FIG. 6.

Proliferative response of PA-specific clones presented with whole-PA protein by HLA DRB1*1302 or DRB1*0407 antigen-presenting cells. PBMC, CD14⁺ PBMC, and CD14⁻ PBMC, separated with magnetic beads, were pulsed with PA protein antigen for at least 4 hours prior to irradiation. The HLA DRB1-matched antigen-presenting cells were added at a 1:1 volume with 50,000 cloned T cells of each specificity. At 48 h, [³H]thymidine was added, and incorporation was measured by scintillation counting 20 to 24 h later. Top panels, recombinant PA; bottom panels, synthetic peptides.