Cell lines monocytes/macrophages

Pre-treatment of human bronchial epithelial cells with 10 [jM isoprenaline or 100 juM salbutamol augmented the adhesion of fluorescently labelled THP-1 cells, a monocyte/macrophage cell line, to human bronchial epithelial cell monolayers by about 40-60 % (Romberger et al. 2(XX)). The increase in THP-1 cell adhesion occurred within 10 min of isoprenaline pre-treatment of human bronchial epithe-Ual cells and gradually decUned but persisted with up to 24 h of isoprenaUne exposure. 

McDevitt, TM, Tchao, R, Harrison, EH, and Morel, DW, 2005. Carotenoids normally present in serum inhibit proliferation and induce differentiation of a human monocyte/macrophage cell line (U937). J Nutr 135, 160-164. 

The study of osteoclast differentiation is important for understanding potential new treatments for osteoporosis. Such therapies are typically explored in tissue culture models such as the Raw264 mouse monocytic cell line, which is capable of differentiation into functional multinuclear osteoclasts after treatment with the cytokine Rankl. Use of transformed cell lines raises the concern that results may not be extrapolated to normal tissue. To address this question, the transcriptional responses for Rankl treatment of the Raw264 cell line, and of two ex vivo primary cell systems (bone marrow macrophages, and hematopoetic stem cells) were compared using Affymetrix GeneChips [23]. The models proved to... 

These forms of human FcyRII are differentially expressed in immune cells. For example, FcyRIIB transcripts are detectable in monocytes, macrophages and lymphocytes, but not in neutrophils, NK cells or T-cell lines. On the other hand, FcyRIIA and FcyRIIC are expressed on monocytes, macro-... 

Overexpression of PKC in U937 histiocytic lymphoma cells increased expression of PKCa and p isoforms. In response to TPA, parental U937 cells displayed growth arrest and differentiated into a monocyte/macrophage-like cell line, while PKC overexpressing cells underwent death. The abUity of GF109203X to inhibit TPA-induced cell death suggested that activation of a conventional isoform was necessary to induce apoptosis (de Vente et al., 1995). Activation of PKC enhanced and down-modulation of PKC activity reduced apoptosis of neuronal cells (Mailhos et al., 1994). Ceramide, an activator of PKC is an inducer of apoptosis (Muller et al, 1995 Hannun, 1998, Obeid et al., 1993). 

The effect of echinacea on the immune system is controversial. In vivo human studies using commercially marketed formulations of E purpurea have shown increased phagocytosis, total circulating white blood cells, monocytes, neutrophils, and natural killer cells but not immunostimulation. In vitro, Epurpurea juice increased production of interleukins-1, -6, and -10, and tumor necrosis factor- by human macrophages. Enhanced natural killer cell activity and antibody-dependent cellular toxicity was also observed with E purpurea extract in cell lines from both healthy and immunocompromised patients. Studies using the isolated purified polysaccharides from Epurpurea have also shown cytokine activation. Polysaccharides by themselves, however, are unlikely to accurately reproduce the activity of the entire extract. 

Monocyte-macrophages are the only principal cells of the immune system that can synthesize all the eicosanoids. T and B lymphocytes are interesting exceptions to the general rule that all nucleated cells produce eicosanoids. However, in a B lymphoma cell line, there is non-receptor-mediated uptake of LTB4 and 5-HETE. Interaction between lymphocytes and monocyte-macrophages may cause the lymphocytes to release arachidonic acid from their cell membranes. The arachidonic acid is then used by the monocyte-macrophages for eicosanoid synthesis. In addition to these cells, there is evidence for eicosanoid-mediated cell-cell interaction by platelets, erythrocytes, PMNs, and endothelial cells. 

Although the etiology of RA is unknown, important steps in its pathogenesis have been elucidated in recent years. It is clear that in addition to T cells, cells of the monocyte/macrophage and fibroblast lineages (of which the hyperplastic synovial lining layer consists) and their cytokines, particularly IL-1 and TNFa, play decisive roles (94-98), TNFa has a variety of proinflammatory effects, such as induction of IL-... 

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