A new mechanism for cotton bellworm virus to inhibit host blacking reaction.

Cotton bellworm virus is an important biopesticide to control the damage of cotton bellworms, it can overcome the host's immune system, establish a systematic infection, and ultimately kill the host insect.
in the current study, the lack of understanding of the mechanism of the host immune system for the cotton bellworm virus overcomes it restricts the further optimization of its insecticidal performance.
blackification reaction is a unique natural immune mechanism of insects, mediated by serine protease cascade reactions to the shearing of phenoloxase genus, a process regulated by the serine protease inhibitor serpin.
previous studies have shown that cotton bellworm virus infection completely inhibits the expression of host immune genes (Xing et al., MCP, 2017).
, Yuan Chuanfei, ph.d'a doctoral student at Wuhan Virus Research Institute of the Chinese Academy of Sciences, and Yu Longsheng, ph.d's doctoral student at the Institute of Zoology, found through proteomic analysis that viral infection inhibited the expression of multiple serine proteases in the blacking reaction pathway of cotton bellworms; further biochemical experiments
and RNAi interference experiments in the body showed that serpin-9 and serpin-5 blocked the activation of the blacking reaction pathway by targeting serinine protease cSP4 and cSP6, respectively.
, the researchers believe that the cotton bellworm virus through the "double insurance" mechanism to inhibit the host's blacking reaction: in the holistic inhibition of the level of serine protease expression in the blacking reaction pathway, the specific "hijacking" of the host's negative regulatory factors, to achieve a complete suppression of the blacking reaction.
the study found the existence of complex blacking defense reaction and regulation in cotton bellworms, revealed the molecular mechanism of virus inhibition of blacking reaction, and laid a theoretical foundation for the development of efficient viral insecticides.
related research published in PLoS Agency.
the research has been supported by the National Natural Science Foundation of China's Innovation Research Group Science Fund, the National Key Research and Development Program, and the Chinese Academy of Sciences' strategic leading science and technology projects, and the key research projects of cutting-edge science.
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