RESUMO
Islet transplantation is a promising therapy for diabetes treatment. However, the molecular underpinnings governing the immune response, particularly T-cell dynamics in syngeneic and allogeneic transplant settings, remain poorly understood. Understanding these T cell dynamics is crucial for enhancing graft acceptance and managing diabetes treatment more effectively. This study aimed to elucidate the molecular mechanisms, gene expression differences, biological pathway alterations, and intercellular communication patterns among T-cell subpopulations after syngeneic and allogeneic islet transplantation. Using single-cell RNA sequencing, we analyzed cellular heterogeneity and gene expression profiles using the Seurat package for quality control and dimensionality reduction through t-SNE. Differentially expressed genes (DEGs) were analyzed among different T cell subtypes. GSEA was conducted utilizing the HALLMARK gene sets from MSigDB, while CellChat was used to infer and visualize cell-cell communication networks. Our findings revealed genetic variations within T-cell subpopulations between syngeneic and allogeneic islet transplants. We identified significant DEGs across these conditions, highlighting molecular discrepancies that may underpin rejection or other immune responses. GSEA indicated activation of the interferon-alpha response in memory T cells and suppression in CD4+ helper and γδ T cells, whereas TNFα signaling via NFκB was particularly active in regulatory T cells, γδ T cells, proliferating T cells, and activated CD8+ T cells. CellChat analysis revealed complex communication patterns within T-cell subsets, notably between proliferating T cells and activated CD8+ T cells. In conclusion, our study provides a comprehensive molecular landscape of T-cell diversity in islet transplantation. The insights into specific gene upregulation in xenotransplants suggest potential targets for improving graft tolerance. The differential pathway activation across T-cell subsets underscores their distinct roles in immune responses posttransplantation.
Assuntos
Transplante das Ilhotas Pancreáticas , Análise de Célula Única , Transplante Homólogo , Animais , Camundongos , Análise de Célula Única/métodos , Camundongos Endogâmicos C57BL , Análise de Sequência de RNA , Transcriptoma , Transplante Isogênico , Perfilação da Expressão Gênica , Diabetes Mellitus Experimental/imunologia , Diabetes Mellitus Experimental/genética , Rejeição de Enxerto/imunologia , Rejeição de Enxerto/genética , Masculino , Subpopulações de Linfócitos T/imunologia , Subpopulações de Linfócitos T/metabolismo , Camundongos Endogâmicos BALB C , Linfócitos T/imunologia , Linfócitos T/metabolismo , Sobrevivência de Enxerto/imunologia , Sobrevivência de Enxerto/genéticaRESUMO
This study examines the interplay between human leukocyte antigen (HLA) compatibility and killer-cell immunoglobulin-like receptor (KIR) genotypes in influencing kidney transplantation outcomes. Understanding these interactions is crucial for improving graft survival and minimizing rejection risks. We evaluated 84 kidney transplant recipients, dividing them into two groups based on post-transplant outcomes: there were 68 with stable graft function (SGF) and 16 who experienced chronic rejection (CR). Patients were selected based on specific inclusion criteria. HLA mismatches (Class I: HLA-A, -B; Class II: HLA-DR) and KIR genotypes were determined using standard genotyping techniques. Statistical analyses, including logistic regression, were performed to correlate these factors with transplant outcomes. Significant age differences were observed, with younger patients more likely to experience graft rejection, while no significant gender-based differences were noted. A significant correlation was found between Class II mismatches and increased rejection rates, highlighting the importance of HLA-DR compatibility. Further analysis revealed that certain inhibitory KIRs, such as KIR3DL1, were associated with favorable outcomes, suggesting a protective role against graft rejection. These findings were corroborated by evaluating serum creatinine levels over multiple years, serving as a biomarker for renal function post transplant. This study underscores the critical need for meticulous HLA matching and the consideration of KIR genotypes in pre-transplant evaluations to enhance graft survival and minimize rejection risks. Integrating these genetic factors into routine clinical assessments could significantly improve personalized transplant medicine strategies, ultimately enhancing patient outcomes. Further research is needed to explore the underlying mechanisms and validate these findings in larger, diverse populations.
Assuntos
Genótipo , Rejeição de Enxerto , Sobrevivência de Enxerto , Transplante de Rim , Receptores KIR , Humanos , Transplante de Rim/efeitos adversos , Masculino , Feminino , Pessoa de Meia-Idade , Receptores KIR/genética , Rejeição de Enxerto/genética , Rejeição de Enxerto/imunologia , Adulto , Sobrevivência de Enxerto/genética , Sobrevivência de Enxerto/imunologia , Antígenos HLA/genética , Antígenos HLA/imunologia , IdosoRESUMO
Heart transplantation is associated with major hurdles, including the limited number of available organs for transplantation, the risk of rejection due to genetic discrepancies, and the burden of immunosuppression. In this study, we demonstrated the feasibility of permanent genetic engineering of the heart during ex vivo perfusion. Lentiviral vectors encoding for short hairpin RNAs targeting beta2-microglobulin (shß2m) and class II transactivator (shCIITA) were delivered to the graft during two hours of normothermic EVHP. Highly efficient genetic engineering was indicated by stable reporter gene expression in endothelial cells and cardiomyocytes. Remarkably, swine leucocyte antigen (SLA) class I and SLA class II expression levels were decreased by 66% and 76%, respectively, in the vascular endothelium. Evaluation of lactate, troponin T, and LDH levels in the perfusate and histological analysis showed no additional cell injury or tissue damage caused by lentiviral vectors. Moreover, cytokine secretion profiles (IL-6, IL-8, and TNF-α) of non-transduced and lentiviral vector-transduced hearts were comparable. This study demonstrated the ex vivo generation of genetically engineered hearts without compromising tissue integrity. Downregulation of SLA expression may contribute to reduce the immunogenicity of the heart and support graft survival after allogeneic or xenogeneic transplantation.
Assuntos
Vetores Genéticos , Transplante de Coração , Antígenos de Histocompatibilidade Classe I , Lentivirus , Animais , Lentivirus/genética , Transplante de Coração/métodos , Vetores Genéticos/genética , Suínos , Antígenos de Histocompatibilidade Classe I/genética , Antígenos de Histocompatibilidade Classe I/imunologia , Antígenos de Histocompatibilidade Classe I/metabolismo , Perfusão/métodos , Antígenos de Histocompatibilidade Classe II/genética , Antígenos de Histocompatibilidade Classe II/metabolismo , Antígenos de Histocompatibilidade Classe II/imunologia , Microglobulina beta-2/genética , Citocinas/metabolismo , Engenharia Genética , Miócitos Cardíacos/metabolismo , Miócitos Cardíacos/imunologia , Humanos , RNA Interferente Pequeno/genética , Sobrevivência de Enxerto/imunologia , Sobrevivência de Enxerto/genética , Células Endoteliais/metabolismo , Células Endoteliais/imunologia , Proteínas Nucleares , TransativadoresRESUMO
Rejection is one of the major factors affecting the long-term prognosis of kidney transplantation, and timely recognition and aggressive treatment of rejection is essential to prevent disease progression. RBPs are proteins that bind to RNA to form ribonucleoprotein complexes, thereby affecting RNA stability, processing, splicing, localization, transport, and translation, which play a key role in post-transcriptional gene regulation. However, their role in renal transplant rejection and long-term graft survival is unclear. The aim of this study was to comprehensively analyze the expression of RPBs in renal rejection and use it to construct a robust prediction strategy for long-term graft survival. The microarray expression profiles used in this study were obtained from GEO database. In this study, a total of eight hub RBPs were identified, all of which were upregulated in renal rejection samples. Based on these RBPs, the renal rejection samples could be categorized into two different clusters (cluster A and cluster B). Inflammatory activation in cluster B and functional enrichment analysis showed a strong association with rejection-related pathways. The diagnostic prediction model had a high diagnostic accuracy for T cell mediated rejection (TCMR) in renal grafts (area under the curve = 0.86). The prognostic prediction model effectively predicts the prognosis and survival of renal grafts (p < .001) and applies to both rejection and non-rejection situations. Finally, we validated the expression of hub genes, and patient prognosis in clinical samples, respectively, and the results were consistent with the above analysis.
Assuntos
Rejeição de Enxerto , Sobrevivência de Enxerto , Transplante de Rim , Proteínas de Ligação a RNA , Humanos , Transplante de Rim/efeitos adversos , Rejeição de Enxerto/genética , Sobrevivência de Enxerto/genética , Proteínas de Ligação a RNA/genética , Prognóstico , Perfilação da Expressão GênicaRESUMO
African American (AA) kidney recipients have a higher risk of allograft rejection and failure compared to non-AAs, but to what extent these outcomes are due to genetic versus environmental effects is currently unknown. Herein, we tested the effects of recipient self-reported race versus genetic proportion of African ancestry (pAFR), and neighborhood socioeconomic status (SES) on kidney allograft outcomes in multiethnic kidney transplant recipients from Columbia University (N = 1083) and the University of Pennsylvania (N = 738). All participants were genotyped with SNP arrays to estimate genetic admixture proportions. US census tract variables were used to analyze the effect of neighborhood factors. In both cohorts, self-reported recipient AA race and pAFR were individually associated with increased risk of rejection and failure after adjustment for known clinical risk factors and neighborhood SES factors. Joint analysis confirmed that self-reported recipient AA race and pAFR were both associated with a higher risk of allograft rejection (AA: HR 1.61 (1.31-1.96), P = 4.05E-06; pAFR: HR 1.90 (1.46-2.48), P = 2.40E-06) and allograft failure (AA: HR 1.52 (1.18-1.97), P = .001; pAFR: HR 1.70 (1.22-2.35), P = .002). Further research is needed to disentangle the role of genetics versus environmental, social, and structural factors contributing to poor transplantation outcomes in kidney recipients of African ancestry.
Assuntos
Rejeição de Enxerto , Sobrevivência de Enxerto , Transplante de Rim , Autorrelato , Humanos , Masculino , Feminino , Pessoa de Meia-Idade , Rejeição de Enxerto/genética , Rejeição de Enxerto/etiologia , Sobrevivência de Enxerto/genética , Fatores de Risco , Adulto , Prognóstico , Seguimentos , População Urbana , Negro ou Afro-Americano/genética , Falência Renal Crônica/cirurgia , Falência Renal Crônica/genética , Transplantados , Etnicidade/genética , Características da Vizinhança , Taxa de Filtração Glomerular , Testes de Função Renal , Estudos de CoortesRESUMO
To study the impact of four gene polymorphisms on acute renal allograft rejection (AR) and graft survival among Egyptian population. These 4 gene polymorphisms include: (1) CD 28 (rs3116496), (2) CD86 (rs1129055), (3) CTLA-4 (rs3087243), (4) PD-1 (rs2227982). This is a non-concurrent cohort study including 50 kidney transplant recipients diagnosed histopathologically as (AR) [study group] and another 50 matched allograft recipients without AR [control group]. Blood samples were taken from both groups and subjected to genotyping for the selected four genetic polymorphisms by TaqMan genotyping assay. The difference in genotypic distribution of CD 28: rs3116496 and CD86: rs1129055 wasn't statistically significant between the study and control groups (P = 0.22 and 0.33 respectively) and also both polymorphisms had no effect on graft survival (P = 0.36 and 0.74 respectively) while the addition of C allele to IVS3 +17T/C polymorphism in CD28 gene showed a protective effect against AR (P = 0.03). CTLA-4: rs3087243 AG genotype showed a protective effect against AR as it was more frequent in no rejection group compared to those with AR (P = 0.001) with a statistically significant impact on graft survival (P < 0.001), while PD-1: rs2227982 AG genotype was equally distributed between both groups (variant of unknown significance). There was no detected association between CD86 polymorphism: rs1129055 and CD 28 polymorphism: rs3116496 with the development of AR. However, C allele of CD 28 IVS3 +17T/C polymorphism and CTLA-4 polymorphism: rs3087243AG genotype both demonstrated a protective effect against AR.
Assuntos
Transplante de Rim , Receptor de Morte Celular Programada 1 , Humanos , Receptor de Morte Celular Programada 1/genética , Antígeno CTLA-4/genética , Sobrevivência de Enxerto/genética , Estudos de Coortes , Egito , Transplante de Rim/efeitos adversos , Polimorfismo Genético , AloenxertosRESUMO
BACKGROUND: The mature state of dendritic cells (DCs) determines their ability to regulate immune responses. Retinoic acid-inducible gene-1 (RIG-1) plays a critical role in DC activation and maturation. RIG-1 activation triggers mitogen-activated protein kinase and nuclear factor-kappa B signal transduction. In this study, we aimed to investigate the effects of inhibiting RIG-1 expression in DCs and its potential in inducing immune tolerance. METHODS: DCs were transduced with the recombinant lentiviral vector (Lv) to inhibit RIG-1 expression. A murine islet and skin transplantation model were constructed to find out whether DC-DDX58-RNAi could prolong allograft survival. The phenotypes of DCs and T-cells were analyzed using flow cytometry. Cytokines in serum were detected by the enzyme-linked immunosorbent assay. Protein levels were determined by Western blot. RESULTS: RIG-1-deficient DCs had low expression of costimulatory molecules and major histocompatibility complex and a strong phagocytic ability. DC-DDX58-RNAi induced regulatory T cell differentiation in the transplant recipient spleens. The DC-DDX58-RNAi-treated recipients showed satisfactory islet allograft function and longer survival time. CONCLUSION: Inhibition of RIG-1 with DDX58-RNAi prevented the activation and maturation of the DCs, affected T cell differentiation, protected the biological function of the allograft, and prolonged graft survival. These findings may have important therapeutic implications for new immunomodulatory regimens.
Assuntos
Linfócitos T , Tretinoína , Camundongos , Animais , Tretinoína/farmacologia , Linfócitos T/metabolismo , Citocinas/metabolismo , Sobrevivência de Enxerto/genética , Aloenxertos , Células Dendríticas/metabolismo , Camundongos Endogâmicos C57BLRESUMO
Donor-recipient (D-R) mismatches outside of human leukocyte antigens (HLAs) contribute to kidney allograft loss, but the mechanisms remain unclear, specifically for intronic mismatches. We quantified non-HLA mismatches at variant-, gene-, and genome-wide scales from single nucleotide polymorphism (SNP) data of D-Rs from 2 well-phenotyped transplant cohorts: Genomics of Chronic Allograft Rejection (GoCAR; n = 385) and Clinical Trials in Organ Transplantation-01/17 (CTOT-01/17; n = 146). Unbiased gene-level screening in GoCAR uncovered the LIMS1 locus as the top-ranked gene where D-R mismatches associated with death-censored graft loss (DCGL). A previously unreported, intronic, LIMS1 haplotype of 30 SNPs independently associated with DCGL in both cohorts. Haplotype mismatches showed a dosage effect, and minor-allele introduction to major-allele-carrying recipients showed greater hazard of DCGL. The LIMS1 haplotype and the previously reported LIMS1 SNP rs893403 are expression quantitative trait loci (eQTL) in immune cells for GCC2 (not LIMS1), which encodes a protein involved in mannose-6-phosphase receptor (M6PR) recycling. Peripheral blood and T cell transcriptome analyses associated the GCC2 gene and LIMS1 SNPs with the TGF-ß1/SMAD pathway, suggesting a regulatory effect. In vitro GCC2 modulation impacted M6PR-dependent regulation of active TGF-ß1 and downstream signaling in T cells. Together, our data link LIMS1 locus D-R mismatches to DCGL via GCC2 eQTLs that modulate TGF-ß1-dependent effects on T cells.
Assuntos
Transplante de Rim , Humanos , Fator de Crescimento Transformador beta1/genética , Rejeição de Enxerto/genética , Rim , Doadores de Tecidos , Antígenos HLA , Sobrevivência de Enxerto/genética , Proteínas de Membrana , Proteínas Adaptadoras de Transdução de Sinal/genética , Proteínas com Domínio LIM/genéticaRESUMO
BACKGROUND: Kidney transplant survival in African American recipients is lower compared with non-African American transplant recipients. APOL1 risk alleles (RA) have been postulated as likely contributors. We examined the graft outcomes in kidney transplant recipients (KTRs) stratified by APOL1 RA status in a multicenter observational prospective study. METHODS: The Renal Transplant Outcome Study recruited a cohort of incident KTRs at 3 transplant centers in the Philadelphia area from 1999-2004. KTRs were genotyped for APOL1 RA. Allograft and patient survival rates were compared by the presence and number of APOL1 RA. RESULTS: Among 221 participants, approximately 43% carried 2 APOL1 RA. Recipients carrying 2 APOL1 RA demonstrated lower graft survival compared with recipients with only 1 or none of APOL1 RA at 1 y posttransplant, independently of other donor and recipient characteristics (adjusted hazard ratio 3.2 [95% confidence interval, 1.0-10.4], P = 0.05). There was no significant difference in overall survival or graft survival after 3 y posttransplantation. There was no difference in death by APOL1 -risk status ( P = 0.11). CONCLUSIONS: Recipients with 2 APOL1 high-risk alleles exhibited lower graft survival 1 y posttransplantation compared with recipients with only 1 or 0 APOL1 RA. Further research is required to study the combined role of the recipient and donor APOL1 genotypes in kidney transplantation.
Assuntos
Transplante de Rim , Humanos , Transplante de Rim/efeitos adversos , Alelos , Apolipoproteína L1/genética , Rim , Doadores de Tecidos , Sobrevivência de Enxerto/genéticaRESUMO
BACKGROUND: In South Korea, pig-to-nonhuman primate trials of solid organs have only been performed recently, and the results are not sufficiently satisfactory to initiate clinical trials. Since November 2011, we have performed 30 kidney pig-to-nonhuman primate xenotransplantations at Konkuk University Hospital. METHODS: Donor αGal-knockout-based transgenic pigs were obtained from 3 institutes. The knock-in genes were CD39, CD46, CD55, CD73, and thrombomodulin, and 2-4 transgenic modifications with GTKO were done. The recipient animal was the cynomolgus monkey. We used the immunosuppressants anti-CD154, rituximab, anti-thymocyte globulin, tacrolimus, mycophenolate mofetil, and steroids. RESULTS: The mean survival duration of the recipients was 39 days. Except for a few cases for which survival durations were <2 days because of technical failure, 24 grafts survived for >7 days, with an average survival duration of 50 days. Long-term survival was observed 115 days after the removal of the contralateral kidney, which is currently the longest-recorded graft survival in Korea. We confirmed functioning grafts for the surviving transplanted kidneys after the second-look operation, and no signs of hyperacute rejection were observed. CONCLUSIONS: Although our survival results are relatively poor, they are the best-recorded results in South Korea, and the ongoing results are improving. With the support of government funds and the volunteering activities of clinical experts, we aim to further improve our experiments and contribute to the commencement of clinical trials of kidney xenotransplantation in Korea.
Assuntos
Sobrevivência de Enxerto , Rim , Animais , Suínos , Transplante Heterólogo/métodos , Macaca fascicularis , Rim/cirurgia , Animais Geneticamente Modificados , Sobrevivência de Enxerto/genética , República da Coreia , Rejeição de Enxerto/genética , Rejeição de Enxerto/prevenção & controleRESUMO
Renal transplantation is the preferred treatment of ESKD, but the shortage of suitable donor kidneys from the cadaver pool means that many patients with ESKD will not receive a kidney transplant. Xenotransplantation has long represented a solution to the kidney shortage, but the occurrence of antibody-mediated rejection has precluded its clinical development. Developments in somatic cell nuclear transfer in pigs and gene editing tools have led to the creation of new donor pigs with greatly improved crossmatches to patients. In addition, improvements in preclinical kidney xenotransplant survival using new anti-CD40/CD154-based immunosuppression have pushed xenotransplantation to the point where it is reasonable to consider initiating a clinical trial to evaluate this potential therapy in patients.
Assuntos
Rejeição de Enxerto , Sobrevivência de Enxerto , Animais , Animais Geneticamente Modificados , Sobrevivência de Enxerto/genética , Rim , Suínos , Transplante Heterólogo , HumanosRESUMO
KiT-GENIE is a monocentric DNA biobank set up to consolidate the very rich and homogeneous DIVAT French cohort of kidney donors and recipients (D/R) in order to explore the molecular factors involved in kidney transplantation outcomes. We collected DNA samples for kidney transplantations performed in Nantes, and we leveraged GWAS genotyping data for securing high-quality genetic data with deep SNP and HLA annotations through imputations and for inferring D/R genetic ancestry. Overall, the biobank included 4217 individuals (n = 1945 D + 2,272 R, including 1969 D/R pairs), 7.4 M SNPs and over 200 clinical variables. KiT-GENIE represents an accurate snapshot of kidney transplantation clinical practice in Nantes between 2002 and 2018, with an enrichment in living kidney donors (17%) and recipients with focal segmental glomerulosclerosis (4%). Recipients were predominantly male (63%), of European ancestry (93%), with a mean age of 51yo and 86% experienced their first graft over the study period. D/R pairs were 93% from European ancestry, and 95% pairs exhibited at least one HLA allelic mismatch. The mean follow-up time was 6.7 years with a hindsight up to 25 years. Recipients experienced biopsy-proven rejection and graft loss for 16.6% and 21.3%, respectively. KiT-GENIE constitutes one of the largest kidney transplantation genetic cohorts worldwide to date. It includes homogeneous high-quality clinical and genetic data for donors and recipients, hence offering a unique opportunity to investigate immunogenetic and genetic factors, as well as donor-recipient interactions and mismatches involved in rejection, graft survival, primary disease recurrence and other comorbidities.
Assuntos
Transplante de Rim , Humanos , Masculino , Pessoa de Meia-Idade , Feminino , Bancos de Espécimes Biológicos , Doadores Vivos , Sobrevivência de Enxerto/genética , DNARESUMO
Background: Ischemia reperfusion injury (IRI) is an inevitable process in renal transplantation, which is closely related to serious postoperative complications such as delayed graft function (DGF), acute rejection and graft failure. Neutrophil extracellular traps (NETs) are extracellular DNA structures decorated with various protein substances released by neutrophils under strong signal stimulation. Recently, NETs have been found to play an important role in the process of IRI. This study aimed to comprehensively analyze the expression landscape of NET-related genes (NRGs) during IRI, identify clusters with different degrees of IRI and construct robust DGF and long-term graft survival predictive strategies. Methods: The microarray and RNA-seq datasets were obtained from the GEO database. Differentially expressed NRGs (DE-NRGs) were identified by the differential expression analysis, and the NMF algorithm was used to conduct a cluster analysis of IRI samples. Machine learning algorithms were performed to screen DGF-related hub NRGs, and DGF and long-term graft survival predictive strategies were constructed based on these hub NRGs. Finally, we verified the expression of Cxcl1 and its effect on IRI and NETs generation in the mouse IRI model. Results: This study revealed two IRI clusters (C1 and C2 clusters) with different molecular features and clinical characteristics. Cluster C1 was characterized by active metabolism, mild inflammation and lower incidence of DGF, while Cluster C2 was inflammation activated subtype with a higher incidence of DGF. Besides, based on DGF-related hub NRGs, we successfully constructed robust DGF and long-term graft survival predictive strategies. The mouse renal IRI model verified that Cxcl1 was significantly upregulated in renal tissues after IRI, and using a CXCL8/CXCL1 inhibitor could significantly improve renal function, alleviate renal tubular necrosis, tissue inflammatory response, and NET formation. Conclusion: This study identified two distinct IRI clusters based on DE-NRGs and constructed robust prediction methods for DGF and graft survival, which can provide references for early prevention and individualized treatment of various postoperative complications after renal transplantation.
Assuntos
Armadilhas Extracelulares , Traumatismo por Reperfusão , Camundongos , Animais , Sobrevivência de Enxerto/genética , Função Retardada do Enxerto/genética , Traumatismo por Reperfusão/etiologia , Rim/fisiologia , Complicações Pós-Operatórias , Inflamação/complicaçõesRESUMO
Interleukin-18 (IL-18) can effectively activate natural killer (NK) cells and induce large concentrations of interferon-γ (IFN-γ). In healthy humans, IL-18 binding protein (IL-18BP) can inhibit the binding of IL-18 to IL-18R and counteract the biological action of IL-18 due to its high concentration and high affinity, thus preventing the production of IFN-γ and inhibiting NK-cell activation. Through previous studies and the phenomena observed by our group in pig-non-human primates (NHPs) liver transplantation experiments, we proposed that the imbalance in IL-18/IL-18BP expression upon transplantation encourages the activation, proliferation, and cytotoxic effects of NK cells, ultimately causing acute vascular rejection of the graft. In this research, we used Lewis-Brown Norway rat orthotopic liver transplantation (OLTx) as a model of acute vascular rejection. AAV8-Il18bp viral vectors as gene delivery vehicles were constructed for gene therapy to overexpress IL-18BP and alleviate NK-cell rejection of the graft after transplantation. The results showed that livers overexpressing IL-18BP had reduced damage and could function longer after transplantation, effectively improving the survival time of the recipients.
Assuntos
Vasos Sanguíneos , Terapia Genética , Rejeição de Enxerto , Sobrevivência de Enxerto , Interleucina-18 , Transplante de Fígado , Animais , Ratos , Rejeição de Enxerto/prevenção & controle , Interferon gama/genética , Interferon gama/metabolismo , Interleucina-18/genética , Interleucina-18/metabolismo , Transplante de Fígado/métodos , Ratos Endogâmicos Lew , Sobrevivência de Enxerto/genética , Vasos Sanguíneos/imunologia , Vetores GenéticosRESUMO
In recent studies, much has been discussed about biomarkers used in the evaluation of the transplanted graft function. However, there remains a lack of research regarding the long-term effects of microRNAs (miRNAs) on the different genders for kidney transplant (KTx) patients. In this study, we aim to assess the functions of miRNAs on long term outcomes of KTx patients by extracting differently expressed miRNAs between patients of normal graft function and graft dysfunction, while further analyzing their impact on the different genders. We analyzed the data of 40 patients who had received KTx for a period of more than ten years and included data regarding renal function, immuno-related markers and plasma miRNAs. Data were classified by gender for further studies. Twelve out of 17 females and 8 out of 23 males had undergone graft dysfunction. Renal function analysis showed significantly worse outcomes in the female patients. There were five differently expressed miRNAs between the female control group and female dysfunction group: miR-128-3p, miR-21-5p, miR-150-5p, miR-92a-3p and miR-15a-5p, and five between the male control group and male dysfunction group: miR-23a-3p, miR-126-3p, miR-142-3p, miR-223-3p and miR-26a-5p. Gender differences exist in incidences of kidney graft dysfunction, with male patients displaying better preservation in graft functions. Overall, these differently expressed miRNAs either enhance or suppress host immune responses. They can be predictive markers for graft survival and can also be important factors that lead to worse long term kidney graft function in females when compared to males.
Assuntos
Transplante de Rim , MicroRNAs , Humanos , Feminino , Masculino , Transplante de Rim/efeitos adversos , Fatores Sexuais , Biomarcadores , Sobrevivência de Enxerto/genéticaRESUMO
De novo thrombotic microangiopathy (TMA) is associated with poor kidney graft survival, and as we previously described, it is a recipient driven process with suspected genetic background. Direct Sanger sequencing was performed in 90 KTR with de novo TMA and 90 corresponding donors on selected regions in CFH, CD46, C3, and CFB genes that involve variations with a functional effect or confer a risk for aHUS. Additionally, 37 recipients of paired kidneys who did not develop TMA were analyzed for the MCPggaac haplotype. Three-years death-censored graft survival was assessed using Kaplan-Meier and Cox regression models. The distribution of haplotypes in all groups was in the Hardy-Weinberg equilibrium and there was no clustering of haplotypes in any group. In the TMA group, we found that MCPggaac haplotype carriers were at a significantly higher risk of graft loss compared to individuals with the wild-type genotype. Worse 3-year death-censored graft survival was associated with longer cold ischemia time (HR 1.20, 95% CI 1.06, 1.36) and recipients' MCPggaac haplotype (HR 3.83, 95% CI 1.42, 10.4) in the multivariable Cox regression model. There was no association between donor haplotypes and kidney graft survival. Similarly, there was no effect of the MCPggaac haplotype on 3-year graft survival in recipients of paired kidneys without de novo TMA. Kidney transplant recipients carrying the MCPggaac haplotype with de novo TMA are at an increased risk of premature graft loss. These patients might benefit from therapeutic strategies based on complement inhibition.
Assuntos
Transplante de Rim , Microangiopatias Trombóticas , Sobrevivência de Enxerto/genética , Haplótipos , Humanos , Transplante de Rim/efeitos adversos , Microangiopatias Trombóticas/genética , Doadores de TecidosRESUMO
Limiting CD4+ T cell responses is important to prevent solid organ transplant rejection. In a mouse model of costimulation blockade-dependent cardiac allograft tolerance, we previously reported that alloreactive CD4+ conventional T cells (Tconvs) develop dysfunction, losing proliferative capacity. In parallel, induction of transplantation tolerance is dependent on the presence of regulatory T cells (Tregs). Whether susceptibility of CD4+ Tconvs to Treg suppression is modulated during tolerance induction is unknown. We found that alloreactive Tconvs from transplant tolerant mice had augmented sensitivity to Treg suppression when compared with memory T cells from rejector mice and expressed a transcriptional profile distinct from these memory T cells, including down-regulated expression of the transcription factor Special AT-rich sequence-binding protein 1 (Satb1). Mechanistically, Satb1 deficiency in CD4+ T cells limited their expression of CD25 and IL-2, and addition of Tregs, which express higher levels of CD25 than Satb1-deficient Tconvs and successfully competed for IL-2, resulted in greater suppression of Satb1-deficient than wild-type Tconvs in vitro. In vivo, Satb1-deficient Tconvs were more susceptible to Treg suppression, resulting in significantly prolonged skin allograft survival. Overall, our study reveals that transplantation tolerance is associated with Tconvs' susceptibility to Treg suppression, via modulated expression of Tconv-intrinsic Satb1. Targeting Satb1 in the context of Treg-sparing immunosuppressive therapies might be exploited to improve transplant outcomes.
Assuntos
Sobrevivência de Enxerto , Proteínas de Ligação à Região de Interação com a Matriz , Linfócitos T Reguladores , Fatores de Transcrição , Tolerância ao Transplante , Animais , Sobrevivência de Enxerto/genética , Sobrevivência de Enxerto/imunologia , Memória Imunológica/genética , Interleucina-2/metabolismo , Proteínas de Ligação à Região de Interação com a Matriz/genética , Proteínas de Ligação à Região de Interação com a Matriz/metabolismo , Camundongos , Camundongos Endogâmicos C57BL , Linfócitos T Reguladores/imunologia , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo , Tolerância ao Transplante/genética , Tolerância ao Transplante/imunologiaRESUMO
The quality and size of liver grafts are critical factors that influence living-donor liver transplantation (LDLT) function and safety. However, the biomarkers used for predicting graft quality are lacking. In this study, we sought to identify unique graft quality markers, aside from donor age, by using the livers of non-human primates. Hepatic gene microarray expression data from young and elderly cynomolgus macaques revealed a total of 271 genes with significantly increased expression in the elderly. These candidate genes were then narrowed down to six through bioinformatics analyses. The expression patterns of these candidate genes in human donor liver tissues were subsequently examined. Importantly, we found that grafts exhibiting up-regulated expression of these six candidate genes were associated with an increased incidence of liver graft failure. Multivariable analysis further revealed that up-regulated expression of LRRN2 (encoding leucine-rich repeat protein, neuronal 2) in donor liver tissue served as an independent risk factor for graft failure (odds ratio 4.50, confidence interval 2.08-9.72). Stratification based on graft expression of LRRN2 and donor age was also significantly associated with 6-month graft survival rates. Conclusion: Up-regulated LRRN2 expression of liver graft is significantly correlated with graft failure in LDLT. In addition, combination of graft LRRN2 expression and donor age may represent a promising marker for predicting LDLT graft quality.
Assuntos
Transplante de Fígado , Doadores Vivos , Idoso , Biomarcadores , Moléculas de Adesão Celular Neuronais , Sobrevivência de Enxerto/genética , Humanos , Transplante de Fígado/efeitos adversos , Estudos Retrospectivos , Resultado do TratamentoRESUMO
Despite significant improvement in the rates of acute allograft rejection, proportionate improvements in kidney allograft longevity have not been realized, and are a source of intense research efforts. Emerging translational data and natural history studies suggest a role for anti-donor immune mechanisms in a majority of cases of allograft loss without patient death, even when overt evidence of acute rejection is not identified. At the level of the donor and recipient genome, differences in highly polymorphic HLA genes are routinely evaluated between donor and recipient pairs as part of organ allocation process, and utilized for patient-tailored induction and maintenance immunosuppression. However, a growing body of data have characterized specific variants in donor and recipient genes, outside of HLA loci, that induce phenotypic changes in donor organs or the recipient immune system, impacting transplant outcomes. Newer mechanisms for "mismatches" in these non-HLA loci have also been proposed during donor-recipient genome interactions with transplantation. Here, we review important recent data evaluating the role of non-HLA genetic loci and genome-wide donor-recipient mismatches in kidney allograft outcomes.
Assuntos
Transplante de Rim , Aloenxertos , Rejeição de Enxerto/genética , Sobrevivência de Enxerto/genética , Antígenos HLA/genética , Humanos , Rim , Transplante de Rim/efeitos adversosRESUMO
Organ transplantation is the most preferred treatment option for end-stage organ diseases; however, allograft rejection is the major hurdle in successful long-term transplant survival. In spite of developing better HLA matching and more effective immunosuppressive regimen, one-year graft survival has been increased by nearly 90% and the incidence of acute rejection by one-year post-transplantation has been decreased by 12.2% in the last decades, chronic allograft rejection has remained as one of the major obstacles to the long-lasting survival of the transplanted allograft. Therefore, seemingly preventing the allograft rejection and inducing immunological tolerance against transplanted allografts is one of the primary goals in transplantation research to enable long-lasting graft survival. Various mechanisms such as long noncoding RNAs (lncRNAs) have been proposed that induce immune tolerance by modulating the gene expression and regulating innate and adaptive immune responses during transplantation. Besides, because of involvement in regulating epigenetic, transcriptional, and post-translational mechanisms, lncRNAs could affect allograft status. Therefore, these molecules could be considered as the potential targets for prediction, prognosis, diagnosis, and treatment of graft rejection. It is suggested that the noninvasive predictive biomarkers hold promise to overcome the current limitations of conventional tissue biopsy in the diagnosis of rejection. Hence, this review aims to provide a comprehensive overview of lncRNAs and their function to facilitate diagnosis, prognosis, and prediction of the risk of graft rejection, and the suggestive therapeutic choices after transplantation.