Ray N B, Ewalt L C, Lodmell D L
Laboratory of Persistent Viral Diseases, Rocky Mountain Laboratories, National Institute of Allergy and Infectious Diseases, Hamilton, Montana 59840.
J Virol. 1995 Feb;69(2):764-72. doi: 10.1128/JVI.69.2.764-772.1995.
To determine whether rabies viruses replicate in macrophage or macrophage-like cells, several human and murine macrophage-like cell lines, as well as primary cultures of murine bone marrow macrophages, were incubated with the Evelyn-Rokitnicki-Abelseth (ERA) virus and several different street rabies viruses (SRV). ERA rabies virus replicated well in human monocytic U937 and THP-1 cells and murine macrophage IC-21 cells, as well as primary cultures of murine macrophages. Minimal replication was detected in murine monocytic WEHI-3BD- and PU5-1R cells, and ERA virus did not replicate in murine monocytic P388D1 or J774A.1 cells. A tissue culture-adapted SRV of bat origin also replicated in IC-21 and U937 cells. Non-tissue culture-adapted SRV isolated from different animal species, particularly bats, replicated minimally in U937, THP-1, IC-21 cells and primary murine bone marrow macrophages. To determine whether rabies virus replication is dependent upon the state of differentiation of the macrophage-like cell, human promyelocytic HL-60 cells were differentiated with 12-O-tetradecanoylphorbol-13-acetate (TPA). ERA rabies virus replicated in the differentiated HL-60 cells but not in undifferentiated HL-60 cells. Persistent infections were established in macrophage-like U937 cells with ERA rabies virus and SRV, and infectious SRV was isolated from adherent bone marrow cells of mice that had been infected 96 days previously. Virus harvested from persistently infected U937 cells and the adherent bone marrow cells had specifically adapted to each cell. This specificity was shown by the inability of the viruses to infect macrophages other than U937 cells and primary bone marrow macrophages, respectively. Virus titers of the persistently infected U937 cells fluctuated with extended cell passage. After 30 passages, virus released from the cells had lost virulence as shown by its inability to kill intracranially inoculated mice. However, the avirulent virus released from the persistently infected cells was more efficient in infecting and replicating in naive U937 cells than the virus which was used to establish the persistent infection. These results suggest that macrophages may serve as reservoirs of infection in vivo, sequestering virus which may subsequently be activated from its persistent state, resulting in clinical infection and death.
为了确定狂犬病毒是否在巨噬细胞或巨噬细胞样细胞中复制，将几种人和鼠巨噬细胞样细胞系以及鼠骨髓巨噬细胞原代培养物与伊夫林 - 罗基特尼基 - 阿贝尔塞思（ERA）病毒和几种不同的街狂犬病毒（SRV）一起孵育。ERA狂犬病毒在人单核细胞U937和THP - 1细胞、鼠巨噬细胞IC - 21细胞以及鼠巨噬细胞原代培养物中复制良好。在鼠单核细胞WEHI - 3BD和PU5 - 1R细胞中检测到极少的复制，并且ERA病毒在鼠单核细胞P388D1或J774A.1细胞中不复制。一种源自蝙蝠的适应组织培养的SRV也在IC - 21和U937细胞中复制。从不同动物物种特别是蝙蝠分离的未适应组织培养的SRV在U937、THP - 1、IC - 21细胞和鼠骨髓巨噬细胞原代培养物中复制极少。为了确定狂犬病毒复制是否依赖于巨噬细胞样细胞的分化状态，用人早幼粒细胞HL - 60细胞用12 - O - 十四酰佛波醇 - 13 - 乙酸酯（TPA）进行分化。ERA狂犬病毒在分化的HL - 60细胞中复制，但在未分化的HL - 60细胞中不复制。用ERA狂犬病毒和SRV在巨噬细胞样U937细胞中建立了持续感染，并且从96天前感染的小鼠的贴壁骨髓细胞中分离出感染性SRV。从持续感染的U937细胞和贴壁骨髓细胞收获的病毒已分别特异性适应了每个细胞。这种特异性表现为病毒无法感染除U937细胞和原代骨髓巨噬细胞之外的其他巨噬细胞。持续感染的U937细胞的病毒滴度随着细胞传代次数的增加而波动。传代30次后，从细胞中释放的病毒失去了毒力，表现为无法杀死颅内接种的小鼠。然而，从持续感染细胞中释放的无毒力病毒在感染和在未感染的U937细胞中复制方面比用于建立持续感染的病毒更有效。这些结果表明巨噬细胞可能在体内作为感染的储存库，隔离病毒，随后病毒可能从其持续状态被激活，导致临床感染和死亡。
