Induction of Fc epsilon RII/CD23 on phytohemagglutinin-activated human peripheral blood T lymphocytes. I. Enhancement by IL-2 and IL-4
Kawabe, T.; Maekawa, N.; Maeda, Y.; Hosoda, M.; Yodoi, J.
Journal of Immunology 147(2): 548-553
1991
ISSN/ISBN: 0022-1767 PMID: 1830067 Document Number: 372512
Despite evidence for the expression of low affinity Fc receptor for IgE (Fc.epsilon.RII)/CD23 in T cells lines and pathologic T cells, Fc.epsilon.RII/CD23 in normal human T cells is still unclear. We studied the expression of Fc.epsilon.RII/CD23 on T cells in short-term culture of normal human PBMC stimulated with 15 .mu.g/ml PHA. PHA stimulation also resulted in the release of soluble Fc.epsilon.RII/CD23 (IgE binding factor). Using two-dimensional flow cytometry, more than 10% of the Fc.epsilon.RII/CD23+ cells were found to co-express CD3 Ag. Both CD4+ and CD8+ T cells expressed Fc.epsilon.RII/CD23. The induction of Fc.epsilon.RII/CD23 on PHA-activated T cells was enhanced by IL-2 as well as IL-4. Both IL-2 and IL-4 also augmented PHA-induced production of soluble Fc.epsilon.RII/CD23. The enhanced expression of Fc.epsilon.RII/CD23 on T cells by both lymphokines was suppressed by rabbit anti-IL-4 antiserum, suggesting the involvement of an IL-4-dependent process even in the IL-2-dependent Fc.epsilon.RII/CD23 expression on T cells. The expression of mRNA for Fc.epsilon.RII/CD23 on PHA and IL-4-stimulated PBMC was examined by Northern blot analysis. Fc.epsilon.RII/CD23 mRNA was detected in RNA prepared from the T cell fraction depleted of B cells and macrophages (Fc.epsilon.RII+CD3+ = 6.2%, Fc.epsilon.RII+CD3- = 0.8%). The expression of the mRNA for Fc.epsilon.RII/CD23 on CD3+ T cells was also confirmed by in situ hybridization with Fc.epsilon.RII/CD23 cDNA combined with CD3 rosette formation at the single cell level.