An avian B-lymphocyte protein associated with beta 2-microglobulin.

A member of the family of beta 2-microglobulin (beta 2m)-associated cell surface glycoproteins was identified by the CB3 monoclonal antibody. The Mr 50,000 heavy chain of the CB3 antigen differs from conventional class I heavy chains (Mr 45,000) in the extent of glycosylation, charge, and peptide composition. Because of its selective expression on avian B cells and its similarity to mammalian class I-like molecules, we speculate that the CB3 antigen may play a role in T- and B-cell interactions,