T cells derived from deletion-deficient chimeras do not induce lethal GVHD. (A) A total of 1.5 × 108 thymocytes or 1.5 × 107 splenocytes were injected IV into sublethally irradiated, anti-NK1.1 antibody-treated hosts. The origin of the T-cell populations is indicated in italics. Survival of the mice was monitored up to 3 months posttransfer. (B) Comparison of GVHD directed to total host (left) or to cotransferred bone marrow cells only (right). (Left) As in (A), but titrated numbers (indicated) of thymocytes were injected. (Right) Lethally irradiated hosts were injected with a mixture of 107 allogeneic bone marrow plus titrated numbers of syngeneic thymocytes. (C) Lethally irradiated, anti-NK1.1 antibody-treated C57BL/6 hosts were injected IV with a mixture of 5 × 106 C57BL/6 bone marrow cells plus 1.5 × 108 thymocytes of indicated origin.
