Recombinant baculovirus effect

The plethora of literature that deals with hormonal regulation of insect development gives some indication of the complexities involved. The role of JHE varies between species during the early larval instars, and the reduced sensitivity of tissues to anti-JH effects via JHE in later instars (54) may well be limiting the insecticidal efficacy of the recombinant baculoviruses expressing JHE. 

Andersen, J.N., "Temperature Effect on Recombinant Protein Production Using a Baculovirus/Insect Cell Expression System", Diploma Thesis, University of Calgary and Technical University of Denmark, 1995. 

Zhang, F., Saarinen, M.A., Itle, L.J. et al. (2002) The effect of dissolved oxygen (DO) concentration on the glycosylation of recombinant protein produced by the insect cell-baculovirus expression system. Biotechnology and Bioengineering, 11 (2), 219-224. 

Individual drug metabolizing enzymes DMEs) like CYPs, FMOs, and UGTs are now routinely expressed, usually in insect cells using a baculovirus. Ultracentrifugation provides vesicles called microsomes, which contain these membrane-bound DMEs. One popular type of recombinant CYP preparation called Supersomes comes with CYP reductase, a necessary cofactor, co-expressed. Not only individual CYPs (2B6, 3A4, etc.) but also allelic variants like CYP2C9 2 are available for the study of possible pharmacogenomic effects on metabolism. 

Pharmacokinetics of JHE. When high titers of purified recombinant JHE from K virescens were injected into M, sexta, a rapid decline of this JHE in the hemolymph was noted (61), JHE was removed by a saturable process, possibly by receptor mediated endocytosis, and there was no difference in clearance rate between different larval stadia of M, sexta and H. virescens. As noted above, it is possible that the recombinant virus-expressed JHE may be removed before having a significant biological effect. However, baculovirus expressed JHE reaches very high activity levels in vivOy up to 20 or 40 times the maximum titers seen during the course of normal larval development in some cases (Table II 51). Despite this fact, precocious development of larvae infected with the various recombinant viruses is not seen. 

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