The loss of p27 and p57 leading to expression of cyclin A may account for the activation of podocyte proliferation in CG. Furthermore, the loss of cyclin D1 from histologically normal glomeruli suggests a possible role of cyclin D1 in mediating the dysregulation of the podocyte cell cycle in CG. These novel findings offer insight into the molecular regulation of mature podocyte differentiation. Podocyte proliferation in CG provides evidence in support of a previously underestimated plasticity of mature podocytes.

Human melanoma cells can process the The discoveries of genes encoding a number of human melanoma-associated antigens (1-6) and of sequences of antigenic peptides serving as the cytolytic T-lymphocyte (CTL) epitopes on the appropriate major histocompatibility complex (MHC)class I molecules (7-11) have raised considerable interest in peptide-based specific melanoma vaccines. All the CTLdetermined melanoma-associated peptide epitopes that have so far been described are, however, "self' peptides (i.e., without any alteration in the sequence in the encoding gene found in the autologous normal cells). The question of whether these self peptide epitopes are immunogenic in humans has, therefore, become a crucial issue. To test the immunogenic potential of a peptide-based melanoma vaccine in vivo, we have taken an approach based on the physiologic principles underlying peptide presentation to T cells. This approach involves presenting a relevant CTL-determined peptide on the appropriate MHC-restricting elements of autologous professional antigen presenting cells (APCs). We chose to study the immunogenicity of the MAGE-1 nonapeptide EADPTGHSY (7) in vivo, since the MAGE-1 gene is not expressed in any normal tissues with the exception of certain cells in the testis (1).We have observed that a population of APCs, obtained by culturing autologous blood-derived monocyte/macrophages in granulocyte-macrophage colony-stimulating factor (GM-CSF), exhibit many of the essential features of authentic APCs (high levels of MHC class I and class II molecules, CD11b antigen, CD54 antigen, B7 molecules, and dendritic morphology expressed by a proportion of the cells). They are also capable of simultaneously providing an additional stimulatory signal(s) toward T-cell activation-analogous to some form of costimulatory, or just another stimulatory, second signal.These cultured APCs can efficiently present the MAGE-1 nonapeptide to the MAGE-1 antigen-specific CTLs (12). More importantly, they seem to be capable of overriding the negative influence of melanoma cells while activating autologous T cells in vitro (12). Based on these findings, this study was designed to examine whether the cultured APCs, pulsed with the synthetic peptide EADPTGHSY, could recruit a MAGE-1-specific CTL response in vivo at the immunization sites and at distant sites of melanoma deposits in patients with advanced stage IV melanoma, who are HLA-A1+, and whose tumor cells express the MAGE-1 gene.MATERIALS AND METHODS Patients. Patients with advanced metastatic melanoma were studied with informed consent.Cell Lines. The melanoma cell lines RM-M (HLA-A1, -3; B8, -44) and HS-M (HLA-A1, -28; B14, -57) were established from explants of metastatic melanoma in our laboratory from the two study cases according to procedures described earlier.The melanoma cell line MZ 3.1 (MAGE-1+/HLA-A1+) and the MAGE-1-/HLA-A1+ variant melanoma line MZ 2.2 and the MAGE-1 antigen-specific CTL line MZ 82/30 were gifts of Thierry Boon (Ludwig Institute, Brussels).APCs. Autologous perip...

Sphingosine-1-phosphate (S1P) is an important regulator of cellular functions via interaction with its receptors S1P 1-5 . To date, nothing is known about the S1P receptor expression and the effects of S1P signaling in Wilms tumor. In this study, we found ubiquitous expression of S1P receptors in Wilms tumor specimens and cell lines. We demonstrated that S1P 1 acted as a promigratory modulator by employing S1P 1 antagonist VPC44116, S1P 1 siRNA and adenoviral transduction in Wilms tumor cells. Further, we clarified that S1P 1 -mediated migration occurred via Gi coupling and activation of PI3K and Rac1. In addition, S1P stimulated WiT49 cell invasion through S1P 1 /Gi signaling pathway. We consider that targeting S1P 1 may be a point of therapeutic intervention in Wilms tumor.

The discoveries of human melanoma-associated antigens in molecular terms have renewed interest in peptide- or peptide- and antigen-presenting-cell (APC)-based cancer vaccines. Considering the limited scope of immunization using defined peptides, we have studied an alternative approach of specific immunization with tumor-lysate-loaded autologous APC (adherent peripheral mononuclear cells cultured in 1000 U granulocyte/macrophage-colony-stimulating factor for 14 days) as a surrogate vaccine. Seventeen patients (11 with active metastatic disease) were intradermally immunized with the vaccine in a phased dose escalation (10(5)-10(7) cells/injection) monthly for 4 months. Thirteen patients completed all four immunizations showing no toxicity (3 patients had to be taken off study because of progressive disease and 1 patient went off study as a result of myocardial infarction due to multi-vessel coronary artery disease). None has shown any immediate or delayed toxicity attributable to the immunization and none has shown any evidence of autoimmunity. One patient showed a partial regression of a subcutaneous nodule. Thirteen patients are alive after 4+ months to 30+ months (17-month median survival for the group). Nine patients showed evidence of delayed-type hypersensitivity at the vaccine sites. Monitoring of biological response in conventional natural killer or cytolytic T lymphocyte assays with pre- and post-immune peripheral blood lymphocytes revealed no consistent differences. The vaccine-infiltrating lymphocytes (VIL) from nine specimens were adequately expanded following in vitro stimulation with the respective autologous-lysate-loaded APC for phenotypic and functional analyses. Five of the nine ex vivo expanded VIL were predominantly CD8+. Evidence of an antigen-specific CD8+ T cell response (cytotoxicity and/or tumor necrosis factor production) was detected in three of the five CD8+ VIL. These observations suggest that this type of vaccine is feasible, that it has biological activity, and that the approach may be improved through additional strategic manipulations.

Sphingosine Kinase-2 (Sphk2) is responsible for the production of the bioactive lipid Sphingosine-1 Phosphate, a key regulator of tissue repair. Here we address the in vivo significance of Sphingosine Kinase -2 in renal inflammation/fibrosis in response to unilateral ureteral obstruction using both genetic and pharmacological strategies. Obstructed kidneys of Sphk2-/- mice showed reduced renal damage and diminished levels of the renal injury markers TGFβ1 and αSMA when compared to wild type controls. We found a consistently significant increase in anti-inflammatory (M2) macrophages in obstructed Sphk2-/- kidneys by flow cytometry and a decrease in mRNA levels of the inflammatory cytokines, MCP1, TNFα, CXCL1 and ILβ1, suggesting an anti-inflammatory bias in the absence of Sphk2. Indeed, metabolic profiling showed that the pro-inflammatory glycolytic pathway is largely inactive in Sphk2-/- bone marrow-derived macrophages. Furthermore, treatment with the M2-promoting cytokines IL-4 or IL-13 demonstrated that macrophages lacking Sphk2 polarized more efficiently to the M2 phenotype than wild type cells. Bone marrow transplant studies indicated that expression of Sphk2-/- on either the hematopoietic or parenchymal cells did not fully rescue the pro-healing phenotype, confirming that both infiltrating M2-macrophages and the kidney microenvironment contribute to the damaging Sphk2 effects. Importantly, obstructed kidneys from mice treated with an Sphk2 inhibitor recapitulated findings in the genetic model. These results demonstrate that reducing Sphk2 activity by genetic or pharmacological manipulation markedly decreases inflammatory and fibrotic responses to obstruction, resulting in diminished renal injury and supporting Sphk2 as a novel driver of the pro-inflammatory macrophage phenotype.

Omental Infarction, the end result of impaired perfusion to the greater omentum, is a rare entity (JBCM Puylaert, Radiology 1992;185:169-172). We recently encountered three patients in whom computed tomography (CT) showed the characteristic findings of omental infarction. The diagnosis was subsequently confirmed intraoperatively and pathologically in two of the cases. The third case showed partial resolution on follow-up computed tomography. All three cases are presented with a brief review of the literature.

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This study suggests that in a murine ureteral obstruction model FTY720 significantly inhibited the production of inflammatory cytokines and factors regulating interstitial fibrosis and extracellular matrix accumulation. These findings were associated with decreased evidence of renal injury on pathological examination, suggesting that FTY720 or related compounds may be valuable modulators of obstruction induced renal injury.