IgE antibody up-regulates high affinity IgE binding on murine bone marrow-derived mast cells.
We have examined 3-week-old alcian blue positive cells (putatively mast cells) derived from mouse bone marrow for their expression of Fc epsilon RI. Using an indirect method of sensitizing the cells with immunoglobulin E (IgE) antibody (anti-DNP IgE) and detecting the level of bound IgE antibody by flow cytometry, we found that prolonged culture (1-5 days) with IgE, but not IgG, increased the total receptor density 6 +/- 1.9 fold. During the same period, histamine release in response to antigen (DNP-HSA) increased approximately 6-fold while the cell's response to either thrombin or ionomycin remained constant. The greatest up-regulation occurred in the first 2 days of culture. Using 2.4G2 to detect Fc epsilon RII RIII, we could not detect any up-regulation of this receptor. Culturing the cells for 1 h after sensitization did not result in any loss of cell surface IgE, suggesting a reasonably high affinity binding similar to that expected for Fc epsilon RI. This up-regulation was completely inhibited by co-culture with 2 micrograms/ml cycloheximide. These data suggest that IgE is capable of inducing a significant, protein synthesis, dependent up-regulation of its own high affinity receptor on mast cells/basophils.
Johns Hopkins Asthma and Allergy Center, Baltimore, MD 21224, USA.
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Hsu
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MacGlashan
D000818:Animals; D001853:Bone Marrow / Q000276:immunology; D001854:Bone Marrow Cells; D002478:Cells, Cultured; D003513:Cycloheximide / Q000494:pharmacology; D004136:Dinitrobenzenes / Q000276:immunology; D006636:Histamine Release; D007073:Immunoglobulin E / Q000378:metabolism*; D008407:Mast Cells / Q000187:drug effects / Q000276:immunology*; D051379:Mice; D011500:Protein Synthesis Inhibitors / Q000494:pharmacology; D017455:Receptors, IgE / Q000378:metabolism*; D015854:Up-Regulation
D004136:Dinitrobenzenes; D011500:Protein Synthesis Inhibitors; D017455:Receptors, IgE; D007073:Immunoglobulin E; D003513:Cycloheximide