TY - JOUR
T1 - B7-1 and B7-2
T2 - Similar costimulatory ligands with different biochemical, oligomeric and signaling properties
AU - Bhatia, Sumeena
AU - Edidin, Michael
AU - Almo, Steven C.
AU - Nathenson, Stanley G.
PY - 2006/4/15
Y1 - 2006/4/15
N2 - B7-1 and B7-2 are homologous costimulatory ligands expressed on the surface of antigen presenting cells (APCs). Binding of these molecules to the T cell costimulatory receptors, CD28 and CTLA-4, is essential for the activation and regulation of T cell immunity. Despite strong structural similarities, B7-1 and B7-2 exhibit different biochemical features, and their binding to the costimulatory receptors results in distinct T cell functional outcomes. Using photobleaching based fluorescence resonance energy transfer (FRET), our previous studies have demonstrated that B7-1 and B7-2 have different cell surface oligomeric states. While B7-1 is present as a dimer, B7-2 exists as a monomer on the cell surface suggesting that the unique cell surface oligomeric states of the costimulatory ligands may play a key role in the regulation of T cell responses. Moreover, signaling via B7-1 and B7-2 in dendritic cells has been reported to be dependent on their simultaneous expression, raising the possibility that their direct interaction or their involvement in synergistic signaling pathways may play a role in the function of antigen presenting cells. We discuss physiological relevance of distinct oligomeric states of B7-1 and B7-2 and address whether these molecules can associate with one another on the cell surface to form hetero-oligomers. Our findings suggest that B7-1 and B7-2 do not form hetero-oligomers, underscoring the biological relevance of dimeric and monomeric state of B7-1 and B7-2, respectively.
AB - B7-1 and B7-2 are homologous costimulatory ligands expressed on the surface of antigen presenting cells (APCs). Binding of these molecules to the T cell costimulatory receptors, CD28 and CTLA-4, is essential for the activation and regulation of T cell immunity. Despite strong structural similarities, B7-1 and B7-2 exhibit different biochemical features, and their binding to the costimulatory receptors results in distinct T cell functional outcomes. Using photobleaching based fluorescence resonance energy transfer (FRET), our previous studies have demonstrated that B7-1 and B7-2 have different cell surface oligomeric states. While B7-1 is present as a dimer, B7-2 exists as a monomer on the cell surface suggesting that the unique cell surface oligomeric states of the costimulatory ligands may play a key role in the regulation of T cell responses. Moreover, signaling via B7-1 and B7-2 in dendritic cells has been reported to be dependent on their simultaneous expression, raising the possibility that their direct interaction or their involvement in synergistic signaling pathways may play a role in the function of antigen presenting cells. We discuss physiological relevance of distinct oligomeric states of B7-1 and B7-2 and address whether these molecules can associate with one another on the cell surface to form hetero-oligomers. Our findings suggest that B7-1 and B7-2 do not form hetero-oligomers, underscoring the biological relevance of dimeric and monomeric state of B7-1 and B7-2, respectively.
KW - B7-1 and B7-2
KW - FRET
KW - Oligomerization
KW - T cell costimulation
UR - http://www.scopus.com/inward/record.url?scp=33644669825&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=33644669825&partnerID=8YFLogxK
U2 - 10.1016/j.imlet.2005.11.019
DO - 10.1016/j.imlet.2005.11.019
M3 - Article
C2 - 16413062
AN - SCOPUS:33644669825
SN - 0165-2478
VL - 104
SP - 70
EP - 75
JO - Immunology Letters
JF - Immunology Letters
IS - 1-2
ER -