Cannabinoid Receptor 2 Agonists Attenuate HIV Replication and Inflammatory Activation in HIV-infected Myeloid Cells

Emerging evidence suggests brain-resident myeloid cells, including macrophages and microglia, provide a reservoir for HIV infection in the central nervous system (CNS), and their inflammatory activation is a proposed pathogenic mechanism in HIV-associated neurocognitive disorders (HAND). We investigated whether cannabinoid receptor 2 (CB2), an immunomodulatory receptor expressed in myeloid cells, regulates viral replication and inflammation in HIV-infected macrophages and microglia. Using the synthetic CB2-specific agonist, JWH-133, we found that CB2 activation reduces HIV replication in primary human monocyte-derived macrophages (MDMs) and human iPSC-derived microglia (iMg) at differing doses, corresponding to the basal expression of CNR2 and related endocannabinoid transcripts in each cell type. Direct CB2 agonism via JWH-133 broadly reduced cytokine release from HIV-infected MDMs, but not iMg. RNA-seq revealed that CB2 agonism primarily altered interferon and integrated stress response pathways in MDMs; homeostatic pathways, including synapse maintenance and phagocytosis, were altered in iMg. Further investigation in iMg found NLRP3 inflammasome activation, but not priming, was reduced by CB2 activation. This study identifies key discrepancies in CB2 response between myeloid cell types and implicates CB2-specific agonists as promising candidates for regulation of HIV-associated neuroinflammation. Human primary monocyte-derived macrophages (MDM) and iPSC-derived microglia (iMg) underwent true or mock infection with HIV-ADA. 24 hours after HIV infection, samples were treated with vehicle (DMSO) or 1 uM JWH-133, a cannabinoid receptor 2-specific agonist. Infected cultures were maintained for 9 days,with cannabinoids replaced during media change every 48 hours. RNA was extracted on day post infection 9 to assess the myeloid cell-type specific responses to HIV infection and concurrent CB2 activation.

越来越多的研究证据表明，脑驻留髓系细胞（包括巨噬细胞与小胶质细胞）是中枢神经系统（central nervous system, CNS）内人类免疫缺陷病毒（Human Immunodeficiency Virus, HIV）感染的储存库，而这类细胞的炎症激活被认为是HIV相关神经认知障碍（HIV-associated neurocognitive disorders, HAND）的潜在致病机制。本研究旨在探究在髓系细胞中表达的免疫调节受体——大麻素受体2（cannabinoid receptor 2, CB2），是否可调控HIV感染的巨噬细胞与小胶质细胞内的病毒复制及炎症反应。本研究使用合成的CB2特异性激动剂JWH-133开展实验，结果发现CB2激活可通过不同剂量下调人原代单核细胞衍生巨噬细胞（primary human monocyte-derived macrophages, MDMs）以及人诱导多能干细胞衍生小胶质细胞（induced pluripotent stem cell-derived microglia, iMg）内的HIV复制，该效应与两种细胞中CNR2及相关内源性大麻素转录本的基础表达水平相关。通过JWH-133实现的直接CB2激动作用，可广泛抑制HIV感染的MDMs释放细胞因子，但对iMg无此调控效应。RNA测序（RNA-seq）结果显示，CB2激动作用主要改变MDMs内的干扰素与整合应激反应通路；而在iMg中，受CB2激动调控的通路则包括突触维持与吞噬作用在内的稳态通路。针对iMg的进一步研究发现，CB2激活可抑制NLRP3炎性小体（NLRP3 inflammasome）的激活，但不影响其启动过程。本研究揭示了不同髓系细胞类型间CB2应答的关键差异，并提示CB2特异性激动剂有望成为调控HIV相关神经炎症的潜在候选药物。本研究对人原代单核细胞衍生巨噬细胞（primary human monocyte-derived macrophages, MDM）与人诱导多能干细胞衍生小胶质细胞（induced pluripotent stem cell-derived microglia, iMg）分别进行HIV-ADA毒株的真实感染与模拟感染处理。HIV感染24小时后，分别用溶媒（二甲基亚砜，dimethyl sulfoxide, DMSO）或1μM CB2特异性激动剂JWH-133处理各组样本。感染后的细胞培养物维持培养9天，每48小时换液时补充添加大麻素类试剂。于感染后第9天提取RNA，以分析不同髓系细胞类型对HIV感染以及同时进行的CB2激活的特异性应答反应。