Preadministration of a T-suppressor factor enhances tumor immunity in DBA/2 mice

Abstract

Previously we have described the isolation and characterization of a T-suppressor factor (TsF) from a T cell hybridoma (A10F), which has a degree of specificity for the DBA/2 mastocytoma P815. Administration of A10F intravenously at the time of tumor cell injection resulted in an accelerated rate of tumor growth, decreased cytotoxic T lymphocyte antitumor activity, and reduced survival time. In the work reported here, we have shown that administration of affinity-enriched A10F 7-14 days prior to tumor cell injection causes what appear to be reverse effects, in that an enhanced resistance to the P815 tumor is observed in vivo, an effect which we can correlate with the demonstration of antitumor cytotoxic T lymphocyte activity in vitro. These effects are dose-dependent since only doses of TsF at 20 micrograms or greater are effective. A similar effect was found when A10F was administered to DBA/2 mice 10 days prior to challenge with two unrelated tumors (L1210 and M-1). However, when another TsF (Fd11F) with apparent specificity for a nominal antigen was tested in this system, it had no effect on tumor growth.

Comparison of T suppressor factors from tumour-bearing mice and mice immunized with a monoclonal anti-idiotypic antibody

“…Deal et al [1] found that whereas administration of a monoclonal T-suppressor factor at the time of tumour transplantation resulted in an accelerated rate of tumour growth, preadministration of this factor enhanced tumour immunity. Studies are underway to derermine whether the suppressor factors induced by MAIA have similar effects on tumour growth.…”

Effects of anti-idiotype vaccine on tumour growth and on production of soluble factors modulating cell-mediated immunity in vitro

“…Whether the MAIA inhibited or accelerated growth of its related tumour was presumably due to relative effects on the competing interactions mentioned above, of MAIA administration at different stages in the development of immune reactivity. These effects were not unexpected, as Deal et al [1] had recently found that monoclonal T-suppressor factor modulated the growth of tumours in various ways depending upon the time of injection in relation to the tumour state of the host.…”

Head and Neck Squamous Cell Carcinoma Cell Line‐Induced Suppression of in vitro Lymphocyte Proliferative Responses

“…10 tumor-derived glycoproteins, 11 and other tumorderived specific suppressor molecules. 12 Of particular interest has been the demonstration of immunosuppression mediated by monocyte-derived prostaglandins in patients with head and neck cancer. 13 Wanebo et al 14 used the prostaglandin inhibitor, indomethacin, in vitro to reverse these suppressive effects.…”