Immunologic Research

, Volume 28, Issue 1, pp 49-59

Cytotoxic T-lymphocyte antigen-4 and programmed death-1 function as negative regulators of lymphocyte activation

  • Laura L. CarterAffiliated withWyeth Research
  • , Beatriz M. CarrenoAffiliated withWyeth Research

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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.

Key words

B7 ligands Cytotoxic T-lymphocyte antigen-4 Rogrammed death-1 T-cell receptor activation Costimulation