TY - JOUR
T1 - Consequences of cytotoxic T-lymphocyte escape
T2 - Common escape mutations in simian immunodeficiency virus are poorly recognized in naïve hosts
AU - Friedrich, Thomas C.
AU - McDermott, Adrian B.
AU - Reynolds, Matthew R.
AU - Piaskowski, Shari
AU - Fuenger, Sarah
AU - De Souza, Ivna P.
AU - Rudersdorf, Richard
AU - Cullen, Candice
AU - Yant, Levi J.
AU - Vojnov, Lara
AU - Stephany, Jason
AU - Martin, Sarah
AU - O'Connor, David H.
AU - Wilson, Nancy
AU - Watkins, David I.
N1 - Copyright:
Copyright 2009 Elsevier B.V., All rights reserved.
PY - 2004/9
Y1 - 2004/9
N2 - Cytotoxic T lymphocytes (CTL) are associated with control of immunodeficiency virus infection but also select for variants that escape immune recognition. Declining frequencies of epitope-specific CTL frequencies have been correlated with viral escape in individual hosts. However, escape mutations may give rise to new epitopes that could be recognized by CTL expressing appropriate T-cell receptors and thus still be immunogenic when escape variants are passed to individuals expressing the appropriate major histocompatibility complex class I molecules. To determine whether peptide ligands that have been altered through escape can be immunogenic in new hosts, we challenged naïve, immunocompetent macaques with a molecularly cloned simian immunodeficiency virus (SIV) bearing common escape mutations in three immunodominant CTL epitopes. Responses to the altered peptides were barely detectable in fresh samples at any time after infection. Surprisingly, CTL specific for two of three escaped epitopes could be expanded by in vitro stimulation with synthetic peptides. Our results suggest that some escape variant epitopes evolving in infected individuals do not efficiently stimulate new populations of CTL, either in that individual or upon passage to new hosts. Nevertheless, escape variation may not completely abolish an epitope's immunogenicity. Moreover, since the mutant epitope sequences did not revert to wild type during the study period, it is possible that low-frequency CTL exerted enough selective pressure to preserve epitope mutations in viruses replicating in vivo.
AB - Cytotoxic T lymphocytes (CTL) are associated with control of immunodeficiency virus infection but also select for variants that escape immune recognition. Declining frequencies of epitope-specific CTL frequencies have been correlated with viral escape in individual hosts. However, escape mutations may give rise to new epitopes that could be recognized by CTL expressing appropriate T-cell receptors and thus still be immunogenic when escape variants are passed to individuals expressing the appropriate major histocompatibility complex class I molecules. To determine whether peptide ligands that have been altered through escape can be immunogenic in new hosts, we challenged naïve, immunocompetent macaques with a molecularly cloned simian immunodeficiency virus (SIV) bearing common escape mutations in three immunodominant CTL epitopes. Responses to the altered peptides were barely detectable in fresh samples at any time after infection. Surprisingly, CTL specific for two of three escaped epitopes could be expanded by in vitro stimulation with synthetic peptides. Our results suggest that some escape variant epitopes evolving in infected individuals do not efficiently stimulate new populations of CTL, either in that individual or upon passage to new hosts. Nevertheless, escape variation may not completely abolish an epitope's immunogenicity. Moreover, since the mutant epitope sequences did not revert to wild type during the study period, it is possible that low-frequency CTL exerted enough selective pressure to preserve epitope mutations in viruses replicating in vivo.
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U2 - 10.1128/JVI.78.18.10064-10073.2004
DO - 10.1128/JVI.78.18.10064-10073.2004
M3 - Article
C2 - 15331739
AN - SCOPUS:4444290418
VL - 78
SP - 10064
EP - 10073
JO - Journal of Virology
JF - Journal of Virology
SN - 0022-538X
IS - 18
ER -