外周血CD4+T细胞表面信号淋巴细胞激活分子在过敏性结膜炎发病中的作用

目的　研究外周血中CD4⁺T细胞表面信号淋巴细胞激活分子（signaling lymphocytic activation molecule，SLAM）在过敏性结膜炎发病中的作用。方法　选取临床过敏性结膜炎患者10例作为病例组，健康体检者10例作为健康对照组。抽取静脉血，用ELISA法检测两组血清中总IgE的表达情况，同时用流式细胞术检测CD4⁺T细胞表面SLAM的表达情况，分析CD4⁺T细胞表面SLAM表达与血清中总IgE表达的相关性。另选取清洁级雌性两月龄Balb/c小鼠20只，随机分为对照组和模型组，每组各10只，第1天于模型组小鼠尾根、足垫皮下处注射弗氏佐剂和豚草花粉PBS液混合物，第7天、第14天腹腔注射强化，对照组用弗氏佐剂和PBS混合液代替；第15天，每只小鼠给予花粉蛋白粗浸液进行滴眼激发，激发后1 h，取眼球用于制作病理切片，收集静脉血用于流式细胞术检测CD4⁺T细胞表面SLAM的表达，ELISA法检测血清豚草花粉特异性IgE表达；分析两组小鼠外周血中SLAM、血清中特异性IgE的表达有无显著差异，并分析二者的相关性。结果　病例组外周血中CD4⁺T细胞表面SLAM表达明显低于健康对照组（P=0.016），病例组血清中总IgE表达明显高于健康对照组（P=0.002），病例组SLAM表达与总IgE呈负相关（r=-0.453，P＜0.05）。实验小鼠模型组外周血中CD4⁺T细胞表面SLAM表达较对照组显著降低（P=0.000），模型组血清中特异性IgE表达较对照组显著升高（P=0.000），模型组SLAM表达与特异性IgE呈负相关（r=-0.527，P＜0.05）。结论　过敏性结膜炎发病时，外周血中CD4⁺T细胞表面SLAM表达明显减少，与血清IgE的产生有一定的相关性，在一定程度上可以反映机体的过敏状态。

Roles of signaling lymphocytic activation molecule expression on CD4+T cells surface in the pathogenesis of allergic conjunctivitis

Objective　To discuss the function of signaling lymphocytic activation molecule (SLAM) expression on CD4⁺T cells surface in the pathogenesis of allergic conjunctivitis.Methods　Totally 10 patients with allergic conjunctivitis were selected as the observation group，and 10 individuals with no history of allergies receiving physical examination were selected as the control group，followed by the collection of venous blood.The expression of total IgE in the serum was tested by ELISA，and the expression of SLAM on CD4⁺T cell surface was assessed by using flow cytometry.Then the correlation between SLAM expression on CD4⁺T cell surface and serum total IgE level were analyzed.Next，20 Balb/c mice (2-month old) were equally divided into two groups (control group and model group) at random，with 10 mice in each group.Model group was firstly sensitized with the mixture of ragweed and complete Freund’s adjuvant by footpad and root of tail injection on day 1.On day 7 and 14，intraperitoneal injection was enhanced，while rats in the control group were intraperitoneally injected with equal amounts of Freund’s adjuvant.On day 15，mice were excited by ragweed pollen crude infusion drops，and，after 1 h，the eyes were taken for histopathology testing.Then，peripheral blood was collected，and the whole blood was used for the detection of SLAM expression，while the serum was used for the detection of specific IgE for ragweed pollen.Finally，the difference between the two groups and the correlation between SLAM expression and specific IgE level were analyzed.Results　The expression of SLAM on CD4⁺T cell surface in the observation group was significantly decreased when compared with the healthy controls(P=0.016)，but the total IgE level was significantly increased in allergic conjunctivitis patients (P=0.002)；and there was a negative correlation between SLAM expression and total IgE level (r=-0.453 4，P<0.05).About mice，the expression of SLAM on CD4⁺T cell surface of the model group was significantly lower than that of the control group (P=0.000).The expression level of specific IgE of the model group was significantly higher than that of the control group (P=0.000).And there was a negative correlation between SLAM expression and specific IgE level in the model group (r=-0.527 4，P＜0.05).Conclusion　In allergic conjunctivitis，the expression of SLAM on CD4⁺T cell surface in peripheral blood is significantly decreased，which is correlated with the production of IgE，and this may reflect the disease severity to some extent.