Determination of cell surface expression of Toll-like receptor 4 by cellular enzyme-linked immunosorbent assay and radiolabeling
Lipopolysaccharide (LPS) is recognized by Toll-like receptor 4 (TLR4) of macrophages triggering production of pro-inflammatory mediators. One of the factors determining the magnitude of responses to LPS, which may even lead to life-threatening septic shock, is the cell surface abundance of TLR4. How...
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Published in | Analytical biochemistry Vol. 413; no. 2; pp. 185 - 191 |
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Main Authors | , , , |
Format | Journal Article |
Language | English |
Published |
United States
Elsevier Inc
15.06.2011
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Subjects | |
Online Access | Get full text |
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Summary: | Lipopolysaccharide (LPS) is recognized by Toll-like receptor 4 (TLR4) of macrophages triggering production of pro-inflammatory mediators. One of the factors determining the magnitude of responses to LPS, which may even lead to life-threatening septic shock, is the cell surface abundance of TLR4. However, quantitation of the surface TLR4 is difficult due to the low level of receptor expression. To develop a method of TLR4 assessment, we labeled the receptor on the cell surface with a rabbit antibody followed by either anti-rabbit immunoglobulin G–fluorescein isothiocyanate (IgG–FITC) for flow cytometry or with anti-rabbit IgG–peroxidase for a cellular enzyme-linked immunosorbent assay (ELISA). Alternatively, the anti-TLR4 antibody was detected by anti-rabbit IgG labeled with
125I. Flow cytometry did not allow detection of TLR4 on the surface of J774 cells or human macrophages. In contrast, application of cellular ELISA or the radiolabeling technique combined with effective blockage of nonspecific binding of antibodies provided TLR4-specific signals. The level of TLR4 on the surface of J774 cells did not change on treatment with 1–100
ng/ml LPS; however, it was reduced by approximately 30–40% after 2
h of treatment with 1
μg/ml LPS. These data indicate that down-regulation of surface TLR4 can serve as a means of negative regulation of cell responses toward high doses of LPS. |
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Bibliography: | http://dx.doi.org/10.1016/j.ab.2011.02.031 ObjectType-Article-1 SourceType-Scholarly Journals-1 ObjectType-Feature-2 content type line 23 |
ISSN: | 0003-2697 1096-0309 |
DOI: | 10.1016/j.ab.2011.02.031 |