Submitted to: Journal of Applied Entomology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: April 11, 2001
Publication Date: August 20, 2001
Citation: MCINTOSH, A.H., GRASELA, J.J., GOODMAN, C.L., IGNOFFO, C.M. GROWTH OF A CLONAL CELL LINE OF HELICOVERPA ZEA IN SUSPENSION CULTURE AND REPLICATION OF ITS HOMOLOGOUS BACULOVIRUS HZSNPV. JOURNAL OF APPLIED ENTOMOLOGY. 2001. V. 36(3). P. 349-352. Interpretive Summary: Baculoviruses are insect viruses which are found in nature and which may be used to control insect pests of agricultural importance. These viruses are produced on a large scale by infecting susceptible insects and recovering the virus from dead larvae as occlusion bodies which contain the viral particles. The problem in this study was to determine if an alternative method of producing virus by infecting insect cells grown in suspension culture in flasks placed on a rotary shaker, could produce high numbers of occlusion bodies. Occlusion bodies can then be recovered from such infected cells, formulated and used as a biological control agent. In the present report, insect cells were grown to high concentrations in suspension culture and produced very high numbers of occlusion bodies following inoculation with a virus that is effective against the corn earworm/cotton bollworm complex, a major pest of field crops. This accomplishment will be valuable in the large scale production of insects cells using fermenters for the production of this virus and will benefit scientists, industry and the farming community.
Technical Abstract: A clonal cell line (BCIRL-HZ-AM1-11) of Helicoverpa zea was grown in stationary and suspension cultures in Ex-Cell 401**TM medium containing 10% fetal bovine serum at 28 deg C. The cell population doubling time was 22 hr in stationary culture as compared with 27 hr in suspension culture. A lag time of approximately 24 hr was observed during the first 24 hr of the suspension culture following initiation but no lag time was observed in th stationary culture. Maximum viral titers were achieved in stationary and suspension cultures at 120 hr (1.80 x 10**6 TCID50/ml) and 168 hr (1.48 x 10**7 TCID-50/ml), respectively, following inoculation with the Helicoverpa zea baculovirus (HzSNPV/Br-CL2). Infected cells harvested at 168 hr from the suspension culture produced a total number of occlusion bodies of 3 x 10**9.