Allergen‐induced CD23 on CD4⁺ T lymphocytes and CD21 on B lymphocytes in Patients with allergic asthma: Evidence and regulation

Abstract

Interaction of CD4+ T cells and B cells is necessary for IgE production. It has been recently demonstrated that cell surface antigen CD21 is a ligand for CD23 (Fc epsilon RII) and that the pairing of these molecules may participate in the control of IgE production. In this study we investigated the effect of the Dermatophagoides pteronyssinus (Dpt) allergen and recombinant interleukin(rIL)-4 on the expression of CD21 and CD23 on T and B cells of asthmatic patients allergic to Dpt and of healthy controls. Peripheral blood mononuclear cells (PBMC) were incubated alone or with Dpt allergen (100 biological units/ml) and/or rIL-4 (100 U/ml) for up to 7 days. The flow-cytometric analysis of double-fluorescence staining revealed that Dpt allergen and/or rIL-4 induced CD23 on CD4+ T lymphocytes only in allergic patients. The allergen-induced CD23 on T cells is de novo synthesized antigen since no induction of CD23 on T cells was observed in cultures with 0.4 microgram/ml actinomycin D. Moreover, 100 U/ml of interferon-gamma inhibited the induction of CD23 on CD4+ T cells. T cells obtained from healthy donors did not express CD23 or CD21 antigen upon incubation with allergen and/or rIL-4. Although rIL-4 also induced CD23 in controls, the expression was only observed on CD20+ cells. The allergen alone induced a significant elevation of the mean fluorescence intensity of both CD21 and CD23 only in allergic individuals. When the cell proliferation was analyzed, a slightly increased stimulation index upon cultivation of PBMC was obtained from non-allergic donors as well, but less than in allergic patients. The co-expression of major histocompatibility complex class II molecules and CD23 on CD4+ T lymphocytes in allergic patients, as assessed by the three-color immunofluorescence analysis, indicates that these cells were activated. We conclude that CD4+ T lymphocytes possess a unique capability to express CD23 upon exposure to allergen. Moreover, the allergen-mediated induction of CD23 on T cells observed only in allergic patients may be the reason for the increase of IgE production. This would not occur in non-allergic individuals as there is no CD23 expression on T cells.

The IgE adjuvant effect of particles: characterisation of the primary cellular response in the draining lymph node

“…CD23 has been shown to facilitate isotype-specific antigen presentation in murine and human B cells, by capturing antigen by the antigen-specific IgE molecules (Mudde et al, 1995). Furthermore, expression of CD23 on human B cells and monocytes is increased in allergic disorders (Gagro and Rabatic, 1994). In our study, OVA + PSP increased the CD23 expression on B cells, whereas the known Th1 adjuvant CpG-DNA (Krieg, 2002;Maletto et al, 2002) and OVA + CpG-DNA reduced the CD23 expression considerably.…”

CD23/CD21 interaction is required for presentation of soluble protein antigen by lymphoblastoid B cell lines to specific CD4+ T cell clones

“…Constitutive expression of CD23 on normal Tcells has not been reported, although it may be induced on lectin-stimulated T cells [HI, and upon in vitro allergen activation of a subet of CD4+CD29+ helper-inducer T cells from asthmatic patients [19,201. In this study, we report that expression of both CD23 and CD21 can be induced on the cell surface of T cell clones exposed to autologous B-EBV cell lines.…”

TLR4-Mediated Signaling Induces MMP9-Dependent Cleavage of B Cell Surface CD23

“…In humans, sCD23 is strikingly increased in the blood of patients with allergic disorders (5). Allergic patients who undergo successful immunotherapy show a significant decrease in the amount of sCD23 in their blood (5-7).…”