肠道病毒71型（EV71）感染患儿外周血NK细胞、NK细胞亚群、受体及免疫效应分子的研究

发布时间：2018-03-31 15:03

本文选题：肠道病毒71型　切入点：手足口病　出处：《重庆医科大学》2012年硕士论文

【摘要】：背景：手足口病（hand-foot-mouth disease, HFMD），是一种全球性常见的儿童传染病，，多发生于学龄前儿童，症状主要为发热和手、足、口腔以及臀部等部位的疱疹、丘疹、丘疱疹或者溃疡，大多数患儿症状较轻微，部分患儿可能会有病毒性心肌炎、病毒性脑炎等并发症，个别患儿可出现严重的并发症而危及生命，如：脑干脑炎、无菌性脑膜炎、肺水肿、肺出血等。本病主要病原体为肠道病毒71型（EV71）和柯萨奇A组16型病毒（CoxA16）。而EV71所致患儿因其病程进展快、病情重、预后差，故引起了广泛的关注。研究表明EV71感染后可能使患儿免疫功能受到抑制、发生紊乱。先天性免疫是机体抗病毒感染的第一道防线，NK细胞作为其关键细胞，在抗肠道病毒感染的过程中起着非常重要的作用，研究报道NK细胞功能低下或缺陷可发生严重的肠道病毒感染。目的：检测EV71所致手足口病患儿外周血中NK细胞比例、NK细胞亚群、激活型受体、抑制型受体及免疫效应分子阳性细胞率，研究EV71感染患儿NK细胞及功能的变化在EV71感染后机体免疫应答过程中可能的地位。方法：试验设2个实验组，即：重症病例组20例、普通病例组20例，1个对照组即：健康对照组30例。实验组病人均为入院诊断为手足口病且经RT-PCR检测结果为EV71阳性的患儿；健康对照组为门诊体检儿童。年龄均为1～3岁。用流式细胞术检测实验组与对照组小儿外周血中NK细胞比例、NK细胞亚群（CD16+%NK、CD16+56+%NK、CD56+%NK）、NK细胞表面受体（NKp30、NKp46、NKG2D、CD94、NKG2A、CD107a）及NK细胞胞内免疫效应分子（PF、GrB和GNLY）阳性表达的细胞所占机体NK细胞的比率，采用单因素方差分析对结果进行统计学分析。结果：重症病例组外周血NK细胞比例较健康对照组明显减少（P0.01），虽然普通病例组NK细胞数较重症组高，但统计学分析无显著差异（P0.05）；CD16~+%NK细胞亚群比例普通病例组均较健康对照组增高（P0.05），而重症病例组较普通病例组低，但无统计学差异（P0.05）；重症病例组、普通病例组激活型受体NKG2D阳性细胞百分率均较健康对照组低（P0.01），而抑制型受体CD94和NKG2A阳性细胞百分率均较健康对照组明显增高（P0.01）；重症病例组和普通病例组脱颗粒标记CD107a、PF、GrB、GNLY的阳性细胞百分率均较健康对照组低（P0.01或P0.05）。上述受体及免疫效应分子重症病例组和普通病例组间无明显差异（P0.05）；NKp30、NKp46阳性细胞率3组之间无明显差异（P0.05）。结论：EV71感染手足口病患儿外周血NK细胞比例及CD16~+NK细胞亚群减少；激活型受体NKG2D的表达下调、抑制型受体CD94和NKG2A的表达上调，说明NK细胞的活化受到抑制；脱颗粒标记受体CD107a表达降低及免疫效应分子（PF、GrB和GNLY）分泌降低，说明NK细胞的功能受到了抑制，这可能与EV71感染患儿临床表现较重有关。重症病例组的NK细胞比例较普通病例组有降低，此可能与重症病例的发生有关。
[Abstract]:Background: hand, foot and mouth disease (HFMDD) is a common global infectious disease in children, mostly in preschool children. The symptoms are fever and herpes, papules, papules, herpes or ulcers in the hands, feet, mouth and buttocks, etc. Most of the children have mild symptoms, some of them may have complications such as viral myocarditis, viral encephalitis, and so on. Some children may have serious complications and endanger their lives, such as: brainstem encephalitis, aseptic meningitis, pulmonary edema, etc. The main pathogens of the disease were enterovirus 71 (EV71) and Coxsackie A group 16 virus (CoxA16C). However, the children caused by EV71 had a rapid progression, a severe illness and a poor prognosis. This has aroused widespread concern. Studies have shown that EV71 infection may inhibit the immune function of children and cause disorder. Congenital immunity is the first line of defense against virus infection, NK cells as its key cells, It plays a very important role in the process of anti-enterovirus infection. It has been reported that serious enterovirus infection can occur due to the low function or defect of NK cells. Objective: to detect the percentage of NK cell subsets, activated receptors, inhibitory receptors and immunoreactive molecule positive cells in peripheral blood of children with hand-foot-mouth disease induced by EV71. To study the possible role of NK cell and function in the immune response after EV71 infection in children with EV71 infection. Methods: two experimental groups were divided into two groups: severe cases group (n = 20), common case group (n = 20) and control group (n = 30). All the patients in the experimental group were diagnosed as hand-foot-mouth disease (HFMD) and were EV71 positive by RT-PCR test. The healthy control group was an outpatient check-up child. The age was 1 ~ 3 years old. Flow cytometry was used to detect the proportion of NK cells in peripheral blood of the experimental group and the control group. The NK cell subsets CD16 and NKP30, NKp46, NKG2D, CD94NKG2, CD107a, NK cell subsets, and NKP30, NKp4NKG2AtCD107a) and NK cell CD107a, respectively, were measured by flow cytometry. The percentage of NK cells positive for PFN GrB and GNLY in the body, Single factor analysis of variance (ANOVA) was used to analyze the results. Results: the percentage of NK cells in peripheral blood of the severe cases group was significantly lower than that of the healthy control group, although the number of NK cells in the common case group was higher than that in the severe case group. However, there was no significant difference in the proportion of NK cell subsets between P0.05and CD16- and the proportion of NK cell subsets in the common case group was higher than that in the healthy control group, while in the severe case group was lower than that in the normal case group, but there was no statistical difference between the two groups (P0.05). The percentage of activated receptor NKG2D positive cells in normal cases was lower than that in healthy controls, while the percentage of inhibitory receptor CD94 and NKG2A positive cells was significantly higher than that of healthy controls, and the degranulation of severe cases and normal cases was significantly higher than that of healthy controls. The percentage of positive cells of CD107a PFN GrBgnLY was lower than that of the healthy control group (P0.01 or P0.05). There was no significant difference in the percentage of NKp30NKp46 positive cells between the three groups. Conclusion the percentage of NK cells and CD16 ~ NK cell subsets in peripheral blood of children with HFMD infected with EV71 were decreased, the expression of activated receptor NKG2D was down-regulated, the expression of inhibitory receptor CD94 and NKG2A was up-regulated, which indicated that the activation of NK cells was inhibited. The decreased expression of degranulated receptor CD107a and the decreased secretion of immune-effector molecules, CD107a and GNLYB, suggested that the function of NK cells was inhibited. This may be related to the severe clinical manifestations of children with EV71 infection. The proportion of NK cells in severe cases is lower than that in normal cases, which may be related to the occurrence of severe cases.
【学位授予单位】：重庆医科大学
【学位级别】：硕士
【学位授予年份】：2012
【分类号】：R725.1

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