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31.
用生物活性法和双抗体夹心桥联酶免疫吸附(ELISA)法检测了人类疱疹病素6型(HHV-6)GS株和南京地方株CN5,8,10感染的淋巴细胞培养上清中的肿瘤坏死因子(TNF)的水平,发现培养24h即可检出高水平的TNF,48~72h述到峰值,此后逐渐下降,与未感染耐照组比较有及其显著的差异(P<0.001)。GS株与地方株同诱生TNF水平无儿著性差异(P>0.1),三株地方株诱生TNF也无显著性差异(P>0.05)。TNF-α单抗可以完全中和培养上清中TNF的活性,证实上清中有TNF-α。与LPS比较,HHV-6诱生TNF-α的能力要强得多。 相似文献
32.
Greer M. Murphy Jr. Yuen LIng Lee Xiao-Chi Jia Albert C. H. Yu Anna Majewska Yaoli Song Karen Schmidt Lawrence F. Eng 《Journal of neurochemistry》1995,65(6):2716-2724
Abstract: Tumor necrosis factor-α is a pluripotent cytokine that is reportedly mitogenic to astrocytes. We examined expression of the astrocyte intermediate filament component glial fibrillary acidic protein in astrocyte cultures and the U373 glioblastoma cell line after treatment with tumor necrosis factor-α. Treatment with tumor necrosis factor-α for 72 h resulted in a decrease in content of glial fibrillary acidic protein and its encoding mRNA. At the same time, tumor necrosis factor-α treatment increased the expression of the cytokine interleukin-6 by astrocytes. The decrease in glial fibrillary acidic protein expression was greater when cells were subconfluent than when they were confluent. Thymidine uptake studies demonstrated that U373 cells proliferated in response to tumor necrosis factor-α, but primary neonatal astrocytes did not. However, in both U373 cells and primary astrocytes tumor necrosis factor-α induced an increase in total cellular protein content. Treatment of astrocytes and U373 cells for 72 h with the mitogenic cytokine basic fibroblast growth factor also induced a decrease in glial fibrillary acidic protein content and an increase in total protein level, demonstrating that this effect is not specific for tumor necrosis factor-α. The decrease in content of glial fibrillary acidic protein detected after tumor necrosis factor-α treatment is most likely due to dilution by other proteins that are synthesized rapidly in response to cytokine stimulation. 相似文献
33.
Robert K. Bright Michael H. Shearer Ronald C. Kennedy 《Cancer immunology, immunotherapy : CII》1995,40(3):206-211
Baculovirus-derived recombinant simian virus 40 (SV40) large tumor antigen (T-Ag) was used to immunize BALB/c mice to examine the lymphokines produced following immunization. Specifically, we examined production of interleukin-2 (IL-2), IL-4, IL-5 and interferon (IFN) from immune lymphocytes cultured with decreasing concentrations of recombinant SV40 T-Ag. We identified elevated levels of IFN and IL-2 by enzyme-linked immunosorbent assay and a murine CTLL-2 proliferation biossay respectively. We were unable to detect either IL-4 or IL-5. These data indicate the previously reported tumor immunity induced by recombinant SV40 T-Ag immunization most likely reflects a TH1-like immune response based on thein vitro production of both IFN and IL-2 by immune lymphocytes. 相似文献
34.
M. Rita I. Young Joe Ihm Yvonne Lozano Mark A. Wright M. Margaret Prechel 《Cancer immunology, immunotherapy : CII》1995,41(1):37-45
Metastatic Lewis lung carcinoma (LLC-LN7) tumors that secrete granulocyte/macrophage-colonystimulating factor (GM-CSF) stimulate myelopoiesis and induce bone marrow-derived immunosuppressor cells that are homologous to granulocyte/macrophage progenitor cells. In vitro treatment of the LLC-LN7 cells with 1,25-dihydroxyvitamin D3 reduced tumor cell production of suppressor-inducing activity, although suppressor-inducing activity could be restored by reconstituting the tumor supernatants with recombinant GM-CSF. Treatment of mice having LLC-LN7 tumors with vitamin D3 reduced tumor production of GM-CSF and the frequency of myeloid progenitor cells. This was associated with a reduction in immunosuppressor activity and an increase in T cell function. Vitamin D3 treatment of mice having palpable tumors transiently retarded tumor growth, but caused a prominent reduction in tumor metastasis. Treating mice with vitamin D3 after tumor excision resulted in a reduction in the tumor-induced myelopoietic stimulation and associated immunosuppressive activity, and enhanced T cell function. These mice had a markedly reduced incidence of tumor recurrence. The results of this study suggest that vitamin D3 treatment of mice with GM-CSF-secreting tumors can interrupt the myelopoiesis-associated immunosuppressor cascade and, in turn, reduce tumor metastasis and recurrence.This study was supported in part by grants from the Medical Research Service of the Department of Veterans Affairs and by grants CA-45080 and CA-48080 from the National Institutes of Health 相似文献
35.
Witold Lasek Anna Wańkowicz Katarzyna Kuc Wojciech Feleszko Jakub Golab Adam Giermasz Wiesŀaw Wiktor-J/cedrzejczak Marek Jakóbisiak 《Cancer immunology, immunotherapy : CII》1995,40(5):315-321
The efficacy of systemic infusion of recombinant human macrophage-colony-stimulating factor (M-CSF) in combination with local treatment with human recombinant tumor necrosis factor (TNF) and mouse recombinant interferon (IFN) was studied in vivo on a subclone of B16 melanoma (MmB16) in mice. Short-term intravenous administration of M-CSF at a dose of 106 units daily had no antitumor effect in vivo. Similarly, local treatment of tumor with TNF (5 g daily) did not produce any therapeutic effect. However, simultaneous administration of the same dose of TNF with IFN (1000 units daily) resulted in a synergistic effects manifested by the retardation of tumor growth. Addition of systemic infusion of M-CSF to the local therapy with TNF and IFN induced further augmentation of antitumor efficacy and delayed progression of MmB16 melanoma. The strengthened antitumor effect of combination therapy including M-CSF, TNF and IFN was most probably due to the increased release of monocytes from the bone marrow, their recruitment into the site of tumor growth and subsequent local stimulation of their antitumor activity. 相似文献
36.
Mikael Dohlsten Peter A. Lando Per Björk Lars Abrahmsén Lennart Ohlsson Peter Lind Terje Kalland 《Cancer immunology, immunotherapy : CII》1995,41(3):162-168
T lymphocytes generally fail to recognize human colon carcinomas, suggesting that the tumour is beyond reach of immunotherapy. Bacterial superantigens are the most potent known activators of human T lymphocytes and induce T cell cytotoxicity and cytokine production. In order to develop a T-cell-based therapy for colon cancer, the superantigen staphylococcal enterotoxin A (SEA) was given tumour reactivity by genetic fusion with a Fab fragment of the monoclonal antibody C242 reacting with human colon carcinomas. The C242Fab-SEA fusion protein targeted SEA-reactive T cells against MHC-class-II-negative human colon carcinoma cells in vitro at nanomolar concentrations. Treatment of disseminated human colon carcinomas growing in humanized SCID mice resulted in marked inhibition of tumour growth and the apparent cure of the animals. Therapeutic efficiency was dependent on the tumour specificity of the fusion protein and human T cells. Immunohistochemistry demonstrated massive infiltration of human T cells in C242Fab-SEA-treated tumours. The results merit further evaluation of C242Fab-SEA fusion proteins as immunotherapy in patients suffering from colon carcinoma. 相似文献
37.
Casein kinase II (CKII) activity is enhanced as much as 2–3 fold in established and 4–5-fold in transformed human cell lines when compared to that of fibroblasts and primary human tumour cell cultures where CKII activity never exceeded a basic level. The high activity of CKII in transformed cells and in established cell lines was reduced to about the same basic level after treatment with heparin, a highly specific inhibitor of CKII activity. The activity of the cAMP-dependent protein kinase was virtually the same in fibroblasts and various human tumour cell lines investigated. 相似文献
38.
Biological activities of chemically synthesized analogues of the nonreducing sugar moiety of lipid A 总被引:12,自引:0,他引:12
M Matsuura Y Kojima J Y Homma Y Kubota A Yamamoto M Kiso A Hasegawa 《FEBS letters》1984,167(2):226-230
Adriamycin-Fe3+ complex catalyzes the formation of hydroxyl radical from hydrogen peroxide but the DNA-adriamycin-iron ternary complex is much more effective. 11-Deoxyadriamycin, which shows no spectral evidence of complex formation with iron, was ineffective. The generation of hydroxyl radical by adriamycin-Fe3+ complex in the presence of DNA correlates with its ability to cleave DNA. Hydroxyl radicals are thus implicated as the reactive oxygen species involved in the DNA damage caused by the adriamycin-Fe3+ complex. 相似文献
39.
Both internal and external proteins in vesicular stomatitis virus were labeled when intact virions were iodinated with 50 μm iodide; however, only the surface proteins were labeled when the same procedure was carried out at low iodide concentrations (below 0.5 μm). This result together with similar observations reported earlier with another enveloped virus, Rous-associated virus-61 (RAV-61), suggest that viral envelopes provide a barrier to iodination by chloramine-T at low, but not at high, iodide concentrations. By monitoring the permeability of the RAV-61 envelope to successive iodinations and to iodination in the presence of chaotropic thiocyanate ions, it was shown that the permeability of the viral envelope was not altered at the higher concentrations of iodide. Further results support the hypothesis that iodination mediated by chloramine-T inolves two different iodinating species: (a) a membrane impermeable one, possibly “iodamine-T,” which predominates at low iodide concentrations, and (b) a membrane permeable species, possibly molecular iodine, which predominates at high concentrations of iodide. These results reinforce the proposal that the chloramine-T procedure is a useful method for specifically labeling surface proteins of lipid-enveloped structures. 相似文献
40.
Identification of a calmodulin-dependent glycogen synthase kinase in rabbit skeletal muscle, distinct from phosphorylase kinase 总被引:3,自引:0,他引:3
A glycogen synthase kinase that is completely dependent on Ca2+ and calmodulin has been identified in mammalian skeletal muscle, and purified approximately 3000-fold by chromatography on phosphocellulose and calmodulin--Sepharose. The presence of 50 mM NaCl in the homogenisation buffer was critical for extraction of the enzyme. The calmodulin-dependent glycogen synthase kinase (app. Mr 850 000) is distinct from myosin light-chain kinase and phosphorylase kinase, but phosphorylates the same serine residue on glycogen synthase as phosphorylase kinase. The physiological role of the enzyme is discussed. 相似文献