OKB7, a monoclonal antibody that reacts at or near the C3d binding site of human CR2

Cell Immunol. 1985 Jul;93(2):549-55. doi: 10.1016/0008-8749(85)90159-5.


OKB7, an IgG2 mouse monoclonal antibody, binds to the C3d receptor (CR2) of human B lymphocytes in or near the active site of the receptor. OKB7 precipitates the same molecule as monoclonal antibodies B2 and HB-5 which have previously been reported to react with the C3d receptor at epitopes distant from the active site. The epitope recognized by OKB7 is distinct from those bound by B2 and HB-5 as shown in competitive binding experiments and is near the complement binding site since OKB7 blocks EAC3d rosetting at concentrations as low as 1 microgram/ml in the absence of cross-linking antibodies.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Animals
  • Antibodies, Monoclonal*
  • B-Lymphocytes / immunology
  • B-Lymphocytes / ultrastructure
  • Binding Sites, Antibody
  • Cross Reactions
  • Humans
  • Mice
  • Receptors, Complement / immunology*
  • Receptors, Complement 3d
  • Species Specificity


  • Antibodies, Monoclonal
  • Receptors, Complement
  • Receptors, Complement 3d