Monoclonal antibodies block murine IL-4 receptor function.

Area of Science:

• Immunology
• Molecular Biology
• Cell Biology

Background:

• Interleukin-4 (IL-4) is a cytokine crucial for B-cell proliferation, Ia expression, and IgE secretion.
• IL-4 exerts its effects by binding to the cell-surface interleukin-4 receptor (IL-4R).
• IL-4R expression is typically low on primary cells and cell lines (<5000 receptors/cell).

Purpose of the Study:

• To generate monoclonal antibodies (mAbs) against the murine IL-4 receptor (IL-4R).
• To characterize these mAbs and their utility in studying IL-4 signaling.
• To identify the molecular properties of the IL-4R.

Main Methods:

• Utilized a high IL-4R expressing subclone of CTLL-2 cells for mAb generation.
• Employed immunoprecipitation and Western blotting to identify the IL-4R.
• Expressed full-length murine IL-4R cDNA in COS-7 cells for further characterization.
• Assessed mAb inhibition of IL-4 binding and IL-4-induced proliferation.

Main Results:

• Two distinct mAbs, M1 and M2, were developed, recognizing specific sequences of the murine IL-4R.
• Immunoprecipitation identified the IL-4R as a 145,000 molecular weight (Mr) cell-surface protein.
• Both M1 and M2 inhibited IL-4 binding to the IL-4R.
• Antibody M1 demonstrated potent inhibition of IL-4-induced proliferation.

Conclusions:

• The generated mAbs (M1 and M2) are valuable tools for studying the murine IL-4R.
• These antibodies facilitate the characterization of the IL-4R as a 145 kDa protein.
• The antibodies can be used to investigate the diverse biological activities mediated by IL-4.