Natural killer (NK) cells play an essential role in antiviral immunity, but knowledge of their function in secondary lymphoid organs is incomplete. Lymph node follicles constitute a major viral reservoir during infections with HIV-1 and simian immunodeficiency virus of macaques (SIVmac). In contrast, during nonpathogenic infection with SIV from African green monkeys (SIVagm), follicles remain generally virus free. We show that NK cells in secondary lymphoid organs from chronically SIVagm-infected African green monkeys (AGMs) were frequently CXCR5⁺ and entered and persisted in lymph node follicles throughout the follow-up (240 d post-infection). These follicles were strongly positive for IL-15, which was primarily presented in its membrane-bound form by follicular dendritic cells. NK cell depletion through treatment with anti-IL-15 monoclonal antibody during chronic SIVagm infection resulted in high viral replication rates in follicles and the T cell zone and increased viral DNA in lymph nodes. Our data suggest that, in nonpathogenic SIV infection, NK cells migrate into follicles and play a major role in viral reservoir control in lymph nodes.

中文翻译：

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自然杀伤细胞迁移并控制非洲绿猴淋巴结滤泡中的猿猴免疫缺陷病毒复制。

天然杀伤（NK）细胞在抗病毒免疫中起着至关重要的作用，但是对它们在次级淋巴器官中的功能的了解尚不完善。在感染HIV-1和猿猴猿免疫缺陷病毒（SIVmac）的过程中，淋巴结滤泡构成了主要的病毒库。相反，在非洲绿猴（SIVagm）感染SIV的非致病性感染过程中，卵泡通常保持无病毒。我们表明，慢性SIVagm感染的非洲绿猴（AGMs）的次级淋巴器官中的NK细胞经常是CXCR5 ⁺并在整个随访期间（感染后240 d）进入并持续存在于淋巴结滤泡中。这些卵泡对IL-15呈强阳性，IL-15主要由卵泡树突状细胞以膜结合形式出现。在慢性SIVagm感染过程中，通过抗IL-15单克隆抗体处理导致NK细胞耗竭，导致卵泡和T细胞区的病毒复制率很高，淋巴结中的病毒DNA增多。我们的数据表明，在非致病性SIV感染中，NK细胞迁移到卵泡中，并在淋巴结的病毒库控制中起主要作用。