title: IL-15-IgG2b fusion protein accelerates and enhances a Th2 but not a Th1 immune response in vivo, while IL-2-IgG2b fusion protein inhibits both.
abstract: We have explored how IL-15 influences Th1 or Th2 type immune response in vivo. Intraperitoneal application of an IL-15-IgG2b fusion protein (FP) to mice did neither significantly affect the footpad swelling nor the production of hemagglutinizing antibodies in a delayed type hypersensitivity reaction to sheep red blood cells. In contrast, in an established murine Th2 model of sensitization to ovalbumin (OVA), IL-15-IgG2b FP plus OVA sensitization resulted in massively accelerated and enhanced allergen-specific IgE and IgG1 antibody production. In vitro, stimulation of spleen cells from OVA-sensitized mice with OVA+IL-15 or OVA+IL-15-IgG2b resulted in a significantly enhanced IgE production. IL-4 secretion was significantly induced by IL-15 but not by IL-15-IgG2b. An IL-2-IgG2b FP with the same Fc tail as the IL-15-IgG2b FP was used as control in both models. In striking contrast to the IL-15-IgG2b FP, IL-2-IgG2b significantly inhibited the Th2 type antibody production in vivo. The current study suggests that IL-15-IgG2b may be employed as a potent accelerator and enhancer of Th2 type immune responses in vivo, while IL-2-IgG2b can suppress the latter.
authors.affiliation: Institute for Immunology, University Hospital Benjamin Franklin, Free University Berlin, Germany.
authors.forename: R
authors.initials: R
authors.lastname: Rückert
authors.forename: U
authors.initials: U
authors.lastname: Herz
authors.forename: R
authors.initials: R
authors.lastname: Paus
authors.forename: D
authors.initials: D
authors.lastname: Ungureanu
authors.forename: T
authors.initials: T
authors.lastname: Pohl
authors.forename: H
authors.initials: H
authors.lastname: Renz
authors.forename: S
authors.initials: S
authors.lastname: Bulfone-Paus
mesh_terms: D000485:Allergens / Q000276:immunology; D000818:Animals; D006968:Hypersensitivity, Delayed / Q000276:immunology; D007073:Immunoglobulin E / Q000276:immunology; D007074:Immunoglobulin G / Q000276:immunology*; D019409:Interleukin-15 / Q000276:immunology*; D007376:Interleukin-2 / Q000276:immunology*; D015847:Interleukin-4 / Q000378:metabolism; D051379:Mice; D008807:Mice, Inbred BALB C; D008810:Mice, Inbred C57BL; D010047:Ovalbumin / Q000276:immunology; D011993:Recombinant Fusion Proteins / Q000276:immunology; D013154:Spleen / Q000276:immunology; D018417:Th1 Cells / Q000276:immunology*; D018418:Th2 Cells / Q000276:immunology*
chemical_list: D000485:Allergens; D007074:Immunoglobulin G; D019409:Interleukin-15; D007376:Interleukin-2; D011993:Recombinant Fusion Proteins; D015847:Interleukin-4; D007073:Immunoglobulin E; D010047:Ovalbumin