title: Heavy-chain only antibodies derived from dromedary are secreted and displayed by mouse B cells.
abstract: Whereas functional heavy (H)-chain antibodies devoid of light (L)- chains account for about half of the circulating immunoglobulins in Camelidae, H-chain only antibodies (HCAbs) are not produced in other healthy mammals including rodents and humans. To test the feasibility of expressing single chain antibodies in the mouse, which on account of their small size and antigen-recognition properties would have a major impact on antibody engineering strategies, we constructed a rearranged dromedary H-chain gene encoding the immunoglobulin G2a (IgG2a) isotype with specificity for hen-egg lysozyme (HEL). This IgG2a H-chain gene was introduced into mouse myeloma cells not expressing endogenous immunoglobulin H- or L-chains. Unexpectedly the mouse cells processed and expressed the introduced H-chain as naturally occurring dromedary antibody. For this the first constant (C) region exon was proficiently removed from the recombinant H-chain transcript. This resulted in specific H-chain antibodies of the correct molecular weight (2 x 50 000 MW) secreted as disulfide-linked homodimers and displayed on the mouse cell surface as glycosyl-phosphatidyl-inositol-linked B-cell receptor. The results indicate that antibody expression and maturation without immunoglobulin L-chain is feasible and paves the way for the generation of transgenic single chain antibody repertoires.
authors.affiliation: Department of Ultrastructure, Vlaams Interuniversitair Instituut voor Biotechnologie, Vrije Universiteit Brussel, Belgium.
authors.forename: Viet Khong
authors.initials: VK
authors.lastname: Nguyen
authors.forename: Xiangang
authors.initials: X
authors.lastname: Zou
authors.forename: Marc
authors.initials: M
authors.lastname: Lauwereys
authors.forename: Lea
authors.initials: L
authors.lastname: Brys
authors.forename: Marianne
authors.initials: M
authors.lastname: Brüggemann
authors.forename: Serge
authors.initials: S
authors.lastname: Muyldermans
mesh_terms: D000818:Animals; D000918:Antibody Specificity; D001402:B-Lymphocytes / Q000276:immunology*; D002162:Camelus / Q000276:immunology*; D005240:Feasibility Studies; D015321:Gene Rearrangement / Q000276:immunology; D007074:Immunoglobulin G / Q000235:genetics; D007143:Immunoglobulin Heavy Chains / Q000096:biosynthesis / Q000235:genetics / Q000378:metabolism*; D051379:Mice; D009101:Multiple Myeloma / Q000276:immunology; D009113:Muramidase / Q000276:immunology; D010455:Peptides / Q000378:metabolism; D013045:Species Specificity; D014162:Transfection
chemical_list: D007074:Immunoglobulin G; D007143:Immunoglobulin Heavy Chains; D010455:Peptides; C421864:hen egg lysozyme; D009113:Muramidase