Selective immunosuppressive action of a factor produced by colon cancer cells.
A soluble substance (HT29 factor) produced by HT29 colon cancer cells markedly suppresses mitogen-induced T-cell proliferation and interleukin-2 production. In this study the range of T-cell functions susceptible to the inhibitory effects of the HT29 factor was evaluated. Serum-free conditioned medium was collected from confluent cultures of HT29 cancer cells, concentrated, and subjected to gel filtration chromatography and anion exchange chromatography, resulting in 24.4-fold purification of the HT29 factor with 31% yield. This factor abolished the development of lymphokine-activated killer cells when present during activation of peripheral blood lymphocytes by interleukin-2 but did not affect the lysis of target cells by normal effectors when added in the lysis stage only. The HT29 factor did not affect the generation of concanavalin A-induced suppressor lymphocytes, even though it markedly inhibited synthesis of DNA, RNA, and protein as well as expression of the CD25 (Tac) antigen during mitogen activation of T-cells. The HT29 factor itself did not induce suppressor cells. These results indicate that the immunosuppressive action of the HT29 factor is selective.
Department of Medicine, University of Medicine and Dentistry of New Jersey-Robert Wood Johnson Medical School, New Brunswick 08903-0019.
E C
EC
Ebert
A I
AI
Roberts
D
D
Devereux
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H
Nagase
D003110:Colonic Neoplasms / Q000276:immunology* / Q000378:metabolism; D004247:DNA / Q000096:biosynthesis; D006801:Humans; D007108:Immune Tolerance; D007166:Immunosuppressive Agents / Q000276:immunology / Q000302:isolation & purification / Q000494:pharmacology*; D008970:Molecular Weight; D009930:Organic Chemicals; D014176:Protein Biosynthesis; D012313:RNA / Q000096:biosynthesis; D013602:T-Lymphocytes, Cytotoxic / Q000166:cytology* / Q000187:drug effects / Q000378:metabolism; D050378:T-Lymphocytes, Regulatory / Q000166:cytology* / Q000187:drug effects / Q000378:metabolism; D014407:Tumor Cells, Cultured / Q000276:immunology
C065745:HT29 factor; D007166:Immunosuppressive Agents; D009930:Organic Chemicals; D012313:RNA; D004247:DNA