title: Quality of the transgene-specific CD8+ T cell response induced by adenoviral vector immunization is critically influenced by virus dose and route of vaccination.
abstract: Adenoviral vectors have been widely used for experimental gene therapy and vaccination, yet there is a surprising lack of knowledge connecting the route and dose of adenovirus administration to the induced transgene-specific immune response. We have recently demonstrated polyfunctional CD8(+) T cells and protective memory responses using adenoviral vectors, which seem to contrast with recent reports suggesting that an exhausted CD8(+) T cell phenotype is induced by inoculation with adenoviral vectors. Accordingly, we investigated the route and dose interrelationship for transgene-specific CD8(+) T cells using adenoviral vectors encoding beta-galactosidase applied either s.c. or i.v. Irrespective of the route of inoculation, most of the adenoviral inoculum was found to disseminate systemically as the dose was raised beyond 10(9) particles. The number of transgene-specific CD8(+) T cells correlated positively with dissemination, whereas the functional capacity of the generated T cells correlated inversely with vector dissemination. A comparison of the immune response to s.c. or i.v. administration at moderate doses revealed that inoculation by both routes induced a transient peak of IFN-gamma-producing CD8(+) T cells 2 to 3 wk postinfection, but following i.v. administration, these cells were only detected in the liver. Two to four months after systemic, but not peripheral, immunization, dysfunctional transgene-specific CD8(+) T cells impaired in both cytokine production and important in vivo effector functions, accumulated in the spleen. These findings indicate that the localization of the adenoviral inoculum and not the total Ag load determines the quality of the CD8(+) T cell response induced with adenoviral vaccines.
authors.affiliation: Department of International Health, University of Copenhagen, Copenhagen, Denmark.
authors.forename: Peter Johannes
authors.initials: PJ
authors.lastname: Holst
authors.forename: Cathrine
authors.initials: C
authors.lastname: Ørskov
authors.forename: Allan Randrup
authors.initials: AR
authors.lastname: Thomsen
authors.forename: Jan Pravsgaard
authors.initials: JP
authors.lastname: Christensen
mesh_terms: D000258:Adenovirus Infections, Human / Q000276:immunology / Q000517:prevention & control; D000260:Adenoviruses, Human / Q000235:genetics* / Q000276:immunology*; D000818:Animals; D018414:CD8-Positive T-Lymphocytes / Q000276:immunology* / Q000821:virology; D003601:Cytotoxicity Tests, Immunologic / Q000379:methods* / Q000639:trends; D004306:Dose-Response Relationship, Immunologic; D005528:Foot; D005822:Genetic Vectors / Q000008:administration & dosage / Q000276:immunology* / Q000592:standards; D006614:Hindlimb; D007156:Immunologic Memory / Q000235:genetics; D007275:Injections, Intravenous; D007279:Injections, Subcutaneous; D051379:Mice; D008810:Mice, Inbred C57BL; D019076:Transgenes / Q000276:immunology*; D014616:Vaccinia virus / Q000201:enzymology / Q000235:genetics / Q000276:immunology; D019562:Viral Load / Q000276:immunology* / Q000592:standards; D001616:beta-Galactosidase / Q000008:administration & dosage / Q000235:genetics / Q000276:immunology
chemical_list: D001616:beta-Galactosidase