Journal of General Virology, Vol 80, 1055-1066, Copyright © 1999 by Society for General Microbiology

ARTICLES

In vitro host range of Autographa californica nucleopolyhedrovirus recombinants lacking functional p35, iap1 or iap2

CM Griffiths, AL Barnett, MD Ayres, J Windass, LA King and RD Possee
NERC Institute of Virology and Environmental Microbiology, Oxford, UK.

We have examined the host range in different insect cell lines of Autographa californica nucleopolyhedrovirus (AcMNPV) recombinants lacking p35, iap1 or iap2. These genes encode, or are predicted to encode, anti-apoptotic proteins. Abrogation of p35 reduced the ability of AcMNPV to replicate in permissive cell lines derived from Spodoptera frugiperda insects by inducing apoptosis. In semi-permissive cell lines, such as Lymantria dispar and Spodoptera littoralis cells, we observed cytopathic effects after infection with AcMNPV but little virus production. Infection of these cells by AcMNPV lacking p35 resulted in apoptosis. However, p35-deficient viruses were still able to replicate normally in Trichoplusia ni, Mamestra brassicae and Panolis flammea cell lines. Disruption of AcMNPV iap1 and iap2 was found not to affect virus replication in any of the cell lines. It was also possible to disrupt both iap1 and iap2 in the same virus without loss of infectivity. A virus without iap1 and p35 demonstrated identical growth characteristics and host range to a virus lacking p35. We conclude that in cells which respond to AcMNPV infection by initiating programmed cell death, the p35 gene product alone is sufficient to inhibit apoptosis. Removal of iap1 or iap2 has no effect on virus replication, even in cell lines which do not undergo apoptosis in response to AcMNPV infection. Our results with two semi-permissive cell lines further indicate that whilst p35 is important in blocking block apoptosis, other factors are involved in restricting AcMNPV replication within these cells.

This article has been cited by other articles:

				B. Bryant and R. J. Clem Caspase inhibitor P35 is required for the production of robust baculovirus virions in Trichoplusia ni TN-368 cells J. Gen. Virol., March 1, 2009; 90(3): 654 - 661. [Abstract] [Full Text] [PDF]

				Q. Yu, T. Lin, G. Feng, K. Yang, and Y. Pang Functional analysis of the putative antiapoptotic genes, p49 and iap4, of Spodoptera litura nucleopolyhedrovirus with RNAi J. Gen. Virol., August 1, 2008; 89(8): 1873 - 1880. [Abstract] [Full Text] [PDF]

				B. J. Kelly, L. A. King, R. D. Possee, and S. D. J. Chapple Dual mutations in the Autographa californica nucleopolyhedrovirus FP-25 and p35 genes result in plasma-membrane blebbing in Trichoplusia ni cells. J. Gen. Virol., March 1, 2006; 87(Pt 3): 531 - 536. [Abstract] [Full Text] [PDF]

				J. C. Means, I. Muro, and R. J. Clem Silencing of the Baculovirus Op-iap3 Gene by RNA Interference Reveals that It Is Required for Prevention of Apoptosis during Orgyia pseudotsugata M Nucleopolyhedrovirus Infection of Ld652Y Cells J. Virol., April 15, 2003; 77(8): 4481 - 4488. [Abstract] [Full Text] [PDF]

				T. Luque, R. Finch, N. Crook, D. R. O'Reilly, and D. Winstanley The complete sequence of the Cydia pomonella granulovirus genome J. Gen. Virol., October 1, 2001; 82(10): 2531 - 2547. [Abstract] [Full Text] [PDF]

				W. F. J. IJkel, E. A. van Strien, J. G. M. Heldens, R. Broer, D. Zuidema, R. W. Goldbach, and J. M. Vlak Sequence and organization of the Spodoptera exigua multicapsid nucleopolyhedrovirus genome J. Gen. Virol., December 1, 1999; 80(12): 3289 - 3304. [Abstract] [Full Text]