Interleukin-1α activation and localization in lipopolysaccharide-stimulated human monocytes and macrophages.
J Immunol Methods 2015;
422:59-71. [PMID:
25870118 DOI:
10.1016/j.jim.2015.03.025]
[Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2015] [Revised: 03/31/2015] [Accepted: 03/31/2015] [Indexed: 10/23/2022]
Abstract
BACKGROUND
Interleukin-1α (IL-1α) is a proinflammatory cytokine belonging to the IL-1 family. It is synthesized as a 33kDa precursor peptide that is cleaved by a calpain-like protease to a 16 kDa propiece and a 17 kDa mature IL-1α peptide. In contrast to its close relative, IL-1β, the role of IL-1α in inflammation is only partly understood.
RESULTS
Human monocyte derived macrophages, stimulated with lipopolysaccharide (LPS) were analysed for production and localization of IL-1α by use of a monoclonal antibody (MAb) generated against recombinant precursor IL-1α. We found that the MAb detected IL-1α within the nuclei of the cells 2h (hours) after LPS stimulation and production continued for up to 20 h. At no time could we demonstrate cleavage of the IL-1α precursor. The MAb was conjugated to fluorescein isothiocyanate (FITC) for use in flow cytometry. Based on the flow cytometric analysis CD68 positive cells were positive for IL-1α in agreement with CD68 being a marker for monocytes.
CONCLUSIONS
Here, we demonstrate, for the first time, a method to visualize and measure the production of IL-1α in both human monocytes and macrophages.
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