| Co-Investigator(Kenkyū-buntansha) |
MATSUZAKI Miwako Saga Medical School, Dept. of Int. Med. Jyoshu, 医学部, 助手 (80190445)
ONO Kazutoshi Saga Medical School, Dept. of Int. Med. Jyoshu, 医学部, 助手 (50185633)
SANO Masayuki Saga Medical School, Dept. of Int. Med. Jyoshu, 医学部, 助手 (30145198)
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| Research Abstract |
Six murine monoclonal antibodies, AT-1, 2, 3, 4, 5 and 6 were produced against human recombinant tumor necrosis factor-alpha (gammaTNF). AT-1, -2, and -3 neutralized the activity of gammaTNF (2x10^3u/ml) over a range of dilutions between 5 and 500 mug/ml, while AT-4, -5 and -6 failed to neutralize the activity in these concentrations. All the antibodies showed immunoprecipitating activity for gammaTNF (2x10^3u/ml) over a range of dilutions between. 0.5 and 500 mug/ml. AT-1, -2, and -3 neutralized the activity of gammaTNF, but not that of lymphotoxin (LT) and interferon (IFN). AT-4, -5, and -6 did not neutralize the activity of gammaTNF. AT-1, -2, -4 and -5 immunoprecipitated about half the LT activity. This seemed due to the homology of TNF and LT. AT-1 protected mice from the lethal effects of endotoxin, while AT-4 failed to do so. The effects of gammaTNF on various T-dependent immune responses, including Delayed Footpad Reaction (DFR), cell mediated cytolysis (CMC), and Plaque-Forming Cells (PFC) were examined in BALB/C mice, immunized ip with chicken erythrocytes (CRBC). A single injection of gammaTNF at the time of the antigen administration, induced the augmentation of CMC to CRBC in a dose-dependent manner.
DFR and PFC were not affected. The increase in CMC by TNF was mediated by T cells and neutralization of TNF by the anti-TNF monoclonal antibody abolished the effect on CMC. These results indicated that TNF induced changed in the T-cell-mediated responses.
The activity of a cytotoxin derived from unstimulated and stimulated monocytes of patients with cancer was studied. Cytotoxic activity in healthy control was almost abolished after the treatment with anti-TNF antibody, whereas in cancer patients 20-40% of the total cytotoxin activity remained. The monocytes from cancer patients seemed to produce some cytotoxic cytokines other than TNF. The assay systems of ELISA or radioimmunoassay besides bioassay were established.
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