Characterization in vivo and in vitro of XXXX cells selected for resistance to syngeneic lymphocyte-mediated cytotoxicity.

@entity5 @entity19 @entity358 @entity3 @entity48401
This report describes the selection and behavior of @entity5 cells resistant to cytolysis by syngeneic lymphocytes. Two B16 melanoma lines, F1 (low metastasis) and @entity48401 (high metastasis), were cultured with lymphocytes from C57BL/6 @entity19 immunized against B16. The selection procedure involved repeated exposure of the @entity5 cells to lymphocytes in vitro. After each interaction, the viable @entity5 cells were trpsinized, replated, and designated lines F1Lr-1 and F10Lr-1. The procedure was repeated five times, yielding lines F1Lr-6 and F10Lr-6, which resisted cytolysis by syngeneic lymphocytes. @entity19 were given s.c. or i.v. injections of cells from lines F1, F1Lr-6, @entity48401 , or F10Lr-6. Tumor growth patterns were the same for all four lines when the cells were injected s.c., however, the incidence of @entity358 differed significantly after i.v. injection. Line @entity48401 cells yielded more @entity358 than an equal number of line F1 cells (p less than 0.01). F1Lr-6 cells yielded significantly fewer @entity3 than an equal number of lines F1 cells (p less than 0.01). A similar difference between F10Lr-6 and @entity48401 cells was observed. The incidence of artificial @entity3 after i.v. injection of F10Lr-6 cells was similar to that for F1 cells. The quantitative organ distribution, arrest, and survival of i.v.-injected @entity5 cells were studied by using [125]-5-iodo-2'-deoxyuridinelabeled cells. There was a significantly greater number of cells from line @entity48401 , arrested and able to survive for 14 days in lungs, than cells from line F1. In contrast, cells from either line F1Lr-6 or F10Lr-6 had a lower incidence of arrest and survival than their lymphocyte-sensitive counterparts.
