Severe-combined immunodeficient rats can be used to generate a model of perinatal hypoxic-ischemic brain injury to facilitate studies of engrafted human neural stem cells

Abstract

Cerebral palsy (CP) encompasses a group of non-progressive brain disorders that are often acquired through perinatal hypoxic-ischemic (HI) brain injury. Injury leads to a cascade of cell death events, resulting in lifetime motor and cognitive deficits. There are currently no treatments that can repair the resulting brain damage and improve functional outcomes. To date, preclinical research using neural precursor cell (NPC) transplantation as a therapy for HI brain injury has shown promise. To translate this treatment to the clinic, it is essential that human-derived NPCs also be tested in animal models, however, a major limitation is the high risk of xenograft rejection. A solution is to transplant the cells into immune-deficient rodents, but there are currently no models of HI brain injury established in such a cohort of animals. Here, we demonstrate that a model of HI brain injury can be generated in immune-deficient Prkdc knockout (KO) rats. Long-term deficits in sensorimotor function were similar between KO and wildtype (WT) rats. Interestingly, some aspects of the injury were more severe in KO rats. Additionally, human induced pluripotent stem cell derived (hiPSC)-NPCs had higher survival at 10 weeks post-transplant in KO rats when compared to their WT counterparts. This work establishes a reliable model of neonatal HI brain injury in Prkdc KO rats that will allow for future transplantation, survival, and long-term evaluation of the safety and efficacy of hiPSC-NPCs for neonatal brain damage. This model will enable critical preclinical translational research using human NPCs.

Moving beyond the mousetrap: current and emerging humanized mouse and rat models for investigating prevention and cure strategies against HIV infection and associated pathologies

“…heart rate, drug metabolism) that more closely mimic humans [112][113][114][115]. Recent advances in genetic engineering, such as the CRISPR/Cas 9 technology has enabled the development of several immunodeficient rat models for transplanting and regenerating human tissues and cells [7,[116][117][118]. Similar to currently used immunodeficient mouse models, immunodeficient rat models carry mutations in Rag1/2 and IL2rγ genes, with or without SIRP1α transgene [7,[116][117][118].…”

“…Recent advances in genetic engineering, such as the CRISPR/Cas 9 technology has enabled the development of several immunodeficient rat models for transplanting and regenerating human tissues and cells [7,[116][117][118]. Similar to currently used immunodeficient mouse models, immunodeficient rat models carry mutations in Rag1/2 and IL2rγ genes, with or without SIRP1α transgene [7,[116][117][118]. A recent study demonstrated that these immunodeficient rats can be reconstituted with a myriad of human immune cells following transplantation with human-fetal liver-derived HSCs and autologous thymus tissues [7] (Fig.…”

Advances in Genome Editing and Application to the Generation of Genetically Modified Rat Models

“…KO of genes involved in early rearrangements of immunoglobulin in B cells and of the T cell receptor genes in T cells, such as Rag1 (Zschemisch et al, 2012;Ménoret et al, 2013;Tsuchida et al, 2014), Rag2 (Kuijk et al, 2016;Liu Q. et al, 2017;Noto et al, 2018), and Prkdc (Mashimo et al, 2012;Ma et al, 2014a;Beldick et al, 2018) have resulted in defective development of B and T cells (Tables 6, 7). KO of the gamma chain receptor of the IL-2 receptor (Il2rg) results in defects of differentiation of T, B, natural killer (NK), and innate lymphoid cells (Mashimo et al, 2010;Samata et al, 2015;Kuijk et al, 2016).…”

Humanization of Immunodeficient Animals for the Modeling of Transplantation, Graft Versus Host Disease, and Regenerative Medicine

“…Furthermore, they have a leaky phenotype whereby older rats produce T cells that develop from a spontaneous rearrangement of their TCRs. 204 , 205 Novel immunodeficient rats have been generated with mutations in key genes, including Rag1 , 166 - 168 Rag2 , 169 - 171 and Il2rg. 172 Rag1 and Rag2 KO rats have normal NK cell generation, and there are residual B and T cells in single Rag1 , Rag2 , or Il2rg mutants.…”

“…A rat strain, deficient in Fah and Il2rg , is suitable for the engraftment of human hepatocytes that demonstrate a competitive proliferative advantage in comparison to the resident rat hepatocytes. 171 Rag1-deficient rats transplanted with human hepatocytes have been able to partially reconstitute the liver. 167 Il2rg and Prkdc mutated rats have been shown to successfully engraft human iPS, tumors, and hepatocytes.…”