Positive selection of natural autoreactive B cells

Lymphocyte development is critically influenced by self-antigens. T cells a re subject to both positive and negative selection, depending on their degr ee of seif-reactivity. Although B cells are subject to negative selection, it has been difficult to test whether self-antigen plays any positive role in B cell development. A murine model system of naturally generated autorea ctive B cells with a germ Line gene-encoded specificity for the Thy-1 (CD90 ) glycoprotein was developed, in which the presence of self-antigen promote s B cell accumulation and serum autoantibody secretion. Thus, B cells can b e subject to positive selection, generated, and maintained on the basis of their autoreactivity.