Engineering stem cells for immunomodulatory cell therapy of cardiovascular diseases

Background Atherosclerosis is the leading cause of cardiovascular diseases (CVD) and it’s driven by increased lipid levels and impaired immune-inflammatory response. The increasing recognition of maladaptive immunity and the availability of biologics targeting human cells, suggest the need of models to translate from animals to human the molecular mechanisms and therapeutic strategies for atherosclerosis. Purpose My PhD project will provide an immune-metabolic characterization of an innovative immunodeficient mouse – on an atheroprone genetic background -, that is humanized with human engineered hematopoietic cells. Methods & Results TKO-LDLR KO mice (generated by crossing dyslipidemic LDLR-KO mice with the immunodeficient C57BL/6J strain Rag2-KO/IL2rg-KO/CD47-KO), develop dyslipidemia, steatosis and vascular lesions, when fed a high-cholesterol diet, validating their suitability for atherosclerosis studies. Humanized TKO-LDLR are generated by low-dose irradiation (200 cGy) and hepatic injections of commercial hCD34+ cells in 2-3 days old pups, as confirmed by the presence of hCD45+ cells (<10%) in the circulation of 2-month-old mice. My aim is to use iPSCs to generate engineered hCD34+ lacking the expression of key genes involved in lipid metabolism that our group has already shown to affect immune cell function (LDLr, SREBP1c and ACLY), to inject in TKO-LDLR pups and study atherosclerosis development. Conclusions Humanized TKO-LDLR generated by our group present human lymphocytes and can serve as a crucial tool to validate immunotherapies for CVD. The use of engineered stem cells will point out the contribution of key metabolic genes on disease progression only when lacking in hematopoietic cells thus contributing to dissect their role, and metabolic regulation in atherosclerosis.