Detection of a novel binding site for T cell derived antigen binding proteins on thymic epithelial cell surfaces

Abstract

The presence of helper T cells that do not recognize major histocompatibility complex encoded antigenic determinants but rather are specific for self idiotypic determinants led us to search for a mechanism by which such cells might be influenced by idiotype expressed on the surfaces of thymic epithelial cells. Thymic epithelial cells were cultured and characterized as being rich in surface Ia antigens and keratin positive. Such cells do not have conventional Fc receptors for immunoglobulin.  However, they will bind specifically to T cell derived antigen binding molecules (T-ABMs). This binding could be detected either by staining with specific anti-T-ABM antisera or by subsequent hapten-specific antigen binding. Using anti-T-ABM antisera, it could also be shown that normal thymocytes transfer antigen binding molecules to thymic epithelial cell surfaces in vitro. These studies indicate that thymic epithelial cells can express passively acquired, T cell derived idiotype on their surface. This surface bound, T cell derived idiotype is proposed to play a role in the selection of anti-self idiotypic T cells.

Jason JM, Bottomly K, Murray J, Cone RE, Rosenstein RW, Ptak W, Janeway CA Jr.

Behring Institute Mitteilung 1982;70:39‑44