登革热发生中单核细胞CD14^+CD16^+亚群的增殖变化及病情与病毒载量的关系

Expansion of CD14^+CD16^+ Monocyte During Dengue Infection and Association between Disease Severity and Viral Load

【目的】观察登革病毒感染时单核细胞及其亚群随临床病程的变化,探讨单核细胞在登革病毒感染中的免疫学作用。【方法】收集76例住院登革热患者急性期和极期血样品,其中轻症44例,重症32例。采用荧光定量RT-PCR法检测登革病毒载量,同时采用多色流式细胞技术分析外周血单个核细胞中的单核细胞(CD14^+)表面CD16分子表达。比较单核细胞及各亚群(CD14^+CD16-,CD14^+CD16^+,CD14dim CD16^-及CD14^(dim) CD16^+亚群)在轻症登革热和重症登革热中随临床病程的变化。【结果】轻症和重症组中单核细胞比率明显增加(P<0.01)。从病程第3-4天就可观察到单核细胞的增殖,可持续至第11天。登革热轻症和重症病例均表现为伴随着CD14^+CD16-亚群减少,CD14^+CD16^+亚群增加。从病程上看,轻症组中CD14^+CD16^+亚群呈逐渐下降趋势,而重症组在病程的第5-7天有一个明显的波动,从第6天的低点有明显的上升趋势。进一步分析CD14^+CD16^+亚群与病毒载量的关系,发现重症病例中CD14^+CD16^+亚群比率在高病毒载量组增加(P=0.016),而在轻症病例中高病毒和低病毒载量组CD14^+CD16^+亚群比率无明显差异。【结论】登革病毒感染可诱导机体单核细胞的增殖及上调CD16表达。CD14^+CD16^+亚群作为促炎症细胞可能在重症登革热发生中起一定作用。

[Objective] To observe the responses of monocyte and its subsets to dengue virus type 1 （DENV-I） during the clinical course and to explore the immunological role of monocyte on dengue infection. [ Methods ] Plasma and PBMCs were collected from the hospitalized 76 patients on febrile-phase or critical-phase during the outbreak of dengue fever in 2014. Among them there were 44 samples in mild dengue group and 32 samples in severe dengue group. Dengue viral load （VL） was determined by fluoreseence quantitative RT-PCR. The expression of CD16 on the surface of the monocytes in the PBMCs was analyzed using multi- color flow cytometry. We also compared the dynamics of monocyte and four subsets （CD14＋CD16-, CD14＋CD16＋, CD14dim D16-, and C D 14dim CD16 ＋） in mild dengue and severe dengue over the clinical course. [ Results ] The fraction of monocyte in both of mild and severe dengue was increased（P 〈 0.01）. The expansion of monocyte was observed on the day3 to day4, and persistent to dayl 1 from the disease onset. CD14＋CD16＋subset was increased accompanied by the reduction of CD14＋CD16- not only in mild dengue but also in severe dengue. During the course of disease in mild dengue, CD14＋CD16＋ declined gradually, whereas there was a fluctuation of CD14＋CD16＋between day5 to dayT, first down and then going up from the bottom on day 6 in severe dengue. Further analyzing the association between increased CDI4＋CD16＋ and viral load, we found that the proportion number of CD14＋CD16＋in high VL was higher than that in low VL （P = 0.016）. But in mild group, there was no statistical difference in the fraction of CD14＋CD16＋between high and low VL. [Conclusions] DENV-1 can induce the expansion of monocyte and up-regulate the CD16 expression. CD14＋CD16＋ subset as proinflammatory cell may contribute to the development of severe dengue.