肠道病毒71型感染患儿外周血自然杀伤细胞比例、亚群、表面受体及免疫效应分子的变化

目的探讨肠道病毒71型(Enterovirus 71,EV71)感染患儿外周血中自然杀伤(Natural killer,NK)细胞比例、亚群、表面受体及免疫效应分子的变化。方法将EV71阳性的急性期患儿按疾病严重程度分为重症病例组和普通病例组,同时设健康对照组。提取各组患儿外周血,采用流式细胞术检测外周血中NK细胞比例、NK细胞亚群、自然细胞毒受体NKp30和NKp46、激活性受体NKG2D、抑制性受体CD94和NKG2A、脱颗粒标记CD107a及免疫效应分子(PF、GrB和GNLY)阳性细胞所占NK细胞的比例。结果重症病例组患儿外周血NK细胞比例较健康对照组明显减少(P<0.01),普通病例组CD16+NK细胞亚群比例较健康对照组升高(P<0.05),重症病例组较普通病例组低,但差异无统计学意义(P>0.05);重症病例组和普通病例组NKG2D阳性细胞百分率均较健康对照组低(P<0.01),而CD94和NKG2A阳性细胞百分率均较健康对照组明显升高(P<0.01),NKp30和NKp46阳性细胞率3组之间差异无统计学意义(P>0.05);重症病例组和普通病例组CD107a、PF、GrB、GNLY的阳性细胞百分率均较健康对照组明显降低(P<0.01或P<0.05)。结论 EV71感染可能抑制宿主NK细胞的增殖、激活及其杀伤功能。重症病例组与普通病例组比较,NK细胞比例和CD16+NK细胞亚群降低,抑制性受体CD94表达增高,胞浆内CD107a、GrB和PF表达显著降低,可能与重症病例的发生有关。

Percentage, subset, surface receptor and immune effector molecules of natural killer cells in peripheral blood of children infected with enterovirus 71

Objective To investigate the changes in percentage,subset,surface receptor and immune effector molecules of natural killer(NK) cells in peripheral blood of children infected with enterovirus 71(EV71).Methods EV71-positive children with hand-foot-mouth disease(HFMD) in acute phase were divided into severe case and ordinary case groups according to the severity of disease,serving healthy children as control.Peripheral blood samples of children were collected and determined for percentage,subset,as well as the ratio of cells positive for natural cytotoxic receptors NKp30 and NKp46,active receptors CD94 and NKG2A,degranulation marker CD107a,immune effector molecules such as perforin(PF),GrB and granulysin(GNLY) to the total NK cells.Results The percentage of NK cells in severe case group decreased significantly as compared with that in healthy control group(P < 0.01).The percentage of subset CD16+ subset of NK cells was significantly higher in ordinary case group than in healthy control group(P < 0.05),while was insignificantly lower in severe case group than in ordinary case group(P > 0.05).The percentages of NKG2D-positive cells in severe and ordinary case groups were significantly lower,while those of CD94-and NKG2A-positive cells were significantly higher,than that in healthy control group(P < 0.01).However,no significant differences were observed in the percentages of NKp30-and NKp46-positive cells in the three groups(P > 0.05).All the percentages of CD107a-,PF-,GrB-and GNLY-positive cells in severe and ordinary case groups were significantly lower than those in healthy control group(P < 0.01 or P < 0.05).Conclusion EV71 infection may inhibit the proliferation,activation and killing function of NK cells.As compared with those in ordinary cases,the percentage of NK cells and CD16+ subset decreased,while the expression level of inhibitory receptor CD94 increased and those of CD107a,GrB and PF decreased significantly,which might be related to the occurrence of severe cases.