Analysis of Sera from SV40-Immunized and Tumor-Bearing Hosts for Blocking Activity and Antibody-Dependent Cellular Cytotoxicity

[摘要] The role of serum factors in tumor immunity to cells transformed by PARA-(defective SV40)-adenovirus 7 was investigated. It was found that sera from SV40-sensitized hosts did not block the specific cytotoxicity of SV40-sensitized spleen cells for PARA-7 cells. However, such sera could collaborate with nonsensitized spleen cells to produce specific killing. This activity could be absorbed out by PARA-7 cells but not by cells transformed by cytomegalovirus.The activity of sera from hamsters bearing tumor isografts depended upon when, after transplantation, the specimens were obtained. Sera collected ≧ 10 days after grafting completely blocked immune spleen cell cytotoxicity and did not mediate target cell killing in the presence of normal spleen cells. Sera obtained at an earlier time, i.e., 3 to 6 days after transplantation, consistently were active in the antibody-dependent cellular cytotoxicity test and exhibited reduced or no blocking of antibody-independent cellular cytotoxicity. Thus, there appears to be an inverse correlation in the capacity of serum from tumor bearing hosts to block effector cell cytotoxicity and mediate antibody-dependent cellular cytotoxicity.

[学科分类] 生物科学（综合）