Understanding B-cell tolerance through the use of immunoglobulin transgenic models

The appearance of autoantibodies in autoimmune diseases such as lupus suggests that B-cell tolerance to self is breached. Hence it becomes important to unravel the precise cellular and molecular mechanisms that are responsible for violations in various B-cell tolerance checkpoints in autoimmune diseases. B-cell immunoglobulin or B-cell receptor transgenic models have been of immense aid in uncovering many of these key tolerance checkpoints during normal B-cell development. By breeding these transgenic models onto mice that are engineered to lack or hyperexpress various B-cell molecules, including signaling intermediates, researchers have delineated the role of these molecules in B-cell tolerance. These transgenic models have also been useful in delineating the impact of various lupus prone genomes and lupus susceptibility loci on B-cell tolerance. This review focuses on some of the more well-studied B-cell receptor transgenic models and the lessons they have taught us over the past two decades.