Cytotoxic T-lymphocyte antigen-4 and programmed death-1 function as negative regulators of lymphocyte activation
Carter, L.L.; Carreno, B.M.
Immunologic Research 28(1): 49-59
2003
ISSN/ISBN: 0257-277X
PMID: 12947224
DOI: 10.1385/ir:28:1:49
Accession: 010411152
The B7 family of ligands and receptors plays a critical role in the modulation of immune responses. The B7/cytotoxic T-lymphocyte antigen-4 (CTLA-4) and the more recently identified programmed death ligand/programmed death-1 (PD-L/PD-1) ligand/receptor pairs define pathways that function as rheostats of lymphocyte activation. Analysis of receptor and ligand expression patterns, as well as the phenotype of CTLA-4 or PD-1-deficient mice, strongly suggests that these pathways are nonredundant. Current data suggest that the B7/CTLA-4 pathway functions primarily to attenuate, limit, and/or terminate naïve T-cell activation in secondary lymphoid organs. The PD-L/PD-1 pathway, on the other hand, may primarily attenuate, limit, and/or terminate T-, B-, and myeloid cell activation/effector function at sites of inflammation in the periphery.