[PDF][PDF] Human CD8+ T cell responses to EBV EBNA1: HLA class I presentation of the (Gly-Ala)–containing protein requires exogenous processing

N Blake, S Lee, I Redchenko, W Thomas, N Steven… - Immunity, 1997 - cell.com
N Blake, S Lee, I Redchenko, W Thomas, N Steven, A Leese, P Steigerwald-Mullen…
Immunity, 1997cell.com
Abstract Epstein-Barr virus (EBV)–induced cytotoxic T lymphocyte (CTL) responses have
been detected against many EBV antigens but not the nuclear antigen EBNA1; this has
been attributed to the presence of a glycine-alanine repeat (GAr) domain in the protein. Here
we describe the isolation of human CD8+ CTL clones recognizing EBNA1-specific peptides
in the context of HLA-B35. 01 and HLA-A2. 03. Using these clones, we show that full-length
EBNA1 is not presented when expressed endogenously in target cells, whereas the GAr …
Abstract
Epstein-Barr virus (EBV)–induced cytotoxic T lymphocyte (CTL) responses have been detected against many EBV antigens but not the nuclear antigen EBNA1; this has been attributed to the presence of a glycine-alanine repeat (GAr) domain in the protein. Here we describe the isolation of human CD8+ CTL clones recognizing EBNA1-specific peptides in the context of HLA-B35.01 and HLA-A2.03. Using these clones, we show that full-length EBNA1 is not presented when expressed endogenously in target cells, whereas the GAr-deleted form is presented efficiently. However, when supplied as an exogenous antigen, the full-length protein can be presented on HLA class I molecules by a TAP-independent pathway; this may explain how EBNA1-specific CTLs are primed in vivo.
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