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End stage renal disease is a clinical state that extends from chronic renal failure and is marked by an irreversible loss of renal function. TGF-β1 mediated renal fibrosis is a common pathology implicated in this form of kidney disease. In this study circulating protein and mRNA levels of TGF-β1 cytokine were investigated among ESRD patients and respective controls from North India. Physician diagnosed 192 ESRD patients, on hemodialysis, and 130 normal controls participated in the present study. TGF-β1 circulating levels were measured by ELISA and its expression was quantified using competitive-PCR. Mean TGF-β1 protein levels were 2.7-fold lower in ESRD patients as compared to normal controls (p0.001). Additionally, TGF-β1 mRNA transcripts of this cytokine were also significantly lower in the diseased population compared to controls (p0.001). These results imply that TGF-β1 has not played its anticipated pro-fibrotic role and anti-inflammatory function in the studied population.

The basic immunosuppressive protocol involves the use of multiple drugs, each directed at a discrete site in the T-cell activation cascade. The prevailing paradigm regarding the mechanisms of action of immunosuppressants is that they function to prevent allograft rejection by preventing cell activation, proliferation and/or cytokine production. A new hypothesis is that some of the immunosuppressants might function by stimulating the expression of immunosuppressive molecules and/or cells.

During normal aging and in chronic diabetes the excessive accumulation of reactive glucose-protein or glucose-lipid adducts known as advanced glycosylation endproducts (AGEs) has been shown to induce tissue dysfunction, in part through interaction with AGE-specific receptors on monocyte/macrophages and other cells. Recognizing that circulating lymphocytes trafficking through tissues interact with tissue AGEs, we searched for the expression of AGE-binding sites on peripheral blood T lymphocytes. Resting rat and human T cells bound 125I-AGE-albumin with an affinity of 7.8 x 10(7) M-1, whereas, after stimulation with phytohemagglutinin (PHA) for 48 h, binding affinity increased to 5.8 x 10(8) M-1. Flow cytometric analysis of resting rat T cells using polyclonal antibodies raised against rat liver AGE-binding proteins (p60 and p90) revealed the constitutive expression of both immunoreactivities. The number of resting CD4+ and CD8+ T cells positive for anti-p60 antibody binding (34.2 and 58.5%, respectively) increased to 92 and 90% of cells after 48-h stimulation with PHA. Exposure of PHA-activated T lymphocytes to AGE-albumin enhanced expression of interferon gamma (IFN-gamma) mRNA 10-fold and induced greater elaboration of the mature protein than did exposure to unmodified protein or PHA treatment alone. These data indicate that T cells contain an inducible system of surface receptors for AGE-modified proteins, and that receptor occupancy is linked to lymphokine production. This T cell AGE-receptor system might serve to target lymphocytes to AGE-rich tissues and involve them in the regulation of tissue homeostasis either by assisting in macrophage-dependent clearance of AGE-proteins, or by exerting direct antiproliferative action on mesenchymal cells. Under conditions of excessive AGE-protein and AGE lipid accumulation (e.g., aging and diabetes), enhanced production of AGE-induced IFN-gamma may accelerate immune responses that contribute to tissue injury.

In view of the importance of the IL-2 receptors in the expression of antiallograft immunity and the currently existing controversy regarding the effect of CsA on the induction of IL-2 receptors, we explored the effect of cyclosporine on the induction of interleukin-2 receptor alpha and beta in normal human T cells. The effect of CsA on the induction of IL-2 receptors was examined at the levels of mRNA expression (with the aid of the polymerase chain reaction), protein (by SDS-PAGE analysis of chemically crosslinked 125I-IL-2 membrane protein complexes and by FACS), and function (by Scatchard analysis of 125I-IL-2 binding to T cells). The T cells were signaled with sn-1,2-dioctanoylglycerol and ionomycin or with crosslinked anti-CD3 and anti-CD2 mAbs. Our experimental design revealed that (A) CsA inhibits the induction of IL-2 receptor alpha and beta in normal human T cells, (B) the inhibitory activity is realized by a direct effect on T cells, and (C) the inhibitory activity is detectable at the pretranslational level--CsA significantly reduced the induction of mRNA encoding IL-2 receptor alpha and IL-2 receptor beta. These observations together persuasively demonstrate the ability of CsA to interrupt the emergence of IL-2 receptors on the surface of normal human T cells.

Bronchial asthma is a complex genetic disorder regulated by the release of cytokines and inflammatory mediators. Tumor necrosis factor alpha (TNF-alpha) and transforming growth factor beta (TGF-beta1) cytokines play pivotal roles in the inflammatory response of the airways. Differential production of these two cytokines is associated with allelic variations in the transcriptional regulatory region of these genes.The objective of the present study was to investigate G-308A TNF-alpha and C-509T TGF- beta1 polymorphisms for their association with Bronchial Asthma.DNA isolated from 123 asthmatics and 100 normal healthy controls were screened for these polymorphisms using the amplification refractory mutation system-polymerase chain reaction (ARMS-PCR) methods, developed in our laboratory.Significant allelic association was observed between G-308A TNF-alpha polymorphism and asthma (P = 0.031) while no association was observed with C-509T TGF- beta1 polymorphism (P = 0.207). Further sub-grouping based on either allergic response or family history failed to reveal any statistical significance among the groups or with controls. The interaction between these polymorphisms revealed statistically significant association between the high producer genotype alleles of TNF-alpha and TGF-beta (A/T) and asthma (P = 0.016).The present study reports, for the first time, the role of two polymorphisms, in concert, for their association with asthma in an Indian population. Our study supports the findings that the G-308A TNF-alpha promoter polymorphism is a risk factor for asthma and furthermore suggests that the patients with high producer alleles for TNF-alpha (-308) and TGF-beta (-509) have the highest risk of getting this disease in the Punjabi population.

In searching for a candidate mechanism for the immunosuppressive as well as fibrogenic consequences of cyclosporine usage, we have explored the hypothesis that cyclosporine stimulates transcription of transforming growth factor- β 1 (TGF- β 1 ), a multifunctional cytokine endowed with immunosuppressive and fibrogenic properties. Our results demonstrate that cyclosporine (i) stimulates TGF- β 1 promoter-dependent transcription of chloramphenicol acetyl transferase gene in transiently transfected human A-549 cells, (ii) stimulates the synthesis of TGF- β 1 RNA transcripts in human T cells, and (iii) permits the expression/emergence of DNA regulatory proteins (retinoblastoma control factor-1 (RCF-1) and RCF-2) that bind and regulate TGF- β 1 promoter activity. Our studies demonstrate for the first time that cyclosporine stimulates TGF- β 1 gene transcription and suggest a novel mechanism of action of cyclosporine.

Advanced glycosylation endproducts (AGEs), the glucose-derived adducts that form nonenzymatically and accumulate on tissue proteins, are implicated in many chronic complications associated with diabetes and aging. We have previously described a monocyte/macrophage surface receptor system thought to coordinate AGE protein removal and tissue remodeling, and purified a corresponding 90-kD AGE-binding protein from the murine RAW 264.7 cell line. To identify AGE-binding proteins in normal animals, the tissue distribution of 125I-AGE rat serum albumin taken up from the blood was determined in rats in vivo. These uptake studies demonstrated that the liver was a major site of AGE protein sequestration. Using a solid-phase assay system involving the immobilization of solubilized membrane proteins onto nitrocellulose to monitor binding activity, and several purification steps including affinity chromatography over an AGE bovine serum albumin matrix, two rat liver membrane proteins were isolated that specifically bound AGEs, one migrating at 60 kD (p60) and the other at 90 kD (p90) on SDS-PAGE. NH2-terminal sequence analysis revealed no significant homology between these two proteins nor to any molecules available in sequence databases. Flow cytometric analyses using avian antibodies to purified rat p60 and p90 demonstrated that both proteins are present on rat monocytes and macrophages. Competition studies revealed no crossreactivity between the two antisera; anti-p60 and anti-p90 antisera prevented AGE-protein binding to rat macrophages when added alone or in combination. These results indicate that rat liver contains at least two novel and distinct proteins that recognize AGE-modified macromolecules, although p90 may be related to the previously described 90-kD AGE receptor isolated from RAW 264.7 cells. The constitutive expression of AGE-binding proteins on rat monocytes and macrophages, and the sequestration of circulating AGE-modified proteins by the liver, provides further evidence in support of a role for these molecules in the normal removal of proteins marked as senescent by accumulated glucose-derived covalent addition products, or AGEs.

Synergy between ionomycin and sn -1,2-dioctanoylglycerol (diC 8 ) was shown at the level of lymphokine gene transcription. Transcriptional activation of interleukin-2 (IL-2), interferon-γ (IFN-γ), and the protooncogene H-ras was accomplished by signaling highly purified normal human resting T-lymphocytes (T-cells) with diC 8 , a physiologic regulator of protein kinase C, and the calcium ionophore, ionomycin. Northern blot analysis of mRNA for early T-cell activation genes demonstrated the synergism between diC 8 and ionomycin at the gene induction level. To amplify very low levels of IL-2 mRNA, sequential reverse transcription and polymerase chain reaction (RT-PCR) of T cell mRNA were used to demonstrate the capacity of the calcium signal (ionomycin) to promote low-level IL-2 transcription in normal human T-cells without additional signals. Cyclosporine (CsA) prevented diC 8 and ionomycin-induced expression of IL-2, IFN-γ, and H-ras genes. The completeness of its inhibitory effect was evident by the absence of IL-2 transcripts in CsA-treated cultures screened by the RT-PCR technique. CsA also prevented IL-2 and IFN-γ gene expression in accessory cell-depleted T-cells stimulated by crosslinking the CD2 and CD3 antigens on the cell surface. Our observations demonstrate that a physiologic regulator of PKC, diC 8 , and cell surface crosslinking of the CD2 and CD3 antigen, promote gene expression in normal human quiescent T-cells independently of accessory cells, and that CsA prevents gene expression via a direct effect on T-cells.