B cell complement receptor 2 transfer reaction.
The B cell C receptor specific for C3dg (CR2) shares a number of features with the primate E C receptor (CR1). Previously, we have demonstrated, both in vitro and in animal models, that immune complexes (IC) bound to primate E CR1, either via C opsonization or by means of bispecific mAb complexes, can be transferred to acceptor macrophages in a process that also removes CR1 from the E. We have now extended this paradigm, the transfer reaction, to include B cell CR2. We used both flow cytometry and fluorescence microscopy to demonstrate that IC bound to Raji cell CR2, either via C opsonization or through the use of an anti-CR2 mAb, are transferred to acceptor THP-1 cells. This reaction, which appears to require Fc recognition of IgG bound to Raji cell CR2, also leads to transfer of CR2. Additional support for the B cell transfer reaction is provided in a prototype study in a monkey model in which IC bound to B cell CR2 are localized to the spleen. These findings may have important implications with respect to defining the role of C in IC handling during the normal immune response.
Lindorfer
Margaret A
MA
Department of Biochemistry and Molecular Genetics, University of Virginia Health Sciences Center, Charlottesville, VA 22908-0733, USA.
Jinivizian
Hasmig B
HB
Foley
Patricia L
PL
Kennedy
Adam D
AD
Solga
Michael D
MD
Taylor
Ronald P
RP
D000818:Animals; D018033:Antibodies, Bispecific / Q000378:metabolism; D000911:Antibodies, Monoclonal / Q000378:metabolism; D017951:Antigen Presentation; D000936:Antigen-Antibody Complex / Q000378:metabolism; D001402:B-Lymphocytes / Q000276:immunology* / Q000378:metabolism*; D002461:Cell Line, Transformed; D006801:Humans; D008252:Macaca fascicularis; D009895:Opsonin Proteins / Q000378:metabolism; D011485:Protein Binding / Q000276:immunology; D017463:Receptors, Complement 3b / Q000378:metabolism; D017464:Receptors, Complement 3d / Q000276:immunology / Q000378:metabolism*; D012397:Rosette Formation; D014407:Tumor Cells, Cultured
D018033:Antibodies, Bispecific; D000911:Antibodies, Monoclonal; D000936:Antigen-Antibody Complex; D009895:Opsonin Proteins; D017463:Receptors, Complement 3b; D017464:Receptors, Complement 3d