Cytotoxic T lymphocytes to Ebola Zaire virus are induced in mice by immunization with liposomes containing lipid A

An eight amino acid sequence (TELRTFSI) present in the carboxy terminal end (aa 577-584) of membrane-anchored GP, the major structural protein of Ebol a virus, was identified as an H-2(k)-specific murine cytotoxic T cell epito pe, Cytotoxic T lymphocytes (CTLs) to this epitope were induced by immunizi ng B10.BR mice intravenously with either irradiated Ebola virus or with irr adiated Ebola virus encapsulated in liposomes containing lipid A. The CTL r esponse induced by irradiated Ebola virus could not be sustained after the second round of in vitro stimulation of immune splenocytes with the peptide , unless the irradiated virus was encapsulated in liposomes containing lipi d A. The identification of an Ebola GP-specific CTL epitope and the require ment of liposomal lipid A for CTL memory recall responses could prove to be a promising approach for developing a vaccine against Ebola virus infectio n. Published by Elsevier Science Ltd. All rights reserved.