title: The effect of pre-existing immunity on the capacity of influenza virosomes to induce cytotoxic T lymphocyte activity.
abstract: Protein antigens encapsulated in virosomes generated from influenza virus can induce antigen-specific cytotoxic T lymphocyte (CTL) responses. In the present study we determined, in a murine model system, whether pre-existing immunity against influenza virus hampers the induction of a CTL response. CTL induction was only slightly reduced by pre-injection of influenza virus-specific antibodies or pre-exposure to influenza virus. Both pretreatments resulted in the same level of reduction, suggesting that virus-specific antibodies rather than T cell responses account for the reduction. Furthermore, a booster immunization enhanced CTL activation, indicating that virosome-specific immunity induced by a prime immunization does not hamper the booster effect. In conclusion, CTL induction against virosome-encapsulated protein antigens is not significantly inhibited by pre-existing humoral or cellular immunity against influenza virus.
authors.affiliation: Department of Medical Microbiology, Molecular Virology Section, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands.
authors.forename: Arjan
authors.initials: A
authors.lastname: de Mare
authors.forename: Laura B
authors.initials: LB
authors.lastname: Bungener
authors.forename: Joke
authors.initials: J
authors.lastname: Regts
authors.forename: Jacqueline
authors.initials: J
authors.lastname: de Vries-Idema
authors.forename: Ate G J
authors.initials: AG
authors.lastname: van der Zee
authors.forename: Jan
authors.initials: J
authors.lastname: Wilschut
authors.forename: Toos
authors.initials: T
authors.lastname: Daemen
mesh_terms: D000818:Animals; D003602:Cytotoxicity, Immunologic; D005260:Female; D007117:Immunization, Secondary; D007252:Influenza Vaccines / Q000276:immunology*; D007371:Interferon-gamma / Q000096:biosynthesis; D051379:Mice; D008810:Mice, Inbred C57BL; D009976:Orthomyxoviridae Infections / Q000276:immunology* / Q000517:prevention & control*; D013154:Spleen / Q000276:immunology; D013602:T-Lymphocytes, Cytotoxic / Q000276:immunology*; D022701:Virosomes / Q000276:immunology*
chemical_list: D007252:Influenza Vaccines; D022701:Virosomes; D007371:Interferon-gamma