Figure 2.

Rat mAbs specifically stain HEL peptide–A^k complexes. (A) Staining of RBL transfected with single peptide–A^k constructs. RBL transfected with covalent A^k–HEL peptide constructs or with wild-type I-A^k were stained with the indicated mAb supernatants (solid thick lines) or isotype-matched irrelevant controls (thin dotted lines) followed by appropriate secondary antibodies conjugated to FITC [mouse F(ab′)₂ anti-rat IgG for rat mAbs or rat F(ab′)₂ anti-mouse IgG for 10–2.16]. Cells were analyzed by flow cytometry and propidium iodide exclusion of dead cells. (B) Staining of spleen cells pulsed with HEL or HEL peptides in vitro. CBA/J spleen cells were incubated overnight in medium alone (thin dotted lines) or with the indicated concentrations of HEL or HEL peptides (thick solid lines) and were stained with the indicated rat mAb supernatants. mAb binding was detected as in Fig. 1B.