A number of cytokines have been implicated in the pathophysiology of congestive heart failure. Genetic polymorphisms of several cytokine genes are known to result in altered gene expression, enabling us to characterize patients as "high" or "low" producers of specific cytokines. We speculate that the cytokine genotypes for a population of children who underwent heart transplantation for end-stage ventricular failure due to cardiomyopathy or congenital heart disease would be enriched for "high producers" of pro-inflammatory cytokines and "low producers" of anti-inflammatory cytokines. Methods: Cytokine genotyping was performed for the following cytokines on 94 transplanted children using polymerase chain reaction-sequence specific technique: tumor necrosis factor-α (−308), interleukin 10 (−1082, −819, −592), interleukin 6 (−174), transforming growth factor-β 1 (codons 10 & 25), and interferon-γ (+874). Patients with ventricular failure after transplantation for dilated cardiomyopathy, numbering 37, or for congenital heart disease, numbering 34, were compared to 15 children transplanted for structural disease, such as hypoplastic left heart syndrome, without ventricular failure, and to data from healthy children. An additional 8 children with restrictive or hypertrophic cardiomyopathy were also studied. Results: No differences in genotypic distribution were seen between the groups, and all patients were comparable to genotypic distributions as assessed from published normal data. Conclusion: No evidence is found to support the hypothesis that these polymorphisms for cytokine genes influence progression to end-stage heart failure in children undergoing transplantation because of cardiomyopathy or congenital heart disease.
Abstract Myeloid‐derived suppressor cells (MDSCs) are a heterogeneous group of immature myeloid cells playing a critical role in immune suppression. In vitro‐generated MDSCs are a convenient tool to study the properties of tumour‐associated MDSCs. Here, we compared six protocols for in vitro generation of functional mouse MDSCs from bone marrow progenitors. The protocols included granulocyte‐macrophage colony‐stimulating factor (GM‐CSF) alone or in combination with interleukin‐6 (IL‐6) or granulocyte colony‐stimulating factor (G‐CSF), with or without a tumour‐conditioned medium (TCM) derived from B16‐F10 melanoma. Obtained MDSCs were characterized by morphology, phenotype, gene expression of key immunosuppressive factors, and in vitro suppression of T cell proliferation. All tested protocols yielded approximately 25% monocytic and 50% polymorphonuclear MDSCs. Protocols using IL‐6 generated MDSCs with reduced maturation and differentiation status, upregulated Arg1 and Nos1 mRNA expression, increased levels of Arg‐1 and TGF‐β proteins and enhanced ROS production compared to the other protocols. All tested protocols yielded MDSCs that efficiently inhibited T cell proliferation in vitro, with some advantage for the GM‐CSF and G‐CSF + GM‐CSF protocols. Interestingly, a combination of protocols with B16‐F10‐derived TCM resulted in the generation of MDSCs with reduced immunosuppressive properties. Our results provide valuable insights into the optimal conditions for in vitro generation of MDSCs with specific immunosuppressive properties.
Background. Cytokine genetic polymorphisms have been associated with transplant outcome in some experimental and clinical studies, but the cytokine profile of patients who are clinically tolerant has not been investigated. Aim. Allelic variations in tumor necrosis factor (TNF)-α, interferon (INF)-γ, transforming growth factor (TGF)-β1, interleukin (IL)-6, and IL-10 were evaluated in patients successfully withdrawn from immunosuppression. Methods. Pediatric liver transplant recipients who were successfully withdrawn from immunosuppression (n=12) or who are on minimal immunosuppression (n=7) were genotyped. A control group of liver recipients who required maintenance immunosuppression served as a control group (n=37). Results. Compared to the control group, low TNF- α and high/intermediate IL-10 profiles were seen in all 12 children maintained off immunosuppression and in 6 of 7 children requiring minimal immunosuppression. Conclusion. Children successfully maintained off immunosuppression are more likely to have a genetic predisposition toward low TNF-α and high/intermediate IL-10 production. Children maintained on minimal immunosuppression exhibit a similar cytokine profile to those successfully weaned.
Objectives: Transforming growth factor β1 (TGF-β1) is a potent immunosuppressive cytokine that promotes fibrosis by enhancing the synthesis of extracellular matrix components. The repair process following lung allograft injury is due to rejection or infection replaces lung parenchyma by fibrotic tissue, leading to pulmonary dysfunction. The role of TGF-β1 in this excessive healing process and increasing the risk of infection is unknown. Methods: We analysed our patient data to investigate the relevance of different factors on allograft fibrosis and its correlation with TGF-β1. Fibrosis was graded in H and E stained sections. TGF-β1 genotype was determined in all patients. Results: Patients were aged between 16 and 62 years (mean age of 39.6 years). Procedures were heart/lung (n=32), double lung (n=18), and SLT (n=41). A total of 46 patients had lung allograft fibrosis diagnosed in transbronchial biopsies sections. Patients who had developed interstitial fibrosis had significantly more acute rejection episodes (mean 3.4±2.8) compared with patients without fibrosis (mean 2.1±2.2) (P=0.024). The presence of eosinophils in the interstitium preceded and were associated with the development of fibrosis regardless of the rejection grade (P=0.0001). TGF-β1 was heavily expressed in sections with fibrosis with a mean score of 6.8±2.9 compared with 2.4±0.6 in sections with no fibrosis (P≪0.0001). TGF-β1 expression correlated positively with fibrosis grades (P≪0.0001). The mean survival for patients with a fibrosis score ≫6 is 892.4±73 days compared with mean survival 427±78 in patients with scores ≪6 (P=0.0001). Patients who developed fibrosis had homozygous TGF-β1 genotype that correlates with excessive TGF-β1 expression (P=0.01). The use of cardiopulmonary bypass was associated with the development of excessive fibrosis (P=0.02), and 7 patients who had severe fibrosis died of septicaemia (17.5%). FEV1 (forced expiratory volume) was significantly higher in patients without fibrosis (1870±111 ml versus 1590±160; P=0.02). Conclusions: The risks of lung allograft fibrosis increases with recurrent rejection, tissue eosinophilia, homozygous TGF-β1 genotype and the use of bypass machine. Fibrosis was associated with higher mortality and morbidity might be explained by the TGF-β1 immunosuppressive and fibrotic properties. Immunological strategies to down-regulate TGF-β1 production might improve survival and function of lung allografts.
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