TABLE 2.

TAP knockout decreases PR molecules on tPEC^a

Peptide	Mice
	B6	TAP−/−
SIINFEKL-Fl	88	63
SIINFEKL	106	71

^aPeptide binding to tPEC was determined by flow cytometry. Values represent mean channel fluorescence of viable cells. SIINFEKL-Fl (SIINFEKL coupled to fluorescein) binding to cells was measured directly. Data represent specific binding to class I molecules as determined by subtracting background binding values obtained when cells were incubated with a competitor peptide prior to the addition of the labeled peptide. Binding of SIINFEKL to K^b was determined by using Cy5-conjugated 25-D1.16. Background binding to cells not exposed to peptide was subtracted from values shown. Similar results were obtained in two additional experiments.