Duction of immunoincompetence of T cells to oxidized-low density lipoprotein in vitro by CTLA4Ig / 中华微生物学和免疫学杂志

ABSTRACT

Objective To induce the immunoincompetence of T cells to oxidized-low density lipoprotein(ox-LDL)in vitro,in order to prevent immune injuries in atherosclerosis(AS)and to find new strategies to prevent AS.Methods Monocytes were separated from peripheral blood to induce dendritic cells (DC).DCs were treated with LPS(30 ng/m1),ox-LDL(10μg/m1)and LDL(10μg/m1)for 48 h,respectively.Then DCs were mixed with allogeneic T lymphocytes to earry out mixed lymphoeytes reaction (MLR).CTLA4Ig in different concentrations was added into the MLR of ox-LDL group.MTr method was used to assay the proliferation of T cells.The CD25 expression and apoptosis of T cells in MLR were tested by flow cytometry.And the excretion of IL-2,IFN-γ and IL-4 were assayed by ELISPOT method.Results SI of the ox-LDL group was higher than that of the LDL group significantly(DCT=15,1.6717±0.3152vs 1.4250±0.2874.P<0.05;DCT=110,1.5458±0.2748 vs 1.3352±0.2991,P<0.05),and CTLA4Ig inhibited the SI of the ox-LDL group in dose-dependence(CTLA4Ig 1.25μg/ml,0.96±0.30 vs μg/ml 1.29±0.28 vs 1.64±0.33 P<0.05).CTLA4Ig caused the decrease of CD25 expression(CTLA4Ig 1.25 μg/ml,11.26±0.58 vs 14.25±1.02,P<0.05;CTLA4Ig 10μg/rnl 8.42±0.45,P<0.01)and induced apoptosis of T cells in MLR(CTLA4Ig 1.25μg/ml,12.54±3.69 vs 6.09 4-2.24,P<0.05;CTLA4Ig 10μg/ml,26.87±5.06 VS 6.09±2.24,P<0.01).CTLA4Ig caused the decrease of ELISPOT counts of IL-2(CTLA4Ig 1.25μg/ml,386±42 VS 534±54,P<0.05;CTLA4Ig 10μg/rnl,230±27 VS 534±54,P<0.01)and IFN-γ(CTLA4Ig 1.25μg/ml,445±48 VS 672±46,P<0.05;CTLA4Ig 10μg/ml,193±39 VS 672±46,P<0.01),while that of IL-4 increased(CTLA4Ig 1.25μg/ml,401±32 VS 332±41,P<0.05;CTLA4Ig 10μg/ml,453±57 VS 332±41,P<0.05).Conclusion CTLA4Ig can induce T cens immunoin competence to ox-LDL in vitro by inhibiting T cells activation,inducing T cells apoptosis and TH 1/TH2 immune deviation.