Chen Xu — Page 4 | PubMed Health

PubMed2002

[Mesenchymal stem cells suppress allogeneic T cell responses by secretion of TGF-beta1].

To investigate the mechanisms underlying the issue that bone marrow mesenchymal stem cells (MSC) could trigger low responsiveness of allogeneic T lymphocytes against alloantigens, phenotypes of T cells were analysed with flow cytometry before and after coculture of allogeneic T lymphocytes with MSC. Further, expression of cytokines including IL-4, IFN-gamma and TGF-beta1 was evaluated by RT-PCR and ELISA as well. The results showed that CD8(+) subpopulation was increased and CD25(+) subset was decreased in proportion after coculture of allogeneic T lymphocytes with MSC for 2 weeks. RT-PCR assay showed that MSC expressed TGF-beta1 but not IL-4 and IFN-gamma, and the result was further proved by ELISA assay showing that the secretion of TGF-beta1 reached to 1 ng/ml in 72 hours. It was concluded that allogeneic MSC suppressed T cells activation by alteration of T cell subpopulations. The suppressive effect was at least in part due to the secretion of TGF-beta1. The results indicate that MSC pretreatment might be useful in the prevention of GVHD in HLA-mismatched bone marrow transplantation and further donors for hematopoietic stem cells could be selected from greater potentials.

Bone Marrow Cells↗

PubMedDate not supplied

Effects of tripterine on mRNA expression of TGF-beta1 and collagen IV expression in BW F1 mice.

Tripterine is a chemical isolated from a traditional Chinese herb which had been testified for its anti-inflammatory and immunosuppressive activities in a previous study. However, little is known about the effects and mechanism of action of Tripterine on treating lupus nephritis. In the present study we investigated the effect of Tripterine on the F1 hybrids of New Zealand Black (NZB) and New Zealand White (NZW) mice which functioned as a model of human systemic lupus erythematosus (BW F1 mice) and evaluated the possible mechanism implicated in the mRNA expression of TGF-beta1 and collagen IV expression of the BW F1 mice kidney tissue. Different doses of Tripterine were injected peritoneally to BW F1 mice at different stages to study the preventive effects of Tripterine on lupus nephritis glomerulosclerosis and its mechanisms. Twenty-four hour urine protein excretion, serum anti-dsDNA antibodies and the expression of collagen type IV were examined by immunohistochemistry while the expression of TGF-beta1 mRNA was detected by RT nested PCR. Tripterine decreased urine protein excretion and the level of serum anti-dsDNA antibodies and also suppressed the expression of collagen type IV and TGF-beta1 mRNA in the murine kidney tissue. Administration of Tripterine before the occurrence of proteinuria had much greater protective effects than if it was administered after the occurrence of proteinuria. No significant difference was found between the 3 mg/kg/week Tripterine-treated-group and the 6 mg/kg/week Tripterine-treated-group. Tripterine had a definite protective effect on glomerulosclerosis of the lupus murine model. Tripterine could significantly reduce the amount of urine protein excretion, suppress the formation of serum anti-dsDNA antibodies, it could also efficiently decrease the expression of renal collagen type IV probably due to its suppressive effect on the expressions of local TGF-(1 mRNA) in this model.

Animals↗