Transcytosis of Junonia coenia densovirus VP4 across the gut epithelium of Spodoptera frugiperda (Lepidoptera: Noctuidae)

In this study, we used fall armyworm,Spodoptera frugiperda to examine the binding of the virus to brush border membrane vesicle proteins by two ‐dimensional ligand blot analysis. We also assessed the rate of flux of the primary viral structural protein, VP4 fused to eGFP with a proline‐rich linker (VP4‐P‐eGFP) through the gut epitheliumex vivo in an Ussing chamber. The mechanisms involved with transcytosis of VP4 ‐P‐eGFP were assessed by use of inhibitors. Bovine serum albumin (BSA) and eGFP were used as positive and negative control proteins, respectively. In contrast to BSA, which binds to multiple proteins on the brush border membrane, VP4‐P‐eGFP binding was specific to a protein of high molecular mass. Protein flux was significantly higher for VP4‐P‐eGFP after 2 h than for albumin or eGFP, with rapid transcytosis of VP4‐P‐eGFP within the first 30 min. In contrast to BSA which transcytosed following clathrin‐mediated endocytosis, the movement of VP4‐P‐eGFP was vesicle‐mediate d but clathrin‐independent. The specificity of binding combined with the efficiency of transport across the gut epithelium suggest that VP4 will provide a useful carrier for insecticidal peptides active within the hemocoel of key lepidopteran pests includingS. frugiperda.

Source: Insect Science - June 3, 2018 Category: Biology Authors: Mariah Kemmerer, Bryony C. Bonning Tags: ORIGINAL ARTICLE Source Type: research