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.
Ebert
E C
EC
Department of Medicine, University of Medicine and Dentistry of New Jersey-Robert Wood Johnson Medical School, New Brunswick 08903-0019.
Roberts
A I
AI
Devereux
D
D
Nagase
H
H
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