Sonja Schrepfer – VJRegenMed

Hypoimmunogenic iPSCs: avoiding immune rejection

admin_vjr_user — Fri, 13 Aug 2021 12:05:08 +0000

Sonja Schrepfer, MD, PhD, Sana Biotechnology, Seattle, WA, explains the rationale behind the development of hypoimmunogenic induced pluripotent stem cells (iPSCs). Lessons learned from the fetal-maternal tolerance concept has led to the understanding that rejection of allogeneic iPSCs upon implantation can be prevented by knocking out human leukocyte antigen (HLA) molecules through gene editing, thus overcoming adaptive immunity. Simultaneous overexpression of CD47 is also required to prevent missing-self recognition by innate immune cells following HLA knockout, thus inhibiting natural killer (NK) cell and macrophage killing of the iPSCs. Various mouse models have been used to demonstrate the regenerative capacity of differentiated hypoimmunogenic iPSCs, as well as their potential application in chimeric antigen receptor (CAR) T-cell therapy for cancer. This interview took place during the American Society for Cell & Gene Therapy 24th Annual Meeting 2021.

Highlights from ASGCT 2021: iPSCs & the immunological barrier

admin_vjr_user — Thu, 12 Aug 2021 10:07:40 +0000

Sonja Schrepfer, MD, PhD, Sana Biotechnology, Seattle, WA, shares her highlights from the American Society for Cell & Gene Therapy (ASGCT) 24th Annual Meeting 2021. Recent developments include an improved focus and understanding of immunological barriers associated with allogeneic induced pluripotent stem cells (iPSCs) and chimeric antigen receptor (CAR) T-cells. Other highlights include advances seen in the development of iPSC-based therapies including iPSC-derived dopaminergic neurons for Parkinson’s disease and iPSC-derived retinal pigment epithelium (RPE) for macular degeneration. This interview took place during the American Society for Cell & Gene Therapy 24th Annual Meeting 2021.

Avoiding immune rejection of allogeneic iPSCs

admin_vjr_user — Tue, 22 Jun 2021 13:25:13 +0000

Sonja Schrepfer, MD, PhD, Sana Biotechnology, Seattle, WA, describes the current landscape of allogeneic induced pluripotent stem cell (iPSC) research. Human leukocyte antigen (HLA) banks are used to facilitate HLA profile matching, however, rejection may still occur upon transplantation due to immune recognition of foreign peptides. This issue may be circumvented through complete allogeneic transplantation of HLA mismatched cells and developing strategies to overcome the immune barrier such as using gene editing approaches. Hypoimmunogenic iPSCs that completely evade the host immune system are currently being investigated which would remove the need for immunosuppression following transplantation. This interview took place during the American Society for Cell & Gene Therapy 24th Annual Meeting 2021.