Hematopoietic Stem Cell Transplantation ; Histocompatibility Antigens Class I ; genetics ; Humans ; Polymorphism, Genetic ; Transplantation, Homologous

OBJECTIVETo investigate the correlation between major histocompatibility complex (MHC) class I chain-related gene A (MICA) gene alleles matching rates and graft rejection in small intestine, liver and kidney transplantation.

METHODSGenome DNA were extracted from blood samples or pathological sections collected from donors and recipients of living-related transplantation, included 4 cases of small bowel transplantation, 5 cases of liver transplantation and 6 cases of kidney transplantation. The correlation between MICA alleles matching rates and acute graft rejection was analyzed following 13 MICA alleles determination by polymerase chain reaction based on sequence-specific primers (PCR-SSP).

RESULTSHLA zygosity of all donors and recipients was confirmed to be half-matching. The recipients displaying higher matching rates of MICA alleles with donors showed lighter clinical and pathological rejection and longer survival time. On the contrary, recipients with lower matching rates of MICA alleles with donors showed severer clinical and pathological rejection and shorter survival time relatively.

CONCLUSIONMatching rates of MICA alleles has negative relevance to acute rejection, and positive relevance to survival time of recipients in small bowel, liver, and kidney transplantation.

Alleles ; Graft Rejection ; genetics ; immunology ; Histocompatibility Antigens Class I ; genetics ; Humans ; Intestine, Small ; transplantation ; Kidney Transplantation ; immunology ; Liver Transplantation ; immunology ; Living Donors ; Organ Transplantation

PURPOSE: Due to their unique capacity to self-renew and for multiple differentiation, stem cells are considered potent candidates for cell replacement therapy in many devastating diseases. However, studies on immune rejection, which is a major problem facing successful stem cell therapy, are rare. Thus, we examined MHC expression of human stem cells and effects of IFN-gamma on the MHC class I expression of the cells in order to determine whether human stem cells might be rejected after transplantation. METHODS: The MHC antigen expressions of human embryonic neural stem cell line (HB1.F3) and human breast epithelial stem cell line (M13SV1) were examined by RT-PCR and FACS. The effects of varying concentrations of IFN-gamma and of varying incubation times with IFN-gamma on the expression of MHC class I antigens in these stem cell lines were also examined by FACS. RESULTS: The results show low expression levels of MHC class I antigens on surfaces of these cells. A dramatic induction of MHC class I expression was observed when the cells were treated with IFN-gamma. Maximal induction of MHC class I antigen expression in HB1.F3 and M13SV1 cells was observed at above the concentrations of 20 ng/mL and 5 ng/mL of IFN-gamma 48 h after treatment, respectively. Elevated MHC class I levels in HB1.F3 and M13SV1 cells were sustained for 48 h and 72 h after withdrawing IFN-gamma, respectively. CONCLUSION: These results suggest that human stem cells express high levels of MHC class I antigens, and thus may be rejected on transplantation unless they are modified. Therefore, in addition to studies on stem cell differentiation, studies on overcoming the immunological barriers to stem cell transplantation are prerequisite for successful clinical application of stem cell therapy.
Adult* ; Breast* ; Histocompatibility Antigens Class I ; Humans* ; Neural Stem Cells* ; Stem Cell Transplantation ; Stem Cells*

BACKGROUND AND OBJECTIVES: Endomyocardial biopsy is obligatory during the first year after heart transplant (HTx) for the surveillance of acute rejection. Previous attempts using cardiac biomarkers for the detection of rejection failed to show enough evidence to substitute endomyocardial biopsy. Therefore, this study sought the possibility of using soluble ST2 (sST2), a novel cardiovascular marker, as a surrogate marker for acute allograft rejection after HTx. SUBJECTS AND METHODS: A total of 494 blood samples acquired at the time of endomyocardial biopsy were analyzed in 67 HTx cases from September 2006 to August 2014. Significant rejection was defined as International Society of Heart and Lung Transplant (ISHLT) score ≥2R and humoral rejection accompanied by hemodynamic instability. RESULTS: Twenty cases of HTx with 22 blood samples showed significant rejection in endomyocardial biopsy at 4.0 (2.0-9.0) months after HTx. The level of sST2 showed positive correlation with cardiac troponin I, and N-terminal pro-B-type natriuretic peptide (all p<0.001), and negative correlation with post-HTx months (p<0.001). The levels of sST2 according to the ISHLT scores were 36 (19-98), 28 (18-62), 15 (16-37), and 191 (85-343) ng/mL, consecutively 0R, 1R, 2R, and 3R+ (3R plus hemodynamically-unstable humoral rejection) (p=0.003). However, when we studied within-subject effects of sST2 using a mixed model, the sST2 level according to the predefined time point was not different according to the presence of significant rejection (p for interaction=0.94). CONCLUSION: Although sST2 is known as a promising predictor for cardiovascular events, its role in HTx patients to predict acute allograft rejection seems to be limited.
Allografts ; Biomarkers ; Biopsy ; Graft Rejection ; Heart Transplantation ; Heart* ; Hemodynamics ; Humans ; Lung ; Troponin I

OBJECTIVETo review the role of polymorphism of major histocompatibility complex class I-related chain A (MICA) gene and antibodies against MICA antigens in transplant immunology.

DATA SOURCESThe data used in this review were mainly from our own results and from the relevant English language literatures published from 1999 to 2010. Some data presented in this review are in press.

STUDY SELECTIONArticles regarding MICA gene discovery and pioneering finding of antibodies against MICA antigen and allograft rejection were selected. This review chronicles the development of our understanding of the role that MICA antigens and antibodies may play in organ transplantation.

RESULTSPolymorphic glycoprotein MICA antigens were detected on freshly isolated human umbilical cord endothelial cells, but not on peripheral lymphocytes. Antibodies were found and typing of recipients and donors by sequencing the MICA alleles has established that de novo antibodies produced in kidney transplant recipients are directed at mismatched MICA epitopes and are associated with acute rejection and chronic transplant failure. The specificity of antibodies against the epitopes of MICA antigens were well characterized by donor MICA typing, single antigen array testing with antibody absorption and elution. Acute graft-versus-host disease was observed in stem-cell recipients who were mismatched for MICA.

CONCLUSIONSImmunization against mismatched MICA epitopes encountered in donor organs after transplantation may result in antibodies against MICA alleles. Testing for MICA donor-specific antibodies (DSA) which are associated with early failure of kidney transplants may be helpful for identifying some of the targets of antibodies against antigens other than the human leukocyte antigen (HLA) and for improving transplantation outcome.

Antibodies ; immunology ; Graft Rejection ; immunology ; Histocompatibility Antigens Class I ; immunology ; Humans ; Organ Transplantation

We performed a procedure to transplant cultured growth plate chondrocyte embedded in type I collagen gel into the defects of the proximal tibial physis in a 6-week-old rabbit. Twenty eight New Zealand White rabbits were used and were divided into 4 groups, of which the medial half of the proximal epiphyseal plate of the right tibia were excised. In group I, the defects were left without collagen gel implantations served as a control. In group II, chondrocytes were embedded in collagen gel were inserted into defect, In group III, chondrocytes cultured with TGF-beta1 in collagen gel, and in group IV chondrocytes cultured with TGFbeta1 in collagen gel three weeks after excision of the growth plate. After transplantations of growth plate chondrocytes, we assessed the varus angulation and the length of tibia, and histological characteristics at 2, 4, 6, 8, and 12 weeks. Bone-bridge formation, growth artiest, and varus deformity between the tibial epiphysis and metaphysis were prevented or minimized in group III and IV. The transplanted chondrocyte retained its normal morphology in a columnar arrangement in group II, III and IV. These results indicate that it is possible to reduce varus angulation and growth arrest in epiphyseal plate defect of immature rabbits by using cultured chondrocytes embedded in type I collagen gel including TGF-beta1.
Chondrocytes* ; Collagen ; Collagen Type I ; Congenital Abnormalities ; Epiphyses ; Growth Plate* ; Rabbits ; Tibia ; Transforming Growth Factor beta1 ; Transplantation

Nanostructured materials are gaining new impetus owing to the advancements in material fabrication techniques and their unique properties (their nanosize, high surface area-to-volume ratio, and high porosity). Such nanostructured materials mimic the subtleties of extracellular matrix (ECM) proteins, creating artifi cial microenvironments which resemble the native niches in the body. On the other hand, the isolation of mesenchymal stem cells (MSCs) from various tissue sources has resulted in the interest to study the multiple differentiation lineages for various therapeutic treatments. In this review, our focus is tailored towards the potential of biomimetic nanostructured materials as osteoinductive scaffolds for bone regeneration to differentiate MSCs towards osteoblastic cell types without the presence of soluble factors. In addition to mimicking the nanostructure of native bone, the supplement of collagen and hydroxyapatite which mimic the main components of the ECM also brings signifi cant advantages to these materials.
Biomimetics ; instrumentation ; methods ; Bone Transplantation ; Collagen Type I ; Extracellular Matrix ; Humans ; Mesenchymal Stromal Cells ; Nanostructures ; Osteogenesis ; Tissue Engineering ; instrumentation ; methods

PURPOSE: Direct recognition of porcine MHC proteins by human T cells is an impediment to successful xenotransplantation. Therefore, reducing human T cell response initiated by the interaction between TCR/CD8 cell and MHC class I on pig endothelial cell may be beneficial in successful pig- to-human xenotransplantation. METHODS: We examined MHC expression on porcine endothelial cell line, MYP30 cells in the absence or presence of IFN-g by FACS analysis. We introduced human cytomegalovirus (hCMV) US genes, which are known to be able to reduce MHC class I expression on the cell surface after infection, into MYP30 cells in order to test the feasibility of modifying these cells to reduced MHC class I antigens by the introduction of hCMV US genes such as US2, 3, 6 or 11. RESULTS: MHC class I expressions in MYP30 cells were dramatically induced by IFN-gamma treatment. FACS analysis showed that cells transfected with the hCMV US2, 3, 6 or 11 genes exhibited 30~40% of MHC class I expression compared with mock-transfected cells. We next established stable cell lines expressing US6 gene, which had been found to exert best down-regulation effect on MHC class I expression. Stable cell line expressing US6 gene products exhibited more than 10% reduced expression level of the MHC class I compared with transiently transfected cells. CONCLUSION: Although the further analysis of the cytotoxicities of T and NK cells on the hCMV US gene transfected cells are needed to clarify the feasibility of their application, these results suggest that virus stealth technology can be exploited for xenotransplantation.
Cell Line ; Cytomegalovirus ; Down-Regulation* ; Endothelial Cells* ; Histocompatibility Antigens Class I ; Humans ; Killer Cells, Natural ; T-Lymphocytes ; Transplantation, Heterologous

BACKGROUNDIn addition to the well-known antibodies against human leukocyte antigens (HLA)-induced kidney-graft rejection, polymorphic major-histocompatibility-complex (MHC) class I-related chain A (MICA) antigens can elicit antibodies and have been suggested to play a role in the antibody-mediated allograft rejection (AMR). We carried out a prospective study of MICA antibodies in post-renal transplant patients to determine the association between MICA antibodies, C4d staining, histological features, and graft outcome.

METHODSWe tested 52 patients who had biopsy results due to graft dysfunction. The MICA antibodies in concurrent sera were determined by Luminex. All patients were followed up for one year after renal biopsy. The influence of antibody production on the function of graft was analyzed.

RESULTSAntibodies against MICA were positive in 15 out of the 52 patients (28.9%). The presence of MICA antibodies was associated with renal-allograft deterioration. During one-year follow-up, the estimated glomerular filtration rate (eGFR) decreased (24.0 ± 3.4)% among recipients with anti-MICA antibodies. However, among recipients without anti-MICA antibodies, the eGFR has declined only (8.4 ± 3.0)% (P = 0.017). The association between C4d staining, histological features and MICA antibody production was found no significant difference.

CONCLUSIONBesides anti-HLA antibodies, the presence of post-transplant MICA antibody is associated with poor graft outcome and increases the risk of graft failure.

Adult ; Antibodies ; blood ; immunology ; Female ; Histocompatibility Antigens Class I ; immunology ; Humans ; Kidney Transplantation ; immunology ; Male ; Middle Aged ; Prospective Studies ; Transplantation, Homologous ; immunology

The interaction of killer cell immunoglobin-like receptors (KIR) with HLA molecules has particular relevance to the genetics, immune responses and allogeneic stem cell transplantation. The genes of KIR and HLA are located in different chromosomes and segregate independently. The repertoire of KIR molecules varies among NK cells and is determined by the KIR genotype. The HLA genotype has only subtle impact on the KIR phenotype. Three major HLA specificity groups are recognized by KIRs. Donor versus recipient NK-cell alloreactivity, when recipients lack HLA ligand for their donor inhibitory KIR, can benefit allogeneic stem cell transplantation, especially the HLA haploidentical hematopoietic stem cell transplantation. The outcome of stem cell transplantation can be best predicted by the presence of KIRs on the donor's NK cells and the absence of corresponding KIR ligand in the recipient's HLA repertoire-a receptor-ligand model. In this paper the interaction of KIR and HLA in hematopoietic stem transplantation, the genetic basis of KIR and HLA, the relation of KIR expression on NK cells with HLA and the role of KIR and HLA in immune responses were reviewed.
Hematopoietic Stem Cell Transplantation ; Histocompatibility Antigens Class I ; genetics ; immunology ; Humans ; Killer Cells, Natural ; cytology ; immunology ; Receptors, Immunologic ; genetics ; immunology ; Receptors, KIR ; Transplantation Immunology