|Budget Amount *help
¥2,600,000 (Direct Cost : ¥2,600,000)
Fiscal Year 1991 : ¥700,000 (Direct Cost : ¥700,000)
Fiscal Year 1990 : ¥700,000 (Direct Cost : ¥700,000)
Fiscal Year 1989 : ¥1,200,000 (Direct Cost : ¥1,200,000)
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.