Attenuation of wild-type yellow fever virus by passage in HeLa cells

• Published in: Journal of general virology Vol. 71; no. 10; pp. 2301 - 2306
• Main Authors: Barrett, A. D. T, Monath, T. P, Cropp, C. B, Adkins, J. A, Ledger, T. N, Gould, E. A, Schlesinger, J. J, Kinney, R. M, Trent, D. W
• Format: Journal Article
• Language: English
• Published: Reading Soc General Microbiol 01.10.1990; Society for General Microbiology
• Subjects: Animals; Antibodies, Monoclonal; Biological and medical sciences; Fundamental and applied biological sciences. Psychology; HeLa Cells; Humans; Macaca fascicularis; Mice; Microbiology; Miscellaneous; Neutralization Tests; Vaccines, Attenuated; Viral Envelope Proteins - immunology; Viral Plaque Assay; Virology; Yellow fever virus - immunology; Yellow fever virus - pathogenicity; Virus; Antigen; Antigenic determinant; Attenuation; Monoclonal antibody; Flaviviridae; Flavivirus; Virus envelope; Hela cell line; Yellow fever virus
• ISSN: 0022-1317; 1465-2099
• DOI: 10.1099/0022-1317-71-10-2301

1 Department of Microbiology, University of Surrey, Guildford, Surrey GU2 5XH, U.K. 2 Division of Vector-Borne Infectious Diseases, Center for Infectious Diseases, Centers for Disease Control, Public Health Service, U.S. Department of Health and Human Services, PO Box 2087, Fort Collins, Colorado 80522, U.S.A. 3 NERC Institute of Virology and Environmental Microbiology, Mansfield Road, Oxford OX1 3SR, U.K. and 4 Infectious Diseases Unit, Department of Medicine, University of Rochester School of Medicine and Dentistry, Rochester, New York 14621, U.S.A. During the 1960s three different research groups reported that passage of wild-type yellow fever (YF) virus [strain Asibi (YF-Asibi)] in HeLa cells resulted in attenuation of the virus for monkeys so that the virus no longer caused viscerotropic disease. We have repeated and extended this observation to analyse the process of attenuation of YF virus during cell culture passage. A large plaque (LP) variant of YF-Asibi virus became attenuated for both monkeys and mice following six serial subcultures in HeLa cells (YF-Asibi-LP HeLa p6). Thus, attenuation was probably due to a genetic change in the virus population rather than to selective enrichment of a pre-existing variant of YF-Asibi-LP virus. No evidence was obtained to implicate defective interfering particles in the attenuation process. Comparison of the YF-Asibi-LP viruses before and after passage in HeLa cells, using a panel of envelope protein-reactive monoclonal antibodies (MAbs), showed that MAbs which specifically neutralize YF-Asibi-LP virus, and not YF 17D-204 vaccine virus, also neutralized YF-Asibi-LP HeLa p6. This indicated that the epitopes involved in the biological process of neutralization were not altered during attenuation. However, two MAbs that recognize envelope protein epitopes did distinguish between HeLa- and non-HeLa-passaged YF-Asibi-LP virus. One of these (MAb 117) which is YF wild-type-specific, recognized YF-Asibi-LP virus but not YF-Asibi-LP HeLa p6 virus, whereas the other (MAb 411), which is YF vaccine-specific, recognized YF-Asibi-LP HeLa p6 virus but not YF-Asibi-LP virus. These results suggest that antigenic changes in the viral envelope protein may determine the relative virulence or attenuation of YF virus. Present address: SGRD-UIV, Virology Division, USAMRIID, Fort Detrick, Frederick, Maryland 21701-5011, U.S.A. Received 20 February 1990; accepted 1 June 1990.