Apoptosis: its role in microbial control of insect pests

摘要

Very little is known concerning insect defence against virus infection. Insect haemocytes can provide cell-mediated immunity to bacterial pathogens through phagocytes and encapsulation. Neither cell-mediated nor humoral immunity has been demonstrated against virus infection in insects. 'Apoptosis' is a distinctive type of programmed cell death, a phenomenon evolved as a primitive viral defence in certain vertebrate animals and invertebrates. In these systems lacking humoral immunity, antiviral defence mechanisms are gaining importance in cellular defence against viral infection. However, insect baculoviruses like nuclear polyhedrosis virus, granulosis virus and other DNA viruses of insects evolved methods apparently to bypass this defence phenomenon of apoptosis by directly blocking this response with the possession of the p35 gene. The future possibility of blocking apoptosis for increasing the virulence and host range of certain baculoviruses is presented. It is very important for assessing thepotential risk of genetically improved baculoviruses. Further understanding the mechanisms for the development of robust cells for in vitro multiplication of insect viruses are also discussed in this paper.