title: Both invariant chain isoforms Ii31 and Ii41 promote class II antigen presentation.
abstract: The invariant chain (Ii) gene encodes two differentially spliced variants Ii31 and Ii41. The Ii31 isotype is the dominant form expressed in all antigen-presenting cells (APC). Ii41 is differentially expressed and can be found in large quantities in Langerhans and dendritic cells. While a functional role of Ii in class II antigen presentation is now well established, a distinct role of the Ii isotypes remains controversial. We tested Ii31 and Ii41 L cell transfectants for antigen presentation of hen egg lysozyme (HEL) to T cell hybridomas. The result indicates that both Ii chains promote antigen presentation equally well. To test other APC than transfected L cells, we introduced a recombinant Ii41 gene into anti-deficient mouse line. There the transgene induces about one-third of total li expression of wild-type mice. Surface expression of class II molecules and the CD4 compartment which are deficient in Ii knock-out mice are restored in Ii41 transgenic mice. B lymphocytes from Ii41 transgenic mice and Ii31-expressing B lymphocytes from wild-type mice were used as APC for presentation of keyhole limpet hemacyanin and ovalbumin to T cell hybridomas. The results show that both Ii chains facilitate antigen presentation equally well.
authors.affiliation: Section of Immunobiology, Institute of Zoology, University of Bonn, Germany.
authors.forename: M
authors.initials: M
authors.lastname: Serwe
authors.forename: G
authors.initials: G
authors.lastname: Reuter
authors.forename: A
authors.initials: A
authors.lastname: Sponaas
authors.forename: S
authors.initials: S
authors.lastname: Koch
authors.forename: N
authors.initials: N
authors.lastname: Koch
mesh_terms: D000818:Animals; D017951:Antigen Presentation / Q000235:genetics; D000938:Antigen-Presenting Cells / Q000276:immunology / Q000378:metabolism; D015703:Antigens, CD / Q000737:chemistry / Q000378:metabolism; D000944:Antigens, Differentiation, B-Lymphocyte / Q000737:chemistry* / Q000235:genetics / Q000502:physiology*; D018076:DNA, Complementary / Q000235:genetics / Q000378:metabolism; D000949:Histocompatibility Antigens Class II / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism* / Q000502:physiology*; D007536:Isomerism; D007739:L Cells; D051379:Mice; D018345:Mice, Knockout; D008822:Mice, Transgenic; D009113:Muramidase / Q000235:genetics / Q000276:immunology; D013601:T-Lymphocytes / Q000276:immunology / Q000378:metabolism; D014162:Transfection / Q000276:immunology
chemical_list: D015703:Antigens, CD; D000944:Antigens, Differentiation, B-Lymphocyte; D018076:DNA, Complementary; D000949:Histocompatibility Antigens Class II; C045084:invariant chain; D009113:Muramidase