2018年33卷2期

Baculoviruses have been used as biocontrol agents against insect pests and also exploited in therapeutic strategies and protein expression. The successful primary infection of baculoviruses in insect host is largely dependent on a family of membrane resident proteins, so-called per os infectivity factors (PIFs), which is likely to play an important role in virus entry into midgut epithelial cells of susceptible insect larvae. In this issue, George Alliwa Makalliwa et al. investigated the functional roles of PIF1, 2, and 3 using PIF-replaced viruses. They found that only PIF3 replacement showed the formation of PIF complex and retained partial oral infectivity, while substitution of either PIF1 or PIF2 inhibited the formation of PIF complex and oral infectivity. These results highlighted that the specificity of PIFs is quite high and the PIF complex is essential for the oral infectivity. The cover is modified from a transmission electron microscopy image of occlusion bodies from PIF3-replaced recombinant Helicoverpa armigera nucleopolyhedrovirus (kindly provided by George Alliwa Makalliwa and Zhihong Hu) with pseudo-color.