TY - JOUR
T1 - EBV latent membrane proteins (LMPs) 1 and 2 as immunotherapeutic targets: LMP-specific CD4(+) cytotoxic T cell recognition of EBV-transformed B cell lines
AU - Haigh, Tracey
AU - Lin, XR
AU - Jia, Hui
AU - Hui, EP
AU - Chan, ATC
AU - Rickinson, Alan
AU - Taylor, Graham
PY - 2008/1/1
Y1 - 2008/1/1
N2 - The EBV-latent membrane proteins (LMPs) 1 and 2 are among only three viral proteins expressed in EBV-associated Hodgkin's lymphoma and nasopharyngeal carcinoma. Since these tumors are HLA class I and class II-positive, the LMPs could serve as both CD8(+) and CD4(+) T cell targets. In contrast to CD8 responses, very little is known about CD4 responses to LMPs. In this study, we describe CD4(+) T cell clones defining four LNIP1- and three LMP2-derived peptide epitopes and their restricting alleles. All clones produced Th1-like cytokines in response to peptide and most killed peptide-loaded target cells by perforin-mediated lysis. Although clones to different epitopes showed different functional avidities in peptide titration assays, avidity per se was a poor predictor of the ability to recognize naturally infected B lymphoblastoid cell lines (LCLs) expressing LMPs at physiologic levels. Some epitopes, particularly within LMP1, consistently mediated strong LCL recognition detectable in cytokine release, cytotoxicity, and outgrowth inhibition assays. Using cyclosporin A to selectively block cytokine release, we found that CD4(+) T cell cytotoxicity is the key effector of LCL outgrowth control. We therefore infer that cytotoxic CD4(+) T cells to a subset of LMP epitopes could have therapeutic potential against LMP-expressing tumors.
AB - The EBV-latent membrane proteins (LMPs) 1 and 2 are among only three viral proteins expressed in EBV-associated Hodgkin's lymphoma and nasopharyngeal carcinoma. Since these tumors are HLA class I and class II-positive, the LMPs could serve as both CD8(+) and CD4(+) T cell targets. In contrast to CD8 responses, very little is known about CD4 responses to LMPs. In this study, we describe CD4(+) T cell clones defining four LNIP1- and three LMP2-derived peptide epitopes and their restricting alleles. All clones produced Th1-like cytokines in response to peptide and most killed peptide-loaded target cells by perforin-mediated lysis. Although clones to different epitopes showed different functional avidities in peptide titration assays, avidity per se was a poor predictor of the ability to recognize naturally infected B lymphoblastoid cell lines (LCLs) expressing LMPs at physiologic levels. Some epitopes, particularly within LMP1, consistently mediated strong LCL recognition detectable in cytokine release, cytotoxicity, and outgrowth inhibition assays. Using cyclosporin A to selectively block cytokine release, we found that CD4(+) T cell cytotoxicity is the key effector of LCL outgrowth control. We therefore infer that cytotoxic CD4(+) T cells to a subset of LMP epitopes could have therapeutic potential against LMP-expressing tumors.
M3 - Article
C2 - 18209060
SN - 1550-6606
VL - 180
SP - 1643
EP - 1654
JO - Journal of Immunology
JF - Journal of Immunology
IS - 3
ER -