Vaccination with a synthetic peptide modulates lymphocytic choriomeningitis virus-mediated immunopathology

Vaccination with a nucleopeptide (NP 118; amino acids 118 to 132) representing a cytotoxic T-cell epitope of lymphocytic choriomeningitis virus (LCMV) can modulate immunopathology. Immunization with NP 118 protected H-2d mice against intracerebral infection with the LCMV-ARMSTRONG isolate. However, when NP 118-primed H-2d mice were challenged intracerebrally with an intermediate dose (5 x 10(4) PFU) of the LCMV-DOCILE strain, all mice primed with NP 118 emulsified in incomplete Freund's adjuvant died, whereas unprimed mice survived. Correspondingly, peptide vaccination enhanced specifically the cytotoxic T-cell response, influencing the critical balance between T-cell response and virus spread.