1. Suppressor deletion therapy: selective elimination of T suppressor cells in vivo using a hematoporphyrin conjugated monoclonal antibody permits animals to reject syngeneic tumor cells
- Author
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Steele Jk, Liu D, Julia G. Levy, A T Stammers, and Whitney S
- Subjects
Graft Rejection ,Cancer Research ,medicine.drug_class ,medicine.medical_treatment ,Immunology ,Population ,chemical and pharmacologic phenomena ,Biology ,Monoclonal antibody ,T-Lymphocytes, Regulatory ,Lymphocyte Depletion ,Epitope ,Mice ,Antigen ,Immunotoxin ,medicine ,Animals ,Immunology and Allergy ,Cytotoxic T cell ,education ,Mice, Inbred BALB C ,education.field_of_study ,Leukemia, Experimental ,Tumor Necrosis Factor-alpha ,Immunotoxins ,Antibodies, Monoclonal ,Immunotherapy ,Molecular biology ,Hematoporphyrins ,Oncology ,Mice, Inbred DBA ,Cell culture ,Female ,Sarcoma, Experimental ,Neoplasm Transplantation - Abstract
A MAb (B16G) which recognizes a constant epitope on TsC and their soluble factors in DBA/2 mice has been described previously. In this study, we show that when this MAb is covalently linked to the photoactivable molecule Hp, and injected i.v. into P815 tumor-bearing mice which were subsequently exposed to light, tumors undergo permanent regression in 10%-40% of these mice (depending on the individual experiment). All control animals died within an average of 22-24 days after tumor cell injection. It is suggested that tumor regression is attributable to immune mechanisms facilitated by the elimination of a population of TsC. When splenocytes of B16G-Hp-treated mice were assayed in vitro for the generation of CTL active against P815 tumor cells, it was found that 24 h after treatment, a significant increase in killer cell activity was noted but that this effect was gone by 48h. We also show that B16G-Hp conjugates are capable in vitro of specifically killing cells of a TsC hybridoma, A10 (which has been shown previously to secrete a T suppressor factor reactive with P815 cell surface antigens). This conjugate had no cytotoxic effect on P815 cells under conditions in which A10 cells were killed.
- Published
- 1988