRNAs, miRNA-18b, miRNA-340 and miRNA-106b were validated by real-time PCR, and the latter two miRNAs were predicted to target the TGF-β pathway.

CONCLUSIONSThe differentially expressed miRNAs in liver transplant recipients with long-term stable survival, namely miRNA-18b, miRNA-340 and miRNA-106b, can be potential clinical biomarkers to predict the outcomes of liver transplantation.

Biomarkers ; metabolism ; Case-Control Studies ; Down-Regulation ; Graft Rejection ; Humans ; Leukocytes, Mononuclear ; metabolism ; Liver Transplantation ; MicroRNAs ; metabolism ; Oligonucleotide Array Sequence Analysis ; Real-Time Polymerase Chain Reaction ; Survival Rate ; Transforming Growth Factor beta

OBJECTIVETo investigate the effects of ursolic acid on corneal graft rejection in a rat model of othotopic corneal allograft transplantation.

METHODSForty-eight recipient Wistar rats were divided into normal control group with saline treatment (group A), autograft group with saline treatment (group B), SD rat allograft group with saline treatment (group C), and SD rat allograft group with intraperitoneal ursolic acid (UA) treatment group (group D). The rats received saline or UC (20 mg·kg(-1)·d(-1)) treatment for 12 days following othotopic graft transplantation. The grafts were evaluated using the Larkin corneal rejection rating system, and the graft survival was assessed with Kaplan-Meier analysis. On day 14, the grafts were harvested for histological examination, Western blotting, and assessment of expressions of interlukin-2 (IL-2), interferon-γ (IFN-γ), nuclear transcription factor-κB (NF-κB) p65, vascular endothelial growth factor (VEGF) and intercellular adhesion molecule-1 (ICAM-1).

RESULTSThe allograft survival was significantly longer in group D than in group C (29.12±9.58 vs 9.67±2.16 days, P<0.05). UC treatment obviously reduced the expression levels of IL-2, IFN-γ, NF-κBp65, ICAM-1 and VEGF and increased inhibitory kappa B alpha (IκB-α) expression in the grafts, where no obvious inflammatory cell infiltration or corneal neovascularization was found.

CONCLUSIONAs a NF-κB inhibitor, ursolic acid can prevent corneal neovascularization and corneal allograft rejection to promote graft survival in rats following orthotopic corneal allograft transplantation.

Animals ; Cornea ; metabolism ; Corneal Neovascularization ; prevention & control ; Corneal Transplantation ; Graft Rejection ; prevention & control ; Graft Survival ; drug effects ; I-kappa B Proteins ; metabolism ; Intercellular Adhesion Molecule-1 ; metabolism ; Interferon-gamma ; metabolism ; Kaplan-Meier Estimate ; NF-KappaB Inhibitor alpha ; Rats ; Rats, Sprague-Dawley ; Rats, Wistar ; Transcription Factor RelA ; metabolism ; Transplantation, Homologous ; Triterpenes ; pharmacology ; Vascular Endothelial Growth Factor A ; metabolism

BACKGROUNDOX40/OX40 ligand (OX40/OX40L) and programmed death-1/programmed death ligand-1 (PD-1/PD-L1) costimulatory signals play important roles in T cell-induced immune responses. The aim of this study was to investigate the roles of OX40/OX40L and PD-1/PD-L1 costimulatory pathways in mouse islet allograft rejection.

METHODSLentiviral vectors containing OX40L siRNA sequences and an adenovirus vector containing the PD-L1 gene were constructed. The streptozotocin-induced model of diabetes was established in C57BL/6 (H-2(b)) mice. Diabetic C57BL/6 mice were randomly allocated into five groups: group 1, untreated control; group 2, Ad-EGFP treatment; group 3, Ad-PD-L1 treatment; group 4, OX40L-RNAi-LV treatment; group 5, OX40L-RNAi-LV combined with Ad-PD-L1 treatment. Lentiviral vector and the adenovirus vector were injected, singly or combined, into the caudal vein one day before islet transplantation. The islets of DBA/2 (H-2(d)) mice were transplanted into the renal subcapsular space of the diabetic recipients. Recipient blood glucose and the survival time of the allografts were monitored. Antigen-specific mixed lymphocyte reaction was also evaluated.

RESULTSThe recombinant lentiviral RNA interference vector OX40L-RNAi-LV reduced OX40L protein expression by 70%. The recombinant adenovirus vector Ad-PD-L1 increased PD-L1 protein expression in vivo in C57BL/6 recipient mice. Combined OX40L-RNAi-LV/Ad-PD-L1 treatment induced a synergistic protective effect in pancreatic islet allografts. Allograft survival time in the combined treatment group was (92.27±9.65) days, not only longer than that of the control ((6.51±0.27) days) and Ad-EGFP groups ((7.09±0.13) days) (P < 0.01), but also significantly longer than that of Ad-PD-L1 and OX40L-RNAi-LV single treatment groups ((40.64±3.95) days and (55.14±5.48) days respectively, P < 0.01). The blood glucose concentration of recipient mice in the combined treatment group was also stable and kept within the normal range. Flow cytometry analysis showed that combined OX40L-RNAi-LV/Ad-PD-L1 treatment significantly decreased proliferation in an antigen-specific mixed lymphocyte reaction. After donor DBA/2 lymphocyte stimulation, 89.71% of lymphocytes from recipient combination treatment C57BL/6 mice were not split and proliferated. In contrast, after stimulation with third party Lewis rat lymphocytes, only 45.84% lymphocytes of C57BL/6 mice were not split and proliferated.

CONCLUSIONSThis study demonstrates the successful construction of the recombinant lentivirus vector OX40L-RNAi-LV and adenovirus vector Ad-PD-L1 for the blockade of OX40/OX40L and activation of PD-1/PD-L1 costimulatory pathways simultaneously in pancreatic islet allografts in diabetic mice. Combination therapy with these two vectors resulted in inhibition of T cell activation, synergistically prolonging the survival time of pancreatic islet allografts.

Animals ; B7-H1 Antigen ; genetics ; metabolism ; Graft Rejection ; genetics ; prevention & control ; Islets of Langerhans Transplantation ; immunology ; Male ; Mice ; Mice, Inbred C57BL ; OX40 Ligand ; genetics ; metabolism ; Receptors, OX40 ; genetics ; metabolism ; Transplantation, Homologous

The induced pluripotent stem cells (iPSCs), derived by ectopic expression of reprogramming factors in somatic cells, can potentially provide unlimited autologous cells for regenerative medicine. In theory, the autologous cells derived from patient iPSCs should be immune tolerant by the host without any immune rejections. However, our recent studies have found that even syngeneic iPSC-derived cells can be immunogenic in syngeneic hosts by using a teratoma transplantation model (Nature 474:212-215, 2011). Recently two research groups differentiated the iPSCs into different germ layers or cells, transplanted those cells to the syngeneic hosts, and evaluated the immunogenicity of those cells. Both of the two studies support our conclusions that some certain but not all tissues derived from iPSCs can be immunogenic, although they claimed either "negligible" or "lack of" immunogenicity in iPSC derivatives (Nature 494:100-104, 2013; Cell Stem Cell 12:407-412, 2013). To test the immunogenicity of clinically valuable cells differentiated from human iPSCs are emergently required for translation of iPSC technology to clinics.
Animals ; Cell Cycle Proteins ; metabolism ; Cell Transplantation ; methods ; Graft Rejection ; immunology ; Induced Pluripotent Stem Cells ; immunology ; transplantation ; Membrane Proteins ; metabolism ; Mice, Knockout ; Teratoma ; immunology ; metabolism

OBJECTIVETo evaluate the association of major histocompatibility complex class I chain related gene A (MICA) antibodies with acute rejection (AR), chronic rejection (CR) and renal function after renal transplantation.

METHODSSerum MICA antibodies were detected with ELISA before and after transplantation with also examinations of panel reactive antibodies (PRA), serum creatinine, urine, graft ultrasound, lymphocyte subsets and the pathology of graft biopsy. The study was carried out in two parts to monitor MICA antibodies in acute and chronic rejections after renal transplantation.

RESULTSIn the first part of the study 18 of the 41 recipients experienced episodes of acute rejection, and the incidence rate was markedly higher in MICA(+) group than in MICA(-) group (P<0.05). Compared with the recipients with stable renal functions, the patients with acute graft rejection showed a significantly higher positivity rate of MICA antibodies. Postoperative MICA antibody monitoring showed that MICA antibody level increased gradually 2-3 days after the occurrence of acute rejection; anti-rejection treatment lowered serum creatinine to a normal level but MICA antibodies remained positive. In the second part, 21 of 40 patients had chronic graft rejection and showed significantly higher positivity rate of MICA than the patients with stable renal functions (P<0.05). In patients with chronic rejections, the serum creatinine levels were significantly higher in MICA(+) than in MICA(-) cases (P<0.05). Graft biopsy of all MICA(+) cases showed C4d deposition.

CONCLUSIONThe status of MICA antibodies can predict the occurrence and treatment outcomes of acute rejection, and also as one of the major causes of chronic graft rejection, they affect the long-term survival of the renal grafts.

Adolescent ; Adult ; Antibodies ; blood ; immunology ; Complement C4b ; metabolism ; Creatinine ; blood ; Follow-Up Studies ; Graft Rejection ; blood ; immunology ; pathology ; HLA Antigens ; immunology ; Histocompatibility Antigens Class I ; immunology ; Humans ; Kidney ; metabolism ; physiopathology ; Kidney Transplantation ; Peptide Fragments ; metabolism ; Young Adult

Transplantation of islet cells into diabetic patients is a promising therapy, provided that the islet cells are able to evade host immune rejection. With improved islet viability, this strategy may effectively reverse diabetes. We applied 2% calcium alginate to generate small and large capsules to encapsulate porcine neonatal pancreatic cell clusters (NPCCs) using an air-driven encapsulator. After encapsulation, the viability was assessed at 1, 4, 7, 14 and 28 days and secretion of functional insulin in response to glucose stimulation were tested at days 14 and 28. Selective permeability of the small alginate capsules was confirmed using various sizes of isothiocyanate-labeled dextran (FITC-dextran). Encapsulation of NPCCs was performed without islet protrusion in the small and large capsules. The viability of NPCCs in all experimental groups was greater than 90% at day 1 and then gradually decreased after day 7. The NPCCs encapsulated in large capsules showed significantly lower viability (79.50 +/- 2.88%) than that of naive NPCCs and NPCCs in small capsule (86.83 +/- 2.32%, 87.67 +/- 2.07%, respectively) at day 7. The viability of naive NPCCs decreased rapidly at day 14 (75.67 +/- 1.75%), whereas the NPCCs encapsulated in small capsules maintained (82.0 +/- 2.19%). After 14 and 28 days NPCCs' function in small capsules (2.67 +/- 0.09 and 2.13 +/- 0.09) was conserved better compared to that of naive NPCCs (2.04 +/- 0.25 and 1.53 +/- 0.32, respectively) and NPCCs in large capsules (2.04 +/- 0.34 and 1.13 +/- 0.10, respectively), as assessed by a stimulation index. The small capsules also demonstrated selective permeability. With this encapsulation technique, small capsules improved the viability and insulin secretion of NPCCs without islet protrusion.
Alginates/chemistry/metabolism ; Animals ; Animals, Newborn ; Capsules/chemistry ; Cell Survival ; Diabetes Mellitus/pathology/*therapy ; Disease Models, Animal ; Glucuronic Acid/chemistry/metabolism ; Graft Rejection/etiology/*prevention & control ; Hexuronic Acids/chemistry/metabolism ; Humans ; Insulin/secretion ; Islets of Langerhans/*metabolism/pathology ; Islets of Langerhans Transplantation/*methods ; Postoperative Complications/etiology/*prevention & control ; *Swine