Multiple viral ligands naturally presented by different class I molecules in transporter antigen processing-deficient vaccinia virus-infected cells.
The transporter associated with antigen processing (TAP) delivers the viral proteolytic products generated by the proteasome in the cytosol to the endoplasmic reticulum lumen that are subsequently recognized by cytotoxic T lymphocytes (CTLs). However, several viral epitopes have been identified in TAP-deficient models. Using mass spectrometry to analyze complex human leukocyte antigen (HLA)-bound peptide pools isolated from large numbers of TAP-deficient vaccinia virus-infected cells, we identified 11 ligands naturally presented by four different HLA-A, HLA-B, and HLA-C class I molecules. Two of these ligands were presented by two different HLA class I alleles, and, as a result, 13 different HLA-peptide complexes were formed simultaneously in the same vaccinia virus-infected cells. In addition to the high-affinity ligands, one low-affinity peptide restricted by each of the HLA-A, HLA-B, and HLA-C class I molecules was identified. Both high- and low-affinity ligands generated long-term memory CTL responses to vaccinia virus in an HLA-A2-transgenic mouse model. The processing and presentation of two vaccinia virus-encoded HLA-A2-restricted antigens took place via proteasomal and nonproteasomal pathways, which were blocked in infected cells with chemical inhibitors specific for different subsets of metalloproteinases. These data have implications for the study of the effectiveness of early empirical vaccination with cowpox virus against smallpox disease.
Centro Nacional de Microbiología, Instituto de Salud Carlos III, 28220 Majadahonda, Madrid, Spain.
Elena
E
Lorente
Susana
S
Infantes
Eilon
E
Barnea
Ilan
I
Beer
Ruth
R
García
Fátima
F
Lasala
Mercedes
M
Jiménez
Carlos
C
Vilches
François A
FA
Lemonnier
Arie
A
Admon
Daniel
D
López
D018528:ATP-Binding Cassette Transporters / Q000235:genetics / Q000276:immunology*; D000818:Animals; D017951:Antigen Presentation; D000938:Antigen-Presenting Cells / Q000276:immunology / Q000821:virology; D018414:CD8-Positive T-Lymphocytes / Q000276:immunology / Q000821:virology; D002460:Cell Line; D015395:Histocompatibility Antigens Class I / Q000235:genetics / Q000276:immunology*; D006801:Humans; D008024:Ligands; D051379:Mice; D018345:Mice, Knockout; D014615:Vaccinia / Q000235:genetics / Q000276:immunology* / Q000821:virology; D014616:Vaccinia virus / Q000235:genetics / Q000276:immunology*
D018528:ATP-Binding Cassette Transporters; D015395:Histocompatibility Antigens Class I; D008024:Ligands; C477327:transporter associated with antigen processing (TAP)