Carini C, Pini C, DiFelice G, Fattorossi A, Fratazzi C
Department of Allergy, University of Rome, Italy.
Int Arch Allergy Immunol. 1993;101(1):31-8. doi: 10.1159/000236495.
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.
IgE的低亲和力Fc受体CD23/FcεRII已在T细胞系和病理性T细胞中表达，但它在正常人T细胞上的存在仍存在争议。我们研究了用10微克/毫升植物血凝素A（PHA）或佛波醇-12-肉豆蔻酸酯-13-乙酸酯（PMA）Ca2+刺激的正常外周血单个核细胞（PBMC）或扁桃体T细胞纯化的T细胞上CD23/FcεRII的表达。使用二维流式细胞术，富含扁桃体T细胞的群体在与CD3抗原共表达时显示出>10%的CD23/FcεRII表达。CD4+T细胞似乎主要参与CD23/FcεRII的表达，尽管我们无法在被PHA或PMA Ca2+激活的PBMC中检测到CD23/FcεRII的清晰表达。PHA刺激导致IgE结合因子（IgEBF）的释放。IL-4增强了PHA和PMA-Ca(2+)激活的T细胞中CD23/FcεRII表达的诱导，但IgE或IL-6没有。IL-4还增强了PHA和PMA-Ca(2+)诱导的IgEBF释放。将爱泼斯坦-巴尔病毒（EBV）感染细胞系的上清液添加到PHA或PMA-Ca(2+)刺激的扁桃体T细胞中不会增加CD23/FcεRII表达。通过Northern印迹分析在从富含扁桃体T细胞的群体制备的RNA中检测到CD23/FcεRII mRNA的表达。
