Dependence of Cell-Mediated Immune Lysis of the EL-4 Ascitic Lymphoma on Its Population Composition and Rhythm

Abstract

Investigations on cell-mediated immune release of ⁵¹Cr from the EL-4 ascitic lymphoma showed that daily rhythmic changes can be correlated with the dominance of certain cell types in the population. Cells in compartment 1 – i.e., those representing true G₀, early G₁S and M – are most sensitive to effector cell attack. During the established 96-hour appearance cycle of the population, each day a different compartment will predominate, with corresponding variations in percent immune release. On days when spontaneous ⁵¹Cr- release shows a maximum, immune release is minimal. The differences between maximal values of immune release may reach more than 300%, when findings from different days in the appearance cycle are compared.