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Biomedical subjects

K Fujio

Publications and source records attributed to K Fujio.

At least 19 recordsLinked to original sources
PubMed2001

Molecular cloning of a human novel type I cytokine receptor related to delta1/TSLPR.

In a search for a human sequence related to a recently identified type I cytokine receptor delta1, which turned out to be a receptor subunit for a cytokine called TSLP, we have now identified a novel human type I cytokine receptor from a human T lymphocyte cDNA library. The deduced amino acid sequence of 371 residues has a typical signal sequence and a membrane-spanning region. The mature protein is predicted to have a molecular mass of 39,698 Da. The N-terminal extracellular region contains two fibronectin type III-like domains, four conserved cysteine residues, and a WSXWS box-like motif. The C-terminal intracellular region contains box 1 and box 2-like motifs. Thus, it has common characteristics of type I cytokine receptor family members, and we tentatively termed this protein CRLF2, which stands for cytokine receptor-like factor 2. Northern blot analysis revealed CRLF2 mRNA in liver, kidney, heart, and skeletal muscle. The fetal liver also expresses CRLF2 transcripts. The gene for CRLF2 was mapped to the pseudoautosomal region, Xp22.3 and Yp11.3 by FISH analysis, a region where genes encoding the IL-3 receptor alpha and the GM-CSF receptor alpha chains are also located. The biological function of this newly identified receptor is now under investigation.

Amino Acid Motifs↗
PubMed2000

Antigen-specific T cells transduced with IL-10 ameliorate experimentally induced arthritis without impairing the systemic immune response to the antigen.

For the treatment of rheumatoid arthritis, efficient drug delivery methods to the inflamed joints need to be developed. Because T cells expressing an appropriate autoantigen-specific receptor can migrate to inflamed lesions, it has been reasoned that they can be employed to deliver therapeutic agents. To examine the ability and efficiency of such T cells as a vehicle, we employed an experimentally induced model of arthritis. Splenic T cells from DO11.10 TCR transgenic mice specific for OVA were transduced with murine IL-10. Adoptive transfer of the IL-10-transduced DO11.10 splenocytes ameliorated OVA-induced arthritis despite the presence of around 95% nontransduced cells. Using green fluorescent protein as a marker for selection, the number of transferred cells needed to ameliorate the disease was able to be reduced to 10(4). Preferential accumulation of the transferred T cells was observed in the inflamed joint, and the improvement in the disease was not accompanied by impairment of the systemic immune response to the Ag, suggesting that the transferred T cells exert their anti-inflammatory task locally, mainly in the joints where the Ag exists. In addition, IL-10-transduced DO11.10 T cells ameliorated methylated BSA-induced arthritis when the arthritic joint was coinjected with OVA in addition to methylated BSA. These results suggest that T cells specific for a joint-specific Ag would be useful as a therapeutic vehicle in rheumatoid arthritis for which the arthritic autoantigen is still unknown.

Animals↗
PubMed2000

Functional reconstitution of class II MHC-restricted T cell immunity mediated by retroviral transfer of the alpha beta TCR complex.

Transfer of the alphabeta TCR genes into T lymphocytes will provide a means to enhance Ag-specific immunity by increasing the frequency of tumor- or pathogen-specific T lymphocytes. We generated an efficient alphabeta TCR gene transfer system using two independent monocistronic retrovirus vectors harboring either of the class II MHC-restricted alpha or beta TCR genes specific for chicken OVA. The system enabled us to express the clonotypic TCR in 44% of the CD4+ T cells. The transduced cells showed a remarkable response to OVA323-339 peptide in the in vitro culture system, and the response to the Ag was comparable with those of the T lymphocytes derived from transgenic mice harboring OVA-specific TCR. Adoptive transfer of the TCR-transduced cells in mice induced the Ag-specific delayed-type hypersensitivity in response to OVA323-339 challenge. These results indicate that alphabeta TCR gene transfer into peripheral T lymphocytes can reconstitute Ag-specific immunity. We here propose that this method provides a basis for a new approach to manipulation of immune reactions and immunotherapy.

Adoptive Transfer↗
PubMed2000

Molecular cloning of a novel type 1 cytokine receptor similar to the common gamma chain.

In a complementary DNA (cDNA) screening of murine Th2-skewed lymphocytes with our recently developed signal sequence trap method termed SST-REX, a novel type 1 cytokine receptor, Delta1 (delta1), was identified. Although delta1 is ubiquitously expressed in multiple tissues, the expression level is higher in Th2-skewed lymphocytes than in Th1-skewed ones. The delta1 cDNA encodes a 359-amino acid type 1 membrane protein. The extracellular domain of 206 amino acids showed 24% identity with the murine common gamma receptor that is shared among the receptors for interleukin(IL)-2, IL-4, IL-7, IL-9, and IL-15. The membrane-proximal region of delta1 includes a box1 motif, which is important for association with Janus kinases (JAKs), and showed a significant homology with that of the mouse erythropoietin receptor (EPOR). A box2 motif was also found in close proximity to the box1 region. Dimerization of the cytoplasmic region of delta1 alone did not transduce proliferative signals in IL-3-dependent cell lines. However, the membrane-proximal region of delta1 could substitute for that of human EPOR in transmitting proliferative signals and activating JAK2. These results suggest that delta1 is a subunit of cytokine receptor that may be involved in multiple receptor systems and play a regulatory role in the immune system and hematopoiesis.

Amino Acid Sequence↗
PubMed2000

Expression of perforin and Fas ligand mRNA in the liver of viral hepatitis.

Cytotoxic T lymphocytes (CTLs) play an important role in the pathogenesis of viral hepatitis. We studied the expression of mRNAs of perforin and Fas ligand (Fas-L) in biopsy specimens from chronic hepatitis B (CHB) (15 cases) and hepatitis C (CHC) patients (13 cases). Both perforin and Fas-L mRNAs were detected in all cases of both CHB and CHC. No messages were detected in the control livers from two cases of fatty liver, a case of Gilbert's syndrome, and a case of Dubin-Johnson syndrome. Semiquantitative analysis revealed a positive correlation between the intensity of perforin and Fas-L mRNAs in both CHB and CHC. In CHB, the intensity of both perforin and Fas-L mRNAs showed a positive correlation with the histological activity and serum alanine aminotransferase level, while the correlation was not apparent in CHC. These results suggest that both perforin and Fas/Fas-L systems are involved in the pathogenesis of liver cell injury of CHB and CHC.

Adult↗
PubMed2000

[Antigen-specific T cells transduced with interleukin-10 ameliorate experimentally induced arthritis without impairing the systemic immune response to the antigen].

For the treatment of rheumatoid arthritis, efficient drug delivery methods to the inflamed joints need to be developed. Since T cells expressing an appropriate autoantigen-specific receptor can migrate to inflamed lesions, it has been reasoned that they can be employed to deliver therapeutic agents. In order to examine the ability and efficiency of such T cells as a vehicle, we employed an experimentally induced model of arthritis. Splenic T cells from DO 11.10 T cell receptor transgenic mice specific for OVA were transduced with murine IL-10. Adoptive transfer of the IL-10-transduced DO 11.10 splenocytes ameliorated OVA-induced arthritis, in spite of the presence of around 95% non-transduced cells. Using GFP as a marker for selection, the number of transferred cells needed to ameliorate the disease was able to be reduced to 10(4). Preferential accumulation of the transferred T cells was observed in the inflamed joint, and the improvement in the disease was not accompanied by impairment of the systemic immune response to the antigen, suggesting that the transferred T cells exert their antiinflammatory task locally, mainly in the joints where the antigen exists. In addition, IL-10-transduced DO 11.10 T cells ameriolated mBSA-induced arthritis when the arthritic joint was co-injected with OVA in addition to mBSA. These results suggest that T cells specific for a joint specific antigen would be useful as a therapeutic vehicle in rheumatoid arthritis for which the arthritic autoantigen is still unknown.

Animals↗
PubMed1999

Directional Converter Arm Method for Surface and Interfacial Tension Measurements with a Top-Loading Balance.

A method is described for utilizing a top-loading balance, with a directional converter arm, in vertical-pull surface force measurements. The Padday rod-pull technique, the du Noüy ring method, and the Wilhelmy plate method are utilized with rods, thin-walled tubes, wire rings, and plates either rigidly attached to the converter arm or hanging freely from a hook at the end of the arm. The robustness, large weighing capacity, and accuracy of top-loading balances make them ideally suited for a variety of types of surface and interfacial tension measurements. The converter arm method can be used with a stainless steel rod (3-7 mm in diameter) in vertical-pull surface tension measurements, with samples having volumes of only a few tenths of a milliliter. Measurements on very small liquid volumes are feasible because the rod is firmly attached to the converter arm rather than hanging freely as in measurements with balances mounted above the sample; therefore, the rod cannot swing toward and attach to the wall of small sample tubes. Automation of force and height measurements with the converter arm/top-loading balance method is straightforward. Copyright 1999 Academic Press.

Journal Article↗
PubMed1999

[Elderly dyserythropoietic anemia first diagnosed after presentation of hemorrhagic gastric ulcer].

A 71-year-old man presented with epigastralgia and tarry stool. Laboratory examination showed anemia (Hb 7.1 g/dl) due to hemorrhagic gastric ulcer and positive Coombs' test without features of hemolysis. Initial bone marrow smears disclosed normal granulocytes and megakaryocytes, but only erythroid hyperplasia with multinuclearity and megaloblastosis was identified. Cytogenetic studies revealed normal karyotype. Congenital dyserythropoietic anemia (CDA) type II was initially suspected. Serologically, however, acid hemolysis and anti-I * i tests were negative as were the results of another Coombs' test. The second bone marrow aspiration disclosed a marked decrease in multinucleated erythroblasts together with an increase in those that had internuclear chromatin bridges. Electron microscopy of bone marrow specimens demonstrated morphological features of CDA types I and II, thus yielding a final diagnosis of elderly dyserythropoietic anemia, which is similar to both CDA types. It was suggested that the reactive secretion of erythropoietin due to bleeding played a role in these pathologic changes.

Aged↗
PubMed1998

Liquid-phase binding assay of alpha-fetoprotein using a sulfated antibody for bound/free separation.

A rapid immunoassay using a sulfated antibody for bound/free separation in a liquid-phase binding assay is described. A first anti-alpha-fetoprotein monoclonal antibody was labeled with peroxidase (Fab'-POD) and a second monoclonal antibody was conjugated with polysulfated tyrosine peptide (Fab'-YS). The monoclonal antibodies and alpha-fetoprotein (AFP) were mixed, incubated, and analyzed directly by anion-exchange column chromatography. The amount of POD activity in the column effluent was determined fluorophotometrically. The bound (Fab'-POD + AFP + Fab'-YS) and free (Fab'-POD) forms of the conjugate were clearly and easily separated by ionic charge, and the free sulfated antibody (Fab'-YS) was not detectable fluorophotometrically. The elution position of the bound conjugate was adjusted by varying the length of the polysulfated tyrosine peptide. This method is convenient for antigen measurement because (1) only two modified antibodies are used in a buffer solution, (2) the concentration of antibodies and other assay conditions are easily set, (3) no solid phase is required, and (4) no washing is necessary.

Antibodies, Monoclonal↗
PubMed1998

Prevalence of hepatitis B and C virus markers in outpatients of Mongolian general hospitals.

In East Asian countries, the prevalence of viral hepatitis has been reported to be high, but precise data for each country remained to be investigated. Here we report the prevalence of viral markers of hepatitis B and hepatitis C in outpatient volunteers visiting two general hospitals in Ulaanbaatar, Mongolia. One hundred fifty sera were tested for HBs antigen (HBsAg), anti-HBs, and anti-HCV by Counting Immunoassay. The backgrounds of groups of patients positive for HBsAg and negative for anti-HCV (group 1; n = 18), negative for HBsAg and positive for anti-HCV (group 2; n = 47), positive for both HBsAg and anti-HCV (group 3; n = 25), and negative for both HBsAg and anti-HCV (group 4; n = 60) were compared. The prevalence of HBsAg, anti-HBs, and anti-HCV in this study group was 28.7%, 39.3% and 48.0%, respectively. Subjects of group 1 (mean +/- SD; 31.3 +/- 12.4 years old) were younger than those of group 4 (39.2 +/- 14.3; p < 0.05), while patients of group 2 (48.7 +/- 15.5) were older than those of group 4 (p < 0.01). More group 2 subjects had histories of jaundice (23/47) than those of group 4 (15/60; p < 0.05). Transaminase levels were higher in group 1 (median (range) IU/l of AST, ALT; 29 (13-95), 32 (9-144) and group 3 (25 (15-187), 22 (8-185)) than in group 4 (18 (9-13), 15 (6-133); p < 0.05, p < 0.005 vs. group 1, and p < 0.005, p < 0.001 vs. group 3, respectively). In HBsAg-negative subjects, those with higher titers of anti-HCV (cut-off index > 15) were older, and had more histories of jaundice and higher levels of AST and ALT than anti-HCV negative subjects (50.3 +/- 14.8 vs. 39.1 +/- 14.3, p < 0.01; 15/28 vs. 15/60, p < 0.01; 22.5 (12-127) vs. 18 (9-93), p < 0.05; 20.5 (7-362) vs. 15 (6-133), p < 0.05; respectively). In conclusion, this preliminary surveillance for hepatitis B and C viral markers showed that both hepatitis viruses are prevalent and may cause liver diseases in Mongolia. A nation-wide survey for these viruses should be urged and preventive measures should be taken to suppress the spread and development of liver diseases in this country.

Adult↗
PubMed1998

Relationship of serum markers of hepatitis B and C virus replication in coinfected patients.

To evaluate viral interference between hepatitis B and C, we studied coinfected patients serologically and molecular biologically. Twenty-seven patients positive for hepatitis B surface antigen (HBsAg) and anti-hepatitis C virus (HCV) antibody, were classified into Groups BC-L and BC-H according to DNA-polymerase activity (less or greater than 100 cpm, respectively). Patients with hepatitis B or C alone were also enrolled as controls. HCV-RNA was detected more often in Group BC-L than in Group BC-H. Genotype 1b of HCV was determined in 75% of Group BC-H, 87.5% of Group BC-L, and 70.7% of hepatitis C-only patients. Activity of DNA-polymerase in coinfected patients was lower in patients positive for HCV-RNA as compared with those negative. HBsAg titers tended to be lower in coinfected patients than in patients with hepatitis B virus (HBV) alone. In conclusion, in coinfection, HBV may suppress the replication of HCV and HCV appears to reduce the expression of HBsAg and probably suppresses HBV replication.

Adult↗
PubMed1997

Enhancement of prostaglandin E2 production by epidermal growth factor requires the coordinate activation of cytosolic phospholipase A2 and cyclooxygenase 2 in human squamous carcinoma A431 cells.

We demonstrated the effect of epidermal growth factor (EGF) on the production of PGE2 in human squamous carcinoma A431 cells. The production of PGE2 was increased by stimulating the cells with EGF for 2 h and reached a maximum for 10 h. EGF was also found to augment the release of arachidonic acid (AA) following the increase in phospholipase A2 (PLA2) activity (1.7-fold). The induced PLA2 activity was diminished by 4-bromophenacyl bromide, but not by dithiothreitol, indicating that the EGF-induced release of AA was due to the increase in the activity of cytosolic PLA2 (cPLA2). On the other hand, cyclooxygenase (COX) activity was increased (1.6-fold) within 2 h after the EGF-treatment and the induced activity was inhibited by cycloheximide. In addition, Northern blot analysis showed that the level of COX-2 mRNA was increased by the EGF-treatment, whereas no COX-2 mRNA was detected in the untreated cells, indicating that the EGF-induced COX activity was resulted from the increase in the production of COX-2. These results suggest that EGF augments the production of PGE2 by increasing not only the activity of cPLA2 but also the production of COX-2 in A431 cells.

Acetophenones↗
PubMed1996

Coexpression of stem cell factor and c-kit in embryonic and adult liver.

Stem cell factor and its receptor c-kit constitute an important signal transduction system implicated in survival, proliferation, and differentiation of stem cells in hematopoiesis, gametogenesis, and melanogenesis. In the present study we used both immunocytochemical methods and Western analysis to demonstrate the presence of this cytokine/receptor system in both embryonic and adult rat liver. Stem cell factor was present in the ductular cells around the portal vein during the late embryonic stage of the liver. In the adult liver both bile ducts and bile ductules were positive for stem cell factor and c-kit. When the activation of the liver stem cell compartment was induced by combining administration of acetylaminofluorene and partial hepatectomy, both stem cell factor and c-kit were expressed in the infiltrating oval cell population, but absent in the newly formed basophilic hepatocytes. Activation of oval cell proliferation following administration Of D-galactosamine also produced a similar but less prominent increase in the level of the stem cell factor. Our data suggest that the stem cell factor/c-kit signal transduction system is involved in the development of bile ducts and that it may also be an important member of the growth factor/receptor systems associated with the biology of liver stem cells.

Age Factors↗
PubMed1996

Expression of transforming growth factor alpha/epidermal growth factor receptor, hepatocyte growth factor/c-met and acidic fibroblast growth factor/fibroblast growth factor receptors during hepatocarcinogenesis.

It is widely believed that abnormal production of polypeptide growth factors, together with other molecular alterations, play an important role in neoplastic development. Transforming growth factor alpha (TGFalpha), hepatocyte growth factor (HGF) and acidic fibroblast growth factor (aFGF) are the three major growth factors that contribute to liver regeneration occurring via both hepatocyte replication and oval cell proliferation. It is not clear, however, whether and to what extent these growth factors are also involved in hepatocarcinogenesis. In the present study, the gene expression of TGFalpha, HGF and aFGF and their corresponding receptors was examined by Northern blotting and in situ hybridization during hepatocarcinogenesis induced by the Solt-Farber protocol. All three growth factor/receptor systems, TGFalpha/epidermal growth factor receptor (EGFR), HGF/c-met and aFGF/FGF receptors (flg and bek) were significantly elevated at early time points when oval cells were proliferating. Their respective expression decreased after 1 month and remained at a low level until the development of liver tumors. In all hepatocellular carcinomas (HCC) examined, the transcripts of TGFalpha and aFGF were highly expressed, while those of HGF were low. With regard to the receptor expression in the tumors, EGFR was present at varying levels, c-met was expressed at higher levels and flg increased significantly, whereas bek remained at low levels. These data suggest that TGFalpha and aFGF are the major growth factors involved in the progression of HCC, and that the signal of aFGF is mainly transduced by the receptor flg in HCC. Furthermore, HCC cells were phenotypically very similar to oval cells with regard to the gene expression of growth factor/receptor systems. These results, along with the finding that all the HCC cells are positive for the oval cell antigen OV6, and that cytokeratin 19 is heavily expressed in both tumor and oval cells, strongly suggest that at least some of the HCC induced by the Solt-Farber protocol may be derived from oval cells.

Animals↗
PubMed1996

Relationship between response to interferon therapy and detection of hepatitis C virus RNA by differential flotation centrifugation.

Circulating hepatitis C virus (HCV) particles can be fractionated by means of differential flotation centrifugation. It is reported that in the bottom fraction HCV is in the form immune complexes, whereas in the top, it is free of antibodies. We evaluated the significance of circulating complex and free HCV in chronic hepatitis C, and assessed the relationship in terms of the response to interferon (IFN) therapy. We examined sera before, just after, and 1 year after administering IFN to 18 patients with chronic hepatitis C, 10 of whom responded (group CR), and 8 did not (group NR). The amounts of virus were similar between both groups before therapy. After differential flotation centrifugation with 1.063 g/ml of NaCl, the top and bottom fractions were assayed for HCV RNA. Before therapy, HCV RNA was detected in the top fraction in 1 of 10 in group CR, and in 6 of 8 in group NR (P < 0.05, chi-square test). HCV RNA was positive in the bottom fraction of all samples. In a follow-up study of group NR, HCV RNA was detected in the top fraction in 3 of 8 just after IFN therapy, and in 7 of 8 after 1 year. This study suggests that the presence of HCV in the top fraction can predict a poor response to IFN therapy.

Adult↗