Induction of Epstein-Barr Virus-Specific Cytotoxic T-Lymphocyte Responses Using Dendritic Cells Pulsed With EBNA-3A Peptides or UV-Inactivated, Recomb
Marion Subklewe, Ann Chahroudi, Alan Schmaljohn, Michael G. Kurilla, Nina Bhardwaj, and Ralph M. Steinman
01/15/2013
Cell-mediated immunity, especially the cytotoxic T lymphocyte (CTL), provides resistance to Epstein-Barr virus (EBV), as is demonstrated by the occurrence of posttransplant lymphoproliferative disease in immunosuppressed patients. We set out to use dendritic cells (DCs) to elicit anti–EBVspecific CTLs in culture. In unselected, HLA-B8+ donors, monocyte-derived mature DCs were pulsed with the HLA-B8– restricted EBNA-3A peptide, FLRGRAYGL, and added to autologous T cells for 7 days at a DC:T ratio of 1:5 to 1:60. The cultured cells specifically lysed EBNA-3A peptide-pulsed, HLA-B8+, B-lymphoblastoid cell lines in a 5-hour 51Cr-release assay. The generation of CTLs did not require the addition of interleukin-2. In comparison, monocytes were weak antigenpresenting cells. DCs were then infected with recombinant vaccinia-EBNA-3A. Vaccinia infection significantly decreased the viability of immature DCs after 3 days of culture (to 25% to 45%) but had a smaller effect on mature DC recovery (40% to 70%). To decrease these cytopathic effects and to expand the potential use of vaccinia vectors for DC therapy in immunocompromised patients, we successfully used psoralen and UV-inactivated virus. Mature DCs pulsedwith either live or inactivated vaccinia EBNA-3A virus could elicit strong EBNA-3A–specific CTLs. Therefore, mature DCs are powerful stimulators of EBV-specific CTLs and their major histocompatibility complex class I products can even be charged with UV-inactivated recombinant vaccinia.