The fate of IgE bound to rat basophilic leukemia cells. IV. Functional association between the receptors for IgE.
Rat basophilic leukemia cells (RBL-2H3) have receptors for immunoglobulin E (IgE) and immunoglobulin G (IgG). These receptors for IgE mediate the endocytosis of chemically or immunochemically cross-linked IgE but not monomeric IgE. However, unoccupied receptors were endocytosed with cross-linked IgE. To further assess the degree and specificity of the observed coendocytosis, we exposed cells carrying monomeric rat IgE and monomeric mouse IgE anti-DNP to a DNP-protein conjugate. We found that up to 30% of the surface-bound monomeric rat IgE redistributed at 0 to 4 degrees C and was then internalized at 37 degrees C with the immunochemically cross-linked mouse IgE. To assess the specificity of the coendocytosis, we exposed cells carrying monomeric rat IgE to immunochemically cross-linked mouse IgG. We found that the binding, patching, and endocytosis of cross-linked mouse IgG had no effect on the monomerically bound rat IgE. The rate of coendocytosis was the same as the rate of endocytosis (t 1/2 3 to 5 min). The extent of coendocytosis depended on the extent of endocytosis but was relatively insensitive to changes in the ratio between mouse and rat IgE over a broad range. These results indicate that some of the receptors for IgE are associated in a specific fashion.
Furuichi
K
K
Rivera
J
J
Triche
T
T
Isersky
C
C
D000818:Animals; D001491:Basophils / Q000378:metabolism*; D001666:Binding Sites, Antibody; D003432:Cross-Linking Reagents; D004136:Dinitrobenzenes / Q000276:immunology; D004140:Dinitrophenols; D004705:Endocytosis; D005455:Fluorescent Antibody Technique; D007073:Immunoglobulin E / Q000378:metabolism*; D007938:Leukemia / Q000276:immunology*; D046911:Macromolecular Substances; D051379:Mice; D051381:Rats; D011961:Receptors, Fc / Q000032:analysis / Q000502:physiology*; D017455:Receptors, IgE; D012709:Serum Albumin / Q000378:metabolism
D003432:Cross-Linking Reagents; D004136:Dinitrobenzenes; D004140:Dinitrophenols; D046911:Macromolecular Substances; D011961:Receptors, Fc; D017455:Receptors, IgE; D012709:Serum Albumin; C058064:dinitrophenyl-human serum albumin conjugate; D007073:Immunoglobulin E