Receptor Editing in B Lymphocytes

The immune system eliminates lymphocytes with antigen receptors reactive to self-tissue and promotes the proliferation of cells that respond to foreign substances. We have discovered that one way that autoreactive lymphocytes are eliminated is not through cell death, but through an induced alteration of their antigen receptor genes. During their development in the bone marrow, immature B cells whose receptors bind antigens renew rearrangement of the genes for antibody light chains, allowing the cells to alter their antigen receptors and to lose self-reactivity. This process, called "receptor editing", is apparently controlled at the level of recombinase genes (RAGs). Recombinase genes can also become reactivated during the immune response to foreign antigens. We are currently trying to understand how signals from the antigen receptor can control recombinase and how this regulation is rewired at different stages of development.