title: Vaccination with TAT-antigen fusion protein induces protective, CD8(+) T cell-mediated immunity against Leishmania major.
abstract: In murine leishmaniasis, healing is mediated by IFN-γ-producing CD4(+) and CD8(+) T cells. Thus, an efficacious vaccine should induce Th1 and Tc1 cells. Dendritic cells (DCs) pulsed with exogenous proteins primarily induce strong CD4-dependent immunity; induction of CD8 responses has proven to be difficult. We evaluated the immunogenicity of fusion proteins comprising the protein transduction domain of HIV-1 TAT and the Leishmania antigen LACK (Leishmania homolog of receptors for activated C kinase), as TAT-fusion proteins facilitate major histocompatibility complex class I-dependent antigen presentation. In vitro, TAT-LACK-pulsed DCs induced stronger proliferation of Leishmania-specific CD8(+) T cells compared with DCs incubated with LACK alone. Vaccination with TAT-LACK-pulsed DCs or fusion proteins plus adjuvant in vivo significantly improved disease outcome in Leishmania major-infected mice and was superior to vaccination with DCs treated with LACK alone. Vaccination with DC+TAT-LACK resulted in stronger proliferation of CD8(+) T cells when compared with immunization with DC+LACK. Upon depletion of CD4(+) or CD8(+) T cells, TAT-LACK-mediated protection was lost. TAT-LACK-pulsed IL-12p40-deficient DCs did not promote protection in vivo. In summary, these data show that TAT-fusion proteins are superior in activating Leishmania-specific Tc1 cells when compared with antigen alone and suggest that IL-12-dependent preferential induction of antigen-specific CD8(+) cells promotes significant protection against this important human pathogen.
authors.affiliation: Department of Dermatology, Johannes Gutenberg-University, Mainz, Germany.
authors.forename: Katharina
authors.initials: K
authors.lastname: Kronenberg
authors.forename: Sven
authors.initials: S
authors.lastname: Brosch
authors.forename: Florian
authors.initials: F
authors.lastname: Butsch
authors.forename: Yayoi
authors.initials: Y
authors.lastname: Tada
authors.forename: Naotaka
authors.initials: N
authors.lastname: Shibagaki
authors.forename: Mark C
authors.initials: MC
authors.lastname: Udey
authors.forename: Esther
authors.initials: E
authors.lastname: von Stebut
mesh_terms: D000818:Animals; D000953:Antigens, Protozoan / Q000276:immunology; D018414:CD8-Positive T-Lymphocytes / Q000276:immunology*; D003713:Dendritic Cells / Q000276:immunology; D018664:Interleukin-12 / Q000276:immunology; D018320:Leishmania major / Q000276:immunology*; D016773:Leishmaniasis, Cutaneous / Q000276:immunology* / Q000517:prevention & control*; D051379:Mice; D008810:Mice, Inbred C57BL; D008817:Mice, Mutant Strains; D015800:Protozoan Proteins / Q000276:immunology; D016052:Protozoan Vaccines / Q000276:immunology*; D018417:Th1 Cells / Q000276:immunology; D014760:Viral Fusion Proteins / Q000276:immunology; D054322:tat Gene Products, Human Immunodeficiency Virus / Q000276:immunology*
chemical_list: D000953:Antigens, Protozoan; D015800:Protozoan Proteins; D016052:Protozoan Vaccines; D014760:Viral Fusion Proteins; D054322:tat Gene Products, Human Immunodeficiency Virus; C093139:LACK antigen, Leishmania; D018664:Interleukin-12