title: Expression of heavy chain-only antibodies can support B-cell development in light chain knockout chickens.
abstract: Since the discovery of antibody-producing B cells in chickens six decades ago, chickens have been a model for B-cell development in gut-associated lymphoid tissue species. Here we describe targeting of the immunoglobulin light chain locus by homologous recombination in chicken primordial germ cells (PGCs) and generation of VJCL knockout chickens. In contrast to immunoglobulin heavy chain knockout chickens, which completely lack mature B cells, homozygous light chain knockout (IgL(-/-) ) chickens have a small population of B lineage cells that develop in the bursa and migrate to the periphery. This population of B cells expresses the immunoglobulin heavy chain molecule on the cell surface. Soluble heavy-chain-only IgM and IgY proteins of reduced molecular weight were detectable in plasma in 4-week-old IgL(-/-) chickens, and antigen-specific IgM and IgY heavy chain proteins were produced in response to immunization. Circulating heavy-chain-only IgM showed a deletion of the CH1 domain of the constant region enabling the immunoglobulin heavy chain to be secreted in the absence of the light chain. Our data suggest that the heavy chain by itself is enough to support all the important steps in B-cell development in a gut-associated lymphoid tissue species.
authors.affiliation: Reproductive Biotechnology, Technische Universität München, WZW Center of Life Science, Freising-Weihenstephan, Germany.
authors.forename: Benjamin
authors.initials: B
authors.lastname: Schusser
authors.affiliation: Crystal Bioscience Inc, Emeryville, CA, USA.
authors.forename: Ellen J
authors.initials: EJ
authors.lastname: Collarini
authors.affiliation: Crystal Bioscience Inc, Emeryville, CA, USA.
authors.forename: Darlene
authors.initials: D
authors.lastname: Pedersen
authors.affiliation: Crystal Bioscience Inc, Emeryville, CA, USA.
authors.forename: Henry
authors.initials: H
authors.lastname: Yi
authors.affiliation: Crystal Bioscience Inc, Emeryville, CA, USA.
authors.forename: Kathryn
authors.initials: K
authors.lastname: Ching
authors.affiliation: Crystal Bioscience Inc, Emeryville, CA, USA.
authors.forename: Shelley
authors.initials: S
authors.lastname: Izquierdo
authors.affiliation: Reproductive Biotechnology, Technische Universität München, WZW Center of Life Science, Freising-Weihenstephan, Germany.
authors.forename: Theresa
authors.initials: T
authors.lastname: Thoma
authors.affiliation: Department of Veterinary Science, Institute for Animal Physiology, Ludwig-Maximilians-Universitaet Muenchen, Munich, Germany.
authors.forename: Sarah
authors.initials: S
authors.lastname: Lettmann
authors.affiliation: Department of Veterinary Science, Institute for Animal Physiology, Ludwig-Maximilians-Universitaet Muenchen, Munich, Germany.
authors.forename: Bernd
authors.initials: B
authors.lastname: Kaspers
authors.affiliation: Crystal Bioscience Inc, Emeryville, CA, USA.
authors.forename: Robert J
authors.initials: RJ
authors.lastname: Etches
authors.affiliation: Crystal Bioscience Inc, Emeryville, CA, USA.
authors.forename: Marie-Cecile
authors.initials: MC
authors.lastname: van de Lavoir
authors.affiliation: Crystal Bioscience Inc, Emeryville, CA, USA.
authors.forename: William
authors.initials: W
authors.lastname: Harriman
authors.affiliation: Crystal Bioscience Inc, Emeryville, CA, USA. pal@crystalbioscience.com.
authors.forename: Philip A
authors.initials: PA
authors.lastname: Leighton
mesh_terms: D000818:Animals; D030801:Animals, Genetically Modified; D000906:Antibodies / Q000235:genetics* / Q000276:immunology; D000917:Antibody Formation / Q000235:genetics / Q000276:immunology; D001402:B-Lymphocytes / Q000276:immunology* / Q000378:metabolism*; D002454:Cell Differentiation / Q000235:genetics / Q000276:immunology; D002645:Chickens; D017353:Gene Deletion; D015870:Gene Expression; D055786:Gene Knockout Techniques; D023061:Gene Order; D018390:Gene Targeting; D005822:Genetic Vectors / Q000235:genetics; D007143:Immunoglobulin Heavy Chains / Q000235:genetics*; D007147:Immunoglobulin Light Chains / Q000737:chemistry / Q000235:genetics*; D010950:Plasma Cells / Q000276:immunology / Q000378:metabolism; D000072417:Protein Domains / Q000235:genetics
chemical_list: D000906:Antibodies; D007143:Immunoglobulin Heavy Chains; D007147:Immunoglobulin Light Chains
keywords: Antibodies; B-cell development; Immunoglobulins; Knockout chickens