-
[show abstract]
[hide abstract]
ABSTRACT: Mast cells are unique immune cells that release a spectrum of chemical mediators contributing to the inflammatory symptoms of allergic disorders. Although mast cell biology has been extensively studied in the rodents, research on human mast cells is hampered by the lack of a convenient preparation source. This problem has now been addressed by culturing human mast cells from CD34(+) progenitors. We have recently discovered that human buffy coat preparations from local blood banks are an abundant and convenient source of progenitors for culturing mature mast cells which express functional high affinity IgE receptors and contain histamine and tryptase in their granules. In the current study, we further characterize these buffy coat-derived mast cells by studying their responses to common mast cell secretagogues and stabilizers. Mature human mast cells were obtained by culturing isolated progenitors in methylcellulose containing stem cell factor (SCF), IL-3 and IL-6 for 6 weeks and subsequently in liquid medium containing SCF and IL-6 for another 6 to 8 weeks. Following sensitisation with human IgE, these cells released histamine dose-dependently upon activation by anti-IgE and calcium ionophores while compound 48/80 and substance P were relatively ineffective. When the effects of anti-asthmatic agents on anti-IgE-induced mediator release from these cells were compared, only the beta(2)-adrenoceptor agonists and phosphodiesterase inhibitors produced dose-dependent inhibition but not cromolyn or nedocromil. In total, mast cells cultured from human buffy coat progenitors shared similar functional properties of MC(T) subtype of mast cells found predominantly in human lung parenchyma and intestinal mucosa.
International Immunopharmacology 05/2007; 7(4):541-6. · 2.38 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: Mast cells are important effector cells of allergy and techniques for culturing human mast cells have been developed in recent years. In the current investigation, we studied the phenotypic and functional characteristics of mast cells cultured from adult human peripheral blood mononuclear cells. Mature human mast cells were obtained by first culturing mononuclear cells in methylcellulose containing stem cell factor (SCF), IL-3 and IL-6 for six weeks and subsequently in liquid medium containing SCF and IL-6 for another six weeks. These cells expressed numerous basophilic cytoplasmic granules that were predominantly tryptase positive but chymase negative. Following sensitization with human IgE, these cells released histamine and synthesized prostaglandin D2 and cysteinyl-leukotrienes dose-dependently upon activation by anti-IgE and calcium ionophores. Compound 48/80 and substance P were ineffective. When the effects of anti-asthmatic agents on anti-IgE induced mediator release from these cells were compared, only the beta2-adrenoceptor agonists and phosphodiesterase inhibitors produced dose-dependent inhibition but not cromolyn. In total, mast cells cultured from human peripheral blood shared similar morphological, immunocytochemical and functional properties of enzymatically dispersed human lung mast cells. These cultured mast cells can be a convenient substitute for the in vitro studies of human lung mast cell reactions and may be useful for investigating the roles of mast cells in allergic diseases.
International Immunopharmacology 06/2006; 6(5):839-47. · 2.38 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: To investigate the effect of CpG-containing oligodeoxynucleotides (CpG ODN) alone or in combination with the chemotherapeutic agent 5-fluorouracil (5-FU) on tumor growth and whether CpG ODN can reverse the immunosuppression caused by the chemotherapy with 5-FU in murine hepatoma model.
Hepatoma model was established by subcutaneous inoculation with hepatoma-22 (H(22)) cells into the right flank of BALB/c mice. Mice with tumor were treated by peritumoral injection of CpG ODN alone or in combination with subcutaneous injection of 5-FU. Tumor size was quantified regularly. Serum levels of IL-12 and IFN-gamma in mice were assayed by enzyme-linked immunosorbent assay (ELISA). The lytic capacity of splenic NK cells was tested by lactate dehydrogenase release assay.
Peritumoral injection of CpG ODN alone or in combination with subcutaneous injection of 5-FU, and the treatment with 5-FU alone all led to significant inhibition of hepatoma growth. The mean tumor volumes fell by 46.66% in mice injected with CpG ODN, 68.34% in the 5-FU treated mice, and 70.23% in mice treated with the combination of CpG ODN and 5-FU than in controls. There was no significant difference in tumor size between 5-FU-treated mice and mice treated with the combination of 5-FU and CpG ODN (P>0.05). The serum levels of IL-12 and IFN-gamma of mice treated with CpG ODN alone (IL-12: 464.50+/-24.37 pg/mL; IFN-gamma: 134.20+/-25.76 pg/mL) or with the co-administration of CpG ODN and 5-FU (IL-12: 335.83+/-28.74 pg/mL; IFN-gamma: 111.00+/-5.33 pg/mL) were significantly higher than that of controls (IL-12: 237.50+/-45.31 pg/mL; IFN-gamma: 56.75+/-8.22 pg/mL). The production of IL-12 and IFN-gamma was suppressed moderately in 5-FU-treated mice (IL-12: 166.67+/-53.22 pg/mL; 53.33+/-16.98 pg/mL) compared to control mice (P>0.05), whereas the combination of CpG ODN and 5-FU significantly increased the serum levels of IL-12 and IFN-gamma compared to 5-FU alone (P<0.05). The NK cell killing activity in CpG ODN-treated mice (44.04+/-1.38%) or the mice treated with CpG ODN combined with 5-FU (30.67+/-1.28%) was significantly potentiated compared to controls (19.22+/-0.95%, P<0.05). The co-administration of CpG ODN and 5-FU also significantly enhanced the lytic activity of NK cells when compared with the treatment with 5-FU alone (12.03+/-1.42%, P<0.05).
The present data suggests that CpG ODN used as single therapeutic agent triggers anti-tumor immune response to inhibit the growth of implanted hepatoma and reverses the immunosuppression caused by the chemotherapy with 5-FU.
World Journal of Gastroenterology 02/2005; 11(8):1220-4. · 2.47 Impact Factor
