RON Expression Mediates Lipopolysaccharide-Mediated Dendritic Cell Maturation via March-I

Area of Science:

• Immunology
• Cell Biology
• Molecular Signaling

Background:

• The macrophage stimulating protein (MSP)-Recepteur d'origine nantais (RON) signaling pathway is crucial for regulating macrophage and dendritic cell (DC) functions.
• Understanding the role of RON in DC maturation is essential for developing immunotherapies and understanding immune responses.

Purpose of the Study:

• To investigate the expression of the RON receptor in bone marrow-derived dendritic cells (BMDCs).
• To determine the impact of RON inhibition on DC maturation markers, ubiquitination levels, and T-cell proliferation.
• To elucidate the role of the MSP-RON signaling pathway in lipopolysaccharide (LPS)-stimulated DC maturation.

Main Methods:

• Verified RON receptor expression in BMDCs using real-time PCR, Western blot, and flow cytometry.
• Assessed changes in MHC II and CD86 expression and ubiquitination following RON inhibition via flow cytometry, immunoprecipitation, and Western blot.
• Measured cytokine release using ELISA and evaluated DC maturity and T-cell proliferation using a mixed lymphocyte reaction.

Main Results:

• RON inhibition increased March-1 transcription, leading to enhanced ubiquitination of MHC II and CD86, and decreased expression of these molecules.
• Inhibition of RON in DCs resulted in reduced T-cell proliferation, indicating impaired DC function.
• The MSP-RON signaling pathway was implicated in regulating LPS-stimulated DC maturation and differentiation.

Conclusions:

• The MSP-RON signaling pathway plays a significant role in regulating DC maturation, particularly in response to LPS stimulation, via March-1 mediated ubiquitination.
• RON inhibition negatively impacts DC function by reducing MHC II and CD86 expression and impairing T-cell activation.
• Targeting the MSP-RON pathway could offer therapeutic strategies for modulating immune responses.