Induc Tion And Identification Of Insect Viral Inhibitory Factor

Recently, the research on antibacterial peptites from insects becomes a key concern in the field of insect immunobiology and molecular biology It has been expected that antibacterial peptites will be used as a new type of antibiont and a new anticancer drug. However, few breakthroughs have been made in the research of insect antiviral immunity which plays an important role in the insect humoral immunity. For further study, in the paper the question as to whether the VIF could be induced in the hemolymph of silkworm larvae and cultured insect cell lines infected with baculovirus was discussed, their antiviral activities were identified and the antiviral activity of insect antibacterial protein was tested as well. The results as follows; 1. The bemolymph of silkworm larvae infected with BmNPV was fractionated gradedly with amznonium sulfate. AcM7NPV was mixed with an equal volume of crude VIF and incubated at 28 0C for 60 mm. The SB 1 cells were infected with two mixtures, Crude VIE I and II, respectively. Four days later, we observed that few cells were infected, compared with the control. And inactivated the virus strongly since the inactivation indexes of them were 1.99 and 2.33, respectively. Crude VIE I and II were further purified with DEAE-Sepharose Fast Flow chromatography and emerged active peak Ci and peak b2 containing the antiviral protein, respectively. They inactivated the virus strongly since the inactivation indexes of peak c1 and peak b2 were 2.17 and 2.50, respectively. Then crude VIF I and II were subjected to SDS-PAGE analysis. Crude VIF I was found to produce four new bands, and the molecular weight of them were:83.7KD, 65.2KD,53.3KD,32.8KD,while crude VIF Ilwas found to produce a single new band with the molecular weight of 36.OKD and three enhanced bands. Five bands were observed in the peak b2, one of which is similar to the 36.OKD band produced iii - MASTER S THESrS by the crude VIE II. Therefore, the results indicated that viral inhibitory factor was induced the hemolymth of silkworm larvae infected with BmINPV. 2. The 5B1 cells were infected with ultra-violet inactivated AcMNPV in 10 mm, 1 5mm, 20 mm, 25 mm and 30 mm, respectively. Their antiviral activities were tested, and their inactivation indexes were ?.21, -0.18, -I-U. 17, ?.31 and 0.13, respectively. We supposed that the antiviral activity couldn抰 be induced in cultured insect cells. 3. The 5B1 cells were treated with heat-killed E. Coli strain DH5 .The antibacterial activity could be detected by measuring the zone of growth inhibition. However, How most people thought the limit value of the antiviral activity was 0.7, and we found the inactivation index of the antibacterial activity was 0.5, we concluded that the antibacterial agent had no antiviral activity.