Novel peptide-based vaccines generate immunity to hepatotropic pathogens.

2004 NOV 3 - (NewsRx.com & NewsRx.net) -- Novel peptide-based vaccines generate immunity to hepatotropic pathogens.

"Vaccines for the prophylactic and/or therapeutic immunization against hepatotropic pathogens (e.g., hepatitis B and hepatitis C virus) should establish long-lasting, specific antiviral effector/memory CD8+ T cell immunity in the liver," researchers in Germany report.

"We describe a novel peptide-based vaccine in which antigenic major histocompatibility complex class I-binding peptides are fused to a cationic (e.g., human immunodeficiency virus tat-derived) domain and complexed to immune-stimulating oligonucleotides. This vaccine formulation efficiently primes liver-homing, class I-restricted CD8+ effector/memory T cell responses," stated N. Dikopoulos and colleagues, University of Ulm, Department of Medical Microbiology and Immunology.

"In different antigen systems, this formulation was more potent in priming liver-homing CD8+ T cell responses than DNA-based vaccines delivering the same epitopes. CD8+ T cell priming was independent of CD4+ T cell 'help' but submitted to regulatory control by CD25+ CD4+ T cells. The vaccine efficiently primed memory/effector CD8+ T cells detectable in the liver for more than 3 months after a single injection.

"With increasing time after priming, the phenotype of these specific memory ...