High efficiency presentation of TNP-conjugated islet antigen to islet-specific T cells by a hybrid B cell line expressing TNP-specific surface Ig.

There is compelling evidence from animal models that type I diabetes is a consequence of T cell-mediated destruction of islet beta-cells. The recent isolation of islet-specific T cell clones from nonobese diabetic mice provides a means of identification of the Ag on islet cells that are responsible for stimulation of autoreactive T cells. We describe an APC line constructed by fusion of spleen B cells obtained from nonobese diabetic mice to a B lymphoma that was transfected with the H and L chains of an IgM specific to the hapten TNP. Using this hybrid APC we have observed a dramatic increase in the efficiency of presentation of TNP-conjugated islet cell protein preparations compared to that seen with conventional APC. Our results illustrate the potential use of this APC line for isolation and characterization of islet Ag relevant to the T cell response.