Pollock J L, Presti R M, Paetzold S, Virgin H W
Department of Pathology, Washington University School of Medicine, 660 South Euclid Avenue, St. Louis, Missouri, USA.
Virology. 1997 Jan 6;227(1):168-79. doi: 10.1006/viro.1996.8303.
In this study we show that macrophages (Mphi) are latently infected with murine cytomegalovirus (MCMV). After clearance of acute MCMV infection, the predominant form of chronic infection in Balb mice is latency rather than persistence. Peritoneal exudate cells (PECs) from latently infected Balb mice (3-9 months postinfection) contained MCMV genome and reactivatable virus. Adherent cells from both resident and thioglycollate-elicited PECs carried more MCMV DNA (measured by PCR) than nonadherent cells, and were selectively enriched for Mphi. FACS sorted F4/80(+) Mphi contained MCMV DNA, while other FACS sorted cell populations from PECs were never positive for MCMV DNA. MCMV reactivated from FACS sorted F4/80(+) Mphi in 32% of cocultures with murine embryonic fibroblasts (MEFs). Since Mphi carry MCMV genome and reactivatable virus, but not lytic virus, they are latently infected with MCMV. We determined the frequency of Mphi carrying MCMV genome in PECs (about 1/50,000) using a limiting dilution PCR assay. Using this frequency and estimates of the total amount of MCMV genome in populations, we estimate that latently infected Mphi carry 1-10 copies of MCMV genome. To evaluate the origin of latently infected Mphi, we compared the frequency of cells carrying MCMV genome in the resident and elicited PECs. The frequency of Mphi carrying MCMV DNA was the same in resident and thioglycollate-elicited PECs, despite the fact that there was a ninefold increase in the number of Mphi recovered after thioglycollate elicitation. This argued for recruitment of bone marrow-derived Mphi (BMMphi) carrying MCMV genome into the peritoneum during inflammatory responses. Consistent with this hypothesis, MCMV genome, but not persistent virus, was detected in bone marrow cells from latently infected mice.
在本研究中，我们发现巨噬细胞（Mphi）受到小鼠巨细胞病毒（MCMV）的潜伏感染。急性MCMV感染清除后，Balb小鼠慢性感染的主要形式是潜伏而非持续存在。来自潜伏感染的Balb小鼠（感染后3 - 9个月）的腹腔渗出细胞（PEC）含有MCMV基因组和可再激活的病毒。来自常驻和巯基乙酸盐诱导的PEC的贴壁细胞比非贴壁细胞携带更多的MCMV DNA（通过PCR测量），并且选择性地富集了Mphi。流式细胞术分选的F4/80(+) Mphi含有MCMV DNA，而来自PEC的其他流式细胞术分选的细胞群体对MCMV DNA从未呈阳性。在与小鼠胚胎成纤维细胞（MEF）共培养的32%的实验中，从流式细胞术分选的F4/80(+) Mphi中重新激活了MCMV。由于Mphi携带MCMV基因组和可再激活的病毒，但不携带裂解病毒，它们受到MCMV的潜伏感染。我们使用有限稀释PCR测定法确定了PEC中携带MCMV基因组的Mphi的频率（约为1/50,000）。利用这个频率和群体中MCMV基因组总量的估计值，我们估计潜伏感染的Mphi携带1 - 10个MCMV基因组拷贝。为了评估潜伏感染的Mphi的来源，我们比较了常驻和诱导的PEC中携带MCMV基因组的细胞频率。常驻和巯基乙酸盐诱导的PEC中携带MCMV DNA的Mphi频率相同，尽管巯基乙酸盐诱导后回收的Mphi数量增加了九倍。这表明在炎症反应期间，携带MCMV基因组的骨髓来源的Mphi（BMMphi）被招募到腹膜中。与此假设一致，在潜伏感染小鼠的骨髓细胞中检测到了MCMV基因组，但未检测到持续存在的病毒。
