Mode of action of NPV (Nuclear Polyhedrosis Viruses)

 

Occlusion bodies are ingested by insect larvae. In the highly alkaline pH of the midgut, the occlusion body protein dissolves and is further degraded by host alkaline proteases. The virus particles are released from polyhedra and subsequently attach to the peritrophic membrane lining the midgut. The lipoprotein membrane surrounding the virus fuses with plasma membrane of the gut wall cells and liberates nucleocapsids into the cytoplasm. The nucleotide transport virus DNA into the nucleus of the cell and virus gene expression begins. The virus multiplies rapidly and eventually fills the body of the host with virus particles.