Surface expression of IgE receptors, IgE occupancy and histamine releasability of mast cells: influence of genetic and T cell factors.
IgE receptor density and IgE occupancy were quantified on individual peritoneal mast cells using cytofluorometry. The secretory capacity of the mast cells was analysed in terms of histamine release as a function of anti-IgE challenge. Histamine releasability was found to be largely a function of the number of IgE molecules on the mast cells. The genetic background influenced IgE receptor expression but also, independently, histamine releasability. Both IgE receptor density and IgE occupancy on the mast cells appeared to be T cell independent under normal conditions. Up-regulated IgE receptor expression and an increased IgE occupancy on the mast cells could be obtained in athymic rats in response to a Nippostrongylus brasiliensis infection, although it was not as pronounced as in euthymic rats. The secretory response was diminished in athymic rats, suggesting that T cell factor(s) enhance secretory signal transduction in the mast cells in vivo.
Chen
X J
XJ
Department of Pathology, Sahlgrenska Hospital, University of Göteborg, Sweden.
Enerbäck
L
L
D000818:Animals; D006636:Histamine Release / Q000235:genetics; D007073:Immunoglobulin E / Q000378:metabolism*; D008297:Male; D008407:Mast Cells / Q000378:metabolism*; D009559:Nippostrongylus; D051381:Rats; D011917:Rats, Inbred Lew; D011919:Rats, Inbred Strains; D011921:Rats, Inbred WKY; D011923:Rats, Nude; D017207:Rats, Sprague-Dawley; D017455:Receptors, IgE / Q000378:metabolism*; D015398:Signal Transduction; D013047:Specific Pathogen-Free Organisms; D017206:Strongylida Infections / Q000276:immunology; D013601:T-Lymphocytes / Q000276:immunology*; D015854:Up-Regulation
D017455:Receptors, IgE; D007073:Immunoglobulin E