INHIBITION OF ONSET OF OVERT MULTIPLICATION OF CHLAMYDIA-PSITTACI IN PERSISTENTLY INFECTED-MOUSE FIBROBLASTS (L-CELLS)
INHIBITION OF ONSET OF OVERT MULTIPLICATION OF CHLAMYDIA-PSITTACI IN PERSISTENTLY INFECTED-MOUSE FIBROBLASTS (L-CELLS)
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DOI：
10.1128/iai.39.2.898-907.1983
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发表时间：
1983-01-01
影响因子：
3.1
通讯作者：
MOULDER, JW
中科院分区：
文献类型：
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作者：
MOULDER, JW
当持续感染鹦鹉热衣原体（菌株 6BC）的小鼠成纤维细胞（L 细胞）单层分散在培养基 199 中并铺在新烧瓶中时，生长的单层细胞几乎完全由不含包涵体的宿主细胞组成，这些细胞保留了对鹦鹉热衣原体重复感染（隐蔽感染）的完全抵抗力。经过与新转移的 L 细胞群初始密度成反比的延迟后，含有可见衣原体包涵体的宿主细胞的百分比迅速增加（明显感染）；大多数L细胞被广泛的衣原体增殖（消灭）所破坏，只留下少数幸存者开始新的持续感染的单层细胞。当将在培养基199中生长的持续感染的L细胞群转移到Eagle基本必需培养基中时，尽管鹦鹉热衣原体的隐性增殖继续有增无减，但显性增殖的开始受到强烈抑制，如宿主细胞对重复感染的抵抗力的保留以及转移回培养基199后显性增殖的迅速恢复所表明的。导致持续感染状态的不同表达的2种培养基之间的差异尚未确定。在持续感染的单层细胞分裂时给予100 U青霉素G/ml培养基199的单剂量，几乎完全抑制了衣原体感染的可见迹象的出现数周；始终保留对重复感染的抵抗力。重新接种后 7 天给予相同量的青霉素并不能阻止第一次预期消灭的发生；在第一次清除和第二次清除之间有很长一段时间的无包涵体 L 细胞生长。因此，鹦鹉热衣原体在持续感染的L细胞中的秘密繁殖可能会无限期地持续下去，而不会出现明显的感染迹象。隐性和显性衣原体增殖之间的转变似乎是一个青霉素敏感的多步骤过程，该过程至少部分地受到宿主细胞密度和生长培养基的组成的调节。
When monolayers of mouse fibroblasts (L cells) persistently infected with C. psittaci (strain 6BC) were dispersed in medium 199 and plated out in new flasks, the monolayers that grew out consisted almost exclusively of inclusion-free host cells that retained full resistance to superinfection with C. psittaci (covert infection). After a delay that was inversely proportional to the initial density of the newly transferred L cell population, the percentage of host cells containing visible chlamydial inclusions increased rapidly (overt infection); most of the L cells were destroyed by extensive chlamydial multiplication (wipeout), leaving only a few survivors to start new persistently infected monolayers. When persistently infected L cell populations grown in medium 199 were transferred to Eagle minimal essential medium, the onset of overt multiplication was strongly suppressed although covert multiplication of C. psittaci continued unabated, as shown by host cell retention of resistance to superinfection and the prompt resumption of overt multiplication after transfer back into medium 199. The difference(s) between the 2 media responsible for the different expression of the persistently infected state was not determined. A single dose of 100 U of penicillin G/ml of medium 199, given at the time persistently infected monolayers were divided, almost completely suppressed the appearance of visible signs of chlamydial infection for several weeks; resistance to superinfection was retained at all times. The same amount of penicillin given 7 days after replating did not prevent the occurrence of the 1st expected wipeout; there was a long period of inclusion-free L cell growth between the 1st wipeout and the 2nd. Thus, covert multiplication of C. psittaci in persistently infected L cells may continue indefinitely without the appearance of visible signs of infection. The transition between covert and overt chlamydial multiplication appears to be a penicillin-sensitive, multistep process that is regulated, at least in part, by the host cell density and the composition of the growth medium.