The role of negative co-stimulation molecule PD-L in the T-cell immune response against murine tumor cell line L929
- VernacularTitle:负性刺激分子PD-L对T细胞介导小鼠L929肿瘤细胞免疫效应的影响
- Author:
Hong DAI
;
Min FANG
;
Guanxin SHEN
- Publication Type:Journal Article
- Keywords:
PD-L;
T cells;
L929;
Tumor immunity
- From:
Chinese Journal of Immunology
2000;0(11):-
- CountryChina
- Language:Chinese
-
Abstract:
Objective:To investigate the possible roles of the negative co-stimulation molecule PD-L(ligand) in the T-cell mediated immune response against tumor.Methods:Flow cytometric analysis was used to examine murine tumor cell line L929 expresses PD-L(L1 and L2).Anti-PD-L blocking monoclonal antibodies combined with injection i.p.of irradiated L929 into C57BL/6 mice was employed to sensitize the T cells of the animals.2 weeks after sensitization,mice were sacrificed,and splenocytes were prepared to perform the examinations of T cell proliferation,cytotoxic T cells(CTL) activity,and apoptosis through in vitro coculture with L929 in the presence of blocking PD-L antibodies.Results:The expression of PD-L1 by L929 was detectable,whereas there was no expression of PD-L2 on these cells.Application of blocking antibody against PD-L1 or PD-L2 together with irradiated L929 cells in the process of in vivo sensitization as well as in vitro stimulation,it was shown that blockade of PD-L1 significantly enhanced the T cell proliferation induced by L929 cells and the CTL activity against L929,evidenced by the increased apoptosis and death rate of L929 cells.In control,blockade of PD-L2 had small effects on these terms.Conclusion:The negative co-stimulation molecule PD-L1 plays a role in the escape of tumor cells from host T-cell mediated tumor immunity.Therefore,blockade of PD-L1 has potential significance for tumor immunotherapy.
