FOXP3 rs3761549 polymorphism predicts long-term renal allograft function in patients receiving cyclosporine-based immunosuppressive regimen

Association of genetic variations in FoxP3 gene with Graves' disease in a Southwest Chinese Han population

BACKGROUND

Graves' disease (GD) is a T cell-mediated organ-specific autoimmune disease. Forkhead box P3 (FoxP3) is an excellent marker for the induction and development of regulatory T cells (Tregs). Recent studies showed that single-nucleotide polymorphisms (SNPs) in the FoxP3 gene were associated with the increased susceptibility to several autoimmune diseases. In the present study, we investigated the association of FoxP3 gene polymorphisms with GD in a Southwest Chinese Han population.

METHODS

A two-stage case-control study was performed in 890 healthy controls (male, 282; female, 608) and 503 patients with GD (male, 138; female, 365). Four SNPs (rs3761548, rs3761549, rs3761547, and rs2280883) were genotyped by the polymerase chain reaction-restriction fragment length polymorphism assay. The χ2 test was used to compare the genotype distributions and allele frequencies between GD patients and healthy controls.

RESULTS

In the first stage, the significantly increased frequencies of the A allele (p = .031, odds ratio [OR] = 1.635) and AA genotype (p = .023, OR = 3.257), together with a significantly decreased frequency of the C allele (p = .031, OR = 0.611) of FoxP3/rs3761548 were found in female patients with GD. None of the other FoxP3 SNPs was associated with GD susceptibility. Subsequent validation and combination of data confirmed the association between FoxP3/rs3761548 and the female patients with GD (A allele: p < .001, OR = 1.672; AA genotype: p = .005, OR = 2.488; CC genotype: p = .001, OR = 0.622; C allele: p < .001, OR = 0.615, respectively).

CONCLUSION

Our findings suggest that FoxP3/rs3761548 is significantly associated with female GD patients in a Southwest Chinese Han population.

Analysis of selected polymorphisms in FOXP3 gene in a cohort of Egyptian patients with schizophrenia

BACKGROUND

Schizophrenia is a chronic mental disorder with different symptoms. The environmental and genetic factors are suggested to be the etiology of schizophrenia. However, the exact cause and pathogenesis of schizophrenia are still unclear. Different studies suggested that the immune system may have a role in schizophrenia. A genetic study found a relation between the disease and the HLA region on the sixth chromosome. Regulatory T cells (Treg) have a role in the regulation of immune response, especially the balance between TH1 and TH2 cells. The FOXP3 protein is a key regulator for Treg cell's functions. FOXP3 is a transcriptional factor, and its gene is present on the short arm of the X chromosome. The selected SNPs present in the promoter region which act as binding sites for transcriptional factors. This study investigated FOXP3 gene polymorphisms (rs3761548, rs3761549, and rs2232365) in Egyptian patients with schizophrenia. There are no previous studies about the association of FOXP3 gene polymorphisms with schizophrenia. The three selected single-nucleotide polymorphisms (SNPs) were investigated using polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) for 125 schizophrenia patients and 160 healthy controls. The Positive and Negative Syndrome Scale (PANSS) was used to evaluate patients with schizophrenia.

RESULTS

No significant associations were found between schizophrenia patients and healthy controls for the alleles and genotypes of the selected SNPs (P-value > 0.05). However, a significant association with ACC and ATC haplotypes was detected (P-value 0.001). No significant association was detected between the PANSS score and any of the studied SNPs.

CONCLUSION

The ATC haplotype of rs2232365, rs3761549, and rs3761548 could be considered a risk factor for schizophrenia in Egyptian patients.

Exosomes Secreted by Mesenchymal Stem Cells Induce Immune Tolerance to Mouse Kidney Transplantation via Transporting LncRNA DANCR

Mesenchymal stem cells induce kidney transplant tolerance by increasing regulatory T (Treg) cells. Bone marrow mesenchymal stem cell exosomes (BMMSC-Ex) promote Treg cell differentiation. Long non-coding RNA differentiation antagonizing non-protein coding RNA (DANCR) is expressed in BMMSCs and can be encapsulated in exosomes. We aimed to explore the role of DANCR in BMMSC-Ex in immune tolerance after kidney transplantation and related mechanism. The isogenic/allograft kidney transplantation mouse model was established, and levels of serum creatinine (SCr) were determined. Hematoxylin-eosin staining was conducted to detect the inflammation, and immunohistochemistry was performed to detect the infiltration of CD4+ T cells. Levels of IFN-γ, IL-17, and IL-2 were examined by ELISA. Flow cytometry was conducted to determine Treg cells. In the allograft group, the inflammatory response was severe, CD4+ T cell infiltration, SCr levels, and plasma rejection-related factors were up-regulated, while injection of BMMSC-Ex reversed the results. BMMSC-Ex increased Treg cells in kidney transplantation mice. Interference with DANCR reversed the promoting effect of BMMSC-Ex on Treg cell differentiation. DANCR bound to SIRT1, promoted ubiquitination and accelerated its degradation. The injection of BMMSC-Ex (after interference with DANCR) promoted SIRT1 levels, inflammatory response, CD4+ T cell infiltration, SCr levels, and plasma rejection related factors' expression, while Treg cells were decreased. LncRNA DANCR in BMMSC-Ex promoted Treg cell differentiation and induced immune tolerance of kidney transplantation by down-regulating SIRT1 expression in CD4+ T cells.

Rapamycin treated tol-dendritic cells derived from BM-MSCs reversed graft rejection in a rat liver transplantation model by inducing CD8+CD45RC-Treg

OBJECTIVE

To investigate the influence of tolerance dendritic cells (tolDCs), generated from Bone marrow mesenchymal stem cells (BM-MSCs) treated with rapamycin (Rapa) on liver allograft survival in a rat acute liver transplantation model.

METHODS

Different GM-CSF induction project was used to obtain immature DCs (imDCs), mature DCs (matDCs) or tolDCs from BM-MSCs. First, MLR was performed to analyze the activity of tolDCs on polyclonaly stimulated total T cells. Then, co-cultured imDCs, matDCs and tolDCs with CD8⁺T cells isolated by magnetic activated cell sorting to analyze the influence on its regulatory characteristic. Last, the established rat acute liver transplantation model were adoptive transfused with imDCs, matDCs or tolDCs isolated by anti-CD11c immunomagnetic beads. The phenotype of DC cells and level of CD8⁺Treg in the culture system and in vivo, the expression of CD8 and CD45RC in the tissues were analyzed by flow cytometry and immunohistochemistry, respectively.

RESULTS

The loGM-CSF plus IL-4 decreased the costimulatory molecules of CD80/86 and MHC class II of DCs comparison with hiGM-CSF from BM-MSCs no matter whether stimulation by LPS (P<0.05). Rapa treated not only reduced the expression of CD80/86 and MHC class II but also down-regulated the expression of CD11c after LPS stimulation which was more obviously in tolDCs by loGM-CSF project (P<0.05). Moreover, tolDCs displayed a rather higher level of IL-10 and low level of IL-12p70 than others (P<0.01), which shown a rather lower stimulative effect on the proliferation of T cells comparison with matDCs and imDCs. Co-cultured with CD8⁺Treg showed an improvement on induction of CD8⁺TCR⁺CD45RC^-T cells (CD8⁺Treg) in ex vivo. The rats transfused with tolDCs has a delayed survival benefits with high level of CD8⁺Tregs (P<0.01) and high expression of CD45RC in liver tissue (P<0.01) and spleen when comparison with other groups. The infused tolDCs improved a mean survival time (MST) of 32 days comparison with a MTS of 9.5 days and 15.75 days displayed by rat that per-infused with matDCs and imDCs, respectively.

CONCLUSION

Rapa modified tolDCs derived from BM-MSCs reversed graft rejection by improve tolerance characteristics of CD8⁺CD45RC^-Treg in acute liver rat transplantation.

The Role of Regulatory Myeloid Cell Therapy in Renal Allograft Rejection

Kidney transplantation is a primary therapy for end-stage renal disease (ESRD) all the time. But it does not mean that we have fully unraveling the mystery of kidney transplantation and confer every patient favorable prognosis. Immune rejection has always been a stumbling block when we try to increase the success rate of kidney transplantation and improve long-term outcomes. Even if the immune rejection is effectively controlled in acute phase, there is a high possibility that the immune response mediated by chronically activated antibodies will trigger chronic rejection and ultimately lead to graft failure. At present, immunosuppressive agent prepared chemically is mainly used to prevent acute or chronic rejection, but it failed to increase the long-term survival rate of allografts or reduce the incidence of chronic rejection after acute rejection, and is accompanied by many adverse reactions. Therefore, many studies have begun to use immune cells to regulate the immune response in order to control allograft rejection. This article will focus on the latest study and prospects of more popular regulatory myeloid cells in the direction of renal transplantation immunotherapy and introduce their respective progress from experimental research to clinical research.

Genetic Variants Associated With Immunosuppressant Pharmacokinetics and Adverse Effects in the DeKAF Genomics Genome-wide Association Studies

BACKGROUND

The immunosuppressants tacrolimus and mycophenolate are important components to the success of organ transplantation, but are also associated with adverse effects, such as nephrotoxicity, anemia, leukopenia, and new-onset diabetes after transplantation. In this report, we attempted to identify genetic variants which are associated with these adverse outcomes.

METHODS

We performed a genome-wide association study, using a genotyping array tailored specifically for transplantation outcomes containing 722 147 single nucleotide polymorphisms, and 2 cohorts of kidney allograft recipients-a discovery cohort and a confirmation cohort-to identify and then confirm genetic variants associated with immunosuppressant pharmacokinetics and adverse outcomes.

RESULTS

Several genetic variants were found to be associated with tacrolimus trough concentrations. We did not confirm variants associated with the other phenotypes tested although several suggestive variants were identified.

CONCLUSIONS

These results show that adverse effects associated with tacrolimus and mycophenolate are complex, and recipient risk is not determined by a few genetic variants with large effects with but most likely are due to many variants, each with small effect sizes, and clinical factors.

Immature dendritic cells derived exosomes promotes immune tolerance by regulating T cell differentiation in renal transplantation

Objective: To investigate the mechanism of immature dendritic cells-derived exosomes (imDECs) in the regulation of T cell differentiation and immune tolerance in renal allograft model mice.

Results: imDECs significantly improved the percent of survival, relieved inflammatory response, and reduced CD4+T cell infiltration. In addition, imDECs reduced the rejection associated cytokines in allograft mice, and increased the percentage of Foxp3+CD4+T cells in spleen and kidney tissues. imDECs suppressed the IL17+CD4+T cells and promoted the Foxp3+CD4+T cells under Th17 polarization condition. Moreover, miR-682 was found to be highly expressed in imDECs which suppressed the IL17+CD4+T cells and promoted the Foxp3+CD4+T cells. Luciferase reporter assay showed ROCK2 was a target of miR-682, and ROCK mRNA level was negative correlated with miR-682 mRNA level.

Conclusion: miR-682 was highly expressed in imDECs, and imDECs-secreted miR-682 promoted Treg cell differentiation by negatively regulating ROCK2 to promote immune tolerance in renal allograft model mice.

Methods: Renal allograft model mice were established, and imDECs or mature dendritic cells-derived exosomes (mDECs) were injected into model mice. Rejection associated cytokines IFN-γ, IL-2, IL-17 levels in plasma were detected by ELISA. IL-17A, Foxp3, miR-682, ROCK2, p-STAT3, p-STAT5 expressions were measured by qRT-PCR or western blot.

Impact of TBX21, GATA3, and FOXP3 gene polymorphisms on acute cellular rejection after liver transplantation

The single nucleotide polymorphisms (SNPs) rs4794067, rs2275806, rs2232365, and rs3761548 map in the genes of TBX21, GATA3, and FOXP3 involved in mediating acute cellular rejection. We investigated whether these SNPs are associated with acute cellular liver transplant rejection. The SNPs were analyzed in recipients with early acute cellular rejection (n = 97), recipients with late acute cellular rejection (n = 49), and recipients without rejection (n = 149). There was no association between acute cellular rejection and SNPs rs4794067, rs2275806, and rs2232365. In contrast, the allele -3279A of FOXP3 SNP rs3761548 exhibited a higher frequency in recipients with late acute cellular rejection as compared with recipients without rejection. This result indicates that the allele -3279A of the SNP rs3761548 may predispose to the development of late acute cellular rejection.

Polymorphisms in mTOR and Calcineurin Signaling Pathways Are Associated With Long-Term Clinical Outcomes in Kidney Transplant Recipients

Monitoring of immunosuppressive drugs, such as calcineurin and mTOR inhibitors, is essential to avoid undesirable kidney transplant outcomes. Polymorphisms in pharmacokinetics-related genes have been associated with variability in blood levels of immunosuppressive drugs and adverse effects, but influence of pharmacodynamics-related genes remains to be elucidated. The influence of polymorphisms in genes of the mTOR and calcineurin signaling pathways on long-term clinical outcomes was investigated in Brazilian kidney transplant recipients within the 1-year post-transplant. Two-hundred and sixty-nine kidney transplant recipients were enrolled at a kidney transplant center in São Paulo city, Brazil, and treated with tacrolimus plus everolimus or mycophenolate sodium (clinical trial NCT01354301). Clinical and laboratory data, including renal function parameters and drug blood levels were recorded. Genomic DNA was extracted from blood samples. Polymorphisms in MTOR rs1057079 (c.4731G>A), rs1135172 (c.1437T>C), and rs1064261 (c.2997C>T); PPP3CA rs3730251 (c.249G>A); FKBP1A rs6033557 (n.259+24936T>C); FKBP2 rs2159370 (c.-2110G>T); and FOXP3 rs3761548 (c.-23+2882A>C) and rs2232365 (c.-22-902A>G) were analyzed by real-time PCR. Frequencies of gene polymorphisms did not differ among the treatment groups. Analysis of primary outcomes showed that patients carrying MTOR c.1437CC and FOXP3 c.-23+2882CC genotypes had higher serum creatinine than non-carriers (p < 0.05) at 1-year post-transplant. MTOR c.4731G allele (AG+GG genotype) was associated with increased risk for acute rejection (OR = 3.53, 95% CI = 1.09-11.48, p = 0.037). Moreover, 1-year cumulative incidence of rejection was higher in MTOR c.4731G allele carriers compared to AA genotype carriers (p = 0.027). Individually, analysis of secondary outcomes revealed that FKBP2 c.-2110GG genotype carriers had higher risk of leukopenia, FKBP1A n.259+24936C allele carriers had increased risk of constipation, and FOXP3 c.-22-902A or c.-23+2882A allele had higher risk of gastrointestinal disorders (p < 0.05). However, these results were not maintained in the multivariable analysis after p-value adjustment. In conclusion, variants in genes of mTOR and calcineurin pathways are associated with long-term impaired renal function, increased risk of acute rejection, and, individually, with adverse events in Brazilian kidney transplant recipients.