The Effects of Heterologous Immune Serums upon HeLa Cells in Vitro and Rat-HeLa Tumors in Vivo2

Abstract

Heterologous immune serums against HeLa cells were prepared in rabbits, rats, and a tuberculin-sensitive cow. The effects of these immune serums in vitro upon HeLa cells were studied by means of a cytotoxic metabolic inhibition test (CMI), the complement-fixation test, and by agglutination tests. The CMI test was sensitive, quantitative, and reproducible. The cytotoxic activity of the cow immune serum was heat resistant, removed by heating to 60° C. for 30 minutes, restored by adding fresh unheated serum, and demonstrated a number of properties compatible with the presence of a specific cytotoxic antibody. The protective effect in vivo of the cow immune serum was studied by the quantitative and reproducible rat-HeLa tumor technique. Good correlation was obtained between the number of HeLa cells killed in the CMI test and the number killed in vivo in the rat-protection tests.