Working closely with immunologists and transplant surgeons, our lab uses synthetic organic chemistry and protein biochemistry to address important biomedical challenges. Our immune system detects the presence of pathogens by using 'toll-like receptor' proteins (TLRs) to recognize generic molecular features found on the 'bad guys'. The first part of this talk will describe the the synthesis of small-molecule agonists of several different TLRs and the development of strategies to attach them to dendritic cell targeting antibodies. These immunoconjugates deliver the TLR agonists selectively to dendritic cells, greatly enhancing their ability to generate a strong immune response and generating more effective vaccines. In a second project, the organic chemistry toolbox is being used to identify efficient and biocompatible methods to covalently modify the outer surface of living cell clusters. This project is a close collaboration with a team that transplants islet cell clusters into type 1 diabetic patients. The transplanted islets produce insulin in the recipient, restoring the patient's ability to respond appropriately to changing glucose levels. Our lab attempts to chemically protects islets prior to transplantation, thereby increasing the survival of the transplanted cells.