FIG. 8.

Proliferation of polyclonal CD4⁺ Th cells from rSm-PEPCK-immunized BL/6 mice in response to synthetic peptides. CD4⁺ Th cells were isolated from popliteal and/or axillary lymph nodes of mice immunized subcutaneously with 15 μg of rSm-PEPCK in CFA 10 days earlier. The cells were incubated with the indicated peptides in the presence of APC, as described in Materials and Methods. [³H]dThd incorporation was assessed by liquid scintillation spectroscopy. Data are expressed as mean counts per minute (error bars, 1 standard deviation). Background counts per minute from cells cultured in the absence of antigen were subtracted. Also shown for comparison are the responses to the native 62-kDa antigen and SEA. This experiment was repeated three times with similar results. (A) First set of peptides; (B) second set of peptides; (C) control antigens.