Toll样受体2、4和9在皮肤结核皮损中的表达

Expression of Toll-like receptors 2, 4 and 9 in cutaneous tuberculosis lesions

目的研究Toll样受体2、4和9（TLR-2、TLR-4、TLR-9）在寻常狼疮和疣状皮肤结核皮损中的表达，探讨其在皮肤结核发病中的作用。方法经临床与病理确诊的皮肤结核（包括寻常狼疮和疣状皮肤结核）患者皮损标本18份，斑块状银屑病皮损15份为阳性对照，色素痣边缘正常皮肤10份为阴性对照。用免疫组化法观察TLR-2、TLR-4、TLR-9的表达情况。采用SPSS13．0统计软件进行统计学分析，组间比较行t检验。结果TLR-2在正常皮肤表达于除基底层外的表皮全层，而在皮肤结核和银屑病皮损表达于表皮的中上层，3组的表达强度均为高表达（A值分别为0．28±0．03、0．25±0．04和0．25±0．05），3组差异无统计学意义（P〉0．05）。TLR-4在正常皮肤和银屑病呈低或无表达（A值分别为0．07±0．09和0．02±0．05），而皮肤结核（O．16±0．07）呈低表达，其表达强度高于正常皮肤（t=2．58，P〈0．05）和银屑病皮损（t=6．24，P〈0．01）。TLR-9在正常皮肤和皮肤结核表达于表皮全层、附属器及血管壁，而皮肤结核的表达强度（A值为0．25±0．05）高于正常皮肤（0．19±0．05），两组比较，t=2．88，P〈0．05。结论TLR-2、TLR-4和TLR-9在皮肤结核皮损中均存在表达，其中TLR-4和TLR-9的表达高于正常皮肤，提示其在皮肤结核的免疫应答中可能起一定的作用。

Objective To observe the expression of Toll-like receptors （TLRs） 2, 4 and 9 in lesions of lupus vulgaris and tuberculosis verrucosa cutis, and to evaluate the possible roles of these receptors in the pathogenesis of cutaneous tuberculosis. Methods Skin specimens were obtained from the lesions of 18 patients with clinically and pathologically diagnosed lupus vulgaris or tuberculosis verrucosa cutis, 15 patients with plaque-type psoriasis （positive control）, and from perilesional normal skin of 10 patients with pigmented nevi （negative control）. Immunohistochemistry was used to detect the expression of TLRs 2, 4 and 9 in these specimens, and the expression intensity was expressed as absorbence values. Data were analysed by using the SPSS 13.0 software, and t test was conducted to assess the differences between the three groups of specimens. Results TLR-2 was observed mainly in the middle and upper layer of epidermis in lesions of cutaneous tuberculosis and psoriasis, and in the whole epidermis except the basal layer in normal skin, with no significant difference in the expression intensity between the three groups of specimens （0.25 ± 0.04 vs. 0.25 ± 0.05 vs. 0.28 ± 0.03, P 〉 0.05）. TLR-4 was weakly expressed in cutaneous tuberculosis lesions, absent or slightly expressed in normal skin and psoriatic lesions, and the expression level of TLR-4 was significantly higher in cutaneous tuberculosis lesions than in normal skin and psoriatic lesions （0.16 ± 0.07 vs. 0.07 ±0.09 and 0.02 ± 0.05, t = 2.58, 6.24, P 〈 0.01 and 0.05）. TLR-9 was expressed in the whole epidermal layer, including appendages and vascular walls, of cutaneous tuberculosis and normal skin, with a significant increase in cutaneous tuberculosis than in the normal skin （0.25± 0.05 vs. 0.19±0.05, t = 2.88, P 〈 0.05）. Conclusions TLRs 2, 4 and 9 are all expressed in cutaneous tuberculosis lesions, and the expression intensity of TLR-4 and TLR-9 is higher in cutaneous tuberculosis lesions than in normal skin, hinting that TLR-4 and TLR-9 play a certain role in the immune response of cutaneous tuberculosis.