Sabarinathan Ramachandran, Ph.D.

Assistant Professor, Department of Surgery

Sabarinathan Ramachandran

Contact Info

sramacha@umn.edu

Office Phone 612-625-9067

Assistant Professor, Department of Surgery


Summary

Dr. Ramachandran, a transplant immunologist, is the Director of the Transplantation Tolerance Laboratory (TTL) at the Schulze Diabetes Institute (SDI) in the Department of Surgery. His research focuses on the development of a clinically translatable tolerance induction regimen for cell and solid organ transplantation. The major objectives of the Transplant Tolerance laboratory are 1. Develop a novel personalized (nanoparticle or recipient cell-based) transplant tolerance regimen; 2. Define the molecular mechanisms of tolerance; 3. Design innovative immune monitoring strategies; and 4. Translate the research findings to a xenotransplant setting to overcome donor organ shortage.

Expertise

The overall focus of Dr. Ramachandran’s research is to determine the immunological mechanisms that contribute to the rejection of transplanted allografts and identify key cellular immune pathways that regulate these antigen-specific immune responses. In a non-human primate model, the TTL has demonstrated that infusions of apoptotic donor leukocytes under induction immunosuppression with antagonistic anti-CD40 antibodies, rapamycin, etanercept and tocilizumab induces long-term islet allograft survival. Tolerance in this model is mediated in part by Tr1cells with indirect specificity for mismatched donor MHC class I peptides. Research in the TTL at the SDI, which Dr. Ramachandran directs, is focused on tracking the fate and specific features of defined immune cell populations through TCR and BCR sequencing, donor MHC peptide-specific MHC class II tetramer staining, epigenetic (ATACseq) and transcriptomic (RNAseq) profiling at the single-cell level in transplant recipients. A related methodology TTL is pursuing involves spatial profiling and whole-genome transcriptome analysis of the graft and the graft infiltrating cells using unique RNA probes specific for islets as well as for CD4+, CD8+ and CD20+ immune cells to define the interactions between the graft and graft infiltrating cells in the induction and maintenance of tolerance.