Identification of differentially expressed host genes in Bombyx mori nucleopolyhedrovirus infected cells by using subtractive hybridization

Abstract

Following baculovirus infection, the level of host messenger RNA (mRNA) declines and the synthesis of host proteins is shutoff in virus-infected cells. To comprehensively understand the regulation of host gene expression by Bombyx mori nucleopolyhedrovirus (BmNPV), we took a complementary DNA (cDNA) subtraction approach. Northern blot analysis was then performed to confirm whether obtained clones are differentially expressed. From these analyses, we obtained 4 down-, 7 up-and 2 non-regulated host gene candidates during the early stage of infection. Sequence analyses showed that these may encode proteins involved in transcription, cell cycle, cell adhesion, protein degradation, apoptosis or energy metabolism. We then measured the ADP/ATP ratio to address the response of host energy metabolism upon baculovirus infection. The ADP/ATP ratio showed cell death-like rapid increase following BmNPV infection with a transient decrease during 12-24 h post-infection (p.i.). Taken together, our results suggest that general events in host cells are controlled at the level of mRNA expression by BmNPV infection.

Dynamic Interactions between Bombyx mori Nucleopolyhedrovirus and Its Host Cells Revealed by Transcriptome Analysis

“…These types of gene sets were highly upregulated in all of the postinfection time points (Table 2; see also Table S5 in the supplemental material). This finding is consistent with an earlier report indicating that energy metabolism-associated genes are overexpressed after BmNPV infection (21). Nevertheless, there is still a lack of knowledge about the role of cellular energy modulation and baculovirus infection.…”

“…The energy metabolism of insect cells is modulated after baculovirus infection (6,10,21,43). Carinhas et al (10) suggested that baculovirus production can be improved by manipulating energy metabolism.…”

“…Carinhas et al (10) suggested that baculovirus production can be improved by manipulating energy metabolism. Iwanaga et al (21) suggested that BmNPV-infected cells need more ATP for abrupt consumption. In our study, gene sets related to mitochondrial function were dramatically altered immediately after viral infection, which might affect mitochondrial respiration and apoptosis.…”

“…The sequencing of the first genome of a lepidopteran insect, the silkworm, greatly facilitated the study of global host genes in response to baculovirus infection. Iwanaga et al (21) reported the upregulation of seven genes and downregulation of four genes in the early phase of infection by subtractive hybridization and Northern blot analysis. Using suppression subtractive hybridization (SSH), Bao et al (4,5) reported that a total of 100 genes might be involved in the host antiviral mechanism.…”

Comprehensive analysis of host gene expression in Autographa californica nucleopolyhedrovirus-infected Spodoptera frugiperda cells

“…Seven up-regulated host genes were identified in BmNPV-infected BmN-4 cells by subtractive hybridization at the early stage of infection (2 and 6 hpi) (Iwanaga et al, 2007). These did not include Hsc70 or any other Hsp70 members.…”