Effect of CD8+ T Cell Depletion in Vivo on Monkeys with Chronic SHIV-KB9 Infection

Abstract

目的 CD8+T細胞在一些病毒感染疾病的免疫反應中起著重要的作用,但CD8+T細胞在HIV無癥狀期的作用尚不明確,本研究通過體內CD8+T細胞剔除,研究CD8+T細胞對SHIV感染猴的影響,進一步了解艾滋病的發病機制。方法選擇8只SHIV病毒感染的恒河猴,均處于無癥狀期,隨機分成兩組,實驗組4只恒河猴在0、3、7 d注射抗CD8+T抗體cM-T807,不同的時間取外周血、腹股溝淋巴結。流式細胞術測定恒河猴外周血和淋巴結中CD8+T細胞數目,Real-time RT-PCR法測定實驗猴血漿病毒載量,并使用IFN-γElispot方法測定其對猴細胞免疫的影響。結果 CD8+T細胞敲除后,4只猴的病毒載量都轉陽,但反應性不一,HIV-1的靶細胞CD4+T細胞有輕微下降,后反彈,與病毒載量無相關性;CD8敲除猴的感染情況(血漿病毒載量和CD4細胞)比SHIV病毒急性感染輕,這與ELIPOT結果一致。結論 CD8+T細胞在HIV無癥狀期發揮重要的作用,但其作用具有個體差別。

Objective CD8+ T cells play an important role in some viral diseases,but the role of CD8+ T cells is not yet fully clear in the asymptomatic phase of HIV infection.The aim of this study was to elucidate the impact of CD8 + T cell in SHIV-infected monkeys with in vivo CD8 + T cells depletion,and to further understand the pathogenesis of AIDS.Methods Eight SHIV-infected rhesus monkeys in the asymptomatic phase were selected and randomly divided into two groups.Anti-CD8 + T antibody cM-T807 were injected intravenously into four monkeys on days 0,3,and 7.Then the CD8 + T cell number in peripheral blood and lymph nodes in the monkeys were detected by flow cytometry,the plasma viral load by real-time RT-PCR,and the cellular immunity by IFN-γ Elispot assay.Results The viral load of the four monkeys was elevated to above of detected after the CD8 + T cell depletion,but the reactions were not uniform.CD4 + T cells,the HIV-1 target cells,rebound and dropped slightly.The infection of monkeys with CD8 + T cell depletion was lighter than that after the SHIV virus first infection(plasma viral load and CD4 cells),which was consistent with the Elispot results.Conclusions CD8 + T cells play an important role in the asymptomatic phase of HIV-1 infection,but with some interindividual variation.