Submitted to: In Vitro Cellular and Developmental Biology
Publication Type: Peer reviewed journal
Publication Acceptance Date: 3/22/2005
Publication Date: 9/29/2005
Citation: Mcintosh, A.H., Grasela, J.J., Popham, H.J. 2005. Acmnpv in permissive, semipermissive and nonpermissive cell lines from arthropoda. In Vitro Cellular and Developmental Biology 41:298-3004. Interpretive Summary: One of the important uses of insect viruses is for the control of major field and forest pests such as the corn earworm and the gypsy moth. These viruses are commonly produced in the susceptible hosts, harvested, formulated and then applied in the field by spraying in much the same manner as chemical insecticides are applied. An alternative method of producing insect viruses is to grow them in cells taken from the insect host and propagated in the laboratory. In testing a variety of insect cells from caterpillars, beetles, mosquitoes and leaf hoppers for their susceptibility and ability to grow the virus, it was found that the caterpillar cells supported the greatest amount of the insect virus. It was also found that a fluorescent marker incorporated into the insect virus could be detected and expressed in cells that did not replicate the entire virus indicating that the virus was able to penetrate and enter such cells. The impact of such a study will benefit industry and scientists engaged in the production of this insect virus as a biological control agent and for studies in the biomedical field whereby such insect viruses can be used as vectors to transport and deliver genes of medical importance to mammalian cells as well as to vertebrate hosts.
Technical Abstract: Insect cell lines from Arthropoda represented by Lepidoptera, Coleoptera, Diptera and Homoptera were evaluated for their ability to support replication of AcMNPV. In addition, some of the cell lines that were refractive to AcMNPV were tested with AcMNPV hsp70 Red, a recombinant carrying the red fluorescent protein (RFP) gene, for their ability to express this protein following inoculation. Of the 10 lepidopteran cell lines tested, only 3 cell lines from Helicoverpa zea (BCIRL -HZ-AM1), Lymantri dispar (IPLB-LD65) and Cydia pomonella (CP-169) failed to support appreciative viral replication as measured by TCID50 assay. Heliothis virescens (BCIRL-HV-AM1) produced the highest viral titer of 2.3 + or - 0.1 x 10**7 TCID50/ml followed by Heliothis subflexa (BCIRL-HS-AM1) at 4.7 + or - 0.1 x 10**6 TCID50/ml and Spodoptera frugiperda (IPLB-SF21) at 4.1 + or - 0.1 x 10**6 TCID50/ml. None of the Coleopteran, Dipteran or Homopteran cell lines supported AcMNPV replication. However, when studies were performed employing AcMNPV hsp70 Red, the Dipteran cell lines Aedes aegypti (ATC-10) and Drosophila melanogaster (Line2) both expressed the RFP as well as the refractive Lepidopteran cell lines from H. zea and L. dispar. No RFP expression was observed in any of the Coleopteran or Homopteran cell lines. Cell lines refractive to AcMNPV did not appear to be adversely affected by the virus as judged by their ability to multiply, nor was there any indication of induced apoptosis as assessed by DNA fragmentation profiles.