IDENTIFICATION OF A 25-AMINO-ACID SEQUENCE FROM THE MAJOR AFRICAN SWINE FEVER VIRUS STRUCTURAL PROTEIN VP72 RECOGNIZED BY PORCINE CYTOTOXICT-LYMPHOCYTES USING A LIPOPROTEIN BASED EXPRESSION SYSTEM

Identification of African swine fever virus (ASFV) proteins recognised by cytotoxic T lymphocytes (CTL) from swine surviving ASFV/NH/P68 inf ection was assessed using expression vectors based on the Pseudomonas aeruginosa outer membrane lipoprotein I gene (oprI). Viral antigens ex pressed as fusion lipoproteins were shown to be taken efficiently by p orcine blood-derived macrophages incubated with outer membrane protein preparations from transformed E. coli. To assess recognition by CTL t he fusion lipoprotein-treated macrophages were used as targets in Cr-5 1 release microcytotoxicity assays. Using this approach it was shown t hat the aminoacid sequence HKPHQSKPILTDENDTQRTCSHTNP from the major st ructural ASFV protein (VP72), encoded by a recombinant clone (pVUB72) is presented by macrophages, which are lysed under restriction of SLA class I antigens. Overall, the results demonstrate that the oprI based vectors are valuable tools to study ASFV-specific CTL activity. (C) 1 998 Elsevier Science B.V. All rights reserved.