Epitope discovery in West Nile virus infection: Identification and immune recognition of viral epitopes.
Cytotoxic T lymphocytes (CTL) play an important role in the control and elimination of infection by West Nile virus (WNV), yet the class I human leukocyte antigen (HLA)-presented peptide epitopes that enable CTL recognition of WNV-infected cells remain uncharacterized. The goals of this work were first to discover the peptide epitopes that distinguish the class I HLA of WNV-infected cells and then to test the T cell reactivity of newly discovered WNV epitopes. To discover WNV-immune epitopes, class I HLA was harvested from WNV (NY99 strain)-infected and uninfected HeLa cells. Then peptide epitopes were eluted from affinity-purified HLA, and peptide epitopes from infected and uninfected cells were comparatively mapped by mass spectroscopy. Six virus-derived peptides from five different viral proteins (E, NS2b, NS3, NS4b, and NS5) were discovered as unique to HLA-A*0201 of infected cells, demonstrating that the peptides sampled by class I HLA are distributed widely throughout the WNV proteome. When tested with CTL from infected individuals, one dominant WNV target was apparent, two epitopes were subdominant, and three demonstrated little CTL reactivity. Finally, a sequence comparison of these epitopes with the hundreds of viral isolates shows that HLA-A*0201 presents epitopes derived from conserved regions of the virus. Detection and recovery from WNV infection are therefore functions of the ability of class I HLA molecules to reveal conserved WNV epitopes to an intact cellular immune system that subsequently recognizes infected cells.
McMurtrey
Curtis P
CP
Department of Microbiology and Immunology, University of Oklahoma Health Sciences Center, 975 NE 10th Street, Oklahoma City, OK 73104, USA.
Lelic
Alina
A
Piazza
Paolo
P
Chakrabarti
Ayan K
AK
Yablonsky
Eric J
EJ
Wahl
Angela
A
Bardet
Wilfried
W
Eckerd
Annette
A
Cook
Robert L
RL
Hess
Rachael
R
Buchli
Rico
R
Loeb
Mark
M
Rinaldo
Charles R
CR
Bramson
Jonathan
J
Hildebrand
William H
WH
D000818:Animals; D001483:Base Sequence; D002522:Chlorocebus aethiops; D017931:DNA Primers / Q000235:genetics; D018984:Epitopes, T-Lymphocyte / Q000235:genetics* / Q000276:immunology / Q000378:metabolism; D006680:HLA Antigens / Q000276:immunology / Q000378:metabolism*; D006801:Humans; D013058:Mass Spectrometry; D008969:Molecular Sequence Data; D017422:Sequence Analysis, DNA; D017385:Sequence Homology; D014709:Vero Cells; D014901:West Nile Fever / Q000276:immunology*; D014902:West Nile virus / Q000235:genetics / Q000276:immunology*
D017931:DNA Primers; D018984:Epitopes, T-Lymphocyte; D006680:HLA Antigens