| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
|
|
|
|||||||
|
|||||||||
1 Health Protection Agency, Porton Down, Salisbury SP4 0JG, UK
2 Division of Retrovirology, National Institute for Biological Standards and Control, South Mimms, Herts EN6 3QG, UK
3 Department of Virology, Biomedical Primate Research Centre, Rijswijk, the Netherlands
4 Department of Cellular and Molecular Medicine, St George's Hospital Medical School, London SW17 0RE, UK
Correspondence
Sally A. Sharpe
sally.sharpe{at}hpa.org.uk
To further investigate mechanisms of protective immunity that are induced by live, attenuated simian immunodeficiency virus (SIV), three macaques were infected with SIVmacGX2, a nef-disrupted molecular clone. In two of these animals, which expressed the MamuA*01 major histocompatibility complex class I allele, loss of functional activity against an SIV-Gag-encoded immunodominant cytotoxic T lymphocyte (CTL) epitope was observed following prolonged infection. Nonetheless, all three animals were resistant to challenge with an uncloned pool of wild-type SIVmac, whereas four naïve controls became infected. Tetramer staining revealed the rapid generation of CD8+ T-cell responses against gag- and tat-encoded immunodominant epitopes in MamuA*01+ challenge controls. The dynamics of these T-cell responses to the wild-type virus were similar to those observed following primary infection of the vaccine group with attenuated virus. In contrast, neither tetramer staining nor gamma interferon ELISpot assay revealed an immediate, systemic, anamnestic response in the wild-type-challenged, attenuated SIV-infected animals. Functional CTL capacity had not been lost in this group, as lytic activity was still evident 17 weeks after challenge. Both attenuated and wild-type viruses induced a disseminated CD8+ T-cell response, which was of a higher magnitude in lymphoid tissues than in the periphery. These results suggest that, at least as measured in the periphery, protection against wild-type infection that is induced by live, attenuated SIV is not dependent on a rechallenge-driven expansion of immunodominant epitope-specific CD8+ T cells and, therefore, pre-existing activity may be sufficient to prevent superinfection.
Present address: Department of Cellular and Molecular Medicine, St George's Hospital Medical School, London SW17 0RE, UK.
This article has been cited by other articles:
|
|
 |
|
  N. Berry, R. Stebbings, D. Ferguson, C. Ham, J. Alden, S. Brown, A. Jenkins, J. Lines, L. Duffy, L. Davis, et al. Resistance to superinfection by a vigorously replicating, uncloned stock of simian immunodeficiency virus (SIVmac251) stimulates replication of a live attenuated virus vaccine (SIVmacC8) J. Gen. Virol., September 1, 2008; 89(9): 2240 - 2251. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 T. L. Tagmyer, J. K. Craigo, S. J. Cook, D. L. Even, C. J. Issel, and R. C. Montelaro Envelope Determinants of Equine Infectious Anemia Virus Vaccine Protection and the Effects of Sequence Variation on Immune Recognition J. Virol., April 15, 2008; 82(8): 4052 - 4063. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
K. J. Metzner, W. J. Moretto, S. M. Donahoe, X. Jin, A. Gettie, D. C. Montefiori, P. A. Marx, J. M. Binley, D. F. Nixon, and R. I. Connor Evaluation of CD8+ T-cell and antibody responses following transient increased viraemia in rhesus macaques infected with live, attenuated simian immunodeficiency virus J. Gen. Virol., December 1, 2005; 86(12): 3375 - 3384. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
R. Stebbings, N. Berry, H. Waldmann, P. Bird, G. Hale, J. Stott, D. North, R. Hull, J. Hall, J. Lines, et al. CD8+ Lymphocytes Do Not Mediate Protection against Acute Superinfection 20 Days after Vaccination with a Live Attenuated Simian Immunodeficiency Virus J. Virol., October 1, 2005; 79(19): 12264 - 12272. [Abstract] [Full Text] [PDF]
|
|
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
| INT J SYST EVOL MICROBIOL | MICROBIOLOGY | J GEN VIROL |
| J MED MICROBIOL | ALL SGM JOURNALS | |
