CD20 DEPLETION IN SIVAGM-INFECTED AGMS

这个子项目是许多研究子项目中利用 资源由NIH/NCRR资助的中心拨款提供。子项目和 调查员(PI)可能从NIH的另一个来源获得了主要资金， 并因此可以在其他清晰的条目中表示。列出的机构是 该中心不一定是调查人员的机构。 体液免疫反应在控制艾滋病毒/SIV感染中的作用仍在争论中。这项研究的目的是调查抗体反应对急性和慢性SIVagm复制的结果的影响。10个接种SIVagm的AGM用于本研究。从SIVagm.sab感染后第7天开始，每21天给4只动物注射50 mg/kg的抗CD20抗体(Rituxan，Genentech赠送)，6只动物只接受SIVagm.sab治疗。用实时荧光定量聚合酶链式反应和原位杂交技术检测血浆和组织中的病毒载量。用流式细胞仪检测外周血、淋巴结和肠道中主要淋巴细胞亚群的动态变化。用流式细胞仪和免疫组织化学(IHS)检测T细胞的免疫激活、增殖和凋亡。进行血清学检查，比较两组间抗SIV抗体产生的差异。两种流式细胞仪检测CD20+和CD79a细胞的动态变化表明，所有给予利妥昔单抗的动物都成功地清除了外周血、LNS和肠道中的CD20细胞。CD20缺失的AGM和对照组的VLS无显著差异：峰值VLS为107-108拷贝/毫升。在感染慢性期，两组均表现出相似的VL控制(设定点值为104-105 SIV RNA拷贝/毫升)。与VLS相关，我们在治疗和非治疗动物的肠道中确定了相同程度的急性CD4T细胞耗竭。与对照组相比，CD20缺失的AGM患者的SIVagm血清转换延迟。与对照组相比，CD20缺失的AGM在中和抗体反应的时间和大小上都有显着差异。综上所述，我们的研究表明，体液免疫反应在自然宿主的急、慢性SIVagm感染过程中对SIV病毒的复制没有显著的控制作用。

This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. The role of humoral immune responses in controlling HIV/SIV infection is under debate. The aim of this study was to investigate the impact of antibody responses on the outcome of acute and chronic SIVagm replication in AGMs. Ten AGMs inoculated with SIVagm were used for this study. Four animals were treated with 50 mg/kg of an anti-CD20 antibody (Rituxan, gift from Genentech) every 21 days, starting from day -7 post-SIVagm.sab infection and six AGMsreceived SIVagm.sab only. Viral loads (VLs) in plasma and tissues were determined by real-time PCR and in situ hybridization (ISH). Dynamics of the major lymphocyte subsets were measured in peripheral blood, lymph nodes (LNs) and intestine by flow-cytometry. Immune activation, proliferation and apoptosis of T-cells were investigated by flow-cytometry and immunohistochemistry (IHS). Serology was performed to compare the differences in emergence of anti-SIV antibodies between the two groups. All the animals treated with Rituxan were successfully depleted of CD20 cells in peripheral blood, LNs and intestine, as illustrated by the dynamics of CD20+ and CD79a cells measured by both flow-cytometry. There was no significant difference in VLs between CD20-depleted AGMs and control monkeys: peak VLs ranged 107-108 copies/ml. During the chronic phase of infection, both groups showed similar control of VL (set-point values ranging from 104 to 105 SIV RNA copies/ml). Correlated to the VLs we determined the same degree of acute CD4 T-cell depletion in the intestine in treated and non-treated animals. SIVagm seroconversion was delayed in the CD20-depleted AGMs compared to controls. There was a significant difference in both timing and magnitude of neutralizing antibody responses in CD20-depleted AGMs compared to controls. In conclusion, our study shows that humoral immune responses play no significant role in the control of SIV viral replication during acute and chronic SIVagm infection in the natural host.