Modulations of the effector function and cytokine production of human lymphocytes by secreted factors derived from colorectal-carcinoma cells

✍ Scribed by Jian S. Luo; Robert Kammerer; Henning Schultze; Sabine von Kleist

• Publisher: John Wiley and Sons
• Year: 1997
• Tongue: French
• Weight: 145 KB
• Volume: 72
• Category: Article
• ISSN: 0020-7136
• DOI: 10.1002/(sici)1097-0215(19970703)72:1<142::aid-ijc20>3.0.co;2-k

✦ Synopsis

We investigated the in vitro effects of factors secreted by 3 freshly explanted human colorectal-carcinoma (CRC) cell lines on lymphocyte proliferation, IL-2-receptor expression, LAK-cell generation and cytokine secretion. We found that the supernatants of all 3 CRC cell lines inhibited T-cell proliferation in a dose-dependent manner, due to the secretion of immunosuppressive factors (ISFs). In addition, the supernatants of 2 cell lines were able to inhibit LAK-cell generation and to depress IL-2R, but not HLA-DR expression, on PHA-activated T cells. Furthermore, the secretion of cytokines, i.e., IFN-g, IL-1b, IL-2 and TNF-a, by peripheralblood mononuclear cells (PBMC) was differently modulated by the tumor-cell supernatants, e.g., the production of IFN-g was reduced in normal PBMC stimulated with PHA. However, the effects induced by the supernatants were not identical: for example, factors from one CRC cell line (w25) influenced early and late events of T-cell activation and division, while 2 others (w19 and te6) contributed only to the inhibition of early events. Some biochemical properties of the ISFs were characterized. Our results suggest that colontumor cells can secrete ISFs, which may lead to the in vivo immunosuppression often observed in patients with these tumors.