Table 1.

The Number of TCR Downregulated on Thymocytes and T Cells in Response to OVAp + APC

OVAp		TCR number internalized‡
		Preselection DP thymocytes		CD8 SP splenocytes
pM*
0		0		0
0.5		−10 ± 16		22 ± 65
1.4		−61 ± 52		182 ± 83
4.1		76 ± 42		252 ± 74
12.3		158 ± 31		601 ± 77
37		351 ± 10		1,070 ± 118
111		581 ± 58		1,666 ± 146
333		860 ± 59		2,279 ± 67
1,000		1,131 ± 63		3,340 ± 301
3,000		1,311 ± 42		4,464 ± 408

^* Preselection (OT-I TAP^o) DP thymocytes or OT-I CD8 SP splenocytes were incubated for 3 h with dilutions of OVAp and APC. The APC in these experiments was the 5AK^b cell line.  

^‡ TCR numbers were quantitated by flow cytometry with reference to beads of known fluorochrome levels. The number of TCR downregulated was calculated by (number of TCR for APC + no peptide) − (number of TCR at peptide dilution). Values shown are the mean ± SD for triplicate samples.