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IgE receptors on human lymphocytes II. Detection of cells bearing IgE receptors in unstimulated mononuclear cells by means of a monoclonal antibody
Author(s) -
Delespesse Guy,
Sarfati Marie,
RubioTrujillo Manuel,
Wolowiec Terry
Publication year - 1986
Publication title -
european journal of immunology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.272
H-Index - 201
eISSN - 1521-4141
pISSN - 0014-2980
DOI - 10.1002/eji.1830160716
Subject(s) - monoclonal antibody , biology , microbiology and biotechnology , immunoglobulin e , peripheral blood mononuclear cell , receptor , antibody , fc receptor , immunology , in vitro , biochemistry
Abstract A monoclonal antibody (mAb) specific for lymphocyte IgE receptors (ER) was employed in a rosette assay for the detection of cells bearing IgE receptors (FcεR). The specificity of the assay was documented by inhibition studies with soluble immunoglobulins (Ig) and anti‐Ig antibodies. Moreover, similar results were obtained by employing the F(ab') 2 fragment of mAbER instead of intact molecule. Circulating mononuclear cells isolated from normal or allergic adults and from umbilical cord blood contained approximately 8% of FcεR‐bearing cells with values ranging from 0.3 to 17%. Tonsillar lymphocytes contained about 30% of FcεR + cells. After the removal of adherent cells, there was a small but significant reduction of the proportion of FcεR + cells. When mononuclear cells were separated into T and B cell fractions by two‐cycle rosetting with 2‐aminoethylisothiouronium bromide hydrobromide‐treated sheep red blood cells, most of the FcεR + cells were in the B cell fraction; however, a small proportion of FcεR + was also found in the enriched T cells and double‐labeling experiments confirmed that these cells were indeed T lymphocytes. FcεR + cells were purified by rosetting with mAbER‐coated erythrocytes and their phenotype was compared to that of FcεR − cells; FcεR + cells contained about 90% of B cells (B1 + ) together with a small proportion of OKT3 + , Leu 7 + and Mo2 + cells. The bulk of T cells, macrophages and natural killer (NK) cells was found in the FcεR − cells which contained fewer B cells than the fraction of FcεR + cells. These data thus indicated that the great majority of FcεR‐bearing cells are B cells but that a small proportion of NK cells, macrophages and T lymphocytes also express FcεR. Upon incubation at 37°C, B cells lost their FcεR and this phenomenon was selectively inhibited by IgE; however, purified T cells seemed to express more FcεR after overnight incubation at 37°C and this was not influenced by IgE. It is finally shown that the expression of FcεR is cyclic and that FcεR‐bearing B cells do not represent a functionally distinct subpopulation of B lymphocytes.