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In this article the author discusses aspects of the history of immunology. He is critical on the components of CD8 regulatory T cells in major histocompatibility complex (MHC) class Ib-restricted manner. Also investigated is the number of CD8 T cells in peripheral circulation and the role of cytokines transforming growth factor in suppressing the delayed type hypersensitivity.

Background: Endothelial cells are known to contribute to kidney fibrosis via endothelial-mesenchymal transition (EndoMT). Matrix metalloproteinase 9 (MMP-9) is known to be profibrotic. However, whether MMP-9 contributes to kidney fibrosis via EndoMT is unknown. Methods: Primary mouse renal peritubular endothelial cells (MRPECs) were isolated and treated by recombinant human transforming growth factor beta 1 (rhTGF-β1) with or without MMP-9 inhibitor or by recombinant human MMP-9 (rhMMP- 9) alone. Kidney fibrosis was induced by unilateral ureteral obstruction (UUO) in MMP-9 knockout (KO) and wide-type (WT) control mice. The effects of MMP-9 on EndoMT of MRPECs and kidney fibrosis were examined. Results: We showed that MRPECs underwent EndoMT after rhTGF-β1 treatment or in UUO kidney as evidenced by decreased expression of endothelial markers, vascular endothelial cadherin (VE-cadherin) and CD31, and increased levels of mesenchymal markers, a-smooth muscle actin (a-SMA) and vimentin. The expression of fibrosis markers was also upregulated significantly after rhTGF-β1 treatment in MRPECs. The EndoMT and fibrosis markers were significantly less in rhTGF-β1-treated MMP-9 KO MRPECs, whereas MMP-9 alone was sufficient to induce EndoMT in MRPECs. UUO kidney ofMMP-9 KO mice showed significantly less interstitial fibrosis and EndoMT in MRPECs. Notch signaling shown by Notch intracellular domain (NICD) was increased, while Notch-1 was decreased in rhTGF-β1-treated MRPECs of MMP-9WT but notMMP-9 KO mice. Inhibition ofMMP-9 or Notch signaling prevented rhTGF-β1- or rhMMP-9-induced a-SMA and NICD upregulation in MRPECs. UUO kidney of MMP-9 KOmice had less staining of Notch signaling transcription factor Hey-1 in VE-cadherin-positive MRPECs than WT controls. Conclusions: Our results demonstrate that MMP-9-dependent Notch signaling plays an important role in kidney fibrosis through EndoMT ofMRPECs. [ABSTRACT FROM AUTHOR]

Background: Endothelial-mesenchymal transition (EndoMT) is a major source of myofibroblast formation in kidney fibrosis. Our previous study showed a profibrotic role for matrix metalloproteinase 9 (MMP-9) in kidney fibrosis via induction of epithelial-mesenchymal transition (EMT). Inhibition of MMP-9 activity reduced kidney fibrosis in murine unilateral ureteral obstruction. This study investigated whether MMP-9 also plays a role in EndoMT in human glomerular endothelial cells. Results: TGF-β1 (10 or 20 ng/ml) induced EndoMT in HKGECs as shown by morphological changes. In addition, VEcadherin and CD31 were significantly downregulated, whereas α-SMA, vimentin, and N-cadherin were upregulated. RT-PCR revealed that Snail, a known inducer of EMT, was upregulated. The MMP inhibitor GM6001 abrogated TGF-β1-induced EndoMT. Zymography indicated that MMP-9 was also upregulated in TGF-β1-treated HKGECs. Recombinant MMP-9 (2 μg/ml) induced EndoMT in HKGECs via Notch signaling, as evidenced by increased formation of the Notch intracellular domain (NICD) and decreased Notch 1. Inhibition of MMP-9 activity by its inhibitor showed a dose-dependent response in preventing TGF-β1-induced α-SMA and NICD in HKGECs, whereas inhibition of Notch signaling by γ-secretase inhibitor (GSI) blocked rMMP-9-induced EndoMT. Conclusions: Taken together, our results demonstrate that MMP-9 plays an important role in TGF-β1-induced EndoMT via upregulation of Notch signaling in HKGECs. [ABSTRACT FROM AUTHOR]

Background: Endothelial-mesenchymal transition (EndoMT) has been shown to be a major source of myofibroblasts, contributing to kidney fibrosis. However, in vitro study of endothelial cells often relies on culture of isolated primary endothelial cells due to the unavailability of endothelial cell lines. Our recent study suggested that peritubular endothelial cells could contribute to kidney fibrosis through EndoMT. Therefore, successful isolation and culture of mouse peritubular endothelial cells could provide a new platform for studying kidney fibrosis. This study describes an immunomagnetic separation method for the isolation of mouse renal peritubular endothelial cells using anti-CD146 MicroBeads, followed by co-culture with mouse renal proximal tubular epithelial cells to maintain endothelial phenotype. Results: Flow cytometry showed that after isolation and two days of culture, about 95% of cells were positive for endothelial-specific marker CD146. The percentage of other cells, including dendritic cells (CD11c) and macrophages (F4/80), was less than 1%. Maintenance of endothelial cell phenotype required vascular endothelial growth factor (VEGF) and co-culture with mouse proximal tubular epithelial cells. Conclusion: In this study, we established a method for the isolation of mouse renal peritubular endothelial cells by using immunomagnetic separation with anti-CD146 MicroBeads, followed by co-culture with mouse renal proximal tubular epithelial cells to maintain phenotype. [ABSTRACT FROM AUTHOR]

Adoptive cell therapies involving cell manipulation to achieve tolerance are increasingly being studied in animal models and in human trials. We have demonstrated that the specific removal of allo-stimulated dividing cells (or "pruning") promotes long-term allograft survival across a major MHC mismatch in transplant models including skin, heart and isiet transplants. In this study, we examine the role of transforming growth factor beta (TGFβ), an important regulatory cytokine, on allograft survival in our allodepletion or "pruning" skin transplant model. Increased proliferation of CD4+ T cells was observed following allo-stimulation of BALB/c spleen cells (labeled with CFSE) in the presence of the regulatory cytokines TGFβ and (interleukin-2) IL-2 in a mixed lymphocyte culture (MLC). Expression of the regulatory gene forkhead box-3 (FoxP3) was increased in both the allo-stimulated non-dividing (ND) (CFSEhigh) and dividing (D) (CFSElow) CD4+ T cell populations, with the highest expression found in tbe D CD4+ T cell population. Mice reconstituted with allo-stimulated ND CD4+ T cells following TGFβ/IL-2 stimulation sbowed prolonged allograft survival, similar to previous data. Significantly, TGFβ/lL-2 stimulation prevented acute rejection of allografts across a major MHC mismatch in the presence of highly activated allo-stimulated D CD4+ T cells. Blockade of TGFβ promoted rejection of allografts even following depletion of allo-stimulated D CD4+ T cells. Tbese studies support a crucial role for TGFβ in tbe survival of allografts and sbows tbat regulatory cytokines TGFβ/IL2 can delay tbe rejection of allografts, even in tbe presence of bighly activated alloreactive T cells. [ABSTRACT FROM AUTHOR]

Background/aims: Hepatitis B infection is a well-known cause of hepatocellular carcinoma (HCC). This study aims to investigate the role that the co-stimulatory molecule CD28 and co-inhibitory molecule programmed death-1 (PD-1) play in compromising the function of tumour-infiltrating lymphocytes (TIL) in hepatitis B virus (HBV)-related HCC. Methods: A total of 45 patients with HBV-related HCC were enrolled during the period February 2008 to March 2010. The immune phenotype and the expression of PD-1, CD28 and CD127 in TIL in biopsy specimens and in peripheral blood lymphocytes (PBL) from the same patients were analysed by flow cytometry. Results: Among the 45 patients, there was a male predominance (80%) and the mean age was 50 ± 13.68 years (range: 29–71). The majority of TIL were CD45RO+CD69+. PD-1 expression was higher and CD28 and CD127 expression levels were lower in TIL than in PBL. The prevalence of portal vein thrombosis was 40%. Furthermore, tumour thrombosis invasion into the portal vein correlated with the expression level of the PD-1 co-inhibitory molecule. Conclusion: PD-1+ tumour-infiltrating lymphocytes correlate with portal vein thrombosis and might serve as a potential prognostic marker of and a novel therapeutic target for HBV-related HCC. [ABSTRACT FROM AUTHOR]