FK506对大鼠正位穿透性角膜移植排斥反应发生过程中外周血淋巴细胞免疫功能的影响

Effect of Fk506 on the Immune Function of Peripheral Lymphocytes of Rat after Orthotopic Keratoplasty

目的研究ＦＫ５０６对角膜移植排斥反应的防治作用机制。方法纯系大鼠正位穿透性角膜移植后球周注射ＦＫ５０６，以后每周注射二次，术后不同时间尾部取血，行双标激光流式细胞分析。结果术后不同时间对照组ＣＤ４、ＣＤ８及ＣＤ４／ＣＤ８比值的差别无明显的统计学意义，但ＣＤ８＋／ＣＤ２５＋及ＣＤ８＋／Ｉａ＋Ｔ细胞逐渐增加，直至角膜移植排斥反应出现。ＦＫ５０６治疗组动物ＣＤ４细胞逐渐降低，ＣＤ８细胞增加，ＣＤ４／ＣＤ８比值降低。ＣＤ８＋／ＣＤ２５＋Ｔ细胞在各时间点无统计学差异，ＣＤ８＋／Ｉａ＋Ｔ细胞在术后第６天升高具有明显统计学差异，但升高值低于对照组。结论ＦＫ５０６球周注射后通过局部作用及吸收作用抑制淋巴细胞活化，延长角膜移植片存活时间。

ObjectiveTo study the immunosuppressive mechanisms of FK506 on corneal allograft rejection.MethodsFK506 was administered by periocular injection after orthotopic keratoplasty in inbred rats while control rats received an equivalent 30% alcohol.Dual fluorescence flow cytometry analysis was used to identify the kinetic variation of the peripheral T cell population,especially the activated T cell subset.ResultsThere was no statistically significant change in CD4 or CD8 T cell population sizes as well as CD4/CD8 ratio before or after the onset of corneal allograft rejection in control rats.However,CD8 +/CD25 + or CD8 +/Ia + T lymphocyte increased constantly until the episode of rejection.In FK506 treated animals,CD4 cells were decreased obviously during day 12 and 15 post surgery,and CD8 cell populations increased gradually,so the CD4/CD8 ratio decreased.The variation of CD8 +/CD25 + T cells was not statistically significant at any time point.The CD8 +/Ia + T cells increased after 6 days,but the value was lower than control.ConclusionFK506 prolongs the survival time of corneal allografts by inhibiting T cell activation.