Effect of NO blockade with or without added IL-2 on inhibited MLRs.

Splenocytes from CTLA4Ig-treated or control LEW.1A rats that received LEW.1W cardiac heart transplants were harvested on day 10 after transplantation and cultured in 96-well plates (A-B) or in the lower compartments of transwell plates (C-D) with irradiated APCs from donor origin. Cultures were performed with L-NMMA or D-NMMA (5 mM) in the absence (A-C) or presence (D) of IL-2 (100 U/mL). Results (D) for 96-well cultures are expressed as delta (allogeneic − spontaneous) cpm ± SD on days 3, 4, and 5 of culture and are representative of 2 experiments with a total of 4 animals. Results for transwell cultures indicate the proliferation in MLRs between naive LEW.1A splenocytes and irradiated LEW.1W APCs in the upper compartment on days 3 and 5 of culture. They are expressed as counts per minute (cpm) ± SD and are representative of 3 experiments with a total of 4 animals in each group.