Kramer L D, Hardy J L, Presser S B
School of Public Health, University of California, Berkeley 94720, USA.
J Med Entomol. 1998 May;35(3):289-95. doi: 10.1093/jmedent/35.3.289.
Two lines of Culex tarsalis Coquillett genetically selected for low or high western equine encephalomyelitis (WEE) virus production (low viral producer [LVP] or high viral producer [HVP], respectively) modulated WEE (i.e., decreased the concentration of virus to < 10(4) plaque-forming units after intrathoracic inoculation). The LVP line modulated WEE more than HVP, and modulation was most pronounced at 32 degrees C. At 15 degrees C, viral replication to high titers occurred in both lines. When infected LVP were transferred to 15 degrees C after 4 d extrinsic incubation at 32 degrees C, replication of WEE to high titers did not occur. Mosquitoes transferred from 15 degrees C after replication to high titers occurred; to 32 degrees C did significantly modulate WEE titer. Incubation at 32 degrees C prior to infection had no effect on the degree or timing of WEE modulation in both LVP and HVP lines. Most LVP infected following feeding on a high dose of WEE had salivary gland infection barriers. Viral modulation by Cx. tarsalis was an alphavirus phenomenon, and was not restricted to WEE.
两系经基因选择的致倦库蚊（Culex tarsalis Coquillett），分别针对低或高西马脑炎（WEE）病毒产量进行选育（分别为低病毒产生者 [LVP] 或高病毒产生者 [HVP]），可调节WEE（即胸腔接种后将病毒浓度降低至<10⁴ 空斑形成单位）。LVP系对WEE的调节作用比HVP系更强，且在32℃时调节作用最为明显。在15℃时，两系均会发生病毒复制至高滴度的情况。当感染的LVP在32℃进行4天外在孵育后转移至15℃时，WEE不会复制至高滴度。在复制至高滴度后从15℃转移至32℃的蚊子，确实会显著调节WEE滴度。感染前在32℃孵育对LVP和HVP系中WEE调节的程度或时间均无影响。大多数在吸食高剂量WEE后被感染的LVP具有唾液腺感染屏障。致倦库蚊的病毒调节是一种甲病毒现象，并不局限于WEE。
