title: A subset of dendritic cells express joining chain (J-chain) protein.
abstract: Joining chain (J-chain) is well known as an integrated component of dimeric immunoglobulin A (IgA) and pentameric IgM. We show here that the J-chain protein is also expressed in a subset of CD11c+ dendritic cells (DC) in C57BL/6 mice. J-chain knockout mice (J-/- mice) had a reduced fraction of CD4-/CD8alpha+ and mPDCA-1+ DC in the spleen. J-/- mice also had reduced levels of RNA for the immunoregulatory enzyme indoleamine 2,3-dioxygenase (IDO) in the spleen. Furthermore, in lymph nodes from C57BL/6 mice the majority of J-chain-expressing CD11c+ cells also expressed IDO, while the number of IDO-expressing cells in lymph nodes and the amount of IDO protein in splenic CD11c+ cells were reduced in J-/- mice. Also, J-/- mice had a lower ratio of kynurenine/tryptophan in serum compared to C57BL/6 mice, indicating a lower overall IDO activity in J-/- mice. We also show that J-/- mice are less susceptible to tolerance induction than C57BL/6 mice. In conclusion, our data show that J-chain protein is expressed outside the B-cell compartment in a subset of immunoregulatory DC that are compromised in animals that cannot express J-chain.
authors.affiliation: Immunology Group, Lund University, Lund, Sweden.
authors.forename: Eva
authors.initials: E
authors.lastname: Källberg
authors.forename: Tomas
authors.initials: T
authors.lastname: Leanderson
mesh_terms: D000818:Animals; D039521:CD11c Antigen / Q000032:analysis; D003713:Dendritic Cells / Q000276:immunology*; D015870:Gene Expression / Q000276:immunology; D007108:Immune Tolerance; D007144:Immunoglobulin J-Chains / Q000096:biosynthesis* / Q000235:genetics; D050503:Indoleamine-Pyrrole 2,3,-Dioxygenase / Q000096:biosynthesis / Q000235:genetics; D051379:Mice; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D012313:RNA / Q000235:genetics; D013154:Spleen / Q000276:immunology
chemical_list: D039521:CD11c Antigen; D007144:Immunoglobulin J-Chains; D050503:Indoleamine-Pyrrole 2,3,-Dioxygenase; D012313:RNA