Browsing by Author "Liu, Cheng-Chi"

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Characterization of canine monocyte-derived dendritic cells with phenotypic and functional differentiation
(2007-07-01)
Wang, Yu-Shan
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Chi, Kwan-Hwa
;
Liao, Kuang-Wen
;
Liu, Cheng-Chi
;
Cheng, Chiao-Lei
For therapeutic purposes, large numbers of dendritic cells (DCs) are essential. In this study, we used 2% autologous canine plasma, granulocyte/macrophage colony-stimulating factor (GM-CSF), fms-like tyrosine kinase 3 ligand (Flt3L), and interleukin 4 (IL-4) in generating monocyte-derived DCs from peripheral blood mononuclear cells of dogs. The plasma enriched the population of CD14-positive monocytes by greatly enhancing the efficiency of monocyte adherence, the proportion of adherent cells increasing from 6.6% with 10% fetal bovine serum to 15.3% with 2% autologous canine plasma. Culturing the adherent monocytes for 6 d with human GM-CSF, canine IL-4, and human Flt3L significantly increased the yield of DCs, more than 90% of which were CD14-negative. Because, in the presence of lipopolysaccharide (LPS), monocytes that were CD14-positive expressed tumor necrosis factor alpha much more than DCs with low levels of CD14, it is important to decrease the numbers of CD14-positive cel, Is in generating monocyte-derived DCs. With flow cytometry and real-time reverse-transcriptase-mediated polymerase chain reaction assays, we found that in canine immature DCs (iDCs) the expression of DLA class 11 molecules, CD1a, CD11c, CD40, and CD86 was high and the expression of CD80, CD83, and CD14 either low or negative. During maturation (stimulated by LPS), the expression of CD1a, CD40, CD83, and CD80 was upregulated. However, the expression of DLA class 11 molecules, CD11c, and CD86 was not increased in mature DCs. Incubating the iDCs with LPS decreased antigen uptake and increased the cells' immunostimulatory capacity (assessed by the allogeneic mixed-lymphocyte reaction), indicating that LPS accelerates the functional maturation of DCs. This protocol may facilitate the use of DCs in cellular immunotherapy.
Inhibiting autophagy potentiates the antitumor efficacy ofEuphorbia royleanafor canine mammary gland tumors
(2020-06-12)
Huang, Yu-Ya
;
Chen, Chia-Hung
;
Hsu, Chia-Hui
;
Kuo, Tsun-Yung
;
Liu, Cheng-Chi
Background Canine mammary gland tumors (cMGTs) are the most common neoplasms in intact female canines and viewed as a suitable model for studying human breast cancers.Euphorbia royleanahas been reported to have a variety of antitumor efficacies. We have prepared the crude extracts ofE. royleanain ethanol and hexane solvents to evaluate the anti-tumor effects for cMGT in vitro and in vivo. Results The results showed thatE. royleanacould inhibit cell proliferation and colony formation in cMGT cells. The suppression of tumor cell growth resulted from necrosis and cell cycle arrest. Moreover, autophagy appears to play a critical role inE. royleana-mediated cell death by triggering cell apoptosis. The in vivo results also revealed thatE. royleanatreatment could reduce the size of solid tumors while exhibiting low toxicity in cMGT-bearing nude mice. Conclusions The anti-tumor mechanisms ofE. royleanawere firstly verified to show it would cause autophagic cell death, apoptosis, and cell cycle arrest in canine mammary tumor cells. The in vitro and in vivo findings in the present study revealedE. royleanahas potential anticancer effects for the treatment of canine mammary gland tumors.