The Immunoglobulin Receptors on B Cells Bind Antigen, Focus Activation Signals to Them and Initiate Antigen-Presentation.

We do not agree with the analysis of Langman and Cohn on the function of Ig receptors. We have reviewed the available literature regarding anti-Ig activation of B cells and found it contradictory and unconvincing. We have presented experimental evidence on the inability of Ig receptors on B cells to mediate activation or tolerogenic signals. We suggest that the Ig receptors serve to focus antigen to specific B cells so the B cells can be activated by TI antigens or helper T cells. The Ig molecules also bind foreign antigen and thereby initiate internalization and antigen processing. The processed peptides are exported to the membrane, where they associate with MI-IC class!! antigens, thus transforming B cells into efficient antigen-presenting cells. [ABSTRACT FROM AUTHOR]