血卟啉单甲醚光动力学疗法对小鼠接触性超敏反应的抑制效应

Effect of Hematoporphyrin Monomethyl Ether Mediated Photodynamic Therapy on Mice Contact Hypersensitivity

目的探讨血卟啉单甲醚光动力学疗法(hematoporphyrin monomethyl ether mediated photodynamic therapy,HMME-PDT)对小鼠接触性超敏反应(contacthypersensitivity,CHS)的影响。方法雌性BALB/c小鼠按功率密度分为50和100mW/cm2两个实验组,同时设置单纯照光组、单纯光敏剂组、空白对照组以及DNFB组。PDT处理后3d,各实验组分别以2,4-二硝基氟苯(DNFB)诱发小鼠右耳变应性接触性皮炎,以游标卡尺测量发敏前后右耳的厚度差;对于功率密度为50mW/cm2组,进一步观察了PDT处理前4d或PDT处理后1、3和12d,DNFB发敏前后小鼠右耳的厚度差,并对PDT后3d组行组织学检查,以目镜网格测微尺计算浸润炎症细胞数量。结果处理前4d预先以DNFB致敏,PDT对CHS无抑制作用(P>0.05)。反之,PDT照射后1、3或12d再以DNFB致敏,则PDT能对CHS产生显著抑制作用(P<0.01),其抑制率分别为58%,63%,47%。且无论是以50mW/cm2还是以100mW/cm2功率密度的激光照射,这种抑制作用均存在。未经任何干预,DNFB致敏组致敏右耳浸润的单核细胞和中性粒细胞的数量增加,而经PDT处理后,浸润的炎性细胞明显减少,二者之间存在显著性差异(P<0.01)。结论HMME-PDT能对正常小鼠接触性超敏反应产生明显抑制作用,并有短暂持续效应。

Objective To elucidate the effect of hematoporphyrin monomethyl ether mediated photodynamic therapy （HMME-PDT） on contact hypersensitivity （CHS） model mice. Methods Female BALB/c mice were divided into PDT 50 mW/cm^2 and 100 mW/cm^2 power density groups, laser irradiating group, photosensitizer group, control group and dinitrofluorobenzene （DNFB） group. Three days after PDT treatment, the murine allergic contact dermatitis was induced by topical application of DNFB, sensitized right ear thickness measurements were made prior to and 24 h after challenge with an engineer＇s micrometer. To the group of PDT 50 mW/cm^2, at different time points before and after PDT, the murine allergic contact dermatitis was also induced and ：sensitized right ear thickness was measured prior to and 24 h after challenge, then the sensitized right ear was cut for H-E staining and inflammation cells were counted by using eye-reticule-piece. Results The magnitude of the CHS response was unaffected if PDT was given after DNFB sensitization, while PDT could significantly down-regulated the CHS response to DNFB when PDT was given prior to DNFB sensitization no matter it was irradiated at power density 50 mW/cm^2 or 100 mW/cm^2. At 1, 3 and 12 d after PDT, the inhibition rate of CHS was 58% , 63% and 47% , respectively. The infiltrative inflammatory cells were also significantly decreased at PDT group compared with DNFB group. Conclusions Cutaneous HMME-PDT could produce systemic immune suppression and could persist for some time.