Enhancement Of IgE Production Research Articles

IgE/antigen-mediated enhancement of IgE production is a mechanism underlying the exacerbation of airway inflammation and remodelling in mice.

IgE is known to enhance some antibody responses to specific antigens, but whether this contributes to allergic asthma remains unclear. We have previously found that repeated antigen challenges in mice sensitized with antigen-specific IgE monoclonal antibody (mAb) exacerbated airway inflammation and remodelling accompanied by increased levels of endogenous antigen-specific IgE and IgG1. Here, we investigated whether IgE/antigen-mediated enhancement of endogenous IgE production contributes to the exacerbation of airway inflammation and remodelling. BALB/c mice passively sensitized with ovalbumin (OVA) -specific IgE mAb were challenged with OVA intratracheally seven times; anti-IgE mAb was intraperitoneally administered 1 day before the fourth challenge. Treatment with anti-IgE mAb inhibited the increased level of endogenous OVA-specific IgE in serum, but not OVA-specific IgG1, and a biphasic increase in airway resistance at the fourth challenge. Furthermore, a biphasic increase in airway resistance, airway hyper-responsiveness to methacholine, OVA-specific IgE and IgG1 production, and infiltrations by neutrophils and eosinophils in the lungs at the seventh challenge were suppressed by treatment; airway remodelling, such as goblet cell hyperplasia and sub-epithelial fibrosis, was also reduced. In addition, the production of interleukin-17A, interleukin-33 and CXCL1 in the lungs related to these IgE-mediated responses was decreased by treatment. Collectively, we found that the mechanism leading to the exacerbation of allergic asthma is closely related to IgE/antigen-mediated enhancement of IgE production, suggesting that this may create a vicious circle leading to the chronic status in asthmatic patients having levels of antigen-specific IgE ready to form complexes with antigen.

Platelet Derived Endothelial Cell Growth Factor/Thymidine Phosphorylase Enhanced Human IgE Production

Angiogenesis is one pathogenesis of allergic airway disease. A potent angiogenic factor is platelet-derived endothelial cell growth factor (PD-ECGF), also known as thymidine phosphorylase (TP) in the field of cancer-associated research. Vascular endothelial growth factor (VEGF) is another representative angiogenic factor. Both factors were added to the culture system of human peripheral blood mononuclear cells (PBMC) with IL-4 and anti-CD40 monoclonal antibody (mAb). Total IgE levels in the supernatants and signal transduction of stimulated PBMC were evaluated. Addition of PD-ECGF enhances in vitro IgE production by PBMC in the presence of IL-4 and anti-CD40 mAb, but VEGF does not enhance IgE production. Although PD-ECGF catalyzes the reversible phosphorolysis of thymidine to 2-deoxy-D-ribose-1-phosphate (2DDR), treatment of 2DDR has no effect on IgE production by human PBMC. Both IL-4 and anti-CD40 mAb induce PD-ECGF by human PBMC. Thymidine phosphorylase inhibitor (TPI), 5-chloro-6-[1- (2-iminopyrrolidinyl) methyl] uracil hydrochloride reduce IgE production via blocking of STAT6- phosphorylation. Taken together, these results suggest TP involvement in the enhancement of IgE production and suggest that TPI is a novel strategy against IgE-related allergic disease.

Effect of recombinant human erythropoietin on human IgE productionin vitro

Recombinant human erythropoietin enhanced spontaneous IgE production (200-300% enhancement) in cultures of peripheral blood mononuclear cells (MNC) from atopic patients. In contrast, IgG and IgA production were only slightly enhanced (30-50% enhancement), and IgM production was not affected by erythropoietin. The enhancement of IgE production by erythropoietin was indirect since it required T cells and monocytes. However, erythropoietin effect was specific since enhancement was blocked by anti-erythropoietin antibody but not by control antibody. Interleukin-4 (IL-4) also enhanced spontaneous IgE production from atopic MNC. However, the enhancing effect by erythropoietin is different from that by IL-4, since the erythropoietin effect was not blocked by anti-IL-4 antibody, and conversely IL-4 effect was not blocked by anti-erythropoietin antibody. In contrast to the enhancing effect on atopic MNC, erythropoietin failed to induce IgE production in cultures of MNC from normal donors while IL-4 induced IgE production from normal MNC. However, when normal MNC were pre-incubated with IL-4, erythropoietin enhanced IgE production from IL-4-pre-incubated MNC. Moreover, B cells separated from IL-4-pre-incubated MNC produced IgE which was enhanced by erythropoietin. However, this effect required T cells and monocytes. These results indicate that erythropoietin could regulate ongoing IgE production in vitro by T cell- and monocyte-dependent mechanisms.

Environmental Stress and Atopic Dermatitis: Cure with Steroid-Free Treatment and Mutual Trust in a Good Life Style

Atopic Dermatitis (AD) is a chronic inflammatory skin disease with severe itching. The exact causes for AD still remain to be elucidated. However, there are at least following 3 causes: 1) allergy, 2) bacterial infection, and 3) environmental stress. These 3 causes are mixed in AD, and consequently symptoms of AD are very complex. In addition, patients with AD are reluctant to take steroid ointment treatment. This is due to the fact that steroid is an anti-inflammatory and immunosuppressive drug. Thus steroid ointment treatment only temporally improved AD by reduction of inflammation, while it failed to cure bacterial infection. Patients had to apply steroid ointment for longterm, which caused many side effects, including enhancement of IgE production, aggravation of skin infection, and rebound phenomenon. Rebound was aggravation of symptoms upon cessation of steroid ointment use. Enhancement of IgE production augmented allergic responses, while aggravation of skin infection worsened skin symptoms. Collectively, lone-term use of steroid ointment complicated AD instead of cure. Patients with AD suffered from these side effects, and they did not trust steroid treatment. Recently, tacrolimus ointment was widely used instead of steroid ointment. However, tacrolimus was more potent immunosuppressive drug, and US FDA warned cancer concern. Therefore, steroid- and tacrolimus-free treatment was considered safer and ideal. Patients with AD were susceptible to stress, which worsened symptoms. Recently, new environmental stress emerged, and patients with AD were suffering from them. In this article, I describe the effect of environmental stress on allergic responses, and explain the details of cases of AD with steroid-free treatment and mutual trust, which resulted in cure of AD.

The extract of syngeneic keratinocytes enhances IgE production from BALB/c mouse splenic lymphocytes in vitro

The increase of serum IgE levels is closely associated with atopic dermatitis. We have previously revealed that cellular extract of PAM212 cells (PAM-extract), BALB/c mouse keratinocyte cell line, induced a remarkable increase of serum IgE levels, in vivo, when subcutaneously injected into BALB/c mice. However, precise mechanism of IgE-increasing activity was unclear. To elucidate the mechanism of IgE-increase in sera of BALB/c mice induced by PAM-extract, we explored the direct influence of PAM-extract on immunoglobulin production and class-switching in the culture of splenic lymphocytes and purified B-cells, in vitro. Splenic lymphocytes or purified B-cells obtained from BALB/c mice were cultured with various combinations of IL-4, anti-CD40 antibody, and PAM-extract for 7 days. IgE and IgG concentrations of culture supernatants were measured by ELISA. Epsilon germ-line transcriptions were assessed by RT-PCR from the cultured cells. IgE and IgG concentrations in culture supernatant of splenic lymphocytes were increased by an addition of PAM-extract in the presence of both IL-4 and anti-CD40 antibody. Epsilon germ-line transcript was also induced in parallel to the increase of IgE production. Similar results were obtained when purified B-cells were employed in stead of whole splenic lymphocytes. The enhancement of IgE production in vitro was also observed, when splenic lymphocytes of CBAj mouse were cultured with cellular extract of KCMH-1 cells, CBAj mouse keratinocyte cell line. The cellular extract of keratinocyte promotes immunoglobulin class-switching to IgE and IgE production from mouse splenic B-cells in an IL-4- and CD40-stimuli-dependent manner. Such enhancement may account for the increase of serum IgE in patients with dermatitis in association with a Th2 microenvironment.

IL-21 dependent IgE production in human and mouse in vitro culture systems is cell density and cell division dependent and is augmented by IL-10

IL-21 is known to enhance immunoglobulin production using human in vitro models. Using either PBMC or purified tonsilar B cells both stimulated with anti-CD40, IL-4 ± IL-21, this enhancement was shown to correlate with increased cell division especially for IgE and to a lesser extent for IgM and total IgG. Cell division was monitored by CFSE staining and maximum cell division was found at low initial cell plating densities. A correlation between increased cell division and IL-10-mediated enhancement of IgE production was also seen; however, increased cell division plays a smaller role with IL-10 than IL-21. This is further emphasized in that when IL-10 and IL-21 were added together there was a further synergistic increase in IgE seen, but no accompanying further increase in cell division. The mouse system was also examined for IL-21 effects as a function of cell concentration, and as in humans, IL-21 added to murine cells increased IgE production over IL-4/CD40 stimulated cells at lower cell concentrations; however, IL-21 significantly reduced IgE at higher plated cell concentrations.

Enhancement of IgE Production in B Cells by Neutrophils via Galectin-3 in IgE-Associated Atopic Eczema/Dermatitis Syndrome

Spontaneous IgE production by B cells from patients with IgE-associated atopic eczema/dermatitis syndrome (AEDS) is enhanced by polymorphonuclear leukocytes (PMN) from patients with AEDS, but not by PMN from non-atopic controls. The enhancement is abolished by preincubation of PMN with lactose, but not with glucose. Anti-galectin-3 serum, but not control rabbit serum, blocked the enhancement. These results indicate that AEDS PMN can enhance IgE production via galectin-3.

Specific enhancement of IgE production by epidermal cells

Specific enhancement of IgE production by epidermal cells

Enhancement of IgE production by anti-CD40 antibody in atopic dermatitis

It has been recently recognized that the obligate requirement for T cells in the development of IgE responses can be substituted for by anti-CD40 antibody. In this study of patients with atopic dermatitis and high IgE levels, we have analyzed the role of the CD40 molecule in IgE production. Costimulation of peripheral blood mononuclear cells (PBMCs) from normal donors with interleukin-4 (IL-4) and anti-CD40 monoclonal antibody resulted in a selective increase in IgE production; either reagent alone, however, was ineffective. In contrast, addition of anti-CD40 monoclonal antibody alone to PBMCs or B cells from patients with atopic dermatitis markedly increased IgE production, even in the absence of exogenous IL-4. With the use of an ELISA spot assay, this increase in IgE production was attributed to an expansion of IgE-secreting B cells. In anti-IgM–stimulated lymphocyte cultures from patients with atopic dermatitis the costimulation with anti-CD40 induced strong lymphocyte proliferation. Similar results were observed with anti-IgM plus IL-4. The augmentation induced by anti-CD40 was inhibited by addition of anti-IL4 to anti-CD40–treated atopic dermatitis cells. In normal subjects the effects of anti-CD40 alone on IgE production could be observed after pretreatment of normal PBMCs with IL-4 for 3 days. The effects of anti-CD40 in atopic dermatitis may be explained in part by differences in CD40 expression. In freshly isolated PBMCs from patients with atopic dermatitis, the mean fluorescence intensity of CD40 expression on B cells was increased when compared with PBMCs from nonatopic donors, and stimulation of normal or atopic dermatitis PBMCs with IL-4 increased the intensity of CD40 staining of cells. (J A LLERGY C LIN I MMUNOL 1994;93:658-68.)

Selective regulation of antigen-specific IgE response by cyclic AMP level in murine lymphocytes.

We have reported that prostaglandin E2 (PGE2) is a selective stimulator of the antigen-specific IgE response [6]. Because PGE2 is known to elevate intracellular cAMP, we investigated the regulatory role of cAMP in the production of antigen-specific IgE. Anti-TNP IgE response was induced by stimulating TNP-KLH-primed BALB/c spleen cells with the same antigen in vitro. Addition of 10-100 microM dibutyryl cAMP (DBcAMP) to the lymphocyte culture resulted in a 2-3-fold increase in anti-TNP IgE response without affecting the production of anti-TNP IgG1 or IgM. Forskolin, a stimulator of adenylate cyclase, also specifically augmented the IgE response. In contrast, 2',5'-dideoxyadenosine, an inhibitor of adenylate cyclase, suppressed IgE production in an isotype-specific manner. These results suggest that IgE synthesis can be selectively modulated by intracellular cAMP level. Enhancement of IgE production by DBcAMP was observed, particularly in highly primed spleen cells, suggesting that IgE-committed B cells are subjected to regulation by cAMP.

Effects of anti-IgE monoclonal antibody on a primary infection ofStrongyloides ratti in mice

Many helminth infections induce profound changes in the immune response of the host. Enhancement of IgE production is one of the characteristic features observed during and after the course of infections. In Strongyloides ratti infection, IgE antibodies have been detected in mice (Dawkins et al. 1982) and in rats (Korenaga et al. 1986). Furthermore, we have shown that multiple infections with infective larvae of S. ratti depress parasitespecific IgE antibody production in rats (Korenaga et al. 1986). Intestinal mast cells have been suggested to be one of the effectors involved in the process of adult worm rejection from the small intestine of mice (Nawa et al. 1985). An involvement of IgE antibodies, however, has not been confirmed in protective immunity in murine strongyloidiasis. In the present study we examined a possible protective role of IgE in mice infected with S. ratti. To clarify this, we used IgE-depleted BALB/c mice, which were injected intraperitoneally with 5 30 gg purified rat antimouse IgE monoclonal antibody (6HD5, IgG2a) twice a week, beginning on the day of their birth. Ageand sex-matched normal mice served as controls. In all experiments, 5-7 mice in each group were infected with 1,000 L3 of S. ratti maintained in our laboratory. Methods for the cultured and inoculation of larvae have previously been described (Tada et al. 1979). For monitoring of fecal larval output, fresh feces were collected individually, weighed, and suspended in 10times their weight of water. Fecal samples (50 gl) were examined under a microscope. Soluble antigen was prepared from the infective larvae according to the methods of Dawkins et al. (1982). Parasite-specific IgE antibody was determined by passive cutaneous anaphylaxis (PCA; Watanabe and Ovary 1977). As a challenge, 2.8 mg L3 antigen was given intravenously with 1 ml 1% Evans blue solution at 24 h after the intradermal injection of serum samples. Blue spots measuring >_ 5 mm in diameter indicated a positive reaction. An enzyme-linked immunosorbent assay (ELISA;

Control of IgE and IgGl antibody production in mice

The production of IgE and IgG1 was studied in untreated, thymectomized. splenectomized, anti-thymocyte serum-treated, or sublethally X-irradiated mice. Dinitrophenyl Ascaris and ovalbumin were used as antigens, and aluminum hydroxide was used as adjuvant. A suppression of IgE production was observed in adult thymectomized mice, although the kinetic pattern of the antibody response was the same as in control animals. IgG1 antibody production was not affected by thymectomy. Splenectomy did not change either IgE or IgG1 production. A single dose of rabbit anti-thymocyte serum (ATS) given 8 days after immunization inhibited IgE antibody production. The effect of ATS was dose dependent and also varied with the amount of antigen used, the immune response to high doses being more susceptible to the effect of ATS. No alteration in IgG1 production was caused by ATS even when IgE antibody formation was completely inhibited. When preceding immunization, sublethal irradiation enhanced IgE antibody formation and partially suppressed IgG1 production; applied after immunization, irradiation caused an enhancement of IgE production which was inversely proportional to the interval elapsed between the two procedures. On the other hand, the IgG1 antibody production was fairly resistant to the same treatment. The results suggest a clearcut separation between the mechanisms regulating IgE and IgG1 production in mice.