Selective delivery of β cell antigen to dendritic cells in vivo leads to deletion and tolerance of autoreactive CD8+ T cells in NOD mice

Type 1 diabetes (T1D) is an autoimmune disease resulting from defects in central and peripheral tolerance and characterized by T cell-mediated destruction of islet β cells. Cytotoxic CD8+ T cells, reactive to β cell antigens, are required for T1D development in the NOD mouse model of the disease, and CD8+ T cells specific for β cell antigens can be detected in the peripheral blood of T1D patients. It has been evident that in nonautoimmune-prone mice, dendritic cells (DCs) present model antigens in a tolerogenic manner in the steady state, e.g., in the absence of infection, and cause T cells to proliferate initially but then to be deleted or rendered unresponsive. However, this fundamental concept has not been evaluated in the setting of a spontaneous autoimmune disease. To do so, we delivered a mimotope peptide, recognized by the diabetogenic CD8+ T cell clone AI4, to DCs in NOD mice via the endocytic receptor DEC-205. Proliferation of transferred antigen-specific T cells was initially observed, but this was followed by deletion. Tolerance was achieved because rechallenge of mice with the mimotope peptide in adjuvant did not induce an immune response. Thus, targeting of DCs with β cell antigens leads to deletion of autoreactive CD8+ T cells even in the context of ongoing autoimmunity in NOD mice with known tolerance defects. Our results provide support for the development of DC targeting of self antigens for treatment of chronic T cell-mediated autoimmune diseases. © 2008 by The National Academy of Sciences of the USA

Adsorption and removal of strontium in aqueous solution by synthetic hydroxyapatite

Hydroxyapatite (HAP) is a main mineral constituent of bone and tooth and has an outstanding biocompatibility. HAP is a possible sorbent for heavy metals in wastewater due to its high adsorption capacity and low water solubility. We developed a removal system of 90Sr from aqueous solution by HAP column procedure. More than 90 % of 90Sr was adsorbed and removed from the 90Sr containing solution. Divalent cations, Ca2+, had little effect on the removal of 90Sr up to a concentration of 1 mmol L−1. This clearly indicates that the HAP column technique is advantageous with respect to the capacity to adsorb 90Sr from water present in the environment

In vitro analysis of radioprotective effect of monoterpenes

Monoterpenes are naturally occurring hydrocarbons composed of two units of isoprenes. They exhibit antioxidant activity to scavenge reactive oxygen species, such as hydroxyl radicals. We investigated the potential of monoterpenes such as thymol, linalool, and menthol to act as radioprotectants. The proliferation of EL4 cells, a mouse lymphoma cell line, treated with linalool at a concentration of 500 μM or more was not affected by X-ray irradiation. Plasmid-nicking assay performed using formamidopyrimidine-DNA glycosylase showed that linalool prevented single strand breaks and oxidized purines on pUC19 plasmid DNA. These findings indicate that linalool has the ability to scavenge reactive oxygen species and is a potential radioprotector

岡山大学における核燃料物質の安全管理のための劣化ウランと天然ウランの鑑別について

In Japan, the Law for the Regulation of Nuclear Source Materials, Nuclear Fuel Materials and Reactors (Regulation Law) controls the nuclear fuel materials such as thorium (Th), uranium (U) and plutonium (Pu). Under the Regulation Law, all related materials and reactors are needed to register to the Government. In Okayama University, many nuclear fuel materials, mainly uranium compounds, are registered and stored in 11 departments, separately. Discrimination between depleted uranium and natural uranium is important for the observance of the Regulation Law and the safety management of the nuclear fuel materials in the Okayama University. However, the discrimination of the two kind of uranium has poorly analyzed. In this study, we analyzed several uranium compounds by using γ-ray spectrometry to determine whether the depleted uranium or not

Functional promoter upstream p53 regulatory sequence of IGFBP3 that is silenced by tumor specific methylation

BACKGROUND: Insulin-like growth factor binding protein (IGFBP)-3 functions as a carrier of insulin-like growth factors (IGFs) in circulation and a mediator of the growth suppression signal in cells. There are two reported p53 regulatory regions in the IGFBP3 gene; one upstream of the promoter and one intronic. We previously reported a hot spot of promoter hypermethylation of IGFBP-3 in human hepatocellular carcinomas and derivative cell lines. As the hot spot locates at the putative upstream p53 consensus sequences, these p53 consensus sequences are really functional is a question to be answered. METHODS: In this study, we examined the p53 consensus sequences upstream of the IGFBP-3 promoter for the p53 induced expression of IGFBP-3. Deletion, mutagenesis, and methylation constructs of IGFBP-3 promoter were assessed in the human hepatoblastoma cell line HepG2 for promoter activity. RESULTS: Deletions and mutations of these sequences completely abolished the expression of IGFBP-3 in the presence of p53 overexpression. In vitro methylation of these p53 consensus sequences also suppressed IGFBP-3 expression. In contrast, the expression of IGFBP-3 was not affected in the absence of p53 overexpression. Further, we observed by electrophoresis mobility shift assay that p53 binding to the promoter region was diminished when methylated. CONCLUSION: From these observations, we conclude that four out of eleven p53 consensus sequences upstream of the IGFBP-3 promoter are essential for the p53 induced expression of IGFBP-3, and hypermethylation of these sequences selectively suppresses p53 induced IGFBP-3 expression in HepG2 cells

Sequence variations in the envelope protein of the hepatitis C virus: comparison with partial cDNA sequence of a new variant virus obtained by the polymerase chain reaction.

It has been reported that the envelope region located at the 3' portion of the structural protein coding region is one of the most variable regions at both nucleotide and amino acid sequence levels in the hepatitis C virus (HCV) genome. We cloned HCV cDNA fragments of an envelope protein coding region (HCVNK), which were derived from serum of a Japanese patient with hepatocellular carcinoma and were amplified by polymerase chain reaction. After determining the nucleotide sequence, deduced amino acid sequence of the envelope protein region was compared with those of six HCV strains already published (HCJ1, HCVUS, HCJ4, HCVJH, HCVJ and HCVBK). Homology analysis among the strains revealed that the seven strains were classified into two subtypes; a US subtype (HCJ1 and HCVUS) and a Japanese subtype (HCJ4, HCVJH, HCVJ, HCVBK and HCVNK), since percentage homologies between two subtypes (70.3-77.3%) were significantly lower than those within each subtype (83.9-93.5%). Detailed analysis of the amino acid sequences also indicates that the region at aa246-aa258, tentatively named intersubtype variable region-1, may distinguish the US subtype from the Japanese subtype

In Vitro Studies to Define the Cell-Surface and Intracellular Targets of Polyarginine-Conjugated Sodium Borocaptate as a Potential Delivery Agent for Boron Neutron Capture Therapy

Boron neutron capture therapy (BNCT) requires pharmaceutical innovations and molecular-based evidence of effectiveness to become a standard cancer therapeutic in the future. Recently, in Japan, 4-borono-L-phenylalanine (BPA) was approved as a boron agent for BNCT against head and neck (H&N) cancers. H&N cancer appears to be a suitable target for BPA-BNCT, because the expression levels of L-type amino acid transporter 1 (LAT1), one of the amino acid transporters responsible for BPA uptake, are elevated in most cases of H&N cancer. However, in other types of cancer including malignant brain tumors, LAT1 is not always highly expressed. To expand the possibility of BNCT for these cases, we previously developed poly-arginine peptide (polyR)-conjugated mercaptoundecahydrododecaborate (BSH). PolyR confers the cell membrane permeability and tumor selectivity of BSH. However, the molecular determinants for the properties are not fully understood. In this present study, we have identified the cluster of differentiation 44 (CD44) protein and translational machinery proteins as a major cell surface target and intracellular targets of BSH-polyR, respectively. CD44, also known as a stem cell-associated maker in various types of cancer, is required for the cellular uptake of polyR-conjugated molecules. We showed that BSH-polyR was predominantly delivered to a CD44(High) cell population of cancer cells. Once delivered, BSH-polyR interacted with the translational machinery components, including the initiation factors, termination factors, and poly(A)-biding protein (PABP). As a proof of principle, we performed BSH-polyR-based BNCT against glioma stem-like cells and revealed that BSH-polyR successfully induced BNCT-dependent cell death specifically in CD44(High) cells. Bioinformatics analysis indicated that BSH-polyR would be suitable for certain types of malignant tumors. Our results shed light on the biochemical properties of BSH-polyR, which may further contribute to the therapeutic optimization of BSH-BNCT in the future

Detection by western blotting of an antibody to the hepatitis C virus E1 envelope protein in sera of patients with chronic liver disease.

We detected an antibody to HCV envelope protein (E1) in sera of patients with HCV-related chronic liver diseases (20 patients with chronic hepatitis and 5 patients with liver cirrhosis) by Western blotting using the fusion protein of E1 envelope protein and beta-galactosidase as an antigen. The antibody to HCV E1 (anti-HCV E1) was detected in 8 (42%) of 19 patients positive for HCV-RNA (16 were positive and 3 were negative for antibody to C100-3) and in 1 (17%) of 6 patients negative for HCV-RNA but positive for antibody to C100-3. HCV-RNA was detected in 8 (89%) of 9 anti-HCV E1 positive sera. The value of alanine aminotransferase was significantly higher in patients positive for anti-HCV E1 than in patients negative for the antibody. Although an antibody to the envelope protein of HCV is suspected to be one of the candidates of virus-neutralizing antibodies, our results suggest this hypothesis appears to be unlikely.</p

Isolation and characterization of human lung cancer antigens by serological screening with autologous antibodies

Serological analysis of a recombinant cDNA expression library (SEREX) derived from two lung adenocarcinoma cancer cell lines using autologous sera led to the isolation of 41 positive cDNA clones comprising 28 different antigens. They coded for a variety of nuclear and cytoplasmic proteins. Among the antigens, nucleoporin 107 (NUP107) was isolated most frequently (5 of 41 clones). The second most frequently isolated antigen was coded for by C21orf58 (4 of 41 clones). During serological analysis of selected antigens based on their reactivity to sera from normal individuals and lung cancer patients, none of the antigens showed a cancer-restricted recognition pattern. However, five genes including NUP107 showed higher expression when we examined the changes in gene expression in five different adenocarcinoma cell lines, including those used in SEREX, compared with their levels in normal lung tissues by cDNA microarray analysis. On the other hand, the expression levels of five genes including C21orf58 were down regulated in all adenocarcinoma cell lines. This SEREX study combining comprehensive gene expression assays has added to the growing list of lung cancer antigens, which may aid the development of diagnostic and immunotherapeutic reagents for patients with lung cancer