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PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
5
pubmed:dateCreated
2008-6-25
pubmed:abstractText
Immunotherapy approaches targeting Epstein-Barr virus (EBV)-encoded antigens induce objective clinical responses only in a fraction of patients with undifferentiated nasopharyngeal carcinoma (UNPC). In the present study, we have characterized the immunogenicity of the EBV-encoded BARF1 oncogene with the aim to assess whether this protein could constitute a new target antigen for immunotherapy in this setting. Spontaneous CD4+ and CD8+ T cell responses specific for the recombinant p29 BARF1 protein were detected by IFNgamma-ELISPOT in both EBV-seropositive donors and UNPC patients, but not in EBV-seronegative individuals. Using immunoinformatic prediction tools, we have selected 5 different candidate BARF1 T cell epitopes presented by HLA-A*0201. Although only one of these peptides was able to bind HLA-A2 with low affinity in the T2 stabilization assay, all 5 BARF1 nonamers readily elicited specific CD8+ T cell responses in EBV-seropositive HLA-A*0201+ donors and UNPC patients. Notably, the magnitude of CD8+ T cell responses to the whole BARF1 protein and derived A*0201 peptides was significantly higher in UNPC patients than in healthy donors. Moreover, cytotoxic T lymphocytes specific for the p2-10, p23-31, or p49-57 BARF1 peptides were easily obtained from HLA-A*0201+ donors. These cultures were not only able to lyse autologous targets loaded with the antigenic peptide, but also recognized tumor cells endogenously expressing BARF1 in an antigen-specific and HLA-A2-restricted manner. These findings, indicate that BARF1 is a particularly attractive antigen with immunogenic properties in most UNPC patients and provide valuable information to develop new strategies to improve the efficacy of EBV-targeting immunotherapy of UNPC patients.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Sep
pubmed:issn
1097-0215
pubmed:author
pubmed:issnType
Electronic
pubmed:day
1
pubmed:volume
123
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
1100-7
pubmed:meshHeading
pubmed:year
2008
pubmed:articleTitle
Spontaneous T cell responses to Epstein-Barr virus-encoded BARF1 protein and derived peptides in patients with nasopharyngeal carcinoma: bases for improved immunotherapy.
pubmed:affiliation
Cancer Bioimmunotherapy Unit, Centro di Riferimento Oncologico, IRCCS-National Cancer Institute, Aviano, PN, Italy.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't