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1.
Unfractionated human peripheral blood mononuclear cells produce a small amount of interleukin 2 (IL 2) by stimulation with a monoclonal anti-T3 antibody (OKT3) in vitro. The IL 2 production could be greatly augmented by the addition of a phorbol ester, 12-O-tetradecanoyl-phorbol-13-acetate (TPA). In the presence of TPA, the T cell enriched fraction deprived of macrophages did not produce IL 2, but the T cells pulse-incubated with OKT3 and reconstituted with macrophages efficiently produced IL 2 in subsequent culture in the presence of TPA as did T cells reconstituted with OKT3-pulse-incubated macrophages. The stimulating effect of OKT3 in the presence of macrophages was inhibited dose-dependently by the addition of immunoglobulins, particularly by mouse IgG2a which is the same isotype as that of the OKT3 antibody, showing that it inhibits by blocking the binding of OKT3 to Fc receptors on macrophages. The same extent of IL 2 production was induced in T cells when paraformaldehyde-fixed macrophages were substituted for intact macrophages. Remarkable IL 2 production was also induced by OKT3 when latex beads coated with rabbit anti-mouse IgG2a antibody and TPA were added to the culture. It was confirmed that the production induced by these stimulations was due to an increase of IL 2 mRNA. These results show that effective signals for IL 2 production are generated by efficient crosslinking of T3 molecules which results from multi-interaction of T3 molecules on the T cell membrane and anti-T3 antibody molecules on macrophage membrane or on the surface of the latex particle. 相似文献
2.
Masanori Shinzato Mikihiro Shamoto Satoru Hosokawa Chiyuki Kaneko Akido Osada Miyuki Shimizu Asako Yoshida 《Biotechnic & histochemistry》1995,70(3):114-118
The present study shows that Langerhans cells can be differentiated from Interdigitating cells at the light microscopic level. Superficial lymph nodes and skin taken from necropsies and the lymph nodes of dermatopathic lymphadenopathy (DPL) were used for this experiment. Sections of lymph node and skin were embedded using the acetone, methyl benzoate and xylene (AMeX) method and dendritic cells were immunostained with anti S-100 protein antibody (S-100, and OKT-6 (CD1a) using the restaining method. Langerhans cells in the skin were positive for both CD1a and S-100. Dendritic cells positive for both CD1a and S-100, and dendritic cells positive for S-100, but not for CD1a were observed in superficial lymph nodes. In normal superficial lymph nodes, there were more interdigitating cells than Langerhans cells. The majority of the dendritic cells in the DPL were Langerhans cells. We conclude that the S-100 and CD1a positive cells are Langerhans cells, and the S-100 positive-CD1a negative cells are interdigitating cells. 相似文献
3.
Matrix Gla protein (MGP) regulates calcification in cartilage and arteries. MGP synthesis during embryonic development and its binding and regulation of growth factors and morphogens of the TGF-beta/BMP superfamily suggests that it has additional functions. Assay by far-western gel overlays and gel filtration shift shows MGP binds vitronectin. Binding is saturable and consistent with a single class of binding sites. MGP binds to vitronectin but not collagen, fibromodulin, heparin, osteocalcin, chondroitin sulfate, laminin, ovalbumin or albumin. We have identified a vitronectin binding site within a 17-amino acid peptide 61-77 near the carboxyl-terminus that corresponds to a naturally occurring MGP C-terminus. MGP and the 61-77 MGP peptide also binds to fibronectin. MGP and vitronectin are focally co-localized in embryonic tissues. Co-localization in vivo suggests that the MGP and vitronectin interactions may modify cell-matrix interactions. Alternatively, vitronectin-bound MGP may have altered function for modulating BMP2 or TGF-beta activity. The current study demonstrates that MGP has a novel binding activity for vitronectin, an extracellular protein that promotes cell-matrix interactions and regulates coagulation. 相似文献
4.
Primary structures of two types of alpha-subunit of rat brain Na+,K+,-ATPase deduced from cDNA sequences 总被引:2,自引:0,他引:2
Y Hara O Urayama K Kawakami H Nojima H Nagamune T Kojima T Ohta K Nagano M Nakao 《Journal of biochemistry》1987,102(1):43-58
A rat brain cDNA library was screened by using as a probe a fragment of cDNA encoding the alpha-subunit of human Na+,K+-ATPase. Two different cDNA clones were obtained and analyzed. One of them was concluded to be a cDNA encoding the alpha-subunit of the weakly ouabain-sensitive rat kidney-type Na+,K+-ATPase. The deduced amino acid sequence consists of 1,018 amino acids. The alpha-subunit of the rat kidney-type Na+,K+-ATPase shows 97% homology in amino acid sequence with the alpha-subunit of human, sheep, or pig enzyme and 87% with that of Torpedo. Based on a comparison of the amino acid sequence at the extracellular domain of the alpha-subunit between weakly ouabain-sensitive rat kidney-type enzyme and the ouabain-sensitive human, sheep, pig, or Torpedo enzyme, it was proposed that only two significant amino acid replacements are unique to the rat kidney-type alpha-subunit. Another cDNA clone obtained showed 72% homology in nucleotide sequence with the former cDNA coding the alpha-subunit of the rat kidney-type Na+,K+-ATPase and the deduced amino acid sequence exhibited 85% homology with that of the alpha-subunit of rat kidney-type Na+,K+-ATPase. 相似文献
5.
Differences in lectin binding patterns of normal human endometrium between proliferative and secretory phases 总被引:3,自引:0,他引:3
Lectin binding patterns in normal human endometrium were examined by light and electron microscopy using seven different lectins (ConA, WGA, RCA, PNA, UEA-1, DBA, and SBA). For light microscopic observations, criteria based on the incidence and intensity of cells positive for the lectin staining were adopted to evaluate the different staining patterns of the proliferative and secretory endometria obtained by the avidin-biotin-peroxidase complex (ABC) technique. At the light microscopic level, ConA, WGA, and RCA stained endometrial glandular cells in both phases. The number of PNA-positive cells with the binding sites entirely limited to the apical surface tended to be reduced slightly in the secretory phase. UEA-1 weakly stained the apical surface of glandular cells in the proliferative phase but not in the secretory phase. Among the lectins used in this study, DBA and SBA displayed remarkable changes between the phases. That is, in the proliferative phase they produced only a faint or slight positive stain at the apical surface, but the incidence and intensity of DBA- and the SBA-positive glandular cells increased in the secretory phase. By electron microscopy, the reaction product of ConA was observed in the plasma membrane, endoplasmic reticulum, nuclear envelope, and the Golgi apparatus, and the binding sites of RCA and DBA were observed in the plasma and Golgi membranes. Between both phases, the reactivity of ConA and RCA showed almost no change. However, the secretory endometrial cells containing the DBA-positive Golgi apparatus were markedly increased in number compared with the proliferative ones bearing the lectin-positive organelles.(ABSTRACT TRUNCATED AT 250 WORDS) 相似文献
6.
Masafumi Abe Naoya Nakamura Shirou Fukuhara Takamasa Hayashi Keiki Kawakami Kenkichi Kita Toshifumi Kinoshita Toyoro Ohsato Haruki Wakasa 《Virchows Archiv. B, Cell pathology including molecular pathology》1990,59(1):107-113
A new human acute lymphoblastic leukemia (ALL) cell line, designated HBL-3, was established from the bone marrow of a patient
with non-T-ALL. The HBL-3 cell line expressed B4 (CD 19), BA-1 (CD 24) and HLA-DR antigens, but not surface immunoglobulin
(SIg) or cytoplasmic immunoglobulin (CIg). The cell line lacked the common acute lymphoblastic leukemia antigen (CALLA) and
antigenic markers characteristic of T-cell and myeloid cell lineages. The HBL-3 cells had structural rearrangements of both
the homologous chromosome 9s, including a translocation with chromosome 1 which has been reported in a patient with common
ALL. The cell line had rearranged immunoglobulin heavy chain genes but retained germ-line κ light chain genes and germ-line
T-cell receptorβ- and γ-chain genes. The HBL-3 cell line was strongly positive for terminal deoxynucleotidyl transferase (TdT). These findings
indicate that the HBL-3 cell line is derived from the earliest B-cell committed to B-cell lineage. 相似文献
7.
Satoru Furukawa Akio Ozaki Yukinobu Kotani Toshihide Nakanishi 《Applied microbiology and biotechnology》1988,29(2-3):253-257
Summary
l-Threonine hyper-producing mutants were obtained fromEscherichia coli W strain KY-8366, by reducingl-threonine degradation activity and enhancingl-threonine biosynthetic activity. Anl-threonine degradation reaction test using resting cells of KY-8366 suggested that the main pathway ofl-threonine degradation by KY-8366 is via glycine. A strain with reducedl-threonine degradation activity was obtained among those mutants that could not utilizel-threonine as sole nitrogen source. Rifampicin-resistant mutants andl-lysine plus methionine-insentitive mutants were isolated. These mutants showed enhanced aspartokinase levels and accumulated morel-threonine than the parental strains. Mutant H-4290 accumulated 58 g/l ofl-threonine. 相似文献
8.
Satoru Furukawa Akio Ozaki Toshihide Nakanishi 《Applied microbiology and biotechnology》1988,29(6):550-553
Summary Growth and l-threonine productivity of l-threonine producer Escherichia coli H-4290 were inhibited by precursor amino acids, l-homoserine and l-aspartate. l-Threonine hyper-producers were isolated among the mutants resistant to l-homoserine and l-aspartate. Mutants H-4351 (Homr) and H-4578 (Homr, Aspr) accumulated 22.2 g/l and 24.3 g/l of l-threonine in test tube cultures, while the parental strain H-4290 accumulated 18.2 g/l. The enzyme level of aspartokinase I (first enzyme of the threonine operon) was enhanced 2.3 times (H-4351) and 3 times (H-4578) that of H-4290. Mutant H-4578 accumulated 76 g/l of l-threonine in a 2-l jar fermentor after 75 h cultivation.Abbreviations DAP
diaminopimeric acid
- Met
l
poor growth in methionine-free medium
- AHV
-amino--hydroxyvaleric acid
- Thr-N-
lack of ability to utilize l-threonine as a nitrogen source
- Rif
rifampicin
- Lys+Metr
resistant to l-lysine and dl-methionine 相似文献
9.
Cotyledons detached from light-grown radish (Raphanus sativusL. cv. Comet) seedlings were used as a model system to studythe changes in nuclear gene expression during dark-induced senescenceof green leaves. Polyadenylated RNA was prepared from the cotyledonsat different times and then translated in a wheat germ system.Approximately 1,000 different polypeptides of the translationproducts were separated from each other by two-dimensional gelelectrophoresis. As judged from the density of autoradiographicspots of the translation products, the induction of senescenceby dark treatment involved an increase in 26 species, a decreasein 11 species, and a temporary increase and subsequent decreasein 8 species of translatable mRNA. A similar pattern of changein protein synthesis was also observed in the dark-treated cotyledonswhen the cotyledons were pulse-labeled with 35S-methionine andthe soluble proteins separated by two-dimensional gel electrophoresis,though the polypeptide pattern on the gel did not coincide exactlywith those of the cell-free translation products. These findingsstrongly suggest that the process of leaf senescence is notsimply a passive and gradual death of the tissue, but involvesa drastic and sequential response of the cells to environmentalstimuli with respect to the gene expression of the cells. (Received July 21, 1987; Accepted September 30, 1987) 相似文献
10.
Senescence-specific increase in cytosolic glutamine synthetase and its mRNA in radish cotyledons 总被引:11,自引:4,他引:7 下载免费PDF全文
Changes in the levels of cytosolic and chloroplastic isoforms of glutamine synthetase were examined in senescing radish (Raphanus sativus L. cv Comet) cotyledons by immunoblotting analysis using antibodies raised separately against maize glutamine synthetase isoforms. Translatable mRNAs for these isoforms were also examined by analyzing translation products from poly(A)+ RNA in a wheat germ system with the antibodies. The relative content of cytosolic isoform (GS1) increased twofold in the cotyledons that were placed in the dark for 72 hours to accelerate senescence, while that of chloroplastic isoform (GS2) declined to half of its initial level. The dark-treatment also increased the relative level of translatable mRNA for GS1 sevenfold after 72 hours, and decreased rapidly that for GS2 and for other nuclear-coded chloroplast proteins as well. Cotyledons also accumulated GS1 mRNA when they became senescent after a lengthy growth period under continuous light. These observations suggested that GS1 genes were activated, while those for GS2 were repressed, and eventually the population of the enzyme was altered in senescent cotyledonary cells. The role of increased cytosolic enzyme is discussed in relation to the nitrogen metabolism in senescent leaves. 相似文献