胰蛋白酶浓度对H9亚型禽流感病毒在MDCK细胞上增殖的影响

目的]探讨不同胰蛋白酶浓度对低致病力禽流感病毒在MDCK细胞上增殖后的HA滴度。方法]通过3株禽流感H9亚型病毒分别接种MDCK细胞单层,加入含有不同胰蛋白酶浓度的DMEM维持液,每隔24 h观察细胞病变,并测定上清液中的HA滴度。结果]当维持液中胰蛋白酶含量为10～20μg/ml时,培养液上清液中的HA滴度最高,达到7 log2（1∶128）。当病毒的接种浓度为10-3和10-4时,MDCK细胞在96 h几乎全部病变,峰值出现在接种后的72～96 h。结论]当维持液中胰蛋白酶含量为10～20μg/ml时,有利于H9亚型AIV病毒在MDCK细胞上增殖。

Effects of Trypsin on Proliferation of Avian Influenza Virus H9N2 Subtype in MDCK Cell

Objective] The study aims to determine the optimal concentration of trypsin for proliferation of avian influenza virus(AIV) H9N2 subtype in Madin-Darby canine kidney(MDCK) cell.Method] Three AIV H9 subtype isolates were inoculated on MDCK cells respectively.Then,DMEM containing different concentrations of trypsin as maintenance media were added to MDCK monolayer cells.The cytopathic effect(CPE) was observed once every 24 h,and the HA titer of the supernatant was measured by HA assay.Result] When the trypsin concentration was 10-20 μg/ml in DMEM,the HA titer of virus culture reached 7 log2(1∶128).Almost all cells were cytopathic after 96 h post inoculation with 1∶1 000 or 1∶10 000 dilution of AIV culture,and the virus titer reached a peak after 72-96 h.Conclusion] The optimal concentration of trypsin is 10-20 μg/ml for proliferation of AIV H9N2 subtype in MDCK cells.