Comprehensive epitope mapping of the Epstein-Barr virus latent membrane protein-2 in normal, non tumor-bearing individuals.
Latent membrane protein (LMP)-2 is one of the Epstein-Barr virus (EBV)-encoded proteins consistently expressed by nasopharyngeal carcinoma (NPC). EBV-transformed lymphoblastoid cell lines (LCL) have been used in patients with NPC to induce LMP-2-recognizing T cell lines which have been in turn utilized for protein-wide mapping of T cell epitopes. However, comprehensive mapping of naturally recognized LMP-2 epitopes in non tumor-bearing individuals has not been reported. Here, we applied a low sensitivity epitope-defining technique for the identification of LMP-2 CTL responses detectable ex vivo in EBV-experienced individuals. This screening tool has been previously validated by analyzing memory CTL responses to Flu, cytomegalovirus (CMV), and the melanoma associated antigen gp100/Mel17. Peripheral blood monocytes (PBMC) from ten Caucasian and ten Chinese individuals were stimulated ex vivo with pools of nonamer (9-mer) peptides overlapping in a stepwise fashion each single amino acid of the LMP-2 sequence. No obvious differences were observed between the immune response of the two ethnic groups save for those related to the divergence in the ethnic prevalence of HLA haplotypes. Several novel and known LMP-2 epitopes were identified. Reactivity toward at least one LMP-2 epitope was detected in 18 of the 20 donors but no prevalent human leukocyte antigen (HLA)/epitope combination was observed confirming that LMP-2 reactivity in the context of common HLA alleles is more pleiotropic than that of FLU and CMV. We believe that the usefulness of these epitopes occurring naturally in non-cancer bearing patients as reagents for the immunization of patients with early or advanced stage NPC deserves further evaluation.
Provenzano
Maurizio
M
Immune Oncology Section, Department of Surgery, University Hospital ZLF, Hebelstrasse 20, 4031 Basel, Switzerland.
Selleri
Silvia
S
Jin
Ping
P
Wang
Ena
E
Werden
Rosemary
R
Slezak
Stephanie
S
Adams
Sharon D
SD
Panelli
Monica C
MC
Leitman
Susan F
SF
Stroncek
David F
DF
Marincola
Francesco M
FM
D000595:Amino Acid Sequence; D044466:Asian People; D016000:Cluster Analysis; D017931:DNA Primers; D018604:Epitope Mapping; D018984:Epitopes, T-Lymphocyte / Q000235:genetics*; D006680:HLA Antigens; D004854:Herpesvirus 4, Human; D006801:Humans; D016899:Interferon-beta / Q000378:metabolism; D007371:Interferon-gamma / Q000378:metabolism; D007963:Leukocytes, Mononuclear / Q000502:physiology; D008969:Molecular Sequence Data; D020133:Reverse Transcriptase Polymerase Chain Reaction; D014763:Viral Matrix Proteins / Q000235:genetics*
D017931:DNA Primers; C037662:EBV-associated membrane antigen, Epstein-Barr virus; D018984:Epitopes, T-Lymphocyte; D006680:HLA Antigens; D014763:Viral Matrix Proteins; D016899:Interferon-beta; D007371:Interferon-gamma