Failure of Terminal Complement Components to Induce Lysis of Moloney Virus Transformed Lymphocytes

Antibody-dependent complement-mediated lysis of a viral-induced lymphoma cell was confined to the G1 phase of the cell cycle. During the portion of the cell cycle in which the cells were resistant to complement-mediated lysis (S, G2, and M), C5 and C8 became bound to the plasma membrane and ultrastructural lesions characteristic of complement membrane attack developed after incubation of the cells with antibody and complement. Quantitative studies revealed that the plasma membrane of cells bound equivalent numbers of C8 molecules in all phases of the cell cycle. These findings emphasize the importance of events occurring subsequent to activation and attachment of the cytolytic effector system for destruction of this tumor cell.