Söderberg-Nauclér C, Fish K N, Nelson J A
Department of Molecular Microbiology and Immunology, Oregon Health Sciences University, Portland, Oregon, 97201, USA.
Methods. 1998 Sep;16(1):126-38. doi: 10.1006/meth.1998.0650.
Human cytomegalovirus (HCMV) is a major human pathogen that causes considerable disease among immunocompromised individuals. A primary infection results in life-long persistence of the virus in a latent form. HCMV is known to be transferred by blood products, bone marrow, and solid organs, but the cell type that carries the latent infection has been difficult to identify. We have recently demonstrated reactivation of latent HCMV in allogeneically stimulated monocyte-derived macrophages (Allo-MDM). Reactivation occurred only in macrophages produced by allogeneic but not mitogenic stimulation. The presence of dendritic cell markers on some Allo-MDM cells suggested that these macrophages were related to dendritic cells. However, dendritic cells obtained by stimulation of monocytes with interleukin-4 (IL-4) and granulocyte-macrophage colony stimulating factor (GM-CSF) were not permissive for HCMV infection. The cellular and cytokine components which are essential for HCMV replication and reactivation of virus were also examined in Allo-MDM. The importance of both CD4- or CD8-positive T cells in the generation of HCMV permissive Allo-MDM was demonstrated by negative selection or blocking experiments using antibodies directed against both HLA class I and HLA class II molecules. Examination of the cytokines essential for the generation of HCMV permissive Allo-MDM identified gamma-interferon (IFN-gamma, but not IL-1, IL-2, tumor necrosis factor alpha, or GM-CSF as critical components in the generation of these macrophages. However, addition of IFN-gamma to unstimulated macrophage cultures was insufficient to reactivate virus. These results indicate the importance of a specific moncyte stimulus in the generation of a unique HCMV permissive macrophage phenotype as well as why virus is commonly reactivated in transplant patients.
人巨细胞病毒（HCMV）是一种主要的人类病原体，在免疫功能低下的个体中可引发严重疾病。初次感染会导致病毒以潜伏形式终生持续存在。已知HCMV可通过血液制品、骨髓和实体器官传播，但携带潜伏感染的细胞类型一直难以确定。我们最近证明，在同种异体刺激的单核细胞衍生巨噬细胞（Allo-MDM）中，潜伏的HCMV会重新激活。重新激活仅发生在由同种异体而非有丝分裂刺激产生的巨噬细胞中。一些Allo-MDM细胞上存在树突状细胞标志物，这表明这些巨噬细胞与树突状细胞有关。然而，用白细胞介素-4（IL-4）和粒细胞-巨噬细胞集落刺激因子（GM-CSF）刺激单核细胞获得的树突状细胞对HCMV感染不敏感。我们还在Allo-MDM中研究了HCMV复制和病毒重新激活所必需的细胞和细胞因子成分。使用针对HLA I类和HLA II类分子的抗体进行阴性选择或阻断实验，证明了CD4或CD8阳性T细胞在产生允许HCMV感染的Allo-MDM中的重要性。对产生允许HCMV感染的Allo-MDM所必需的细胞因子进行检测，确定γ-干扰素（IFN-γ），而非IL-1、IL-2、肿瘤坏死因子α或GM-CSF是这些巨噬细胞产生过程中的关键成分。然而，向未刺激的巨噬细胞培养物中添加IFN-γ不足以重新激活病毒。这些结果表明了特定单核细胞刺激在产生独特的允许HCMV感染的巨噬细胞表型中的重要性，以及病毒在移植患者中通常重新激活的原因。
