While developing treatments with iPSCs and ESCs is promising, the use of these cells in allogenic settings raises the issue of cell rejection or clearance by the recipient’s immune system. As such, systemic immunosuppression is likely required for allogenic transplantations. panCELLa seeks to generate a stem cell line that evades the immune response through expression of membrane bound proteins and thus, alleviates the need for systemic immunosuppression.
A cell genetically modified to comprise at least one mechanism for providing a local immunosuppression at a transplant site when transplanted in an allogeneic host. The cell comprises a set of transgenes, each transgene encoding a gene product that is cytoplasmic, membrane bound, or local acting, and whose function is one or more of:
- to mitigate antigen presenting cell activation and function;
- to mitigate graft attacking leukocyte activity or cytolytic function;
- to mitigate macrophage cytolytic function and phagocytosis of allograft cells;
- to induce apoptosis in graft attacking leukocytes;
- to mitigate local inflammatory proteins; and
- to protect against leukocyte-mediated apoptosis.
Cloaking allows for localized immunosuppression. This technology can be applied to allogenic cell products and would avoid the need for systemic immunosuppression during transplantation. Cloaking technology has been proven effective in pre-clinical trials with mouse models. To move toward a more relevant model of allograft tolerance, a Marmoset iPSC line (non-human primate) for testing the combination of the two mechanisms (Cloaking and FailSafe) has been established.