Effect of syngeneic tumor cells bound to concanavalin a on tumor growth

Transplanted MOPC 315 solid myelomas in BALB/cCR mice were treated with single injections of 1.6 × 106 syngeneic MOPC 315 cells combined either with human gamma globulin or with Concanavalin A (Con A). The group of mice which received injections of MOPC 315 cells coupled with human gamma globulin failed to show any significant response. The second group which received injections of MOPC 315 cells coated with Con A responded in variable fashion. Response was measured in terms of delay of tumor growth, differences in growth pattern, and prolongation of survival time. Slight response was observed in 8 of the 20 mice; moderate response was seen in 6 mice; 6 mice did not respond. The data obtained point to a possibly effective tumor vaccine which deserves further study.