Effect of Intraperitoneal Pristane on Established Immunity to the Adj-PC-5 Plasmacytoma2

Abstract

A sinsle injection (35 mg/kg/body wt) of N,N-di-2-chloroethylaniline [aniline mustard (AM)] into BALB/cAnN female mice caused complete regression of large intradermal (id) or subcutaneous (sc) transplants of BALB/c Adj-PC-5 plasmacytoma. After the AM induced regression of the id tumors, 88% of these mice were immune to sc challenges of 105 viable Adj-PC-5 cells and 73% were immune to intraperitoneal (ip) challenges of ≤104 viable cells. Also studied was the effect of 1 or 2 ip 0.5-ml injections of 2,6,10,14-tetramethylpentadecane (pristane) on the ability of Adj-PC-5-immune mice to resist challenges of Adj-PC-5 cells by various routes. When 103-104 of these cells were injected ip into pristane-treated, immunized mice, the tumors grew in 83–100% of the mice, in contrast to only 30% of non-pristane-treated, immunized mice. When 5×102 of these cells were injected ip, the tumors grew in 1 of 10 immune mice and 9 of 13 (68%) pristane-treated, immune mice. Challenges of 20 or 100 cells were eliminated in both pristane-conditioned and normal mice. By contrast, 105 Adj-PC-5 cells given sc to ip pristane-treated, immunized mice were rejected. Apparently pristane directly or indirectly blocked the effectivity of established immunity in the peritoneum but not in the sc site and also caused Adj-PC-5 cells to grow more efficiently.