Related Experiment Video
Updated: Jul 6, 2026
Quantification of Monocyte Chemotactic Activity In Vivo and Characterization of Blood Monocyte Derived Macrophages
Published on: August 12, 2019
Rapid and quantitative detection of p38 kinase pathway in mouse blood monocyte
Jingyong Zhao1, Glenn Evans, Weiming Li
1Cancer Inflammation and Cell Survival, Lilly Research Laboratories, Eli Lilly, Indianapolis, IN 46285, USA.
Abstract:
The p38 alpha mitogen-activated protein kinase (MAPK) is essential in controlling the production of many proinflammatory cytokines, and its specific inhibitor can effectively block their production for treating human diseases. To effectively identify highly specific p38 alpha inhibitors in vivo, we developed an ex vivo mouse blood cell-based assay by flow cytometry to measure the intracellular p38 alpha kinase activation. We first attempted to identify the individual blood cell population in which the p38 alpha kinase pathway is highly expressed and activated. Based on CD11b, combined with Ly-6G cell surface expression, we identified two distinct subsets of non-neutrophilic myeloid cells, CD11b(Med)Ly-6G(-) and CD11b(Lo)Ly-6G(-), and characterized them as monocytes and natural killer (NK) cells, respectively. Then, we demonstrated that only monocytes, not NK cells, expressed a high level of p38 alpha kinase, which was rapidly activated by anisomycin stimulation as evidenced by the phosphorylation of both p38 and its substrate, MAPKAP-K2 (MK2). Finally, the p38 alpha kinase pathway activation in monocytes was fully inhibited by a highly selective p38 alpha kinase inhibitor dose-dependently in vitro and in vivo. In conclusion, we demonstrated an effective method for separating blood monocytes from other cells and for detecting the expression level and activation of the p38 alpha kinase pathway in monocytes, which provided a new approach for the rapid identification of specific p38 alpha inhibitors.
Insights
Researchers developed a novel assay to measure p38 alpha kinase activation in mouse monocytes. This method aids in identifying specific inhibitors for treating inflammatory diseases by targeting the p38 alpha mitogen-activated protein kinase (MAPK) pathway.
Area of Science:
- Immunology
- Molecular Biology
- Pharmacology
Background:
- The p38 alpha mitogen-activated protein kinase (MAPK) pathway regulates proinflammatory cytokine production, making it a therapeutic target for human diseases.
- Specific inhibitors of p38 alpha MAPK are sought for effective treatment, necessitating reliable in vivo identification methods.
Purpose of the Study:
- To develop and validate an ex vivo mouse blood cell assay using flow cytometry to measure intracellular p38 alpha kinase activation.
- To identify specific blood cell populations expressing and activating the p38 alpha kinase pathway.
Main Methods:
- Utilized flow cytometry with CD11b and Ly-6G cell surface markers to distinguish monocyte and natural killer (NK) cell subsets.
- Measured p38 alpha kinase activation via phosphorylation of p38 and its substrate MAPKAP-K2 (MK2) after anisomycin stimulation.
- Assessed dose-dependent inhibition of p38 alpha kinase pathway activation by a selective inhibitor in vitro and in vivo.
Main Results:
- Identified monocytes (CD11b(Med)Ly-6G(-)) as the primary cell type expressing high levels of p38 alpha kinase, with rapid activation observed.
- NK cells (CD11b(Lo)Ly-6G(-)) showed minimal p38 alpha kinase pathway activation.
- Demonstrated effective dose-dependent inhibition of monocyte p38 alpha kinase activation by a selective inhibitor.
Conclusions:
- Established an effective ex vivo assay for isolating monocytes and detecting p38 alpha kinase pathway activation.
- The developed method provides a new approach for the rapid identification of specific p38 alpha inhibitors in vivo.
- This assay facilitates targeted therapeutic strategies for inflammatory conditions by focusing on monocyte-mediated pathways.
