Expression and functional analysis of murine B7 delineated by a novel monoclonal antibody

Cell Immunol. 1994 Feb;153(2):298-311. doi: 10.1006/cimm.1994.1030.


The B cell surface molecule designated B7 has been shown to be expressed by activated human B cells and monocytes and to be a ligand for the CD28 and CTLA-4 molecules on T cells. B7/CD28 interactions can provide a second signal to T cells (in addition to occupancy of the T cell antigen receptor) that is needed for T cell activation. COS cells transfected with the mouse homologue of B7 have been demonstrated to provide a stimulatory signal to murine and human T cells. In this report we describe a rat anti-mouse B7 mAb designated 1G10. Scatchard and/or FACS analyses utilizing 1G10 demonstrated that B7 was not expressed on resting splenic T cells or B cells, but could be induced at high levels on B cells cocultured with a syngeneic I-Ak-restricted autoreactive T cell hybridoma. Furthermore, activation of B cells with dibutyryl-cAMP (db-cAMP), a second messenger for class II MHC signaling, or with LPS induced the expression of B7 and the two agents showed additive effects. In contrast to B cells, freshly isolated mouse peritoneal macrophages constitutively expressed B7. Antibody-blocking experiments indicated that anti-B7 antibody partially inhibited T cell proliferative responses to primary antigenic stimulation but had no effect on the responses of previously activated T cells to antigenic restimulation.

MeSH terms

  • Animals
  • Antibodies, Monoclonal*
  • Antigen-Presenting Cells / immunology
  • B-Lymphocytes / immunology
  • B7-1 Antigen / immunology
  • B7-1 Antigen / metabolism*
  • Binding, Competitive
  • Bucladesine / pharmacology
  • Female
  • Humans
  • In Vitro Techniques
  • Leukocytes / drug effects
  • Leukocytes / immunology
  • Lymphocyte Activation
  • Lymphocyte Cooperation / immunology
  • Mice
  • Mice, Inbred C3H
  • Mice, Inbred C57BL
  • Rats
  • Second Messenger Systems / immunology
  • T-Lymphocytes / immunology


  • Antibodies, Monoclonal
  • B7-1 Antigen
  • Bucladesine