Human B Cell Antigen Receptor Complexes

摘要

In the thesis experiments are presented which demonstrate that the human B-cellantigen receptor is physically associated with two newly defined B-lineage specific membrane proteins. In addition, evidence is provided that may be indicative for a role of another, formerly defined B-cell antigen, CD19, in antigen-receptor functioning. Contents: Introduction; Identification of two distinct phosphoproteins as components of the human B cell antigen receptor complex; The membrane IgM-associated heterodimer on human B cells is a newly defined B cell antigen that contains the protein product of the mb-1 gene; Comparison of human B cell antigen receptor complexes: Membrane-expressed forms of immunoglobulin (Ig)M, IgD and IgG are associated with structurally related heterodimers; Architecture of the human BCR: Evidence for a direct physical interaction of mIgM, mIgD and mIgG with the B29 gene product; The B29 and mb-1 polypeptides are differentially expressed during human B cell differentiation; The CR2/CD19 complex on human B cells contains the src-family kinase Lyn; Dual antigen recognition by B cells.