Effect of CD62L^– T cells from unprimed animals on GVHD. T cells were transplanted into lethally irradiated allogeneic host along with T cell–depleted bone marrow cells. The data were pooled from 2 to 3 independent experiments. (A) Survival. P < .0001, CD62L^– versus unseparated or CD62L⁺. (B) Weight curve.