Effect of irradiation on the inhibition of MLRs and of splenocytes from CTLA4Ig-treated rats on MLRs of allogeneically sensitized splenocytes and T cells.

Splenocytes were harvested on day 10 after transplantation from CTLA4Ig-treated (♦) or control (▵) LEW.1A rats that received LEW.1W heart transplants. These cells were either (A) untreated or (B) irradiated and cocultured (1:1 cell ratio) with naive LEW.1A splenocytes in the presence of irradiated LEW.1W APCs. Splenocytes from CTLA4Ig-treated (♦) or control (▵) rats were cocultured with irradiated LEW.1W APCs and either (C) allogenically primed LEW.1A splenocytes (1:1 cell ratio) or (D) allogenically primed LEW.1A T cells (1:1 cell ratio) harvested 10 days after heart transplantation. [³H]Tdr incorporation was assessed at the indicated time points. Results are expressed as delta (allogeneic − spontaneous) cpm ± SD and are representative of 3 identical experiments.