Biology of IR (Ligand Receptor Pairs involved in T cell Activation)

LFA-1 (has an integrin to maintain binding)

function = adhesion Ligand = ICAM-1 expressed on = APC, endothelium

CTLA-4 (regulates binding)

function = inhibition Ligand = B7-1/B7-2 expressed on = APC

PD-1 (regulates binding)

function = inhibition Ligand = PD-L1/PD-L2 expressed on = APC, tissue cells, tumor cells

CD8 (t cytotoxic)

function = signal transduction Ligand = Class 1 MHC expressed on = All nucleated cells

CD4 (t helper)

function = signal transduction Ligand = Class 2 MHC expressed on = APC

CD3

function = signal transduction by TCR complex Ligand = none expressed on = _____

CD28

function = signal transduction by costimulation Ligand = B7-1/B7-2 expressed on = APC