Tolerance and the Costimulatory Pathway

摘要

Two barriers stand in the way of the cure of insulinopenic diabetes by pancreaticislet transplantation: a ready supply of islets and a means of preventing the immune-mediated rejection of the islets once transplanted. The latter problem may he particularly difficult in patients with type 1 diabetes because of the underlying autoimmune pathogenesis of the disease such that the affected individuals' T lymphocytes are sensitized against pancreatic beta cells even before any grafting is attempted.1,2 Other chapters in this series document the myriad approaches being developed to address these two central problems facing the diabetologist. In this chapter we will discuss the problems from an immunologist's perspective. We will first briefly review some basic immunology and definitions, then discuss our current understanding of T cell activation. With this background, we will turn to exciting new research that suggests it may