Experimental study of the effect of T cell on alveolar bone resorption induced by bacterial endotoxin

点击翻译按钮获取中文摘要

Periodontal disease are caused by bacterial infection and some immune cells locally infiltrated against it. There cells secrete cytokines which have been reported to act not only as regulatory substances for immune responses, but mediators of tissue destruction. In fact, there have been many reports which suggest the relation between some cytokines secreted from T cell, a mediator of immune responses, and alveolar bone resorption. However, it has been unclear that T cells truly relate with periodontal tissue destruction. So in first study, alveolar bone resorption induced by every 48 h injections of E.coli endotoxin was investigated in normal mice, T cell deficient nude mice and SCID mice congenitally lacking both T and B cells. In addition, CD4 and/or CD8 depleted mice by the administration of anti-CD4 and/or anti-CD8 monoclonal antibodies were used in this study. In normal mice, alveolar bone resorption was observed after 4 times injection, and after 7 times in nude mice and 10 times in SCID mice. T cell depleted mice, especially CD4 depleted mice, also revealed the weaker and delayd bone resorption. These findings strongly suggested the relation between T cells and bone resorption. So in second experiment, mice transfered with T cells were established and injected with endotoxin as same as in first study. After 4 times injection, these mice showed the weak but obvious bone resorption similarly in normal mice. Based on these results, T cells closely related the bone resorption induced by endotoxin and further study should be investigated on cytokine production by T cells.