CR2 Complement Receptor

Expression of human complement receptor 2 (CR2, CD21) in Cr2-/- mice restores humoral immune function.

Complement receptor type 2 (CR2, CD21) is expressed by both human and murine B cells and has been demonstrated to play a pivotal role in the humoral immune response. We have reconstituted Cr2-/- mice with an 80-kb human genomic fragment (designated P1-5) containing the full-length human CR2 (hCR2) gene. Transfection of P1-5 into the mouse A20 B cell line confirmed that it would direct expressio...

Functional and antigenic properties of complement receptor type 2, CR2

This is the first report demonstrating that C3d receptor (CR2) has functional activity in regulating complement cascade. Purified CR2 was examined for its cofactor activity in factor I-mediated cleavage of membrane-bound iC3b. CR2 plus C3b inactivator (I) released C3c from EA 125I-iC3b, and the release was inhibited when CR2 was preincubated with OKB7 monoclonal anti-CR2. Furthermore, immunoele...

Structure of complement receptor (CR) 2 and CR2-C3d complexes.

Using X-ray crystallography, we have determined the structure of the first two short consensus repeats (SCRs) of human complement receptor (CR) 2 in complex with C3d. These studies revealed: (i) a primary site of interaction for C3d within SCR2 of CR2, (ii) a hydrophobic patch holding SCR1 to SCR2 in a rigid V-shape, (iii) a dimer formed by interactions between SCR1 of each molecule, (iv) sever...

Expression and modulation of complement receptor 2 (CR2/CD21) in the pathophysiology of rheumatoid arthritis

Rheumatoid arthritis (RA) is a systemic autoimmune disease characterized by the presence of autoantibodies, joint inflammation and subsequent destruction of cartilage and bone. 1 The disease affects multiple organs, including the joints, skin, heart, lungs and eyes. However, the primary target of the abnormal autoimmune response is the synovial joints. 2 RA involves all elements of the immune r...

Cd21) and 2 of Complement Receptor Type 2 (cr2; Characterization of C3dg Binding to a Recess