Immune responses to mouse neuroblastoma C1300. I. Preliminary observations on cell-mediated immune responses.

In vitro cell-mediated cytotoxicity (CMC) for [3H]proline-labeled target cells was demonstrated with the use of unfractionated populations of regional lymph node, spleen, and peritoneal cells (RLNC's, SPC's, PC's, respectively) from C57BL/6 and strain A mice. Syngeneic and allogeneic hosts were immunized sc or ip with C1300 tumor or syngeneic SPC's. The syngeneic and allogeneic host effector lymphoid cells showed various degrees of cytotoxicity for C1300 target cells 3-9 days after one immunization with C1300, whereas the effector lymphoid cells of hosts immunized with syngeneic SPC's generally showed less CMC for C1300 and frequently increased the growth of C1300 target cells when compared to C1300 targets plus media controls. Effector cells obtained from lymphoid organs in the region nearest the immunization (i.e., RLNC from sc-inoculated hosts) demonstrated significantly more CMC than did effector cells from more remote lymphoid organs. The PC's and SPC's of C1300 ip hyperimmunized allogeneic hosts produced greater CMC than did those of mice immunized once. This was not observed if syngeneic C1300 or SPC's were used as hyperimmunizing antigens. The CMC of nonimmunized host effector lymphoid cells for syngeneic labeled target cells was demonstrated.