DIFFERENTIAL-EFFECTS OF FLANKING RESIDUES ON PRESENTATION OF EPITOPESFROM CHIMERIC PEPTIDES

Chimeric peptides in which the optimal H-2(d) mouse hepatitis virus nu cleocapsid (pN) and human immunodeficiency virus type 1 (p18) epitopes , separated by 38, 7, or 2 amino acids, were expressed from a single o pen reading frame by using recombinant vaccinia viruses to analyze ant igen processing of proximal class I-restricted epitopes. Recognition o f the carboxy-terminal D-d-restricted p18 epitope was independent of t he amino-terminal flanking residues. By contrast, proximity of the car boxy-terminal epitope decreased recognition of the amino-terminal L(d) -restricted pN epitope. Immunization resulted in the induction of both p18- and pN-specific antiviral cytotoxic T lymphocytes, irrespective of the number of amino acids separating the epitopes.