SIVmac239病毒经不同途径感染恒河猴急性期CD4^+T细胞数量与其细胞表面CD95表达量的变化关系

CD95 Expressed on the Surface of CD4^+ T Cells During the Acute Phase of SIVmac239-Infection in Rhesus Monkeys by Different Routes

目的研究SIVmac239病毒分别通过直肠(rectal infection:IR)及静脉(intravenous infection:IV)感染恒河猴,在感染急性期外周血CD4+T细胞数量与其细胞表面的死亡受体(CD95)表达量之间的变化关系。方法将SIVmac239经直肠及静脉途径各感染14只恒河猴。监测病毒载量、CD4+T淋巴细胞数量及CD4+/CD8+比值的变化,从而明确感染。同时,在感染急性期内9个时间点采集静脉血,并利用流式细胞术分析CD4+T细胞表面CD95的表达量。结果静脉组恒河猴CD95表达量于第2天开始升高,第7天达到最高,同时CD4+T淋巴细胞数降到最低。直肠组恒河猴也于感染后第2天开始升高,但第10天才达到最高值,CD4+T淋巴细胞数于第17天降到最低。同静脉组相比,直肠组CD95表达量增高及CD4+T细胞数降低均较晚出现,且其CD4+T细胞数量降至最低晚于CD95表达量达到峰值一周后出现。结论 SIVmac239经直肠及静脉感染恒河猴后,伴随CD4+T细胞表面CD95表达的升高,CD4+T细胞数量逐渐下降。但不同感染途径对CD4+T细胞表面CD95的表达量与CD4+T淋巴细胞数的变化不尽相同,这可能由于不同感染途径造成CD95在感染急性期CD4+T细胞数量降低中发挥的作用不同。

Objective To study the expression of death receptor（CD95） on the surface of peripheral blood CD4＋T cells and the CD4＋ T cell numbers during the acute phase in SIVmac239 virus-infected rhesus monkeys challenged by rectal（rectal infection： IR） and intravenous（intravenous infection： IV） routes,respectively.Methods Fourteen rhesus monkeys were challenged with SIVmac239 intrarectally or intravenously.Infection was determined by monitoring the viral load,CD4＋T lymphocyte number and CD4＋/CD8 ＋ ratio.Flow cytometry analysis was used to assess the CD95 expression on the surface of CD4＋ T cells at nine time points during the acute-phase infection.Results In the intravenous infection group,CD95 expression on the CD4＋T cells began to increase on the next day after infection,and reached the peak value on the 7th day,meanwhile the CD4＋T lymphocyte number was declined to the lowest point.In the rectal infection group it also began to rise on the following day after infection and the CD95 expression reached the peak value at 10 days after infection,but the number of CD4＋T cells was reduced to the lowest point until the 17th day.Compared with the intravenous infection,the peak value of CD95 expression and the lowest point of CD4＋T cell number appeared later in the IR group,and the peak value of CD95 expression occurred a week earlier to the lowest point of CD4＋T cells.Conclusions CD95 expression of the CD4＋T cells is increased and the amount of CD4＋T cells is decreased in SIVmac 239-infected rhesus monkeys challenged intrarectally or intravenously.Our results show that CD95 expressed on the surface of CD4＋T cells vary in the SIVmac 239-infected rhesus monkeys.It may be due to the different effects of CD95 during the acute phase infection induced by different routes.