De. Anderson et al., WEAK PEPTIDE AGONISTS REVEAL FUNCTIONAL DIFFERENCES IN B7-1 AND B7-2 COSTIMULATION OF HUMAN T-CELL CLONES, The Journal of immunology, 159(4), 1997, pp. 1669-1675
The influence of costimulation on the T cell response to altered pepti
de ligands that act as either partial or weak agonists for human CD4() T cell clones was examined. Using stable Chinese hamster ovary (CHO)
cell transfectants expressing DR2 (DRB11501) and human B7-1 or B7-2
as APC, presentation of native myelin basic protein (MBP) p85-99 pepti
de Ag or a partial agonist of MBP p85-99 induced equivalent T cell act
ivation as measured by [H-3]TdR incorporation and cytokine secretion.
In marked contrast, presentation of cross-reactive peptides of MBP p85
-99 that act as weak agonists with B7-1, but not B7-2, costimulation r
esulted in significant T cell activation as measured by [H-3]TdR incor
poration and cytokine secretion. These data suggest that decreasing th
e strength of the signal provided to the TCR allows differences in B7-
1 and B7-2 signaling to be observed. Thus, the costimulatory environme
nt during T cell activation may tie a mechanism of regulating T cell c
ross-reactivity; in the periphery.