title: Vaccine requirements for sustained cellular immunity to an intracellular parasitic infection.
abstract: The humoral immunity induced by many viral and bacterial vaccines mediates protection that is maintained over a long period of time. In contrast, for other intracellular infections (such as with Leishmania major or Mycobacterium tuberculosis) for which cell-mediated immunity is required for protection, the mechanisms for developing durable responses after vaccination have not been well defined. Here we demonstrate that vaccination with plasmid DNA encoding a specific leishmanial antigen is more effective than leishmanial protein plus recombinant IL-12 in eliciting long-term immunity capable of controlling L. major infection. We also show that leishmanial protein plus IL-12 DNA produces an immunity that lasts much longer than does immunity elicited by leishmanial protein plus IL-12 protein, indicating that the persistence of IL-12 may be the essential determinant in maintaining durable cell-mediated immune responses for an intracellular parasitic infection.
authors.affiliation: National Institutes of Health, Bethesda, Maryland 20892, USA.
authors.forename: S
authors.initials: S
authors.lastname: Gurunathan
authors.forename: C
authors.initials: C
authors.lastname: Prussin
authors.forename: D L
authors.initials: DL
authors.lastname: Sacks
authors.forename: R A
authors.initials: RA
authors.lastname: Seder
mesh_terms: D000276:Adjuvants, Immunologic / Q000627:therapeutic use; D000818:Animals; D000953:Antigens, Protozoan / Q000276:immunology*; D007111:Immunity, Cellular; D007371:Interferon-gamma / Q000096:biosynthesis; D018664:Interleukin-12 / Q000235:genetics / Q000627:therapeutic use; D018320:Leishmania major / Q000276:immunology*; D016773:Leishmaniasis, Cutaneous / Q000276:immunology / Q000517:prevention & control*; D051379:Mice; D008807:Mice, Inbred BALB C; D015800:Protozoan Proteins / Q000276:immunology*; D016052:Protozoan Vaccines / Q000276:immunology*; D011994:Recombinant Proteins / Q000627:therapeutic use; D019444:Vaccines, DNA / Q000276:immunology*
chemical_list: D000276:Adjuvants, Immunologic; D000953:Antigens, Protozoan; D015800:Protozoan Proteins; D016052:Protozoan Vaccines; D011994:Recombinant Proteins; D019444:Vaccines, DNA; C093139:LACK antigen, Leishmania; D018664:Interleukin-12; D007371:Interferon-gamma