DOI： 10.1023/A:1008183400709

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Language：English   Publisher：SPRINGER  

We examined the effects of tea polyphenols on the activation process of human mature basophils by stimulation with Ca2+ ionophore A23187 or IgE receptor crosslinking. IL-4 was used to induce differentiation in human leukemia cell line KU812 into the morphological and functional human mature basophils used in this study. Among the tea polyphenols examined, (-)-epicatechin gallate (ECG) and (-)-epigallocatechin gallate (EGCG) inhibited degranulation caused by IgE receptor crosslinking as well as by A23187. Thus, our findings suggest that the effects of ECG and EGCG may act on signaling pathway which regulates degranulation in human basophils after the increase of intracellular Ca2+ concentration.

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Language：English   Publisher：SPRINGER  

The human leukemia cell line KU812 have been described as an immature pre-basophilic cell line and exhibits a potential to differentiate into mature basophilic KU812 cells produce modest amount of histamine and express Fc epsilon RI, the high affinity IgE receptor, which plays a central role in the allergic responses system. Previously, we observed that hydrocortisone can enhance Fc epsilon RI expression in KU812 cells. In this study, we demonstrate that KU812 cells treated with hydrocortisone are able to release histamine in response to stimulation with IgE and anti-IgE antibody, suggesting that the Fc epsilon RI induced by hydrocortisone was functional enough to transduce a signal for degranulation. Fc epsilon RI is a tetramer consisting of an alpha chain, a beta chain and two gamma chains. We measured the mRNA level of each subunit in KU812 cells by RT-PCR followed by Southern blotting. After treatment with 1 mu M hydrocortisone for 35 days, the cells showed an increase in the amount of mRNA for Fc epsilon RI gamma. Almost no significant change in the amount of mRNA for Fc epsilon RI alpha and Fc epsilon RI beta was observed, This result suggests that the enhanced expression of Fc epsilon RI on the surface of KU812 cells by hydrocortisone was related to the upregulaion of Fc epsilon RI gamma mRNA.

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Language：English   Publisher：ACADEMIC PRESS INC  

The human leukemia cell line KU812 had been described as an immature prebasophilic cell line and exhibits a potential to differentiate into mature basophils. We studied the effect of interleukin-4 (IL-4) on the basophilic differentiation of KU812 cells. When KU812 cells were cultured with 1 ng/ml IL-4, cellular histamine content increased more than 10-fold. IL-4 also enhanced the expression of Fc epsilon RI, a high affinity IgE receptor, on the cell surface. KU812 cells treated with IL-4 expressed higher levels of Fc epsilon RI alpha, Fc epsilon RI beta and Fc epsilon RI gamma mRNA than non treated KU812 cells. After 21 days in culture with IL-4, KU812 cells became morphologically mature basophilic cells as demonstrated by staining positive for cytoplasmic granules and heparin proteoglycan by Wright dye and toluidin blue dye respectively. In addition, IgE-mediated histamine release was observed, suggesting that the Fc epsilon RI induced by IL-4 was functional and was able to transduce a signal for degranulation. These results suggest that IL-4 promotes differentiation of KU812 cells into mature basophilic cells both morphologically and functionally. (C) 1998 Academic Press.

DOI： 10.1006/bbrc.1998.8816

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Language：English   Publisher：SPRINGER  

The human leukemia cell line KU812 exhibits a potential to differentiate into basophilic cells and has been described as a basophilic precursor cell line KU812 cells produce inflammatory mediators such as histamine and arachidonic acid metabolites. In addition, the cell line expresses high affinity IgE receptor (Fc epsilon RI) which is central to an allergic responses, but formation of cytoplasmic granules has not been accomplished When basophilic differentiation was induced in basophilic lineage cells, the synthesis of inflammatory mediators are increased and granulated cells are appeared in culture.
Previously, we found that hydrocortisone can enhance the expression of Fc epsilon RI on KU812 cells. In this study, the effect of hydrocortisone on the formation of basophilic granules in KU812 cells was examined When the cells were cultured with 1 mu M hydrocortisone for 3 weeks, granulated cells that were stained metachromatically with Wright-Giemsa dye were observed In addition, the cellular histamine content of hydrocortisone-treated KU812 cells markedly increased after 3 weeks. These results suggest that hydrocortisone induces basophilic differentiation of KU812 cells.

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Language：English   Publisher：KLUWER ACADEMIC PUBL  

We cultured human leukemia cell line KU812 to induce differentiation into basophil or mast cell. KU812 belongs to the myeloid cell lineage and is at least a bipotential cell that can differentiate into basophilic and monocyte/macrophage-like cells (1-3). When the KU812 cells were treated with recombinant human interleukin-3 (IL-3) or hydrocortisone (HC), we observed induction of differentiation (as measured morphologically and cytochemically) into monocyte/macrophage-like, neutrophilic and erythrocytic cells. Although basophilic granules were not detected on Wright-Giemsa stain, 5% of induced KU812 cells were stained positive with toluidine blue. Moreover, expression of high affinity IgE receptor Fc epsilon RI on the surface of KU812 cells was enhanced with IL-3 or HC. These results suggest that basophilic and mast cell-like cells present in cultures supplemented with IL-3 or HC.

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Language：English   Publishing type：Article, review, commentary, editorial, etc. (scientific journal)   Publisher：TAYLOR & FRANCIS LTD  

Many protein-free media have been deveoped, because protein-free media are usually more economical than serum-free. or serum-containing media and facilitate the purification of bioactive materials, We evaluated various iron salts and chelating agents replacing transferrin to develop a protein-free medium for a human-human hybridoma, HB4C5, and found out that ferric citrate,vas favorable for the production and the productivity of monoclonal antibodies.

DOI： 10.1271/bbb.59.743

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Language：English   Publisher：SOC POLYMER SCIENCE JAPAN  

The effects of sodium poly(styrene sulfonate) on an antibody production and cell growth of a hybridoma cell were studied. Although sodium poly(styrene sulfonate) inhibited the antibody production and cell growth at lower concentration with increasing molecular weight in serum-free cultures, sodium poly(styrene sulfonate)s with medium weight-average molecular weights (M(w)) such as 35000 and 18000 suppressed antibody production without inhibiting cell growth at appropriate concentrations. Sodium poly(styrene sulfonate) (M(w)=35000) decreased the extracellular concentration of a mu heavy chain forming an antibody, while it had no effect on an intracellular antibody or mu heavy chain concentration. This suggests that the sodium poly(styrene sulfonate) suppresses secreting the antibody assembled by mu heavy chains and lambda light chains out of the cell without inhibiting the synthesis and association of both chains in the cell.

DOI： 10.1295/polymj.27.719

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