Sustained Expression of Insulin by a Genetically Engineered Sertoli Cell Line after Allotransplantation in Diabetic BALB/c Mice1

Abstract

Immune-privileged Sertoli cells (SCs) exhibit long-term survival after allotransplantation or xenotransplantation, suggesting they can be used as a vehicle for cell-based gene therapy. Previously, we demonstrated that SCs engineered to secrete insulin by using an adenoviral vector normalized blood glucose levels in diabetic mice. However, the expression of insulin was transient, and the use of immunocompromised mice did not address the question of whether SCs can stably express insulin in immunocompetent animals. Thus, the objective of the current study was to use a lentiviral vector to achieve stable expression of insulin in SCs and test the ability of these cells to survive after allotransplantation. A mouse SC line transduced with a recombinant lentiviral vector containing furin-modified human proinsulin cDNA (MSC-EhI-Zs) maintained stable insulin expression in vitro. Allotransplantation of MSC-EhI-Zs cells into diabetic BALB/c mice demonstrated 88% and 75% graft survival rates at 20 and 50 days post-transplantation, respectively. Transplanted MSC-EhI-Zs cells continued to produce insulin mRNA throughout the study (i.e., 50 days); however, insulin protein was detected only in patches of cells within the grafts. Consistent with low insulin protein detection, there was no significant change in blood glucose levels in the transplant recipients. Nevertheless, MSC-EhI-Zs cells isolated from the grafts continued to express insulin protein in culture. Collectively, this demonstrates that MSC-EhI-Zs cells stably expressed insulin and survived allotransplantation without immunosuppression. This further strengthens the use of SCs as targets for cell-based gene therapy for the treatment of numerous chronic diseases, especially those that require basal protein expression.

The Sertoli cell: one hundred fifty years of beauty and plasticity

“….). These unique immunomodulatory properties suggest that Sertoli cells are not only important for the overall protection and development of germ cells, they have therapeutic potential beyond the testis where they can protect co‐grafted cells and even be engineered to express clinically relevant proteins like insulin to treat diabetes or neurotrophin‐3 to treat spinal cord injury (Pelletier, ; Halley et al ., ; Kaur et al ., 2014b, 2015). Sertoli cells create this immune privileged environment by expressing immunoregulatory factors that actively suppress innate, humoral and cell‐mediated immune responses while at the same time inducing regulatory immune cells (regulatory T cells and M2 macrophages).…”

Generation and characteristics of human Sertoli cell line immortalized by overexpression of human telomerase

“…Firstly, Sertoli cells could secrete insulin persistently after being genetically transformed [7], which may provide new therapeutic approach for diabetes. Secondly, Sertoli cells could be reprogrammed to the pluripotent stem cells and to morphologic, phenotypic and functional neural stem cells by transferring certain genes or transcription factors [8–10].…”

Long-term culture and significant expansion of human Sertoli cells whilst maintaining stable global phenotype and AKT and SMAD1/5 activation

“…Thirdly, Sertoli cells have been reprogrammed to generating the induced pluripotent stem (iPS) cells [ 43 ], and notably, Sertoli cells can be directly converted into morphologic, phenotypic, and functional neural stem cells [ 44 ]. Sertoli cells have been engineered to secrete the necessary proteins capable of restoring normal cell and metabolic function [ 45 ], indicating extreme promise of Sertoli cells to be exploited in cell-based therapy. Thus, Sertoli cells may have important implications for disease modeling and regenerative medicine.…”