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γδ T cells play important roles in innate immunity against tumors and infections. Inhibitory effect of dihydroartemisinin on growth of cancer cells has been found in recent years. In this study, we investigated the effect of dihydroartemisinin on human γδ T cell proliferation by MTT assay and killing activity against pancreatic cancer cells SW1990, BxPC-3 and PANC-1 by LDH release assay in vitro. Intracellular molecule alterations were verified by flow cytometry. The results suggested that appropriate concentration of dihydroartemisinin favored the expansion of γδ T cells and enhanced γδ T cell mediated killing activity against pancreatic cancer cells. Up-regulation of intracellular perforin, granzyme B expression and IFN-γ production may be the important mechanism of dihydroartemisinin on increased antitumor activity of γδ T cells., (© 2013. Published by Elsevier B.V. All rights reserved.)

Objective: To explore the effect and mechanism of Phloretin on human γδ T cells killing colon cancer SW-1116 cells., Methods: γδ T cells were amplified in vitro from human peripheral blood mononuclear cells through isopentenyl pyrophosphate method (IPP). After cocultured different concentrations of Phloretin with γδ T cells or SW-1116 cells for 48h respectively, MTT assay was used to test the growth curve of these two cells; Flow cytometry to test the expression of Granzyme B (GraB), perforin (PFP), CD107a and IFN-γ of γδ T cells; Lactate dehydrogenase (LDH) release assay to test the cytotoxic activity of the γδ T cells on SW-1116 cells; and Western blot to test the Wnt3a expression of the γδ T cells., Results: After cultured with IPP for ten days, the percentage of γδ T cells increased from 3.31±3.00% to 78.40±10.30%. Compared to the control group, when the concentration of Phloretin increased from 2.35μg/ml to 18.75μg/ml, it could significantly proliferate the γδ T cell growth (P<0.05) and inhibit the growth of SW-1116 cells in dose-response, and the expression of GraB, PFP, CD107a and Wnt3a significantly increased (P<0.05). Significant positive relationships were observed among CD107a and PFP, GraB, cytotoxicity (P<0.05). The percentage of IFN-γ producing γδ T cells treated with Phloretin was significantly higher than control group., Conclusion: Phloretin can enhance the killing effect of γδ T cells on SW-1116 cells; the mechanism may be that Phloretin could proliferate the γδ T cell growth, increase the expression of PFP and GraB, activate the Wnt signaling pathway, and produce higher level of IFN-γ. Indeed CD107a expression probably correlates quite well with antitumor activity., (Copyright © 2012 Elsevier B.V. All rights reserved.)

Aim: To observe the costimulation of multiple activating factors effects on the proliferation and phenotype of T lymphocytes in vitro., Methods: Peripheral blood mononuclear cells (PBMCs) were separated by fractionation on Ficoll-Hypaque gradient. According to adding different cytokines (CD3 mAb, CD28 mAb, IFN-γ, IL-1α, IL-2 and IL-15), the experiments were divided into seven groups. Effects of different cytokines on the proliferation of PBMC were counted by automated hematology analyzer five categories. The phenotypes (CD3, CD4, CD8, CD28, CD16, CD56(+);CD16, CD3(+);CD8(+);, CD3(+);CD4(+);, CD3(+); CD56(+);, CD45RO) expressing on the surface of costimulatory cells were detected by flow cytometry, and the cytotoxicity of costimulatory cells on SGC-7901, SW-1990 and SW-116 cell lines was examined by lactate dehydrogenase release method., Results: The proliferation has significant difference when adding different cytokines into PBMCs culture system, the highestest proliferation multiples group is the one contains cytokines CD3, CD28, IFN-γ, IL-2, IL-1α, IL-15 and IL-21, which proliferation multiple is 255.3±6.3 at the tenth day of cell culture, obviously higher than the other culture systems which only contains CD3, IFN-γ and IL-2 (166.6±5.5) (P<0.05). Part of cells'phenotype changed when adding different activating factors. Without IL-15, the proportion of CD16(+);CD56(+);(NK) cells and CD3(+);CD56(+); cells was higher than the other groups; CD45RO(+); memory cells is most evident when delayed adding IL-15 and IL-21 for three days. The cytotoxicity of PBMCs cultured for ten days with different activating factors had significant difference, the highest was the one which delayed adding IL-15 and IL-21 for three days (76.2%, 60.3% and 70.6%, respectively.), higher than the cell culture groups containing CD3, IFN-γ and IL-2 (54.9%, 44.6% and 50.4%, respectively) (P<0.05). The cultured cells had the strongest cytotoxicity on SGC-7901 gastric adenocarcinoma cells., Conclusion: The PBMCs' proliferation, phenotype and cytotoxicity had significant difference after being activated by different stimulating factors, adding matching stimulating factors into the culture system have great value on cell-directed culture.

Aim: To explore the effect of aspirin on human's gammadeltaT cells killing digestive system tumor cell lines., Methods: Use the isopentenyl pyrophosphate method to amplify human peripheral blood gammadeltaT cells in vitro. Various concentrations of aspirin were used to induce gammadeltaT cells and digestive system tumor cells SGC-7901, SW-1990, SW-480, SW-1116, LOVO cells lines, LDH assays was used to measure the cytotoxic activity of gammadeltaT cells, flow cytometry analysis the apoptosis percentage of before and after induced gammadeltaT cells and SGC-7901, SW-1990, SW-480, SW-1116, LOVO cell lines., Results: gammadeltaT cells were cultivated for ten days which proliferation ratio increase from 4.21% to 70.35%. When gammadeltaT cells induced via aspirin concentrations rang from 0.4 mmol/L to 0.8 mmol/L which cytotoxic activity on the five kinds of tumor cell lines was the highest, if aspirin's concentration surpassing 3.2 mmol/L, cytotoxic activity of gammadeltaT cells present decrease tendency. SGC-7901, SW-1990, SW-480, SW-1116, LOVO cells lines were induced by different concentrations of aspirin for 24 hours, just SW-480, SW-1116 and LOVO were enhanced as far as the cytotoxic activity of gammadeltaT cells on these cell lines was concerned, other groups and control group have no notable changed. The apoptosis percentage of gammadeltaT cells(52.71%) were induced by aspirin which concentration was 3.2 mmol/L, which was strikingly higher than SGC-7901, SW-1990, SW-480, SW-1116, LOVO cells lines, (respectively 7.88%, 8.89%, 6.21%, 4.47% and 3.67%)., Conclusion: When aspirin's concentration for clinical routine used can enhance the effect of gammadeltaT cells killing the tumor cells, if surpassing this concentration can obvious inhibited the proliferation capacity and cytotoxic activity of gammadeltaT cells and augment apoptosis ratio, however, it is not obvious for digestive tract tumor lines.