In vitro growth of murine T cells. VI. Accelerated skin graft rejection caused by adoptively transferred cells expanded in T cell growth factor

The ability of adoptively transferred cytotoxic T cells expanded in T cell growth factor (TCGF) to induce accelerated graft rejection of B10.BR skin grafts from normal B6AF ₁ recipient mice was tested. In vitro sensitized cells expanded in regular TCGF were capable of accelerating graft rejection when adoptively transferred i.v. 1 day after grafting. Cells expanded in LF-TCGF (lectin-free) were more effective in accelerating graft rejection than cells expanded in lectin containing TCGF. Nonsensitized cells or cells sensitized to irrelevant B10.D2 antigenic determinants in vitro and subsequently expanded in LF-TCGF were unable to induce accelerated rejection of the B10.BR grafts. Expanded cytotoxic effector cells known to be immunologically active in vivo were also unable to accelerate graft rejection if irradiated with 2000 R before adoptive transfer. The ability of cells to lyse the appropriate targets in 4-hr ⁵¹Cr release assays correlated poorly with the effectiveness of these cells after in vivo injection. These studies are the first to demonstrate that cytotoxic cells expanded in TCGF are capable of mediating a cytotoxic function in vivo.