Abstract Mutated p21 ras proteins (muRas) are present in approximately 90% of pancreatic adenocarcinomas and express mutants which can function as cancer-specific antigens. To evaluate the frequency and magnitude of the natural T-cell response against muRas in 19 HLA-A2-positive patients with muRas-positive pancreatic carcinomas, antigen-experienced T lymphocytes in fresh peripheral blood mononuclear cells were shown by IFN-gamma enzyme-linked immunospot using muRas peptides (5-21) that encompass both HLA class I (HLA-A2)- and class II-restricted (HLA-DRB1) epitopes. Six of 19 patients (32%) were found to have a specific T-cell response against individual mutation-specific ras(5-21) but not against other ras mutations or wild-type ras. In contrast, none of 19 healthy subjects had T cells specifically secreting IFN-gamma (P = 0.004). The T-cell response consisted of both CD8(+) and CD4(+) T cells but was dominated by CD8 T cells in three of four patients. MuRas(5-14) and muRas(6-14) were shown to specifically induce CD8(+) T-cell mediated cytotoxicity against HLA-A2-positive, muRas-bearing pancreatic carcinoma cells. The T-cell response was not correlated with prognostic or clinical variables such as tumor-node-metastasis status, stage, or survival. In conclusion, a natural T-cell response against muRas proteins that could be exploited for immunostimulatory therapeutic approaches has been shown in a significant proportion of patients with pancreatic cancer.
We have investigated the magnetorelaxation (MRX) of various magnetite (Fe3O4) nanoparticle samples with organic shells with regard to their suitability for the realization of a magnetic relaxation immunoassay. The MRX of magnetic nanoparticles (MNP), immobilized by freeze-drying, was measured for magnetization fields between 0.2 and 2.0mT and for magnetization times between 0.2 and 20s using a differential fluxgate setup. The experimental data were analyzed on the basis of the magnetic-moment superposition model, providing information on magnetic properties, such as anisotropy constant and saturation magnetization, on the dynamics of the magnetization and relaxation process, as well as on the size distribution of MNP cores.
In rat liver and kidney preservation, hepatic and renal uptake of 3H-adenosine, 3H-glutathione, and 3H-raffinose from University of Wisconsin solution and diffusion to the interstitial space were measured. At 4 degrees C only 0.38+/-0.47% and 2+/-0.92% of the total 3H-adenosine remained in the kidney and in the liver, respectively, but at 37 degrees C the amount remaining was 1+/-1% and 12+/-3% (P<0.001). Hepatic and renal uptake of the impermeant 3H-raffinose was unaffected by temperature. During flush out, interstitial accumulation of adenosine was significantly higher in livers than in kidneys and decreased during 24-h cold storage. Glutathione accumulation in the interstitial space was two orders of magnitude lower than 3H-adenosine accumulation and comparable to the impermeant raffinose. In summary, the bioavailability of components of preservation solutions at 4 degrees C is lower than at physiological temperatures, so that the application of cytoprotectants at 37 degrees C to organ donors, rather than simple addition to the cold storage solution, might improve cold storage preservation of livers and kidneys.
Partial glycerides such as monoacylglycerides (MAGs) are important functional ingredients with various applications in the cosmetics and food industry.
Interactions between CXCR4 and its ligand CXCL12 have been shown to be involved in cancer progression in colorectal cancer (CRC). We performed a comparative CXCL12/CXCR4 expression analysis and assessed the effect of external CXCL12 stimulation on migration of CRC cells without and with CXCR4 inhibition.Expression of CXCL12/CXCR4 was assessed by quantitative real-time PCR, ELISA and immunohistochemistry in resection specimens of 50 CRC patients as well as in the corresponding normal tissues and in three human CRC cell lines with different metastatic potential (Caco-2, SW480 and HT-29). Migration assays were performed after stimulation with CXCL12 and CXCR4 was inhibited by siRNA and neutralizing antibodies.In CRC tissues CXCL12 was significantly down-regulated and CXCR4 was significantly up-regulated compared to the corresponding normal tissues. In cell lines CXCR4 was predominantly expressed in SW480 and less pronounced in HT-29 cells. CXCL12 was only detectable in Caco-2 cells. CXCL12 stimulation had no impact on Caco-2 cells but significantly increased migration of CXCR4 bearing SW480 and HT-29 cells. This effect was significantly abrogated by neutralizing anti-CXCR4 antibody as well as by CXCR4 siRNAs (P < 0.05).CXCR4 expression was up-regulated in CRC and CXCL12 stimulation increased migration in CXCR4 bearing cell lines. Migration was inhibited by both neutralizing CXCR4 antibodies and CXCR4 siRNAs. Thus, the expression and functionality of CXCR4 might be associated with the metastatic potential of CRC cells and CXCL12/CXCR4 interactions might therefore constitute a promising target for specific treatment interventions.
