In vivo suppression of Ehrlich ascites carcinoma by human antibody-dependent splenocytes.

Inbred CFW/L1 mice were inoculated i. p. with Ehrlich ascites carcinoma (EAC) cells. Two and a half hours later they were given i. p. injection of human splenocytes or rabbit anti-EAC serum, or human splenocytes together with rabbit anti-EAC serum. When given alone splenocytes did not exert any antitumor effect. Anti-EAC serum given alone inhibited tumor growth in 50% of mice. Simultaneous application of splenocytes and antiserum inhibited tumor growth in 85% of mice. In vitro experiment suggests that antibody-dependent cellular cytotoxicity (ADCC) may be responsible for the observed antitumor effect in vivo.