Recently, it has been suggested, that differentiated cells are more resistant to the apoptotic effect of DNA damaging agents possibly due to the decreased activity of "damage detecting/apoptosis ...triggering" mechanism. Previously, we have shown, that PMA pretreatment reduced etoposide-(ETO) but enhanced staurosporine- (STA) -induced apoptosis in HT58 cells. Data presented here show that the HT58 human, "mature" B-lymphoma cells exposed to PMA secrete more IgM into the supernatant indicating commitment of cells to perform differentiated function. The sensitivity of HT58 cells to ETO- or STA-induced apoptosis is influenced diversely with PMA pre- or posttreatment. Interestingly, the DNA damage (gamma radiation, bleomycin, ETO) or okadaic acic (30 nM) reduced the PMA+STA induced apoptosis.
Previous studies have demonstrated that culture supernatants of LPS-stimulated murine splenic B lymphocytes (BLPSSN) are able to inhibit the growth of freshly isolated B cells via an IgM antibody. In ...this work we investigated the progress of LPS-activated B lymphocytes through the cell cycle in the presence of this antibody. We found that the regulatory IgM did not affect the entry of LPS-stimulated B lymphocytes into G0*, as assessed by the increased expression of I-A antigens. Events that characterize the early G1 phase (G1A), such as cell enlargement and increased RNA synthesis, also occurred in the presence of the antibody. In contrast, events which mark the G1B phase, such as further cell enlargement and late RNA synthesis were inhibited. Moreover, a significant portion of the cells failed to incorporate 3Hthymidine and did not progress through S, G2, or M, as revealed by their DNA content. Therefore, our work points toward a well-defined stage of the early G1 phase at which the antibody inhibits the progression of B lymphocyte activation. This result shows a new insight into the mechanism of antibody-mediated down-regulation of polyclonal B cell responses.
A new flow cytometric method was developed to detect apoptotic cells with fragmented DNA and to determine cell cycle distribution of viable cells, in the same sample, by propidium iodide staining. ...Apoptosis, in HT58 human B lymphoma cells, was induced by etoposide and/or by staurosporine. Using appropriate alkaline solutions (between 1-10 mN NaOH in 150 mM saline) followed by neutralization with buffer solution, the fragmented DNA can be extracted quantitatively from ethanol fixed cells. Further, good resolution of the cell cycle distribution can be obtained in unimpaired cells without RNase treatment. Furthermore, unlike the widely used hypotonic-detergent extraction of unfixed cells, the suggested extraction method can prevent drug-induced disintegration of dead cells when karyorrhexis occurs.
Culture supernatants of LPS-stimulated murine B lymphocytes are able to inhibit the growth of freshly isolated splenic B cells via an IgM antibody. The binding specificity of this IgM is not yet ...defined, but appears to be a B lymphocyte surface structure distinct from membrane immunoglobulin, MHC class II antigen, transferrin and Fc gamma receptors, and B220. The regulatory autoantibody allows the normal progression of early, but not late steps in the cycle of polyclonally-stimulated B lymphocytes and does not affect the increased antigen-presenting capacity of activated B cells. Therefore, this autoregulatory cycle is apparently ubiquitous and may be a major component of B lymphocyte homeostasis under physiological, as well as pathological conditions. Moreover, these findings bring into focus a possible regulating role of B lymphocytes in the humoral immune response.
Provider: - Institution: - Data provided by Europeana Collections- Titre uniforme : Wiener Blut. RV 354. Adapt.- Titre uniforme : Kaiser-Walzer. RV 437- Titre uniforme : Geschichten aus dem ...Wienerwald. RV 325- Titre uniforme : An der schönen blauen Donau. Orchestre. RV 314. Adapt.- Titre uniforme : Radetzky-Marsch. Op. 228. Adapt.- Titre uniforme : Wien, du Stadt meiner Träume- Titre uniforme : Vienne reste Vienne- Comprend : VIENNE, O VILLE EXQUISE (Wien, du Stadt meiner Traume) / SIECSYNSKY - SANG VIENNOIS ("Wiener Blut") op. 354 / Johann STRAUSS Jr - DU ALTER STEFANSTURM ("Vieux dôme de Saint Stéphane") / BRANDL et KLEIN - VINDOBONAMARSCH ("Marche de Vindobona") / KOMZAK - HISTOIRES DE LA FORET VIENNOISE (G'schichten aus dem Wienerwald) op. 325 / Johann STRAUSS Jr - IM PRATER BLUH'N WIEDER DIE BAUME ("Les arbres refleuriront encore au Prater") / STOLZ et ROBITSCHEK - WIEN BLEIBT WIEN ("Vienne restera toujours Vienne") / SCHRAMMEL - FRUHLING IN WIEN ("Printemps à Vienne") / STOLZ et REBNER - WIEN WIRD BEI NACHT ERST SCHON ("Vienne s'embellit la nuit") / STOLZ et STERK - ICH HAB' MIR FUR GRINZING EINEN DIENSTMANN ENGAGIERT ("J'ai engagé un porteur pour me ramener de Grinzing") / UHER - LE TROISIEME HOMME ("Der dritte Mann") / Anton KARAS - JA, JA DER WEIN IST GUT ("Oui, oui, le vin est bon") / STRECKER et GRIBIZ - LE BEAU DANUBE BLEU ("An der schönen blauen Donau") op. 314 / Johann STRAUSS Jr - RADETZKY MARSCH (Marche de Radetzky) op. 228 / Johann STRAUSS Jr - VALSE DE L'EMPEREUR ("Kaiserwalzer") / J. STRAUSS Jr - VIENNE, O VILLE EXQUISE ("Wien, du Stadt meiner Traume") / SIECZYNSKI- BnF-Partenariats, Collection sonore - Believe- BnF-Partenariats, Collection sonore - Believe- All metadata published by Europeana are available free of restriction under the Creative Commons CC0 1.0 Universal Public Domain Dedication. However, Europeana requests that you actively acknowledge and give attribution to all metadata sources including Europeana
