Table I.

TCR down-regulation and cytokine release induced by antigenic stimulation is dependent on the format of Ag presentationa

ELAGIGILTVAAGIGILTVOKT3
HLA-A2wtHLA-A2mHLA-A2mA2wt
MonomerTetramerMonomerTetramerMonomerTetramerMel624
Ag presentation in “fluid phase” assays
TCR-expression3079%60%82%92%100%100%n.d.b100%
80100%96%68%81%100%20%n.d.100%
Cytokine-release (pg/ml)IL-20>4000>4000<200n.d.0
IFN-γ or GM-CSF0>2500>2500<100n.d.0
Ag presentation in “solid phase” assays
TCR-expression3083%80%59%78%n.d.n.d.90%80%
18058%97%16%44%n.d.n.d.42%63%
Cytokine-release (pg/ml)IL-2>400>400>400<200>400<200>400>400
IFN-γ or GM-CSF<100<100<100<100<100<100>250>250
  • a The T cell clone SK-Mel-29.1.1 was exposed to antigenic stimulation as described in detail in Figs. 1 and 3 and tested a various time points (5–360 min) for cellular CD3/CD8 cell surface and intracellular ζ-chain expression. Supernatants were harvested at 3, 6, and 24 h after initiation of Ag contact and tested for IL-2, IFN-γ and GM-CSF by ELISA. The table represents a description of TCR modulation and cytokine release. CD3/CD8 levels are given at either 30 (30′) or 180 min (180′) after Ag exposure as compared to CD3/CD8 cell surface expression on nonstimulated T cells. Cytokine release data (IL-2 and IFN-γ or GM-CSF) represent values at 24 h after Ag exposure and are given in picograms per milliter.

  • b n.d., Not done.