Induction of virus-specific cytotoxic T lymphocytes by in vivo electric administration of peptides

Generally, major histocompatibility complex (MHC) class I presentation of p eptide antigens only occur for proteins' which are actively synthesized and processed intracellularly, so that immunization with a cytotoxic T lymphoc yte (CTL) target peptide does not usually elicit effective CTL responses. I n the present study, we explored the use of epitope peptides by in vivo ele ctroporation to introduce directly into the cytoplasm for the vaccine elici tation of virus-specific CTLs in a mouse system. BALB/c mice were immunized with human immunodeficiency virus (HIV) env (P18, residues 311-320) or hep atitis C virus (HCV) NS5 (P17, residues 2423-2434) with or without electric pulses. Effector cells against peptide-labeled target cells were elicited in mice immunized with peptides with electric administration but not withou t electric administration. Moreover, cytolytic activities of CTL against pe ptide-labeled target cells were enhanced by the addition of plasmid having the immunostimulatory sequence (ISS) or cDNA of the B7-1 molecule in electr ic administration of peptides. The results of the present study suggest tha t a peptide vaccine against a virus using electric administration is effect ive in eliciting virus specific CTLs. (C) 2001 Elsevier Science Ltd. All ri ghts reserved.