To elucidate the role of retinoic acid (RA) in anti-CD40 1 interleukin-4 (IL-4)–mediated B-cell activation, the effect of 10212 to 1026 mol/L RA was studied in anti-CD40 (1 mg/mL) 1 IL-4 (5 ng/mL)-mediated proliferation and Ig synthesis by human peripheral blood mononuclear cells (PBMC) and B cells in healthy donors. Anti-CD40 1 IL-4–mediated proliferation of PBMC and B cells was inhibited by R...

CD23, also known as the low affinity IgE receptor (FcepsilonRII), has been hypothesized to have a role in IgE regulation. A new CD23 transgenic mouse was generated using the MHC class I promoter and IgH enhancer to further test the hypothesis that CD23 plays a role in the down-regulation of IgE. Study of three founder lines by FACS showed overexpression to varying extents on both B and T lympho...

tries. Most allergic reactions are mediated by allergen-specific IgE antibodies. Therefore, development of a method for inhibiting allergen-specific IgE production is a useful approach to prevent food-allergic diseases. IgE synthesis is considered to be caused by development and activation of T helper-2 (Th2) cells and B cells. This specific Th2 cell produces predominantly interleukin (IL)-4 an...

CD23, a differentiation marker of B cells is identified with the low-affinity receptor for IgE--FcepsilonRII. The CD23 molecule is continuously cleaved by autoproteolysis into soluble fragments called sCD23, considered as a multifunctional cytokine. sCD23 is supposed to play an important role in IgE synthesis. IgE is a hallmark of atopy and its overproduction is a characteristic feature of alle...

BACKGROUND The regulation and function of IgE in healthy individuals and in antigen-naïve animals is not well understood. IL-33 administration increases serum IgE in mice with unknown mechanism. We tested the hypothesis that IL-33 provides an antigen-independent stimulus for IgE production and mast cell degranulation. METHODS IL-33 was administered to naïve wild-type (WT), nude and ST2(-/-) ,...

BACKGROUND Immunoglobulin E (IgE) binds to high affinity receptor FcεRI numerously expressed on mast cells. Recent findings have revealed that IgE by itself may regulate various aspects of mast cell biology, however, detailed data is still limited. METHODOLOGY/FINDINGS Here, we have examined the influence of IgE alone, used at different concentrations, on mast cell activity and releasability....

Interleukin-7 (IL-7) is a B-cell growth factor produced by both bone marrow stroma cells and follicular dendritic cells (FDCs) located in primary lymphoid follicles and germinal centers. In this study, we have evaluated the role of IL-7 on human Ig class switching. IL-7 was added to peripheral blood mononuclear cells (PBMCs) or tonsillar B cells in the absence or presence of IL-4 and/or anti-CD...

Interleukin 4 (IL-4) and IL-13 share many biological functions. Both cytokines promote growth of activated human B cells and induce naive human surface immunoglobulin D+ (sIgD+) B cells to produce IgG4 and IgE. Here we show that a mutant form of human IL-4, in which the tyrosine residue at position 124 is replaced by aspartic acid (hIL-4.Y124D), specifically blocks IL-4 and IL-13-induced prolif...

BACKGROUND Our laboratory has demonstrated previously that human tonsillar B lymphocytes express IL-13 mRNA OBJECTIVE: We sought to investigate IL-13 production by human B cells and the association between B cell-derived IL-13 and IgE secretion. METHODS Human B lymphocytes were isolated from tonsils and purified by means of rosetting with sheep RBCs or positive or negative selection with magn...