2005 Volume 74 Issue 2 Pages 79-82
Non-viral 45.5K and 44K polypeptides have been shown to accumulate in virus-infected degenerate cells in the midgut epithelium of the silkworm, Bombyx mori. These polypeptides are detectable first temporally at around 3 days postinfection (pi) and then persistently at around 8 days pi onwards, when day 1 fifth-instar larvae of the silkworm are infected with B. mori densovirus type 2 (BmDNV-2). In this study, we found that the amount of 45.5K and 44K polypeptides accumulated in BmDNV-2-infected midgut epithelium was inversely correlated with that of BmDNV-2 structural polypeptides. TUNEL staining showed that the degeneration of BmDNV-2-infected cells enriched in 45.5K and 44K polypeptides was not due to apoptosis. These results suggest that 45.5K and 44K polypeptides are involved in the clearance of the cells damaged by virus multiplication from BmDNV-2-infected midgut epithelium by a mechanism different from apoptosis induction, resulting in a restricted accumulation of viruses in BmDNV-2-infected midgut epithelium.
