FIG. 3.

Proliferation of polyclonal CD4⁺ Th cells from SEA-immunized BL/6 mice in response to rSm-PEPCK. CD4⁺ Th cells were isolated from popliteal and axillary lymph nodes of mice immunized subcutaneously with 50 μg of SEA in CFA 10 days earlier. The cells were incubated with the indicated antigens 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 rSm-p40 and SEA. This experiment was repeated three times with similar results.