Studies on the defense mechanisms of the silkworm, Bombyx mori, against the replication of a nuclear polyhedrosis virus in continuous cell cultures

通过对家蚕幼虫或蛹进行抗原刺激，研究了家蚕对核型多角体病毒（NPV）感染的防御机制。然而，防御反应并不容易证明。本研究的目的是研究家蚕连续培养细胞（s.p.c. Bm36细胞和Bm-N细胞）对NPV复制的防御机制。1)采用福尔马林处理或紫外线照射的方法，从s.p.c.m b36细胞中提取NPV（非闭塞病毒）制备疫苗。在接种NPV前分别将疫苗接种于培养细胞2和24小时。然而，在S. P. C. Bm- 36细胞和Bm- n细胞中均未表现出防御反应的诱导作用。2)接种前24小时和48小时，分别加入经免疫的家兔抗桑小蠊NPV（非排除病毒）血清，均不能产生被动免疫。另外，在接种B. B.接种后立即和60min分别加入抗npv血清。然而，抗NPV血清对细胞内病毒复制的防御作用尚未得到证实。3)研究了非受纳病毒对受纳病毒在卵夜蛾细胞（IPLB-SF-21AEII）复制的干扰作用。在细胞培养液中分别接种对frugiperda细胞具有非受让性的mori病原菌NPV，在0 min和60 min后分别接种对frugiperda细胞具有受让性的Xestia c-nierum NPV。然而，尚不清楚家蚕NPV对X. c . nigum NPV的干扰作用。

The investigations on the defense mechanism of the silkworm against the infection of a nuclear polyhedrosis virus (NPV) have been done by means of antigenic stimulation to silkworm larvae or pupae. However, the defense reaction has not been easily demonstrated.The objective of the present study is to investigate the defense mechanism against NPV replication in Bombvx mori continuous cell cultures (S. P. C. Bm36 cells and Bm-N cells).1) The vaccines were made from the NPV (nonoccluded virus) derived from S. P. C. Bm 36 cells by treatment with formalin or irradiation with UV. The vaccine was inoculated to cultured cells 2 and 24 hr, respectively, before the inoculation of NPV. However, the induction of the defense reaction was not shown in both of S. P. C. Bm 36 cells and Bm-N cells.2) The passive immunity, , could not be recognized when the immunized rabbit serum against B. mori NPV (nonroccluded virus) derived from S. P. C. Bm 36 cells was added to the cell culture 24 and 48 hr, respectively, before the inoculation of NPV. In addition, the anti-NPV serum was added to the cell culture immediately and 60 min, respectively, after the inoculation of B. . mori NPV, however, the defense effect of the anti-NPV serum against the replication of the intracellular virus was not demonstrated.3) The interference of nonpermissive virus with the replication of permissive virus in Spodoptera frugiperda cells (IPLB-SF-21AEII) was tested. B. mori NPV which is a nonpermissive against S. frugiperda cell was inoculated to the cell culture, then after 0 and 60 min, respectively, Xestia c-nierum NPV which is permissive against S. frugiperda cell was inoculated. However, the interference of B. mori NPV with X. c-nigrum NPV was not recognized.