Generation and Characterization of Severe Combined Immunodeficiency Rats

Abstract

Severe combined immunodeficiency (SCID) mice, the most widely used animal model of DNA-PKcs (Prkdc) deficiency, have contributed enormously to our understanding of immunodeficiency, lymphocyte development, and DNA-repair mechanisms, and they are ideal hosts for allogeneic and xenogeneic tissue transplantation. Here, we use zinc-finger nucleases to generate rats that lack either the Prkdc gene (SCID) or the Prkdc and Il2rg genes (referred to as F344-scid gamma [FSG] rats). SCID rats show several phenotypic differences from SCID mice, including growth retardation, premature senescence, and a more severe immunodeficiency without "leaky" phenotypes. Double-knockout FSG rats show an even more immunocompromised phenotype, such as the abolishment of natural killer cells. Finally, xenotransplantation of human induced pluripotent stem cells, ovarian cancer cells, and hepatocytes shows that SCID and FSG rats can act as hosts for xenogeneic tissue grafts and stem cell transplantation and may be useful for preclinical testing of new drugs.

Preclinical Studies for Induced Pluripotent Stem Cell-based Therapeutics

“…Cancer cells must be detected early after transplantation into the host and eliminated. A sensitive and facile method for tumor detection in small animals is the use of the firefly luciferase reporter construct and bioluminescence imaging (92). However, this approach is not suitable for large animal models and clinical applications.…”

“…Therefore, additional studies using improved animal models and tests are required. Several new severely immunodeficient mouse and rat models have been developed that will be useful for detecting small numbers of tumorigenic cells in iPSC-derived products (91,92). Tumorigenicity tests should determine the limit of detection and sensitivity of the assay and should contain positive and negative controls.…”

Engineered Nucleases Lead to Genome Editing Revolution in Rats

“…We have also generated SCID rats that are deficient for the Prkdc gene, and F344-scid Il2rg (FSG) rats that are simultaneously deficient for both the Prkdc and Il2rg genes ( Fig. 12.2 ) (Mashimo et al 2012 ). In contrast to the "leaky" phenotype of the SCID mouse, where immunoglobulins such as IgG, are detected in the blood, SCID rats did not show such a leaky phenotype (Bosma et al 1988 ).…”

“…This Platinum Gate TALEN construction system has been deposited with Addgene as the 'TALEN Construction and Evaluation Accessory Pack' ( www.addgene.org/TALEN/ PlatinumGate ). We applied Platinum TALENs to target the Il2rg gene in rat zygotes, and the mutant-generating effi ciency was much higher than that of other TALENs (Tesson et al 2011 ;Mashimo et al 2013 ) and ZFNs (Mashimo et al 2010b(Mashimo et al , 2012. Platinum TALENs have already been used in other species Treen et al 2014 ;Nakagawa et al 2014 ) and have made a valuable contribution to genome editing research.…”

Exacerbation of Intracranial Aneurysm and Aortic Dissection in Hypertensive Rat Treated With the Prostaglandin F–Receptor Antagonist AS604872

“…Indeed, in some genetically engineered animals, phenotype is quite different between rats and mice (37). 3) such a difference may just reflect the strain difference between the mouse C57BL/6 strain and the rat SD strain.…”