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T Ebihara

Publications and source records attributed to T Ebihara.

At least 73 records · Page 4Linked to original sources
PubMed1993

Further analyses of epitopes for human monoclonal anti-basement membrane zone antibodies produced by stable human hybridoma cell lines constructed with Epstein-Barr virus transformants.

We previously established Epstein-Barr virus (EBV)-transformed bullous pemphigoid (BP) patient lymphoblastoid cell lines, which produced human monoclonal anti-basement membrane zone antibodies. In the present study, we established two independent human-human hybridomas by fusion of these EBV transformants with a human B-cell line. These hybridomas, designated 5E-HY-4B and 10D-HY-8B, were very stable and showed a high yield of monoclonal antibody (MoAb) secretion. Each cell line was tetraploid and showed combined rearranged segments of immunoglobulin heavy-chain gene derived from both an EBV transformant and a parent cell. Immunoblot analysis showed that the 5E-HY-4B MoAb recognized the 230-kDa BP antigen but that the 10D-HY-8B MoAb did not show any reactivity. In contrast, both MoAbs precipitated the 230-kDa BP antigen with immunoprecipitation. These results indicate that the two MoAbs reacted with different epitopes on the 230-kDa BP antigen: a continuous epitope for the 5E-HY-4B MoAb and a conformation-dependent epitope for the 10D-HY-8B MoAb. This speculation was confirmed at the molecular level by the result that the fusion protein produced by a partial cDNA for the 230-kDa mouse BP antigen reacted with the 5E-HY-4B MoAb but not with the 10D-HY-8B MoAb. Furthermore, the study of the reactivity with fusion proteins of a series of deleted clones restricted the epitope for the 5E-HY-4B MoAb within the region with 114 amino acid residues in the C-terminal domain of the 230-kDa BP antigen.

Antibodies, Monoclonal↗
PubMed1993

Comparative study of bullous pemphigoid antigens among Japanese, British, and U.S. patients indicates similar antigen profiles with the 170-kD antigen present both in the basement membrane and on the keratinocyte cell membrane.

There are a number of controversies relating to studies of bullous pemphigoid (BP) antigens from different institutions, mainly regarding the detection of the 230-kD and 170-kD BP antigens. In this study, in an attempt to resolve the discrepancies, we have examined and compared the reactivity by immunofluorescence, immunoblotting, and immunoprecipitation among the sera from Japanese, British and U.S. BP patients. Both the 230-kD and 170-kD BP antigens were detected by various sera from all populations with immunoblotting, whereas immunoprecipitation detected only the 230-kD BP antigen but not the 170-kD BP antigen. Immunoprecipitation was more sensitive than immunoblotting to detect the 230-kD antigen. These results indicate that both the 230-kD and 170-kD proteins are BP antigens found in all three populations. By immunofluorescence cell surface staining in the lower epidermis in addition to basement membrane zone staining was shown by a considerable number of patients' sera in all populations. Comparison between the results of immunofluorescence and immunoblotting revealed a clear correlation of this cell surface staining with the presence of antibodies against the 170-kD BP antigen. That the affinity-purified antibodies specific to the 170-kD BP antigen showed this cell surface staining further confirmed this correlation. These results may indicate a different nature of the 170-kD BP antigen from that of the 230-kD BP antigen.

Antigens, Surface↗
PubMed1993

Human autoantibodies against the 230-kD bullous pemphigoid antigen (BPAG1) bind only to the intracellular domain of the hemidesmosome, whereas those against the 180-kD bullous pemphigoid antigen (BPAG2) bind along the plasma membrane of the hemidesmosome in normal human and swine skin.

Bullous pemphigoid (BP) is a blistering skin disease in which autoantibodies develop to hemidesmosomal components of the epidermal basement membrane zone, including two major antigenic proteins of the 230-kD antigen (BPAG1) and the 180-kD antigen (BPAG2). The present study demonstrated the precise ultrastructural localization of the epitopes for autoantibodies against BPAG1 and BPAG2 in normal skin. Autoantibodies against either BPAG1 or BPAG2 were affinity-purified using nitrocellulose membrane, which was blotted with SDS-PAGE-fractionated antigens from human epidermal extract as the immunoabsorbent. Postembedding, immunogold electron microscopy was performed after skin was processed by rapid freezing and freeze substitution fixation without chemical fixatives. Purified autoantibodies against BPAG1 bound only to the intracellular domain of the hemidesmosome, and 80% of the gold labeling was within 40-140 nm from the plasma membrane (mean distance 91 nm inside). In contrast, the autoantibodies against BPAG2 bound along the plasma membrane of the hemidesmosome, and 80% of the gold labeling was within 10 nm outside to 50 nm inside the cells (mean distance 12 nm inside). These results suggest that the autoantibodies against BPAG1 and BPAG2 react with the epitopes localizing in distinct regions of the hemidesmosome complex, and may play different roles in the blister formation in patients with BP.

Animals↗
PubMed1992

Expression of intercellular adhesion molecule 1 (ICAM-1) during the development of invasion and/or metastasis of gastric carcinoma.

In this study, using two-color flow-cytometric analysis, we examined the expression of histocompatibility locus antigens (HLA) classes I and II, and intercellular adhesion molecule 1 (ICAM-1) in 10 cases of normal gastric mucosa, 13 cases of primary carcinoma on the stomach, 16 cases of metastatic carcinoma from malignant ascites in patients with gastric carcinoma and 14 samples of their cultured carcinoma cells. Compared with normal gastric mucosa, HLA class I were highly expressed in a considerable number of tumor cells in each experimental group. The expression of HLA class II tended to reduce in the order of normal gastric mucosa, primary gastric carcinoma and peritoneal-effusion-associated carcinoma. Altogether, 85.7% of cases of cultured tumor cells showed abrogation and loss of HLA class II. The ICAM-1 molecule was not detected on normal gastric epithelial cells. In few cases, carcinoma cells from large volumes of tumor located in the stomach showed detectable amounts of ICAM-1. On the other hand, all of the metastatic carcinoma cells from peritoneal effusions showed a high level of expression of the ICAM-1 molecule. The expression of ICAM-1 on adenocarcinoma cells was maintained and/or augmented by in vitro cultivation with tumor-infiltrating lymphocytes (TIL). Furthermore, two-color fluorescence-activated cell sorting analysis of TIL revealed that significant correlation was observed between the expression of ICAM-1 and the degree of TIL, composed mainly of CD3+ T cells including CD8+CD11b-, CD8+CD28+, CD8+S6F1+ and CD4+Leu8+, and CD57+CD16- and CD57+CD16+ NK cells, and HLA-DR+LeuM3+ macrophages.

Adenocarcinoma↗
PubMed1991

Suppression by sorted CD8+CD11b- cells from T-cell growth factor-activated peripheral blood lymphocytes on cytolytic activity against tumour in patients with gastric carcinoma.

To confirm the phenotypic characteristics of lymphokine-activated suppressor (LAS)effector cells, we isolated CD8+CD11b- and CD8-CD11b- cells from T-cell growth factor (TCGF)-activated peripheral blood lymphocytes (PBL) in 7 patients with gastric carcinoma (4 non-resectable and 3 resectable carcinoma) and 3 healthy controls. Sorted CD8+CD11b- cells from 3 of the patients with non-resectable carcinoma and from 1 of the patients with resectable carcinoma showed LAS cell activity. However, the LAS cell activity could not be observed in CD8+CD11b- cells from healthy controls. In addition, a sorted CD8-CD11b- subset of cells from both cancer patients and control did not express any suppressive activity. These facts clearly show that the cell populations responsible for suppression of cell-mediated antitumour immunity reside within CD8+CD11b- T-cells, at least in patients with advanced carcinoma.

Adult↗
PubMed1991

Autoantigens for IgA anti-intercellular antibodies of intercellular IgA vesiculopustular dermatosis.

A new disease characterized by the presence of in vivo bound and/or circulating IgA anti-intercellular (IC) antibodies has recently been identified. We propose the term intercellular IgA vesiculopustular dermatosis (IAVPD) for this entity, which seems to be divided clinicopathologically into at least two distinct subtypes: intraepidermal neutrophilic IgA dermatosis (IEN type) and subcorneal pustular dermatosis-like cases (SPD type). Using immunoblot technique, we examined the antigen substances for the IgA anti-IC antibodies in the sera from one Japanese patient with IEN type of IAVPD and three Japanese patients with SPD type. A serum from a patient with IEN type reacted exclusively with a 120-kD protein in both the normal human skin extract and the bovine desmosome sample. Sera from three patients with SPD type reacted specifically with a doublet of 115-kD and 105-kD proteins, which appeared to be identical to desmocollins I and II, well known desmosomal core proteins, in the bovine desmosome sample. IgA antibody from our patients with IAVPD bound to neither pemphigus vulgaris antigen nor pemphigus foliaceus antigen. From these results, we suggest that IAVPD is different from pemphigus and is heterogeneous in terms of the antigens to which IgA autoantibodies bind.

Autoantibodies↗
PubMed1991

[Studies on the anticomplementary activity of Jozann. Anticomplementary activity of steroid derivatives].

Methanol extracts of 53 crude drugs were tested on the anticomplementary activity. Of these, 12 samples showed the potent activity. Of these 12 samples, the extract of Jozann (Dichrome Radix) was studied on the isolation and structural elucidation of the anticomplementary constituents. As active constituents, 3 beta-hydroxystigmast-5-en-7-one was isolated and its structure was confirmed by deriving this compound from beta-sitosterol. The activity of such steroid derivatives as stigmastane, cholestane, androstane and pregnane type steroids were further studied. Of these, several kinds of steroids showed the potent activity. From these experiments, the structure and activity relationship was discussed.

Androstanes↗
PubMed1990

Functional and phenotypic characteristics of recombinant interleukin-2 or T-cell growth factor-activated splenic lymphoid cells from patients with gastric or hepatocellular carcinoma.

Fourteen days' culture of human spleen cells with recombinant interleukin-2 (rIL-2) or T-cell growth factor (TCGF) results in the generation of lymphokine-activated killer (LAK) effector cells that have the unique property of lysing natural killer (NK)-resistant human tumor cells, Daudi, and NK-sensitive K562 cells. LAK cells were generated from patients with advanced cancer or liver cirrhosis. The splenic LAK-effector cell types were analyzed by two-color flow cytometry. The rIL-2-induced LAK cells showed an increased proportion of CD8+CD11- and CD57+CD16- and a decreased proportion of CD4+Leu-8- cells. In contrast, TCGF-induced LAK cells revealed a significantly increased proportion of CD8+CD11- and CD4+Leu-8- cells and a decreased proportion of CD57+CD16- cells. Thus, splenic LAK cells with different surface phenotypes were induced by the cultivation with rIL-2 or TCGF. Furthermore, TCGF-induced LAK cell activities in patients with cancer were found to be lower than the rIL-2-induced LAK cell activities. It was noted that the TCGF-activated splenic lymphoid cells did not inhibit the effector process of tumor cell lysis by LAK cells that had been activated by rIL-2. Other mechanisms of lower LAK cell activities of TCGF-activated splenic lymphoid cells from patients with cancer were discussed. The findings suggest that spleens of examined patients with gastric or hepatocellular carcinoma do not seem to be responsible for suppression of cell-mediated antitumor immunity.

Adult↗
PubMed1990

CD8+ T cell subsets of cytotoxic T lymphocytes induced by Epstein-Barr virus infection in infectious mononucleosis.

Mononuclear peripheral blood lymphocytes (PBL) from patient with infectious mononucleosis (IM) were tested in a 51Cr-release assay for cytotoxicity against autologous and allogeneic lymphoblastoid cell line (LCL), or Epstein-Barr virus (EBV)-genome positive and negative cell line. In acute phase, PBL lyse an autologous LCL as well as allogeneic LCL (Wa cells). High levels of cytotoxicity were observed in the combinations between effector and target cells sharing HLA-Class 1 product. EBV-genome positive Daudi and Raji cells which lack HLA-Class 1 antigen and have mismactched HLA-Class 1 antigen, respectively showed resistance to killing. EBV-genome negative tumor cells except NK sensitive K562 cells were not killed by IM lymphocytes. However, the IM lymphocytes without atypical form in convalescent phase failed to show killing activity against autologous and allogeneic LCL. These findings suggest that cell surface membrane antigen structure on EBV-infected LCL may be able to explain the recognition and triggering of lysis of target cells by HLA-Class 1 restricted cytotoxic T cells (CTL) from acute IM. Phenotypic analysis of PBL with atypical form from IM was made by two-color flow cytometry. The data demonstrate that CD8+ T cells quantitatively represent the major population of lymphocytes expanded during acute IM. Furthermore, approximately 70% of these CD8+ T cells express HLA-DR on these surface, suggesting that they have undergone activation. However, IL 2R (CD25 antigen) expression was not significantly elevated on activated T cells. The salient profile on cytofluorographs of an acute IM was the increased number of CD3+CD19-, CD8+CD11b-, CD8+CD28+ and CD8+S6F1+ cells. However, CD3-CD19+, CD8+CD11b+, CD8+S6F1-, CD4+Leu8- and CD25+HLA-DR+ antigens were little expressed. Increased number of CD8+CD11b-, CD8+CD28+ and CD8+S6F1+ cells, which are regarded as CTL were reduced according to the improvement of the clinical symptoms and laboratory findings. These results together with HLA typing analysis suggested a possibility HLA-Class 1 restriction of the CTL with surface phenotype of CD8+CD11b-, CD8+CD28+, and CD8+S6F1+.

Adult↗
PubMed1990

Functional and phenotypic characteristics of effusion-associated lymphoid cells cultured in the presence of either recombinant interleukin 2 or T-cell growth factor from malignant pleural and peritoneal effusions in patients with advanced carcinoma.

Malignant pleural or peritoneal effusion-associated lymphoid (EAL) cells from 17 patients with advanced carcinoma were cultured with autologous carcinoma cells in the presence of either recombinant interleukin 2 (rIL 2) or T-cell growth factor (TCGF). Considerable cytolytic activity of the cells against allogeneic tumor cells, such as K562 and Daudi cells was induced by the cultivation. TCGF-activated EAL cells acquired higher anti-Daudi tumor cytotoxicity than rIL 2-activated EAL cells. The resultant TCGF-activated EAL cells from cancer patients significantly exceeded lytic activity of TCGF-activated EAL cells from patients with liver cirrhosis for control (p less than 0.01). Four of 6 cases examined also showed cytotoxic activity against autologous tumor. In facts, viable carcinoma cells co-cultured with EAL cells and TCGF mostly disappeared during 14 days. Similar phenomenon was not observed in rIL 2-activated EAL cells. Thus, it was suggested that more additional lymphokine other than IL 2 was necessary to generate cytotoxic activity against autologous tumor cells. The cell populations responsible for cytolytic activity to allogeneic and/or autologous tumor cells were investigated by two-color flow cytometry. The majority of killer-effector cells against allogeneic cells in rIL 2-activated EAL cells from cancer patients showed CD4+Leu8- phenotype at population level. In contrast, it was suggested that cytolytic activity against allogeneic and/or autologous tumor cells in TCGF-activated EAL cells might be mediated by CD8+ CD11- and CD8+ CD28+ effector cells.

Adenocarcinoma↗
PubMed1990

Plummer-Vinson syndrome complicated by gastric cancer: a case report.

Plummer-Vinson syndrome has been brought to attention as a precancerous lesion of hypopharyngeal and cervical lesions of the esophagus, but that involving the stomach is uncommon. We report a case of Plummer-Vinson syndrome with gastric cancer. A brief literature review of this disorder is presented, and possible causes in this unusual case are discussed.

Aged↗
PubMed1990

[Effects of 5-hydroxyeicosatetraenoic acid (5-HETE) on progesterone and prostaglandin production by human corpora lutea].

The present study was undertaken to assess the effects of 5-hydroxyeicosatetraenoic acid (5-HETE) on steroidogenesis and prostaglandin (PG) production in cultured luteal cells derived from human corpora lutea in the mid-luteal phase. The luteal cells were cultured with 5-HETE at 10, 100, 500, or 1,000 ng/ml in the absence or presence of hCG at 100 ng/ml for 10 days. The addition of 5-HETE to the culture media did not affect growth curves of cultured luteal cells. 5-HETE significantly inhibited progesterone (P) production by cultured luteal cells in a dose-related fashion on day 2. P production stimulated by exposure to hCG was also reduced significantly in response to 5-HETE. The addition of 5-HETE did not affect estradiol production by cultured luteal cells. The production of 6-keto-PGF1 alpha by cultured luteal cells in the presence of 5-HETE was slightly but not significantly less than that observed in the absence of 5-HETE. However, 5-HETE affects neither PGF2 alpha nor PGE2 production by cultured luteal cells throughout the culture period. The present study demonstrates that 5-HETE inhibits P production in cultured luteal cells by a mechanism(s) other than through PG production. These data suggest the involvement of a lipoxygenase pathway in the synthesis of P and 6-keto-PGF1 alpha of luteal cells.

Adult↗
PubMed1990

[In vitro induction of cytotoxic activity against carcinomatous pleural or peritoneal lymphoid cells cultivated with cytokines, and an immunological phenotypic analysis of the effector cells].

The functional and phenotypic characteristics of carcinomatous pleural or peritoneal lymphoid cells cultivated with either rIL 2 or TCGF have been investigated. The cultivation of the lymphoid cells with cytokines was initiated by a mixture of coexisting, viable carcinoma cells for 14 days. Results have indicated that cytokine-activated lymphoid cells from malignant pleural and peritoneal effusions showed considerable cytolytic activity against K562 and Daudi cells. The cell population responsible for LAK and/or CTL effector cells of TCGF-activated lymphoid cells were CD8+ CD11- cells. Further, in rIL 2-expanded cultures from pleural and peritoneal lymphoid cells, the CD4+ Leu 8- population was found to contain effector cells of cytotoxic activity against the tumor cells. It further was seen that the TCGF-activated CD8+ CD11- T cells possessed a more potent killing activity, in comparison to the rIL 2-activated CD4+ Leu8- T cells. However, rIL 2-activated lymphoid cells from ascites in liver cirrhosis (used for a control) showed a higher tumoricidal activity.

Aged↗
PubMed1989

Lymphokine-activated suppressor (LAS) cells in patients with gastric carcinoma.

T-cell-growth-factor (TCGF) activate peripheral blood lymphocytes (PBL), cultured for 14 days, showed killer cell activities against natural-killer resistant Daudi cells in a 4 h 51Cr-release assay. However, the effector cells obtained from patients with nonresectable carcinoma exhibited very much lower cytotoxicity to tumor cells. To analyze the mechanism of depression, we have attempted to examine suppressor cell activities of the TCGF-activated PBL. The assay for the suppressor cell activities was made by in vitro inhibition of cell-mediated cytotoxicity by incubating radiolabeled target tumor cells with lymphokine-activated killer (LAK) cells and TCGF-activated PBL. LAK cells were induced by cultivation with recombinant interleukin-2. TCGF-activated PBL, obtained from four out of ten patients with resectable carcinoma and nine out of ten patients with nonresectable carcinoma, significantly suppressed the LAK cell activities. However, this suppression was not observed in TCGF-activated PBL from ten normal healthy control subjects. TCGF-activated PBL with immunosuppressive reactivity were named lymphokine-activated suppressor (LAS) cells. To investigate the phenotypic characterization of TCGF-activated PBL, the cells were analyzed by two-color flow cytometry. TCGF preferentially expanded CD8+CD11- cells and decreased the growth of CD8+CD11+ cells in both normal healthy control subjects and gastric cancer (resectable and nonresectable) patients. Dominantly expressed CD8+CD11- cells on TCGF-activated PBL in patients--especially those with nonresectable gastric carcinoma--showed strong LAS cell activity, irrespective of the presence of killer cell activities of CD8+CD11- cells in TCGF-activated PBL from normal healthy control subjects. The results suggested the generation of CD8+CD11- LAS cells from cancer patients, and revealed that CD8+CD11- T-cells contained killer and/or suppressor cell function. In addition, it was found that the TCGF-activated PBL from gastric cancer patients were associated with an increased proportion of CD4+ Leu8+, HLA-DR+CD8+ and HLA-DR+CD25+ cells.

Adult↗