Skip to main content
Open Access Publications from the University of California

Isolation and initial characterization of tumoricidal monokine(s) from the human monocytic leukemia cell line thp-11, 2

  • Author(s): Armstrong, CA
  • Klostergaard, J
  • Granger, GA
  • et al.

A cloned subline of the human monocytic leukemia cell line, THP-1, was induced to produce high levels of cytotoxic activity following an 18-hour phorbol myristate acetate (CAS: 16561-29-8) stimulation in vitro. This activity, termed monocyte cell line cytotoxin(s) (MCCT), was tested in vitro on different human continuous cell lines (Chang, ESH-7, GM3104A, HeLa, HT-1080, K562, Mel, T-24) and on primary human fibroblasts (GM3468, Manz). The continuous cell lines exhibited a spectrum of sensitivity to MCCT-containing supernatants whereas the primary fibroblasts were resistant to lysis. Enzymatic degradation and heat denaturation studies indicate that MCCT is a protein. Its bioactivity can be resolved into three lytic peaks after molecular sieving on Ultrogel AcA 44. The major peak, designated ±MCCT, eluted with a molecular weight of 100, 000140, 000 daltons. A minor peak, MCCT, was seen at 60, 00080, 000 daltons, and a third, unstable minor peak, MCCT, eluted at less than 10, 000 daltons. The peak was examined further and was found to migrate as a single peak in 7% native polyacrylamide gel electrolysis tube gels with an rfof 0.250.30. None of the MCCT forms were immunologically cross-reactive with human. Various protease inhibitors known to inhibit monokine- and macrophage-mediated direct cell lysis in vitro were tested for their inhibitory effects on ±MCCT activity. The irreversible binding inhibitor-L-lysyl chloromethyl ketone inhibited the biologic activity of ±MCCT. The reversible binding inhibitors N-L-arginine methyl ester and soybean trypsin inhibitor were able to block in vitro lytic activity when added to ±MCCT in the presence of the target cell. In contrast, the inhibitors phenylmethylsulfonyl fluoride,L-1-tosylamide, 2-phenylethyl chloromethyl ketone, andL-lysine methyl ester were not effective in blocking cytolysis. Finally, the hydrogen peroxide scavenger catalase inhibited MCCT lytic activity in vitro; however, the hypochlorous acid scavengers alanine, serine, and valine were without effect. © 1985 Oxfor University Press. All Rights Reserved.

Many UC-authored scholarly publications are freely available on this site because of the UC Academic Senate's Open Access Policy. Let us know how this access is important for you.

Main Content
Current View