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BM Culture (bm + culture)
Selected AbstractsIL-33 promotes DC development in BM culture by triggering GM-CSF productionEUROPEAN JOURNAL OF IMMUNOLOGY, Issue 12 2009Nobuyasu Mayuzumi Abstract Short-term DC cultures generated with GM-CSF and other cytokines have markedly improved our ability to study the immunobiology of DC. Here, we tested 65 cytokines individually for their potential to promote the generation of CD11c+ cells in a murine BM culture system. In addition to several cytokines known to promote DC survival and/or growth, IL-33 was found to augment DC development time- and dose-dependently. Although the resulting CD11c+ cells generated in the presence of IL-33 exhibited a typical dendritic morphology, they expressed MHC class II molecules only at modest levels, showed negligible responses to TLR ligands, produced no detectable IL-12 p70, displayed PD-L1 and PD-L2 on the surface, and failed to activate immunologically naïve T cells efficiently. IL-33-induced expansion of CD11c+ cells was completely blocked by anti-GM-CSF mAb, and GM-CSF mRNA and protein expression in BM culture was markedly elevated by added IL-33, indicating that IL-33 promotes in vitro DC generation indirectly by a GM-CSF-dependent manner. With regard to the cellular source, IL-33-dependent GM-CSF production was observed exclusively within the CD45+/Fc,RI+ BM population. Not only do our results reinforce the notion that GM-CSF serves as a primary DC growth factor, but they also reveal a previously unrecognized mechanism supporting DC development. [source] Modulation of cell adhesion and viability of cultured murine bone marrow cells by arsenobetaine, a major organic arsenic compound in marine animalsBRITISH JOURNAL OF PHARMACOLOGY, Issue 1 2001Teruaki Sakurai In this study, we investigated the biological effects of trimethyl (carboxymethyl) arsonium zwitterion, namely arsenobetaine (AsBe), which is a major organic arsenic compound in marine animals using murine bone marrow (BM) cells and compared them with those of an inorganic arsenical, sodium arsenite, in vitro. Sodium arsenite showed strong cytotoxicity in BM cells, and its IC50 was 6 ,M. In contrast, AsBe significantly enhanced the viability of BM cells in a dose-dependent manner during a 72-h incubation; about a twofold increase in the viability of cells compared with that of control cells cultured with the medium alone was observed with a ,M level of AsBe. In morphological investigations, AsBe enhanced the numbers of large mature adherent cells, especially granulocytes, during a 72-h BM culture. When BM cells were cultured together with AsBe and a low dose (1 u ml,1) of recombinant murine granulocyte/macrophage colony-stimulating factor (rMu GM-CSF), significant additive-like increasing effects were observed on the numbers of both granulocytes and macrophages originated from BM cells. However, AsBe did not cause proliferation of BM cells at all as determined by colony-forming assay using a gelatious medium. These findings demonstrate the unique and potent biological effects in mammalian cells of AsBe, a major organic arsenic compound in various marine animals which are ingested daily as seafood in many countries. British Journal of Pharmacology (2001) 132, 143,150; doi:10.1038/sj.bjp.0703790 [source] Transforming growth factor-beta1 affects interleukin-10 production in the bone marrow of patients with chronic idiopathic neutropeniaEUROPEAN JOURNAL OF HAEMATOLOGY, Issue 6 2007Katerina Pyrovolaki Abstract Background:, Chronic idiopathic neutropenia (CIN) is a bone marrow (BM) failure syndrome characterized by accelerated apoptosis of myeloid progenitor cells because of a local imbalance between pro-inflammatory and anti-inflammatory cytokines. In this study, we investigated the interplay among transforming growth factor-beta1 (TGF-,1), interleukin-10 (IL-10), and soluble flt-3 ligand (sFL) within the BM of CIN patients and probed the role of these cytokines in the pathophysiology of CIN. Design:, We used long-term BM cultures (LTBMC) to evaluate TGF-,1, IL-10, and sFL levels in CIN patients (n = 70) and healthy subjects (n = 35). Cytokine levels in LTBMC supernatants were correlated with the number of circulating neutrophils and the proportion of BM CD34+/CD33+ myeloid progenitor cells. Results:, CIN patients had increased TGF-,1 and sFL levels in LTBMCs compared with controls and individual cytokine values were found to be correlated inversely with the number of neutrophils and the proportion of CD34+/CD33+ cells. Patients displayed low supernatant IL-10 levels compared with controls and cytokine values were found to be correlated positively with the number of neutrophils and the proportion of CD34+/CD33+ cells. The levels of TGF-,1 were found to be inversely correlated with IL-10 and positively with sFL values in LTBMC, supernatants suggesting a possible interplay among these cytokines in CIN BM. Neutralization of TGF-,1 in LTBMCs increased IL-10 levels significantly in patients but not in controls, while neutralization had no effect on sFL levels. Conclusion:, Excessive production of TGF-,1 within the BM microenvironment of CIN patients results in downregulation of IL-10 and reduction of myeloid progenitor cells. Overexpression of sFL probably represents a compensatory mechanism to the low myeloid progenitor cells. [source] Involvement of leptin signaling in the survival and maturation of bone marrow-derived dendritic cellsEUROPEAN JOURNAL OF IMMUNOLOGY, Issue 12 2006Kwan Lam, Queenie Abstract Previous studies demonstrated that lymphocyte development is impaired in leptin receptor (Ob - R)-deficient db/db mice. However, it remains unclear whether or not leptin signaling plays a physiological role in dendritic cell (DC) development and function. In this study, we first detected Ob-R expression in murine DC. Using db/db mice at a pre-diabetic stage, we demonstrate that the total number of DC generated from bone marrow (BM) cultures is significantly lower than in WT controls. Similarly, selective blockade of leptin with a soluble mouse Ob-R chimera (Ob-R:Fc) inhibited DC generation in wild-type BM cultures. The reduced DC yield in db/db BM culture was attributed to significantly increased apoptosis, which was associated with dysregulated expression of Bcl-2 family genes. Moreover, db/db DC displayed markedly reduced expression of co-stimulatory molecules and a Th2-type cytokine profile, with a poor capacity to stimulate allogeneic T cell proliferation. Consistent with their impaired DC phenotype and function, db/db DC showed significantly down-regulated activities of the PI3K/Akt pathway as well as STAT-3 and I,B-,. In conclusion, our findings demonstrate the involvement of leptin signaling in DC survival and maturation. See accompanying commentary: http://dx.doi.org/10.1002/eji.200636770 [source] Increased expression of CD40 on bone marrow CD34+ hematopoietic progenitor cells in patients with systemic lupus erythematosus: Contribution to Fas-mediated apoptosisARTHRITIS & RHEUMATISM, Issue 2 2009Katerina Pyrovolaki Objective Patients with systemic lupus erythematosus (SLE) display increased apoptosis of bone marrow (BM) CD34+ hematopoietic progenitor cells. This study was undertaken to evaluate the expression of CD40 and CD40L in the BM of SLE patients, and to explore the possible involvement of these molecules in apoptosis of CD34+ cells. Methods The proportion and survival characteristics of CD40+ cells within the BM CD34+ fraction from SLE patients and healthy controls were evaluated by flow cytometry. The production of CD40L by BM stromal cells was assessed using long-term BM cultures, and the effect of CD40L on the survival characteristics and clonogenic potential of CD34+ cells was evaluated ex vivo by flow cytometry and clonogenic assays. Results SLE patients displayed an increased proportion of CD40+ cells within the CD34+ fraction as compared with controls. The CD34+CD40+ subpopulation contained an increased proportion of apoptotic cells compared with the CD34+CD40, fraction in patients and controls, suggesting that CD40 is involved in the apoptosis of CD34+ cells. Stimulation of patients' CD34+ cells with CD40L increased the proportion of apoptotic cells and decreased the proportion of colony-forming cells as compared with untreated cultures. The CD40L-mediated effects were amplified following treatment with recombinant Fas ligand, suggesting that the effects of these ligands are synergistic. CD40L levels were significantly increased in long-term BM culture supernatants and adherent layers of BM cells from SLE patients as compared with controls. Conclusion These data reveal a novel role for the CD40/CD40L dyad in SLE by demonstrating that up-regulation and induction of CD40 on BM CD34+ cells from patients with SLE contribute to the amplification of Fas-mediated apoptosis of progenitor cells. [source] | ||||||||||