Search PubMed⌕ Search

Biomedical subjects

S Kano

Publications and source records attributed to S Kano.

At least 235 records · Page 13Linked to original sources
PubMed1987

Generation of continuous large granular lymphocyte lines by interleukin 2 from the spleen cells of mice infected with Moloney leukemia virus. Involvement of interleukin 3.

Continuous cell lines could be reproducibly established by culturing spleen cells from adult mice injected with MLV-producer cells or directly infected with Mo-MLV with rIL-2, whereas the culture of normal splenic cells with rIL-2 induced only transient and limited proliferation resulting in no such lines. All of the lines showed morphological characteristics as LGL with Thy-1+,Lyt-1-,L3T4-,Lyt-2-,AsGM1+,FcR gamma+ phenotype without exception, and most of them exhibited typical NK-patterned cytotoxicity. Analysis of reverse transcriptase activity of the culture supernatants as well as Southern hybridization of the DNA from the lines using an Mo-MLV-specific cDNA probe indicated no evidence of retroviral replication or proviral integration, suggesting that the generation of cell lines reflected a reactive process and viral infection was not directly responsible. It was subsequently revealed that Thy-1+,Lyt-1+,Lyt-2- spleen cells from mice infected with Mo-MLV in vivo spontaneously produced surprising amounts of IL-3 in vitro, leading to the possibility that IL-3 was responsible for the generation of lines. The possibility was directly supported by the observation that continuous lines with identical characteristics could be generated completely in vitro by sequential stimulation with rIL-3 and rIL-2 from normal spleen cells without any involvement of Mo-MLV. The C beta gene of TCR was shown to be rearranged in all the lines examined, indicating the LGL lines were all genetically committed to T cell lineage. Unlike the situation in normal splenic populations expanded by rIL-2, where the expression of IL-2-R was progressively lost, constitutive expression of high-affinity-IL-2-R was observed in all the lines and thus, this was considered to explain the unlimited proliferation of them in response to rIL-2 alone. These results suggested the probable role of IL-3 in the regulation of growth and differentiation of a set of LGL committed to T cell lineage. The possible implications of the phenomenon in the regulation of hematopoiesis as well as in the control of Mo-MLV-induced leukemogenesis were discussed.

Animals↗
PubMed1987

Stimulation of superoxide anion formation by the non-TPA type tumor promoters palytoxin and thapsigargin in porcine and human neutrophils.

The non-12-O-tetradecanoylphorbol-13-acetate (TPA) type tumor promoters palytoxin and thapsigargin provoked a respiratory burst in porcine and human neutrophils. The amounts of oxygen consumed and superoxide anion (O2-) produced were found to be stoichiometric. Concentrations of 6.5 X 10(-8) M palytoxin and 1.2 X 10(-6) M thapsigargin were required for half-maximal stimulation to 3 X 10(6) porcine cells/ml in Hanks' solution. Combinations of palytoxin and thapsigargin, and of one non-TPA type and one TPA-type tumor promoter, had synergistic effects in stimulating O2- formation in neutrophils, suggesting that these compounds activate the cells by different signal transduction mechanisms.

Acrylamides↗
PubMed1987

Pathophysiology of hypoxia in mice infected with Plasmodium berghei.

Pathophysiological significance of hypoxia in malarial infection was investigated in mice infected with Plasmodium berghei NK65. Intraperitoneal inoculation of mice with 1 X 10(7) parasitized red blood cells resulted in death of the hosts 6-7 days later. Anaemia of infected animals developed on day 4 after inoculation and oxygen affinity of whole blood, measured as P50 act pH, increased simultaneously. This change may be a physiological adaptive response to a reduction in oxygen delivery to the tissues to day 5. However, the blood oxygen supply on day 6 appeared to be deteriorating and this is thought to be an important factor contributing to the death of the host. The value of adenylate energy charge in red cells during malarial infection, however, was comparatively well-maintained. Allopurinol stimulated the multiplication of malaria parasites and seems to have induced collapse in host-parasite balance more rapidly. Decrease in blood pH and in blood oxygen transport may be important factors for the pathogenesis of the allopurinol-treated hosts.

Adenine Nucleotides↗
PubMed1987

Inhibitory immunization using complete Freund's adjuvant on ongoing eosinophilia induced by repeated antigen-stimulations in guinea pigs.

Ongoing eosinophilia, in guinea pigs repeatedly sensitized with dinitrophenylated (DNP)-Ascaris antigen (DNP-Asc) into the peritoneal cavity, was suppressed significantly by complementary immunizations with a heterologous antigen, e.g., ovalbumin (OA) or bovine gamma-globulin (BGG) emulsified in complete Freund's adjuvant (CFA). Challenge injections of DNP-OA or DNP-BGG elicited peritoneal eosinophilia in animals that were sensitized repeatedly with DNP-Asc. Under these conditions, antigen specificity in suppressive immunization was studied. Eosinophilia, induced by DNP-OA challenge, was suppressed by immunization with either OA in CFA or BGG in CFA. However, Asc (homologous carrier of sensitizing antigen) elicited no suppression. Additionally, CFA, used as an adjuvant, played an important role in suppressive immunization, but CFA alone had no effect in suppressing peritoneal eosinophilia. Anti-DNP antibody, detected by hemagglutination test or passive cutaneous anaphylaxis, was not affected by complementary immunization. These results suggested that peritoneal eosinophilia was suppressed concomitantly by a supplemental immunization in an antigen-nonspecific manner. Eosinophilia in the bone marrow also was suppressed significantly by complementary immunization, but the pattern was quite different from that shown in the peritoneal cavity. The first nuclear cell response peak after challenging, including eosinophils, was stanched completely by CFA itself. The second nuclear cell peak, on day 5, recovered, but eosinophil response continued to be suppressed.

Animals↗
PubMed1987

Selective impairment of alpha-interferon-mediated natural killer augmentation in Sjögren's syndrome: differential effects of alpha-interferon, gamma-interferon, and interleukin 2 on cytolytic activity.

Natural killer (NK) function has been shown to be impaired in several autoimmune diseases including Sjögren's syndrome (SS). In the present study, in vitro effects of alpha-interferon (alpha-IFN), gamma-IFN and interleukin 2 (IL-2) on the NK cell activity were examined to analyse the regulatory system of NK-augmentation in patients with SS. The responsiveness of NK cell activity to alpha-IFN was markedly depressed in SS patients compared with normal controls, whereas the responsiveness to gamma-IFN was within normal limits. This is the first demonstration of the selective hyporesponsiveness of NK cell activity to one type of IFN in a certain disease. In addition, the kinetics study of NK-augmentation in normal donors revealed that alpha-IFN enhanced NK cell activity with a faster profile than gamma-IFN. These findings imply substantial differences between the two types of IFN in their mechanisms for enhancing NK cell activity, which deserve attention in evaluating the effects of IFNs. The present study also demonstrated that IL-2 could induce significantly higher levels of NK cell activity than alpha-IFN or gamma-IFN in SS and that this enhancing effect was almost comparable to that in normal controls. Thus, there seem to be multiple regulatory mechanisms for enhancement of NK cell activity, and a portion of the mechanisms may be selectively impaired in certain human diseases such as SS. The selective hyporesponsiveness to alpha-IFN could be relevant to the idea of viral participation in pathogenesis of SS.

Cytotoxicity, Immunologic↗
PubMed1986

Expression and rearrangement of the alpha, beta, and gamma chain genes of the T cell receptor in cloned murine large granular lymphocyte lines. No correlation with the cytotoxic spectrum.

Using cloned murine large granular lymphocyte (LGL) lines, the expression and the rearrangement of the alpha, beta, and gamma chain genes of the T cell receptor (TCR) were analyzed. Morphological, phenotypical, as well as functional studies indicated that the LGL lines were identical to normal, endogenous NK cells. Northern blot hybridization analysis indicated that the full-length transcripts of all the alpha, beta, and gamma chain genes were expressed in most of the LGL lines, including two lines derived from athymic nude mice. In one line, SPB, however, no transcript of the gamma chain gene was detected, whereas the alpha and beta chain genes were clearly expressed. In every LGL line studied, all of the alpha, beta, and gamma chain genes were rearranged. Conforming to the results of Northern blot hybridization study, the gamma chain gene of the SPB line was aberrantly rearranged, whereas those of all the other lines were productively rearranged. The results clearly revealed that NK cells represented a population of lymphocytes genetically committed to the T cell lineage. It was also suggested that the expression and rearrangement of the TCR genes of NK cells might occur in a thymus-independent fashion. An SPB line without expression of the gamma chain gene could exhibit NK activity indistinguishable from other NK lines. Furthermore, the rearrangement patterns of the beta chain gene did not correlate with the specificity of the cytotoxic activity. These results strongly suggested that the cytotoxic activity in NK cells was not directly mediated by TCR on them. We particularly noted that the beta chain gene of most independently established LGL lines showed identical patterns of rearrangement, indicating that they used the same V beta and J beta gene segments. The significance of the restricted pattern of rearrangement of the beta chain gene in LGL lines, as well as the possible functional roles of TCR on NK cells, was discussed.

Animals↗
PubMed1986

Mechanisms of lymphocyte adhesion to human vascular endothelial cells in culture. T lymphocyte adhesion to endothelial cells through endothelial HLA-DR antigens induced by gamma interferon.

The effects of interferons (IFNs) on lymphocyte adhesion to cultured human vascular endothelial cells (EC) were investigated using an in vitro assay. Endothelial cells obtained from umbilical vein were first cultured at a low density with a conditioned medium (CM) from 12-O-tetra decanoylphorbol 13-acetate-concanavalin A (TPA-Con A) stimulated human peripheral blood lymphocytes (PBL), or with recombinant (r) gamma interferon (IFN-gamma) or r alpha interferon (IFN-alpha), and then were incubated with freshly isolated PBL. Natural IFN-gamma in the TPA-Con A CM and rIFN-gamma (12.5-500 U/ml) induced major histocompatibility complex-class II antigens (HLA-DR, HLA-DP, and HLA-DQ) and significant lymphocyte adhesion to the EC, whereas rIFN-alpha did not. The lymphocyte adhesion to the EC and the expression of DR antigens on the EC were well correlated in terms of both kinetics and the dose-response pattern of rIFN-gamma. When EC expressing I region associated (Ia) antigen were preincubated with monoclonal anti-DR antibody before the addition of lymphocytes, the lymphocyte adhesion was significantly inhibited in both allogeneic and syngeneic combinations, whereas anti-HLA-DP, anti-HLA-DQ, and anti-HLA-ABC antibodies did not inhibit the binding at all. Cell fractionation experiments indicated that the majority of lymphocytes adhering to Ia-expressed EC were Leu-3+ T cells, whose binding was again almost completely inhibited by anti-DR antibody. Moreover, anti-Leu-3a, but not anti-Leu-2a, antibody effectively inhibited the T cell adhesion to the EC. These results strongly suggest that the interaction of the Leu-3(T4) receptor of T cells with IFN-gamma-induced DR antigens on EC plays a central role in the selective adhesion of Leu-3+ T cell to EC.

Antibodies, Monoclonal↗