Characterization of immunoglobulin heavy chain knockout rats

• Published in: European journal of immunology 2010-10, Vol.40 (10), p.2932-2941
• Main Authors: Ménoret, Séverine, Iscache, Anne-L, Tesson, Laurent, Rémy, Séverine, Usal, Claire, Osborn, Michel J, Cost, Gregory J, Brüggemann, Marianne, Buelow, Roland, Anegon, Ignacio
• Format: Article
• Language: English
• Subjects: Amino Acid Sequence; Animals; Animals, Genetically Modified; B-Lymphocytes - cytology; B-Lymphocytes - immunology; B‐cell deficient; Cell Differentiation - immunology; Embryonic Stem Cells - immunology; Graft Survival - immunology; Heart Transplantation - immunology; Immunoglobulin Constant Regions - genetics; Immunoglobulin Constant Regions - immunology; Immunoglobulin Heavy Chains - genetics; Immunoglobulin Heavy Chains - immunology; Immunoglobulin Isotypes - blood; Immunoglobulin Joining Region - genetics; Immunoglobulin Joining Region - immunology; Knockout rat; Lymphoid Tissue - immunology; Molecular Sequence Data; Rats; Rats, Inbred Lew; Rats, Mutant Strains; Rats, Sprague-Dawley; Reverse Transcriptase Polymerase Chain Reaction; RNA - chemistry; RNA - genetics; Specific Pathogen-Free Organisms; Transgenic rat; Zinc Fingers - genetics; Zinc‐finger nucleases
• ISSN: 0014-2980; 1521-4141
• DOI: 10.1002/eji.201040939

The rat is a species frequently used in immunological studies but, until now, there were no models with introduced gene-specific mutations. In a recent study, we described for the first time the generation of novel rat lines with targeted mutations using zinc-finger nucleases. In this study, we compare immune development in two Ig heavy-chain KO lines; one with truncated Cμ and a new line with removed JH segments. Rats homozygous for IgM mutation generate truncated Cμ mRNA with a de novo stop codon and no Cγ mRNA. JH-deletion rats showed undetectable mRNA for all H-chain transcripts. No serum IgM, IgG, IgA and IgE were detected in these rat lines. In both lines, lymphoid B-cell numbers were reduced >95% versus WT animals. In rats homozygous for IgM mutation, no Ab-mediated hyperacute allograft rejection was encountered. Similarities in B-cell differentiation seen in Ig KO rats and ES cell-derived Ig KO mice are discussed. These Ig and B-cell-deficient rats obtained using zinc-finger nucleases-technology should be useful as biomedical research models and a powerful platform for transgenic animals expressing a human Ab repertoire.