Abstract
JOSK-I is a newly established human monocytic leukemia cell line derived from the peripheral blood of a patient with acute myelomonocytic leukemia. The cells possess immature monocytic features, both cytochemical and immunochemical.
It was found that a high level of interleukin 1 (IL-1) was produced by JOSK-I cells without any stimulation. The IL-1 production by JOSK-I cells has the following characteristics: (a) constitutive; (b) cell concentration dependent; and (c) minimal at the logarithmic growth phase and maximal at the saturation density of cell growth. This constitutive production of IL-1 was little affected by the addition of polymyxin B.
Partial purification of JOSK-I-derived IL-1 was performed by high-performance liquid chromatography on HPHT hydroxylapatite and TSK gel G3000 SW columns. The activity was found in the molecular weight range of 14,000 to 30,000 and over 70,000.
In chromatofocusing, JOSK-1-derived IL-1 exhibited two isoelectric points, pI 6.9 and pI 5.9. Nearly 90% of the activity was immunoprecipitated with rabbit anti-human IL-1 antibody. These characteristics are consistent with those of human monocyte-derived IL-1.
This cell line might be an ideal source of native IL-1 for investigating the biological and biochemical characteristics of human IL-1 and its clinical application.
Footnotes
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↵1 Supported in part by Grants-in-Aid from the Ministry of Education, Science and Culture, Japan.
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↵2 To whom requests for reprints should be addressed.
- Received March 3, 1986.
- Revision received October 24, 1986.
- Revision received February 12, 1987.
- Accepted February 16, 1987.
- ©1987 American Association for Cancer Research.
Volume 47, Issue 10
