Processing of high-molecular-weight form adrenocorticotropin in human adrenocorticotropin-secreting tumor cell line (DMS-79) after transfection of prohormone convertase 1/3 gene

Ectopic ACTH-producing tumors preferentially secrete biologically inactive ACTH precursors and ACTH-related fragments. DMS-79 is known to secrete unprocessed high-molecular-weight (HMW) form ACTH. To determine whether prohormone convertase (PC) 1/3 is involved in the abnormal processing of proopiomelanocortin (POMC), we studied whether PC1/3 and 2 genes are expressed in DMS-79, and whether overexpression of PC1/3 gene affects POMC processing pattern. Steady-state mRNA levels of PC1/3 and 2 were determined by real-time RT-PCR. Molecular weights of ACTH-related peptides were determined by chromatographical analyses coupled with ACTH and beta-endorphin (beta-END) radioimmunoassays. PC1/3 gene was transfected into DMS-79 by retrovirus transduction using pMX-IP vector encoding PC1/3 cDNA. The steady-state mRNA levels of PC1/3 and 2 in DMS-79 were lower than those in ACTH-secreting and nonfunctioning pituitary tumors. DMS-79 predominantly secreted HMW form with both ACTH and beta-END immunoreactivities by size-exclusion chromatography. After purification by immunoaffinity chromatography with anti-ACTH antibody, the apparent molecular weight of HMW form ACTH was estimated to be 16 kDa by sodium dodecyl sulfate-polyacrylamide gel electrophoresis with silver staining. After retroviral transfection of PC1/3 cDNA into DMS-79 and puromycin selection, PC1/3 stably-expressing cell line (DMS-79T) secreted two immunoreactive ACTH components, a major one coeluting with ACTH(1-39) and a minor one as a HMW form as well as two beta- END immunoreactive components coeluting with beta-lipotropic hormone and beta-END, respectively. Thus, we have established PC1/3 stably-expressing cell line (DMS-79T) capable of proteolytically processing ACTH precursor molecule(s) into mature ACTH and beta-END.

Tumor suppressive efficacy through augmentation of tumor-infiltrating immune cells by intratumoral injection of chemokine-expressing adenoviral vector

Our goal in the present study was to evaluate antitumor effects and frequency of tumor-infiltrating immune cells upon intratumoral injection of RGD fiber-mutant adenoviral vector (AdRGD) encoding the chemokines CCL17, CCL19, CCL20, CCL21, CCL22, CCL27, XCL1, and CX3CL1. Among eight kinds of chemokine-expressing AdRGDs, AdRGD-CCL19 injection most efficiently induced infiltration of T cells into established B16BL6 tumor parenchyma, whereas most of these T cells were perforin-negative in immunohistochemical analysis. Additionally, the growth of AdRGD-CCL19-injected tumors decreased only slightly as well as that of other tumors treated with each chemokine-expressing AdRGD, which indicated that accumulation of naive T cells in tumor tissue does not effectively damage the tumor cells. Tumor-bearing mice, in which B16BL6-specific T cells were elicited by dendritic cell-based immunization, demonstrated that intratumoral injection of AdRGD-CCL17, -CCL22, or -CCL27 could considerably suppress tumor growth and attract activated T cells. On the other hand, AdRGD-CCL19-injection in the immunized mice showed slight increase of tumor-infiltrating T cells compared to treatment using control vector. Collectively, although AdRGD-mediated chemokine gene transduction into established tumors would be very useful for augmentation of tumor-infiltrating immune cells, a combinational treatment that can systemically induce tumor-specific effector T cells is necessary for satisfactory antitumor efficacy.

Cotransduction of CCL27 gene can improve the efficacy and safety of IL-12 gene therapy for cancer

Interleukin-12 (IL-12) is a potent antitumoral cytokine, but high doses are toxic. Herein, we demonstrate that combinational transduction of IL-12 and CC-chemokine ligand-27 (CCL27) genes into pre-existing murine OV-HM ovarian carcinoma and Meth-A fibrosarcoma, by using RGD fiber-mutant adenoviral vectors, could induce tumor regression and relieve systemic side effects more effectively than either treatment alone. The antitumor activity of the IL-12 and CCL27 combination treatment was T-cell-dependent, and development of long-term specific immunity was confirmed in rechallenge experiments. Immunohistochemical analysis of tumors transduced with CCL27 gene alone or cotransduced with IL-12 and CCL27 genes showed significant increases in numbers of infiltrating CD3(+) T cells, which included both CD4(+) and CD8(+) cells. Additionally, cotransduction with IL-12 and CCL27 genes could more efficiently activate tumor-infiltrating immune cells than transduction with CCL27 alone, as determined by the frequency of perforin-positive cells and expression levels of IFN-gamma. Furthermore, mice treated with the IL-12 and CCL27 combination compared with those treated with IL-12 alone showed milder pathological changes, for example, lymphocyte infiltration and extramedullary hematopoiesis, in lung, liver and spleen. Our data provide evidence that combinational in vivo transduction with IL-12 and CCL27 genes is a promising approach for the development of cancer immunogene therapy that can simultaneously recruit and activate tumor-infiltrating immune cells.

Brain site-specific gene expression analysis in Alzheimer's disease patients

BACKGROUND

Alzheimer's disease (AD) is an age-related neurodegenerative disorder that is characterized by a progressive loss of higher cognitive functions. The brain of an individual with AD exhibits extracellular senile plaques (SPs) of aggregated amyloid-beta peptide (Abeta) and intracellular neurofibrillary tangles (NFTs). Given the critical role of neuronal transport of both proteins and organelles, it is not surprising that perturbation of microtubule-based transport may play a major role in the pathogenesis of AD.

MATERIALS AND METHODS

We used the cDNA subtraction methodology and in vitro neural cell culture analyses to study the meaning of the brain site-specific gene expression pattern in cerebral tissue obtained from AD patients and also from control subjects at autopsy.

RESULTS

We observed that cytoskeleton-associated proteins were down-regulated in AD subjects. We also noted an altered expression of the microtubule-associated protein 1B (MAP1B), the heat-shock protein (HSP)-90 (a key chaperone molecule), the tripartite motif-containing proteins (TRIM)-32/37 (an anti apoptotic enzyme with ubiquitin-protein ligase activity) and the Reticulon-3 (a modulator of the amyloid-precursor-protein (APP) cleavage) in AD brains. Additional molecular- and cell-biological studies revealed that small interfering RNA (siRNA)-mediated down-regulation of MAP1B expression leads to neuronal cell death in vitro.

CONCLUSION

Altered expression of MAP1B, HSP90, TRIM32/37 and Reticulon-3 provides new clues by which the ubiquitin-proteasome-, the protein-chaperon- and the APP-processing systems are disturbed in AD, thus, leading to neuritic amyloid plaques and neurofibrillary tangles.

Simultaneous five cell-lineage flow cytometric analysis system for detection of leucocyte antibodies

Although flow cytometric (FCM) analysis is one of the most widely used approaches to screen the presence of leucocyte antibodies, it has several drawbacks. First, neutrophils and, especially, monocytes exhibit high background reactivity. Second, to determine antibody specificity, it is often necessary to examine not only neutrophils and monocytes but also other lineage cells including T cells, B cells and platelets. Therefore, we attempted to establish an FCM analysis system in which four lineages of leucocytes and platelets are simultaneously tested with low background. FCM analysis was performed using ethylene diamine tetraacetic acid-anticoagulated whole blood as cell sample without any cell preparation. Discrimination of five cell lineages was carried out based on the differences in forward vs. side scatter distribution and in the expression of CD4, CD20 and CD14. When anti-HNA (human neutrophil antigen) 1b antiserum was applied to HNA 1b-positive blood samples, only neutrophils were unambiguously positive. When anti-Naka (anti-CD36) antiserum was applied, only platelets and monocytes were positive. The background reactivity of neutrophils and monocytes was low enough. When anti-human leucocyte antigen (HLA) class II antiserum was tested, only B-lymphocytes and monocytes were positive. When anti-HLA class I antiserum was tested, all the five-lineage cells were positive.

A single base insertion of the 4-alpha-galactosyltransferase gene led to the deficiency of Gb3 biosynthesis

cDNAs for alpha 1,4 galactosyltransferase (A4GALT) have been isolated. To explore the molecular basis of the p phenotype in Japanese donors, we analyzed the A4GALT gene sequences of normal and p phenotype samples. The coding region in the A4GALT gene for DNA sequencing was amplified by PCR amplification. A4GALT expression vectors for individual were constructed by PCR amplification of the coding region using primers and subsequent subcloning into an expression vector. The expression of Gb3/CD77 antigen on the cell surface was evaluated by flow cytometry and by immunochemical techniques. All individuals with the p phenotype were found to have a single base insertion (A4GALT/insC) at the same nucleotide position. Neither the transfectant cells with a mutant gene (A4GALT/insC) of donor origin or those with a synthesized mutant gene (A4GALT/insC-Mu) expressed Gb3 antigen indicating that the presence of A4GALT/insC diminished the A4GALT enzyme activity. In addition, an allele-specific PCR (ASP) system was developed in which of the p phenotype with A4GALT/insC can be unambiguously discriminated from normal donors. Based on the finding that a single base insertion (A4GALT/insC) diminishes A4GALT activity, an ASP assay was developed to detect individuals with this particular p phenotype.

Screening for microorganisms with specific characteristics by flow cytometry and single-cell sorting

Flow cytometry used in combination with single-cell sorting is a powerful technique for the identification and isolation of microbial cells with particular characteristics, especially when such cells grow more slowly than other cells in a large heterogeneous population. Many applications of flow cytometry with cell sorting, originally used by specialists studying mammalian cells, have been modified so that microorganisms also can be evaluated. The methods can now be used more widely because of the increasing availability of the expensive equipment. There are means for the fluorescence detection of a wide variety of properties, such as amounts of various cell components, specific sequences of peptides and nucleotides, cell functions, and enzyme activities. From the extensive literature, representative reports of an assortment of uses of flow cytometry with cell sorting are reviewed in this article, intended to introduce the technique and its many advantages to microbiologists.

Glycolaldehyde-forming route in Bacillus subtilis in relation to vitamin B6 biosynthesis

Glycolaldehyde (GA) was shown to be a precursor of vitamin B6 (B6), and to be formed from glycolate by glycolaldehyde dehydrogenase (GADH) in Escherichia coli. In this study, we show the glycolaldehyde-forming route in B6 biosynthesis in Bacillus subtilis. In the crude extract of B. subtilis, the oxidizing activity of GADH was detected. However, coexisting NADH/NADPH oxidase activity interfered with the determination of the reducing (GA-forming) activity of GADH. NADH/NADPH oxidase was purified and identified as the product of ahpF. In an ahpF disruptant, NADH/NADPH activity was almost eliminated, but the reducing activity of GADH was not detected. We also investigated another possible GA-forming enzyme, glyoxal reductase (GR). GR was partially purified and identified as the product of yvgN. yvgN disruptant did not require B6, and retained the ability to synthesize the same amount of B6 as the wild-type strain. From these results, we concluded that neither GADH nor GR is involved in B6 biosynthesis in B. subtilis.

Purification and characterization of an enzyme that has dihydroxyacetone-reducing activity from methanol-grown Hansenula ofunaensis

An intracellular enzyme having reduction activity towards dihydroxyacetone (DHA), and that was induced by DHA, was purified and characterized from a methanol-grown yeast, Hansenula ofunaensis. After harvesting cells grown in a 1% methanol medium until the early stationary phase, the enzyme was purified through ammonium sulfate fractination and a series of ion-exchange, hydrophobic, and gel-filtration column chromatographies. SDS-PAGE and HPLC showed the enzyme to be a homo dimer composed of two identical subunits, each with a molecular mass of 38 kDa. The optimum pHs for DHA reduction and glycerol oxidation were 6.0 and 7.0, respectively. The optimum temperature for enzyme activity was 55 degrees C. The enzyme reduced several other compounds, including acetaldehyde, acetol, 2-butanone and 3-methyl-2-butanone, more effectively than it did DHA, while its oxidation activity was higher towards ethanol, 2-propanol, 1,2-propanediol, 2,3-butanediol and 1,3-butanediol than towards glycerol. The K(m) values for DHA in reduction and glycerol in oxidation were 430 mM and 4 M, respectively. The K(m) values for DHA in reduction and glycerol in oxidation were 430 mM and 4 M, respectively. The purified enzyme had high K(m) values for glycerol and DHA and low K(m) values for 2-butanol and butanone, although physiologically it had a role in DHA metabolism. There were similarities between the purified enzyme and sec-alcohol dehydrogenases reported previously in their behavior towards inhibitors and metal ions, as well as in their K(m) values for 2-butanol and 2-butanone, but differences in their subunit molecular masses and activities for ethanol. At pH 9.8, the oxidative activity of the purified enzyme for l-2-butanol was about eleven times higher than that for d-2-butanol.

Stereoselective oxidation of alkylbenzenes by fungi

Oxygenase is useful when oxygen is to be introduced at a nonactivated carbon-hydrogen bond to give an optically active center. To obtain such an enzyme from microorganisms, we screened soil samples for organisms that assimilated methylethylketone as their sole carbon source. Yeasts and molds that converted ethylbenzene and propylbenzene into their respective oxygenated products during incubation together as resting cells were isolated. One particularly potent strain was identified as Fusarium moniliforme. The fungus oxidized the side chains of ethylbenzene and propylbenzene selectively at the benzylic position. The products were found to be 1-phenylethanol and 1-phenylpropanol, respectively, by GC-MS and HPLC with a chiral column, with 100% enantiomeric excess of the (R-(+)-form.

Optimal conditions for production of (R)-1-phenylpropanol by Fusarium moniliforme strain MS31

Resting cells of Fusarium moniliforme strain MS31 produced (R)-1-phenylpropanol from propylbenzene. The components of the medium and the reaction conditions were adjusted to increase the specific activity of the hydroxylating enzyme involved. Glucose and sodium nitrate were selected as carbon and nitrogen sources, respectively. The substrate, propylbenzene, inhibited fungal growth and the activity of the enzyme. Acetoin added to the medium increased both growth and activity of the enzyme, and hydroxylation of propylbenzene increased by 1.4-fold. Maximum bioconversion of propylbenzene by resting cells of the fungus was at 25-30 degrees C and pH 7.0 with cells at concentration of 40 mg (dry) per milliliter of reaction mixture. Conversion was accelerated as soon as propylbenzene was added; slowing 2 h later. In the end, F. moniliforme strain MS31 produced (R)-1-phenylpropanol with an enantiomeric excess of 98% at the concentration of 16 mM (2.2 mg.ml(-1)).

Degradation of dibenzothiophene by sulfate-reducing bacteria cultured in the presence of only nitrogen gas

To remove sulfur compounds in petroleum, we isolated sulfate-reducing bacteria that could degrade dibenzothiophene in the presence of only nitrogen gas. Among the 19 strains isolated, some could grow in the presence of 10% (v/v) kerosene and of which two strains were identified as Desulfomicrobium escambium and Desulfovibrio longreachii. Gas chromatography of the ethyl-acetate extract of bacterial cultures, in which 10% or more of the dibenzothiophene initially present was degraded, gave five unknown peaks as the presumable degradation products. Thus, desulfurization of dibenzothiophene could be carried out without oxygen or hydrogen in a pathway different from the anaerobic one already reported, in which biphenyl is detected as the main product.

Conversion of various aromatic compounds by resting cells of Fusarium moniliforme strain MS31

Resting cells of Fusarium moniliforme strain MS31 convert propylbenzene to 1-phenylpropanol with high regio- and stereospecificity. To elucidate the scope of substrate acceptability by the fungus, we used various aromatic compounds for the bioconversion. The fungus hydroxylated various alkylbenzenes at the benzylic position to produce optically active alcohols. Butylbenzene was converted to nonbenzylic alcohols. In all cases, the R absolute configuration of products was more abundant. Aromatic compounds with linear side chains and (1-methylethyl)benzene were converted to their corresponding alcohols with an enantiomeric excess of 94% to 100%. Further oxidation of the alcohols was detected, but it was weak.

Enlarged and astaxanthin-accumulating cyst cells of the green alga Haematococcus pluvialis

The cyst cells of Haematococcus pluvialis were separated into fractions of relatively uniform size by sucrose density gradient centrifugation. The fraction at the bottom of the centrifuge tube with the largest specific gravity from density gradients of mature cysts mainly consisted of enlarged, red cyst cells and had the highest astaxanthin content. To examine the relationship between cell size and astaxanthin content of cysts, formation of the fluorescent dichlorofluorescein (DCF) from 2',7'-dichlorohydrofluorescein diacetate of cyst cells in each fraction from density-gradient centrifugation under oxidative stress caused by methyl viologen (1.0 mM) was studied. The formation of DCF in cyst cells was decreased with larger cell diameter. This decrease was also correlated with increases in astaxanthin content. Therefore, both cell diameter and the fluorescent DCF content of cyst cells would be good parameter to select astaxanthin-hyperproducing strains from native populations of H. pluvialis.

Epithelial-stromal tumor of the seminal vesicles in the transgenic adenocarcinoma mouse prostate model

The transgenic adenocarcinoma mouse prostate (TRAMP) model, designed for researching human prostatic cancer, was genetically engineered to harbor a transgene composed of the simian virus 40 Large-T/small-t antigen promoted by the rat probasin gene. In addition to prostatic neoplasms, the TRAMP mouse develops tumors in the seminal vesicles. This study was conducted to evaluate the pathology and histogenesis of TRAMP seminal vesicle neoplasms. Tissues of accessory sex organs harvested from 72 TRAMP mice of various ages (11-40 weeks of age) were fixed in neutral buffered formalin and stained with hematoxylin and eosin, desmin, 5-bromo-2'-deoxyuridine (BrdU, treated animals only), and SV40 Large-T antigen (SV40-Tag). In the seminal vesicles, we found neoplastic stromal cells that emerged multicentrically just beneath the epithelium, densely packed between the epithelium and the smooth muscle layer. These stromal cells frequently exhibited mitotic figures and showed BrdU incorporation and SV40-Tag protein expression in the nuclei and immunopositivity for desmin. The proliferative mesenchymal cells were lined by cuboidal to columnar epithelium. Some of the larger papillary, polypoid lesions exhibited a phyllodes pattern resembling that seen in mixed epithelial-stromal tumors of the breast, prostate, and seminal vesicles of humans. Although the epithelium was negative for SV40-Tag and showed only occasional incorporation of BrdU, it clearly participated in the biphasic proliferation, forming papillary, cystic, and tubuloglandular structures. No conclusive evidence of malignancy (invasion or metastasis) was identified. Our recommended diagnosis of this lesion in the seminal vesicles is epithelial-stromal tumor.

Insertion of a C in the exon 28 of integrin alphaIIb gene leading to a frameshift mutation is responsible for Glanzmann thrombasthenia in a Japanese case

BACKGROUND

Glanzmann thrombasthenia (GT) is a hereditary bleeding disorder caused by a qualitative or quantitative defect in the integrin alphaIIbbeta3.

OBJECTIVE

Our objective is to identify the gene mutation that resulted in GT.

PATIENTS AND METHODS

The patient was a 66-year-old male with a history of frequent bleeding. The expression levels of the integrin proteins in the platelets were determined by flow cytometry and Western blot analysis. The sequences of genomic DNA and mRNA encoding for alphaIIb and beta3 were analyzed by the dye-terminator cycle sequencing method. For transfection experiments, expression vectors encoding for wild-type alphaIIb, mutated alphaIIb, beta3, green fluorescent protein (GFP) fusion wild-type alphaIIb, GFP fusion mutated alphaIIb and DsRed fusion beta3 were constructed. These vectors were transfected to COS-7 cells, and the expression levels were determined.

RESULTS

The alphaIIb protein was remarkably reduced in the patient's platelets, and gene analysis showed that the patient possessed compound heterozygous mutations in the alphaIIb gene. One was a C --> G substitution at the splice acceptor site (- 3) of exon 26 (CAG -->GAG) and the other was the insertion of an additional C at the region including six C bases between 2911 and 2916 in exon 28 (InsC). Transfection experiments using COS-7 cells showed that alphaIIb containing InsC had expressed and formed a complex with beta3, but had not been transported to the Golgi apparatus.

CONCLUSIONS

In the present study the novel mutation InsC, leading to a frameshift that affects the transmembrane domain and the cytoplasmic tail, was found to be responsible for GT.

Double heterozygosity for a novel missense mutation of Ile304 to Asn in addition to the missense mutation His280 to Pro in the integrin beta3 gene as a cause of the absence of platelet alphaIIbbeta3 in Glanzmann's thrombasthenia

BACKGROUND

Glanzmann's thrombasthenia (GT) is a hereditary bleeding disorder characterized by a defect in the expression or the function of alphaIIbbeta3.

OBJECTIVES

The purpose of the present study was to identify genetic defects in a GT patient.

METHODS

The expression of alphaIIbbeta3 was determined by flow cytometric analysis and Western blotting. We analyzed the cDNA sequences of both alphaIIb and beta3, and performed transfection experiments using COS7 cells to confirm that a specific mutation was responsible for the GT case.

RESULTS

Flow cytometric analysis and Western blotting showed remarkably reduced expression of alphaIIbbeta3. Sequence analysis of the patient's cDNA indicated a new missense mutation that led to the amino acid substitution of Ile304 (ATC) with Asn (AAC) in exon 6 of the beta3 gene. This was in addition to the missense mutation of His280 (CAT) to Pro (CCT) in exon 5, which had been previously reported. The missense mutation of Ile304 (ATC) to Asn (AAC) in beta3 was found to be responsible for this GT case. This was because transfection experiments using COS7 cells indicated that alphaIIbbeta3 possessing Asn304 in beta3 was not expressed on the surface of the transfected cells. In addition, immunoprecipitation analysis demonstrated that alphaIIbbeta3 was absent inside the transfected COS7 cells possessing Asn304 in beta(3).

CONCLUSION

In this study, we describe a new missense mutation (ATC to AAC) at position 1009 in exon 6 that leads to an amino acid substitution (Ile304 to Asn) in beta3, which is responsible for this GT case.

Antibacterial and antipeptide antibodies in Japanese and Finnish patients with rheumatoid arthritis

It has been suggested that Proteus infection may be involved in the pathogenesis of rheumatoid arthritis (RA). Bacterial and peptide immune responses in patients with RA and other control subjects were investigated in two geographically different populations. Serum samples from Finnish patients with early ( n=72) and advanced ( n=27) RA and 30 Finnish healthy controls, as well as from Japanese RA patients from two different locations: Tokyo ( n=30) and Otsu ( n=30), 18 patients with systemic lupus erythematosus (SLE) and 23 Japanese healthy controls were all screened for the total, and class-specific (IgG, IgA and IgM) antibodies against Proteus mirabilis, Escherichia coli and Serratia marcescens by indirect immunofluorescence assay. These samples were also tested for the determination of levels of isotypic antibodies against the shared epitope involving 16-mer synthetic peptides containing the EQRRAA or ESSRAL sequences and compared to scrambled control peptide by using an enzyme-labeled immunosorbent assay method. Significantly elevated levels of IgG and IgM antibodies to P. mirabilis and antibodies against both EQRRAA and ESSRAL peptides were detected in sera of Finnish patients with early and advanced RA, and in Japanese patients from Otsu or Tokyo compared to their corresponding control groups. In contrast, no difference either in the total or in any of the isotypic antibodies were observed between these groups when serum samples were screened against each of E. coli and S. marcescens or against the control peptide. Furthermore, there was a significant correlation between the antibody levels against Proteus bacteria only and both EQRRAA and ESRRAL peptides. Our findings support the possibility for specific involvement of P. mirabilis in the etiopathogenesis of RA even in early cases.

Glanzmann's thrombasthenia due to a point mutation within intron 10 results in aberrant splicing of the beta3 gene

Glanzmann's thrombasthenia (GT) is an hereditary bleeding disorder caused by a quantitative or qualitative defect in the integrin alphaIIbbeta3. We attempted to identify genetic defects responsible for a case of GT in Korea. The patient was a 6-year-old boy who had suffered from hemorrhage and purpura. The cDNAs of alphaIIb and beta3 were amplified by reverse transcription (RT)-PCR and were sequenced. RT-PCR of COS7 cells transfected with Exontrap vectors containing the beta3 genomic DNA fragments were performed to verify an aberrant splicing. Transient expression of alphaIIbbeta3 on transfected-COS7 cells was determined by flow cytometry, and the presence of alphaIIbbeta3 was confirmed by immunoprecipitation. We discovered an abnormality with the insertion of 38 bp between exon 10 and exon 11, including a stop codon, in beta3 cDNA. Sequence analysis of genomic DNA showed a point mutation, G-->T, at the position 29 107 of intron 10. RT-PCR analyses of COS7 cells transfected with Exontrap vector containing the mutant beta3 gene revealed that the point mutation at the position 29 107 of intron 10, G-->T, was responsible for an aberrant splicing in the beta3 gene. The transfection experiments and immunoprecipitation revealed the absence of alphaIIbbeta3 in the COS7 cells transfected with mutant gene. The mutation at the position 29 107 of intron 10, G-->T, in the beta3 genomic DNA was found to induce an aberrant splicing and to be responsible for GT in this patient.

Behçet's disease and sacroiliitis in a child

Abstract We describe the case of a Japanese girl who suffered from both Behçet's disease (BD) and bilateral sacroiliitis. This patient was diagnosed with BD at 8 years of age, and began to complain of buttock pain when she was 10 years old. X-rays of her pelvis showed bilateral grade 3 sacroiliitis, and bone scintigraphy showed an increased uptake in the sacroiliac joints. Movements of the spine and chest expansion were not restricted. HLA typing was positive for B44 and DR4, but negative for B27. The patient was not diagnosed as having seronegative spondyloarthropathy. This case indicates that erosive sacroiliitis is an intrinsic condition of BD.

Section 1B: Rh flow cytometry. Coordinator's report. Rhesus index and antigen density: an analysis of the reproducibility of flow cytometric determination

Fifty-seven IgG monoclonal anti-D antibodies were evaluated in the Rh flow cytometry section, in which 12 laboratories participated. Staining protocols and a fluorescein (FITC)-conjugated Fab fragment goat anti-human IgG (H + L) as a secondary antibody were recommended but not mandatory. A CcDEe red blood cell (RBC) sample that was shown to be homozygous for RHD by molecular methods was supplied and used as internal 'standard RBC' throughout all experiments. An RBC panel comprising two partial D and four weak D types was supplied as well. The use of standard RBC reduced the variability of the data among the laboratories and allowed the conversion of fluorescence data into epitope densities, which were compounded in an antigen density (antigen D per RBC). The highest antigen density was determined for DVI type III, followed by DVII and weak D type 3; the lowest antigen density were determined for weak D type 1 and type 2. Nine of the 12 participating laboratories discriminated three groups of aberrant RhD that had similar Rhesus indices (RI): D category VI with RI = 0; weak D type 2 and type 3 with an high RI; and D category VII and weak D type 1 with an intermediate RI. The antigen densities and the Rhesus indices obtained correlated well among the laboratories of this Workshop section despite different staining protocols, secondary antibodies and instrumentation.

Decreased expression of Bcl-x protein during hepatocarcinogenesis induced exogenously and endogenously in rats

Dysregulations of apoptosis have been widely recognized as important events in multi-stage carcinogenesis. Bcl-x, a member of the Bcl-2 family, is known to act as a regulator of apoptosis. The present study was conducted to assess the role of altered Bcl-x protein expression in exogenous and endogenous hepatocarcinogenesis in rats. In the short-term exogenous models, male Fischer 344 rats, 6 weeks old, were given a single intraperitoneal injection of diethylnitrosamine (DEN) at a dose of 200 mg / kg body weight, partially hepatectomized at the end of week 3, administered phenobarbital at a concentration of 0.05% from the end of week 2 for 6 weeks, and sacrificed. In the livers, glutathione S-transferase (GST-P)-positive, putative preneoplastic lesions were induced, and Bcl-x protein expression was decreased in 24.7% of such lesions. The incidence of GST-P-positive lesions with decreased Bcl-x increased depending on the size of the lesions; 18.9%, 32.4% and 86.5% in the lesions smaller than 0.03, between 0.03 and 0.3, and larger than 0.3 mm(2), respectively. In GST-P-positive lesions larger than 0.3 mm(2), both apoptosis induction and cell proliferation activity were enhanced when Bcl-x protein expression was decreased. In the long-term exogenous models, rats were given 10 mg / kg of DEN, partially hepatectomized 4 h after treatment, administered 0.5 mg / kg of colchicine at the end of days 1 and 3, subjected to a selection procedure, and sacrificed at the end of week 45. Hepatocellular carcinomas were induced with the decreased Bcl-x protein expression. In the endogenous model, rats were fed a choline-deficient, L-amino acid-defined diet for 16 or 80 weeks and sacrificed. Bcl-x protein expression was decreased both in GST-P-positive lesions and hepatocellular carcinoma. These results suggest that this decrease of Bcl-x protein might serve as an indicator of the advanced form of preneoplastic lesions, and that this decrease could also be associated with a potential to progress into carcinoma in both exogenous and endogenous hepatocarcinogenesis of rats.

RHC/c genotyping based on polymorphism in the promoter region of the RHCE gene

Designing of PCR tests for the RHC allele is difficult because of the high DNA sequence homology between RHC and RHD genes, which differ by only a one-nucleotide substitution at position 48 in exon 1 of the RHCE gene. We sequenced the promoter region of the RHCE gene, and compared our results with the reported sequence. Genomic DNA was prepared from blood samples collected from 656 Japanese donors. The DNA segment encompassing the promoter region and exon 1 of the RHCE gene from 30 donors was amplified by PCR and analyzed by DNA sequencing. Four nucleotide differences between RHC/c and RHD were found at positions -468, -304, -58, and -46. On the basis of the nucleotide differences at positions -468 (RHCE vs. RHD) and -292 (RHC vs. RHc), we then developed a novel polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method for RHC/c genotyping. Analysis of the genomic DNA from the 656 donors revealed that this method could discriminate RHC from RHc, irrespective of the RHD genotype, with only a few exceptions. The combination of our system and the intron 2-based PCR-RFLP method previously reported may prove to be more accurate than either of the methods alone, and therefore, useful and valuable for RHC/c genotyping.

Intelligent yeast strains with the ability to self-monitor the concentrations of intra- and extracellular phosphate or ammonium ion by emission of fluorescence from the cell surface

Saccharomyces cerevisiae strains that respond to environmental changes and transmit the information by emission of fluorescence from the cell surface were constructed. The technique of cell surface engineering enabled the yeast cells to display enhanced cyan blue fluorescent protein (ECFP) or enhanced yellow fluorescent protein (EYFP) on the surface under the control of promoters that sense environmental changes. Two model promoters were examined in this study. For monitoring the intra- and extracellular concentrations of phosphate ion, the PHO5 promoter was chosen to display ECFP. The MEP2 promoter was used to display EYFP to sense the concentrations of ammonium ion. Fluorescence was observed by fluorescence microscopy and immunofluorescence microscopy, and the intensity was measured by a flow cytometer. The relationship between ion concentration inside and outside the cells was evaluated by the change in the rate of fluorescence. This S. cerevisiae system enables environmental changes to be transmitted as intra- and extracellular information using a suitable promoter functioning at real time and in a non-invasive manner.

Molecular characterization of weak D phenotypes by site-directed mutagenesis and expression of mutant Rh-green fluorescence protein fusions in K562 cells

BACKGROUND AND OBJECTIVES

Mutations detected in 161 weak D samples from Caucasians have been classified into 16 types. Because flow cytometry using monoclonal anti-D antibodies (mAbs) has shown that weak D red cells display type-specific antigen density, these mutations in transmembranous regions have been assigned weak D phenotypes. The present study attempts to confirm or refute this assignment.

MATERIALS AND METHODS

We amplified DNA from four Japanese weak D samples using the polymerase chain reaction (PCR), and directly sequenced the amplified DNA. Using site-directed mutagenesis, we constructed three vectors expressing mutant RHDs-- G212C, V270G (weak D type 1) and G358A (type 2)--in K562 cells. The expression of RhD antigens was examined by flow cytometry using mAbs.

RESULTS

A new mutation resulting in a conversion at amino acid residue 212 (Gly to Cys) was detected in a Japanese weak D sample. K562 cells transduced with mutant RhD cDNA reacted weakly in a type-specific manner with mAbs.

CONCLUSIONS

The mutations--G212C (new weak D type), V270G (weak D type 1) and G358A (type 2)-- in transmembranous regions had obvious effects on the D epitopes recognized by mAbs. The results of this study provide direct evidence that these mutations can account for weak D phenotypes.

Reactivity of autoantibodies of autoimmune hemolytic anemia with recombinant rhesus blood group antigens or anion transporter band3

The specificity of autoantibodies in autoimmune hemolytic anemia (AIHA) has been studied using the serological procedure and immunoprecipitation technique with rare phenotype red cells. We attempted to analyze specificity using recombinant rhesus (Rh) blood group and band3 antigens expressed on erythroleukemic cell lines, KU812E. The autoantibody eluates were isolated by the acid elution procedure from the red cells of 20 AIHA patients. The recombinant Rh antigens, RhD, cE, ce, CE, and chimera antigens CE-D and D-CE, were obtained by retroviral cDNA transduction into KU812E cells, and the cell line expressing the antigens was cloned. Band3 cDNA was also obtained and introduced into KU812E and cloned KU812 expressing RhcE. The reactivities of AIHA eluates with recombinant Rh and band3 antigens were studied by flow cytometry. Fifteen eluates reacted with at least one of the RhcE, ce, or CE antigens, and four eluates reacted with RhD. Seven eluates with strong Rh specificity were studied further using chimera antigen. Five eluates showed reduced or lost reactivity, although two eluates reacted identically with the chimera antigens as wild type. These results indicated that conformational epitopes constituted by RhD or CE specific exofacial peptide loops are important for autoantibodies in most cases. Seven eluates reacted with band3, five exclusively. The coexpression study of RhcE and band3 did not enhance the expression of either antigen nor the reactivity with patient eluates, indicating that association of Rh and band3 was not involved in the appearance of autoantigen.

Human L-type amino acid transporter 1 (LAT1): characterization of function and expression in tumor cell lines

System L is a major nutrient transport system responsible for the transport of large neutral amino acids including several essential amino acids. We previously identified a transporter (L-type amino acid transporter 1: LAT1) subserving system L in C6 rat glioma cells and demonstrated that LAT1 requires 4F2 heavy chain (4F2hc) for its functional expression. Since its oncofetal expression was suggested in the rat liver, it has been proposed that LAT1 plays a critical role in cell growth and proliferation. In the present study, we have examined the function of human LAT1 (hLAT1) and its expression in human tissues and tumor cell lines. When expressed in Xenopus oocytes with human 4F2hc (h4F2hc), hLAT1 transports large neutral amino acids with high affinity (K(m)= approximately 15- approximately 50 microM) and L-glutamine and L-asparagine with low affinity (K(m)= approximately 1.5- approximately 2 mM). hLAT1 also transports D-amino acids such as D-leucine and D-phenylalanine. In addition, we show that hLAT1 accepts an amino acid-related anti-cancer agent melphalan. When loaded intracellularly, L-leucine and L-glutamine but not L-alanine are effluxed by extracellular substrates, confirming that hLAT1 mediates an amino acid exchange. hLAT1 mRNA is highly expressed in the human fetal liver, bone marrow, placenta, testis and brain. We have found that, while all the tumor cell lines examined express hLAT1 messages, the expression of h4F2hc is varied particularly in leukemia cell lines. In Western blot analysis, hLAT1 and h4F2hc have been confirmed to be linked to each other via a disulfide bond in T24 human bladder carcinoma cells. Finally, in in vitro translation, we show that hLAT1 is not a glycosylated protein even though an N-glycosylation site has been predicted in its extracellular loop, consistent with the property of the classical 4F2 light chain. The properties of the hLAT1/h4F2hc complex would support the roles of this transporter in providing cells with essential amino acids for cell growth and cellular responses, and in distributing amino acid-related compounds.

Molecular events involved in up-regulating human Na+-independent neutral amino acid transporter LAT1 during T-cell activation

We investigated the regulation of system-L amino acid transporter (LAT1) during T-cell activation. In quiescent T-cells, L-leucine transport is mediated mainly by the system-L amino acid transport system and is increased significantly during T-cell activation by PMA and ionomycin. In quiescent T-cells, the LAT1 protein was heterocomplexed with 4F2 heavy chain (4F2hc) in the plasma membrane. During T-cell activation, the amounts of 4F2hc and LAT1 heterocomplex were significantly elevated compared with those in quiescent T-cells. In addition, by Northern-blot analysis, these increments were found to be due to elevated levels of LAT1 and 4F2hc mRNA. Transient expression of constructs comprising various LAT1 gene promoter fragments, which contained all three of the GC boxes, was sufficient for promoting luciferase expression in Jurkat T-cells, but the promoter of the LAT1 gene did not respond to PMA and ionomycin. Similar observations were observed in the human 4F2hc gene promoter. In nuclear run-on assay, the LAT1 and 4F2hc genes were actively transcribed even in quiescent T-cells, but the low levels of both transcripts were shown to be the result of a block to transcription elongation within the exon 1 intron 1 regions. These findings indicated that a removal of the block to mRNA elongation stimulates the induction of system-L amino acid transporter gene transcripts (LAT1 and 4F2hc) in activated T-cells.

Focal enhancement of expression of c-Met/hepatocyte growth factor receptor in the myocardium in human myocardial infarction

To determine the distribution and expression level of hepatocyte growth factor (HGF) specific receptor, c-Met, in human myocardial infarction. Autopsies of 13 patients who died without heart diseases (control) and 13 patients with a history of myocardial infarction (2 h to 10 years before death). The harvested myocardial tissues were stained with hematoxylin-eosin (H&E) and immunohistochemically stained for c-Met expression by the avidin-biotin-horseradish peroxidase complex method using an antibody to c-Met. C-Met expression was only slightly increased in control subjects and in noninfarcted myocardium of the test group. In contrast, high expression was noted in the peripheral region of the myocardial infarction and in some hypertrophic myocardial cells. C-Met was not expressed in the infarcted myocardium, but overexpression was noted in the surrounding myocardial cells of blood vessels and in the subendocardium and subepicardium in a band-like pattern. The expression level of c-Met was most enhanced at the time of appearance of coagulative necrosis and least in the myocardium of subjects with old infarcts. Our results indicate that HGF preferentially reaches the ischemic regions of the myocardium and has local and direct effects on the myocardium in patients with myocardial infarction.

Therapeutic Effect of Novel Anti-Human Fas Antibody HFE7A on Graft-versus-Host Disease Model

In order to evaluate anti-human Fas antibody, we have established a new graft-versus-host disease (GVHD) model wherein splenocytes of human Fas transgenic mice (hFas-TgM) were transferred to immune-deficient SCID mice. In this model, although host SCID cells are not activated by or responsive to graft hFas-TgM cells, graft hFas-TgM cells are activated by and responsive to host SCID cells and thus cause GVHD symptoms. SCID mice that received hFas-TgM splenocytes had increased human Fas-positive lymphocytes in lymph nodes, decreased in body weight, and developed skin diseases, including rash and alopecia. Administration of novel anti-human Fas antibody HFE7A, which did not induce liver toxicity after administration to mice, decreased the level of the human Fas-positive lymphocytes, blocked the decrease of body weight, and suppressed development of skin diseases in this model. These results indicate that induction of apoptosis to activated graft cells with nontoxic anti-Fas antibody could reduce GVHD symptoms.

Quantitative immunohistochemical evaluation of HER2/neu expression with HercepTestTM in breast carcinoma by image analysis

HercepTestTM (DAKO A/S, Glostrup, Denmark) is an immunohistochemical assay that detects HER2/neu gene products, and evaluates the overexpression status of the HER2/neu protein in determining eligibility for the Trastuzumab (HerceptinR, Genentech, San Francisco, CA, USA) therapy. However, practically, interobserver variability of the HER2/neu interpretation of the immunostained results has caused marked disagreement with regard to the intensity of tumor staining. In this study, we quantitated HER2/neu expression by image analysis, and applied this analyzing system to help to minimize interobserver variability of the interpretation of the HercepTestTM. All the immunostained results were scored semiquantitatively on a range of 0 to 3+ in accordance with the criteria described as per the manufacturer's instructions, and quantitatively evaluated using an image analyzing system with image processing software. Among the 92 cases, 15 were scored as 3+, six were 2+, and 32 were 1+ under intraobservers agreement. When the cases were quantitated, a high correlation was shown between the signal area extracted by image analysis and the corresponding score of staining intensity with the HercepTestTM. By converting the quantitatively extracted data into a scoring system based upon the criteria, the outcome demonstrated a strong concordance with the scoring data obtained from immunostaining. The results indicated that a quantitative scoring system performed by simple image analysis may provide to improve interobserver agreement of the interpretation of the HercepTest TM in clinical practice.

Type 2-biased expression of cytokine genes in lung granulomatous lesions induced by Nippostrongylus brasiliensis infection

Infections with helminthic parasites occasionally induce pulmonary diseases with possible involvement of immunological mechanisms. In rats infected with the nematode Nippostrongylus brasiliensis, pulmonary granulomatous lesions develop and persist after the larvae have migrated through the lungs. To determine the pathogenesis of this lesion, we examined cytokine gene expression in the lungs using RT-PCR and in situ hybridization. Two weeks after infection, when fully developed lesions appeared, levels of IL-3 and of type2 cytokines IL-4, IL-5, IL-6 and IL-13 gene expression were markedly enhanced in whole lung homogenates. Those of IL-2 and IFN-gamma were also slightly increased 2 weeks postinfection. IL-12 mRNA level did not change after 2 weeks but was slightly increased after 4 weeks. Levels of IL-10 and proinflammatory cytokine TNF gene expression did not show significant changes, although a slight increase was observed in IL-1beta message after 2 weeks. In situ hybridization studies showed that lung granulomatous lesions were composed mainly of lymphoid cells expressing IL-3, IL-4 and IL-13 mRNA, but not IFN-gamma mRNA. IL-5 mRNA-expressing cells were fewer in number than these cells. RMCP II immunohistochemistry revealed that mast cells increased in number in the lung granulomas. From these results, it was concluded that the nematode infection-associated lung granuloma was a type 2 lesion.