紫色杆菌内毒素抑制小鼠GVHR的免疫学机理

Immunological Mechanisms of Inhibition of GVHR by Ch. Violaceum Endotoxin

We had confirmed that treatment of donor mice with Ch. Violaceum endotoxin (lipopolysacchari-de,LPS)could inhibit GVHR. In this paper, its immunological mechanisms were explored. The results showed that the LPS could augment [3H] -TdR uptake by mouse spleen cells, but decrease their proliferative responses to LPS and Con A, and suppress unidirectional MLR and NK cell activity, with inhibitory rate of 64.5%, 66.1%, 51.7% and 59.3%, respectively, suggesting it had inhibitory effects on B, T lymphocytes and NK cells. In vitro experiments using mixtures of spleen cells from treated and normal mice showed there existed non-specific suppressor cell activity in LPS-and Con A-induced lymphocyte transformation but not in MLR and NK activity assays. That meant suppressor cells were not responsible for suppressive effects on T cells and NK cells which are thought to be main effector cells mediating GVHD.