INHIBITOR OF LYMPHOCYTE-PROLIFERATION PRODUCED BY A HUMAN COLONIC ADENOCARCINOMA CELL-LINE IN CULTURE

  • 1 January 1980
    • journal article
    • research article
    • Vol. 40  (1) , 29-35
Abstract
The culture fluid taken from a human colonic adenocarcinoma cell line, SKCO-1, inhibited mitogenic stimulation of mouse lymphocytes measured by reductions in blast information or [3H]thymidine uptake. The inhibitor was not cytotoxic to lymphocytes nor did it alter the growth rates of 21 other cell lines examined. However, the in vitro growth rates of 2 murine lymphoid tumor lines were also markedly reduced by the SKCO-1 medium. The tumor cell culture media could be added up to 40 h after concanavalin A stimulation and still effect complete inhibition of [3H]thymidine uptake. A similar inhibition was observed for phytohemagglutinin (from red kidney bean), lipopolysaccharide and mixed lymphocyte response assays. The inhibitor had a MW of greater than 100,000 and was stable to heat and UV radiation, but was destroyed by mild periodate oxidation. The inhibitor may play a role in immunosuppression.