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Published on: March 2, 2011
Soluble interleukin-6 receptor is released from receptor-bearing cell lines in vitro
T Nakajima1, S Yamamoto, M Cheng
1Laboratory of Immunology, AIDS Research Center, National Institute of Health, Tokyo.
Insights
Soluble interleukin-6 receptor (sIL-6R) is released by myeloma and myelomonocytic cells. This finding suggests sIL-6R could serve as a diagnostic marker for these specific cell types.
Area of Science:
- Biochemistry
- Immunology
- Cell Biology
Background:
- Interleukin-6 receptor (IL-6R) plays a crucial role in cellular signaling pathways.
- The existence and release of soluble forms of receptors can impact biological processes.
Purpose of the Study:
- To investigate the spontaneous release of soluble interleukin-6 receptor (sIL-6R) from human cell lines.
- To determine if sIL-6R release is specific to certain cell types, particularly myeloma and myelomonocytic cells.
- To characterize the molecular properties of the released sIL-6R.
Main Methods:
- Utilized fluorescence sandwich enzyme-linked immunosorbent assay (ELISA) for quantitative measurement of sIL-6R.
- Employed antibodies specific to IL-6R for assay development.
- Analyzed the molecular weight of sIL-6R using SDS-PAGE.
Main Results:
- Soluble IL-6R (sIL-6R) was spontaneously released from the human myeloma cell line U266.
- sIL-6R was detected in the supernatant of IL-6R-positive cell lines, including myeloma (RPMI8226, PRMI1788) and myelomonocytic (U937, THP-1, HL-60) lines.
- No sIL-6R release was observed from IL-6R-negative cell lines (Molt-4, Raji).
- SDS-PAGE indicated the molecular weight of sIL-6R is approximately 50-55 kDa, smaller than the cell surface receptor.
Conclusions:
- The spontaneous generation of sIL-6R is associated with IL-6R-positive myeloma and myelomonocytic cells.
- sIL-6R release may serve as a potential biomarker for identifying myeloma and myelomonocytic cells.
Abstract:
Soluble interleukin-6 receptor (sIL-6R) was found to be spontaneously released from human myeloma cell line U266 cells into culture supernatant, and was quantitatively measured with a fluorescence sandwich enzyme-linked immunosorbent assay employing antibodies specific to IL-6R. The supernatant IL-6R was generated only from IL-6R-positive cell lines; myeloma cell lines RPMI8226 and PRMI1788, and myelomonocytic cell lines U937, THP-1, and HL-60. In contrast, it was not released from the IL-6R-negative cells; T cell line Molt-4 and Burkitt lymphoma cell line Raji. SDS-PAGE analysis of the soluble IL-6R from U266 cells suggested a molecular weight of approximately 50-55 kDa, 25-30 kDa smaller than the mature cell surface receptor. These results suggest that the generation of soluble IL-6R may be a maker of myeloma cells and myelomonocytic cells.
