Method The expression levels of CD28, CTLA4, CD40 and CD40L molecules on PBMC were examined by immunohistochemical method in rat cardiac allograft recipients.

• 方法采用大鼠异位心脏移植模型，用免疫组化方法动态检测外周血单核细胞(PBMC)CD28、CTLA4、CD40及CD40L分子的表达。