CD23/Fc epsilon RII expression on phytohemagglutinin-A- or phorbol-12myristate-13acetate-Ca(2+)-activated human tonsil T cells.
The low-affinity Fc receptor for IgE, CD23/Fc epsilon RII, has been expressed in T cell lines and pathologic T cells, but its presence on normal human T cells is still debated. We studied the expression of CD23/Fc epsilon RII on purified T cells from normal peripheral blood mononuclear cells (PBMC) or tonsil T cells stimulated with 10 micrograms/ml phytohemagglutinin A (PHA) or phorbol-12myristate- 13acetate (PMA) Ca2+. Using two-dimensional flow cytometry, the tonsil T-cell-enriched population showed > 10% of CD23/Fc epsilon RII expression when coexpressed with the CD3 antigen. CD4+ T cells appear to be principally involved in the expression of CD23/Fc epsilon RII, although we were unable to detect a clear expression of CD23/Fc epsilon RII in PBMC that were activated with either PHA or PMA Ca2+. PHA stimulation resulted in the release of IgE binding factor (IgEBF). The induction of CD23/Fc epsilon RII expression in PHA- and PMA-Ca(2+)-activated T cells was enhanced by IL-4, but not by IgE or IL-6. IL-4 also augmented the PHA- and PMA-Ca(2+)-induced release of IgEBF. The addition of supernatant from the Epstein-Barr virus (EBV)-infected cell line to PHA- or PMA-Ca(2+)-stimulated tonsil T cells did not increase CD23/Fc epsilon RII expression. The expression of CD23/Fc epsilon RII mRNA was detected in RNA prepared from a tonsil T-cell-enriched population by Northern blot analysis.
Carini
C
C
Department of Allergy, University of Rome, Italy.
Pini
C
C
DiFelice
G
G
Fattorossi
A
A
Fratazzi
C
C
D015152:Blotting, Northern; D002118:Calcium / Q000494:pharmacology; D002462:Cell Membrane / Q000737:chemistry; D002469:Cell Separation; D006801:Humans; D007073:Immunoglobulin E / Q000494:pharmacology; D007378:Interleukins / Q000494:pharmacology; D008213:Lymphocyte Activation; D008222:Lymphokines / Q000378:metabolism; D014066:Palatine Tonsil / Q000737:chemistry / Q000166:cytology / Q000276:immunology*; D010835:Phytohemagglutinins / Q000494:pharmacology*; D029584:Prostatic Secretory Proteins; D017455:Receptors, IgE / Q000032:analysis* / Q000187:drug effects; D012995:Solubility; D013601:T-Lymphocytes / Q000276:immunology*; D013755:Tetradecanoylphorbol Acetate / Q000494:pharmacology*
D007378:Interleukins; D008222:Lymphokines; D010835:Phytohemagglutinins; D029584:Prostatic Secretory Proteins; D017455:Receptors, IgE; C043076:beta-microseminoprotein; C013059:immunoglobulin-binding factors; D007073:Immunoglobulin E; D013755:Tetradecanoylphorbol Acetate; D002118:Calcium