IgE, IgG1, and IgG4 antibody responses to Blomia tropicalis in atopic patients

BACKGROUND: Allergens from house dust mites (HDMs), Dermatophagoides pteronyssinus and Blomia tropicalis are clinically relevant in atopic respiratory diseases in tropical countries. AIMS OF THE STUDY: To evaluate immunoglobulin (Ig)E, IgG1, and IgG4 antibody responses to B. tropicalis in Brazilian atopic patients. METHODS: About 110 patients with allergic rhinitis with/without asthma and 33 control subjects underwent skin prick testing (SPT) with HDM extracts, and their sera were tested for IgE and IgG subclass antibodies to D. pteronyssinus and B. tropicalis by enzyme-linked immunosorbent assay (ELISA) and immunoblotting. RESULTS: Most patients (56%) had positive SPT to B. tropicalis extract (B. tropicalis+ group), although 51% were reactive to both B. tropicalis and D. pteronyssinus and 6% were sensitized to B. tropicalis only. IgE-ELISA detected 43%B. tropicalis positivity with high-specific IgE levels in B. tropicalis+ patients. Specific IgG4 levels were higher in B. tropicalis+ than B. tropicalis- groups and correlated with specific IgE levels. The IgG1 levels to B. tropicalis were higher in patients than controls. The major allergenic B. tropicalis components recognized by B. tropicalis+ patient sera were the 54, 66, and 68 kDa proteins. The IgG4-binding protein profiles closely resembled that of IgE. The IgG1 antibodies recognizing multiple B. tropicalis protein species were detected in sera of all three patient groups. CONCLUSIONS: A large percentage of our allergic patients are B. tropicalis+. They are more frequently sensitized to high-molecular weight (HMW) B. tropicalis components than the major low-molecular weight (11-15 kDa) allergens detected in other studies. The results suggest that HMW B. tropicalis antigenic components are potential candidates for evaluating allergen exposure and sensitization, and for immunotherapy treatment.     

Suppression of polyclonal and antigen-specific murine IgG1 but not IgE responses by neutralizing interleukin-6 in vivo

The crucial role of interleukin (IL)-4 in the induction of murine IgG¹ and IgE responses, which are coupled through the process of sequential isotype switching, has been well documented. Whereas IL-4 is obligatory for the induction of IgE responses, it enhances IgG¹ responses. In this study, using neutralizing antibodies, we provide evidence that, besides IL-4, also IL-6 is required for obtaining peak IgG¹ responses. The mRNA levels of these two cytokines are coordinately expressed in the spleen of mice immunized with trinitrophenol-keyhole limpet hemocyanin (TNP-KLH). No IL-6 requirement was observed for peak IgE responses. The IL-6 dependence of IgG¹ responses was found for both antigenspecific and polyclonal responses. Moreover, it was noted using TNP-KLH and goat anti-mouse (GAM) IgD as antigen that polyclonal IgG¹ responses are more dependent on IL-6 than antigen-specific responses. In vitro experiments revealed that exogenous IL-6 neither enhanced nor inhibited the IgG¹ and IgE production by naive B cells, suggesting that IL-6 did not interfere with the IL-4-induced isotype switch potential. Primary and memory IgG¹ responses were both similarly dependent on IL-6. These observations point to a role of IL-6 in the terminal differentation of B cells switched to IgG¹. Neutralization of IL-6 did not inhibit either antigen-specific or polyclonal IgE responses. Therefore, it was concluded that IL-6 is not involved in the terminal differentiation of B cells switched to IgE. These findings thus provide a distinct role for IL-6, besides IL-4, in regulating murine IgG¹ responses. The formation of IgE, however, is completely dependent on IL-4 alone.     

Enhancement of murine IgE antibody detection by IgG removal

RATIONALE: Although animal models for the study of allergic reactions are desirable, the use of mice has been hindered by the lack of sufficiently sensitive in vitro immunoglobulin epsilon (IgE) antibody assays. The aim of this study was to enhance IgE antibody measurements by immunoglobulin gamma (IgG) depletion. METHODS: Seven- to eight-week-old female mice of four strains (C3H/HeJ, CBA/J, C57Bl/6J, and Balb/c) were immunized (20 mice/group) with shrimp or peanut extracts using Al(OH)(3) as adjuvant. Following immunization, animals were sacrificed by exsanguination and the sera of each group pooled. Initial measurements of IgE antibody levels by enzyme-linked immunosorbent assay (ELISA) were relatively low; IgG and IgE reactivity patterns by immunoblot were similar. Thus, sera from shrimp or peanut immunized mice were depleted of IgG (absorbed 3-6 times with immobilized protein G) and then tested for IgE antibody to shrimp or peanut allergen. RESULTS: A 3- to 5-fold increase in IgE antibody reactivity as measured by ELISA was demonstrated when >80-90% of the IgG was removed. This increase in detection of allergen-specific IgE occurred in sera from all mouse strains and to all allergens tested. In addition, reactivity of IgE antibodies to peanut or shrimp allergens by immunoblot increased visually approximately 4- to 10-fold. CONCLUSIONS: These studies indicate that allergen-specific IgG antibodies, which may be in more than 100-fold excess to IgE antibodies, interferes with detection of allergen-specific IgE, probably by competitive binding to allergenic epitopes. Substantial depletion of IgG antibodies (>80%) result in a significant increase in the sensitivity of the antibody measurements.     

Effects of anti-IL-4 receptor monoclonal antibody on in vitro T cell cytokine levels: IL-4 production by T cells from non-atopic donors

IL-4 is a pleiotropic cytokine which is involved in the development of atopic diseases. Only limited data exist on IL-4 production in humans, and the relative contribution to atopy of either unbalanced IL-4 production, or increased IL-4-responsiveness of target cells, is still unknown. The use of a MoAb to the IL-4 receptor α-chain (IL-4Rα) enabled us to demonstrate that IL-4 production in vitro is usually underestimated, due to in vitro consumption, even in cultures of purified T cells. When IL-4 consumption was blocked, it became evident that CD80 and CD86 both provide effective costimulatory signals for high IL-4 production. Moreover, we found that even stimulation with a soluble antigen (tetanus toxoid) induces IL-4 production by T cells from healthy non-atopic donors. Both sets of data imply that IL-4 is not required for IL-4 production by memory and/or effector T cells. Our data further show that endogenous IL-4 activity modulates IL-10 and interferon-gamma production by T cells in opposite directions. The use of this receptor-blocking antibody will thus be helpful for in vitro studies on IL-4 regulation. Consumption of IL-4 by different cell types during in vitro cultures might have interfered with previous attempts to quantify IL-4 production by human T cells.     

Anti-interleukin-6 monoclonal antibody inhibits autoimmune responses in a murine model of systemic lupus erythematosus

Systemic lupus erythematosus (SLE) is an autoimmune disease resulting from dysregulation of the immune system. Interleukin-6 (IL-6) is a multifunctional cytokine produced by macrophages, monocytes and T and B cells. It stimulates B-cell differentiation/maturation, immunoglobulin secretion, and T-cell functions. Elevated levels of IL-6 in serum, urine and renal glomeruli were detected in patients with active SLE and in murine models of SLE. Our study investigated the role of IL-6 in an SLE-like disease in New Zealand Black/White (NZB/W) F1 mice by administration of an anti-murine IL-6 monoclonal antibody (mAb). Intraperitoneal administration of the anti-IL-6 mAb suppressed the production of anti-dsDNA autoantibody. B-cell proliferation induced by anti-IgM and anti-CD40 was lower in the anti-IL-6 mAb-treated mice, ex vivo studies demonstrated that anti-IL-6 mAb treatment inhibited anti-dsDNA production. Anti-CD3-induced T-cell proliferation and mixed lymphocyte reactions were inhibited by anti-IL-6 mAb treatment, indicating a partial down-regulation of T cells. Histological analysis showed that treatment with anti-IL-6 mAb prevented the development of severe kidney disease. These results suggest that treatment with anti-IL-6 mAb has a beneficial effect on autoimmunity in murine SLE and that autoreactive B cells may be the primary target for anti-IL-6 mAb treatment; its effect on autoreactive T cells is also indicated.     

IL-4 和sCD40 L 协同增强体外IgE 的生成

应用 Ｅ Ｌ Ｉ Ｓ Ａ 和 Ｃ Ａ Ｐ 变应原系统, 检测２４ 例对屋尘螨过敏的Ⅰ型超敏反应患者血浆中总 Ｉｇ Ｅ 和特异性 Ｉｇ Ｅ 的水平,以及外周血单个核细胞（ Ｐ Ｂ Ｍ Ｃ） 在 Ｉ Ｌ ４ 、可溶性 Ｃ Ｄ４０ 配体（ｓ Ｃ Ｄ４０ Ｌ） 作用下, 其培养上清液中总 Ｉｇ Ｅ 和特异性 Ｉｇ Ｅ 的水平。结果表明： （１ ） Ⅰ型超敏反应患者血浆中 Ｉｇ Ｅ 水平比正常组高（ Ｐ＜ ００１ ） ; （２ ） 在 Ｉ Ｌ ４ 和ｓ Ｃ Ｄ４０ Ｌ 共同作用下, Ｐ Ｂ Ｍ Ｃ 培养上清液中总 Ｉｇ Ｅ 和特异性 Ｉｇ Ｅ 的水平比 Ｉ Ｌ ４ 或ｓ Ｃ Ｄ４０ Ｌ单独作用下明显升高（ Ｐ＜ ００１ ） 。提示 Ｉｇ Ｅ 的生成不仅需要 Ｉ Ｌ ４ 的作用, 还需要 Ｔ、 Ｂ 细胞接触介导的信号传导或 Ｔ 细胞释放的细胞因子作用, 而ｓ Ｃ Ｄ４０ Ｌ 就是其中的重要因子之一。     

In vivo suppression of T-dependent antibody responses by treatment with a monoclonal anti-L3T4 antibody

Minute amounts of the anti-L3T4 antibody designated GK1.5 were found to deeply suppress in vivo antibody responses to T-dependent antigens. Primary responses to sheep erythrocytes were completely inhibited even when GK1.5 was administered up to 6 days before or 4 days after the antigen. Secondary responses to potent immunogens like sheep erythrocytes or keyhole limpet hemocyanin were also completely abolished by a single injection of GK1.5 just before the boost. This treatment had no effect on T-independent reactions such as the polyclonal activation of B lymphocytes with lipopolysaccharide or the anti-2,4,6-trinitrophenyl (TNP) response elicited by injection of TNP-Ficoll.     

Mast cell-mediated immune responses through IgE antibody and Toll-like receptor 4 by malarial peroxiredoxin

In this study, 2-Cys Plasmodium berghei ANKA (PbA) peroxiredoxin (Prx) was identified as an antigenic protein recognized by an anti-PbA IgE antibody using two-dimensional polyacrylamide gel electrophoresis and proteomic analysis. Innate immune responses to PbAPrx were examined using cells from mice deficient in Toll-like receptors (TLR) or related molecules, and it was demonstrated that responses were severely impaired in TLR4(-/-), MyD88(-/-) and MD-2(-/-) mice, but not in Toll/IL-1 receptor domain-containing adaptor inducing IFN-gamma (TRIF)(-/-), TLR2(-/-) or radioprotective 105 (RP105)(-/-) mice. An association between PbAPrx and TLR4 was observed following immunoprecipitation and immunoblotting, suggesting that PbAPrx was associated with TLR4/MD-2. Interactions between Prx and TLR4/MD-2 were also examined by flow cytometry using TLR4/MD-2- or TLR2-expressing cells. NFkappaB/GFP activity was observed in TLR4/MD-2- but not in TLR2-expressing cells following stimulation with Prx. However, this effect was not observed after treatment with proteinase K, suggesting that PbAPrx is a protein ligand for TLR4 and that the PbAPrx activity observed in this study is not due to contamination with LPS. These findings indicate that malarial Prx induces IgE-mediated protection through FcepsilonRI on mast cells and innate immunity through TLR4 with MyD88 and MD-2, suggesting a novel function for malarial Prx in innate and acquired immune responses in malaria.     

Prolonged inhibition of an antigen-specific IgE response in vivo by monoclonal antibody against lymphocyte function-associated antigen-1

Intraperitoneal injection of ovalbumin (OVA) into BALB/c mice caused the induction of OVA-specific IgE production in vivo. However, administration of monoclonal antibody against lymphocyte function-associated antigen-1 (anti-LFA-1 mAb) at days 0 and 1 after OVA immunization resulted in an inhibition of OVA-specific primary and secondary IgE production in a dose-dependent manner. The inhibition of the antigen-specific IgE response due to anti-LFA-1 mAb was seen up to 8 weeks after anti-LFA-1 mAb administration. The OVA-specific IgG1 response was also blocked by anti-LFA-1 mAb. The spleen cells obtained from OVA-immunized mice showed enhanced proliferation against secondary stimulation with OVA in vitro. However, the spleen cells obtained from the mice treated with both OVA and anti-LFA-1 mAb revealed a markedly decreased proliferative responses to OVA, while they showed no reduced responses against keyhole limpet hemocyanin stimulation, indicating that anti-LFA-1 mAb might induce antigen-specific anergy in vivo. It was also demonstrated that treatment of the mice with anti-LFA-1 mAb significantly inhibited the interleukin-4-producing ability of OVA-immunized mouse spleen cells. These results demonstrated that LFA-1-dependent cell-cell interaction is essential for the production of IgE in vivo and may be important in IgE-dependent allergic disease.     

Regulation and targeting of T-cell immune responses by IgE and IgG antibodies.

A set of chimeric antibodies with identical F(ab')2 fragments specific for the hapten 5-iodo-4-hydroxyl-3-nitrophenacetyl (NIP), but with different human Fc parts (gamma 1, gamma 2, gamma 3, gamma 4, epsilon), was used to compare the role of IgG and IgE antibodies in antigen presentation by human Epstein-Barr virus (EBV) B cells. Two or three molecules of NIP were coupled to one molecule of Der pI (Der pI-(3)NIP), a major allergen of Dermatophagoides pteronyssinus. Both monomeric IgG and performed complexes of various Der pI/IgG ratios failed to bind significantly to the Fc receptor for IgG on B cells (Fc gamma RII; CD32). Binding of IgG3 (> IgG1)-containing complexes (optimal ratio of antigen to antibody = 1:1) could be enhanced by increasing the number of haptens per Der pI molecule to nine or more. However, antigen presentation mediated by IgG and CD32 was not seen with either pulsed B cells or B cells that were allowed to capture the IgG complexes during the whole stimulation period. IgE binding to CD23 and subsequent IgE-mediated antigen presentation was seen under all conditions tested. Even monomeric immune complexes (IC) (Der pI-(3)NIP/IgE), in the absence of CD23 cross-linking, induced an immune response. As the number of natural epitopes for human antibodies on Der pI was less than five, we conclude that, in vivo, complexes consisting of Der pI/IgG will be directed to antigen-presenting cells expressing the high-affinity receptor for IgG (CD64), whereas IgE will allow antigen presentation by CD23-expressing cells, including B cells.     

Clinical research of specific IgE and IgG4 antibody in allergic children. Correlation specific IgE antibody to specific IgG4 antibody to food allergen

We analysed the correlation specific IgE antibodies to specific IgG4 antibodies to food allergens in 150 asthmatic children by Multiple Factor Analysis-Type II and examined the role of both antibodies. The following results were obtained. 1) Of soybean, there was the stronger influence power between specific IgE and IgG4 antibody than the other 2 food allergens. 2) IgE antibody to soybean had the strong influence power to IgG4 antibodies to egg white and cow's milk and IgG4 antibody to soybean had same influence power to IgE antibodies to egg white and cow's milk. So, the specific IgE and IgG4 antibodies to soybean may be play the role of "the bride" between specific IgE antibody group and specific IgG4 antibody group of food allergens.     

Prevalence of atopy,eosinophilia, and IgE elevation in IgG4‐related disease

IgG4‐related disease (IgG4‐RD) is a fibroinflammatory disorder that can affect virtually every organ system. T‐helper type 2 responses have been presumed to be pathogenic in this disease, and a high proportion of patients with IgG4‐RD are reported to have longstanding allergies, peripheral blood eosinophilia, and serum IgE elevation. It has therefore been proposed that allergic mechanisms drive IgG4‐RD. However, no epidemiological assessment of atopy, peripheral blood eosinophilia, and serum IgE concentrations has ever been undertaken in patients with IgG4‐RD. In this study, we evaluated these parameters in a large cohort of patients with IgG4‐RD in whom a wide range of organs were affected by disease. Our results demonstrate that the majority of patients with IgG4‐RD are nonatopic. Nevertheless, a subset of nonatopic subjects exhibit peripheral blood eosinophilia and elevated IgE, suggesting that processes inherent to IgG4‐RD itself rather than atopy per se contribute to the eosinophilia and IgE elevation observed in the absence of atopy.     

Regulation of IgE and IgG4 synthesis in patients with hyper IgE syndrome

In order to investigate the imbalance of IgG subclasses and its relationship to IgE level, 14 patients with hyper IgE syndrome (HIE syndrome) were examined for serum IgG subclasses and IgE levels and five of these patients were studied for in vitro IgE and IgG subclass production by peripheral blood lymphocytes (PBL) in response to interleukin-4 (IL-4)/interferon-gamma (IFN-gamma). Serum IgE levels were highly correlative with serum IgG4 levels (r = 0.75, P less than 0.005), but not with IgG1, IgG2 or IgG3 levels (r = 0.21, 0.43 and 0.41, respectively). In an in vitro study, recombinant IL-4 enhanced not only spontaneous IgE synthesis but also IgG4 synthesis in cultures of PBL from patients with HIE syndrome as well as in healthy donors (P less than 0.01), and the effect of recombinant IL-4 on both IgE and IgG4 synthesis was inhibited by low concentrations of recombinant IFN-gamma (P less than 0.01). The disturbed regulation of IgE and IgG4 seen in patients with hyper IgE syndrome may be caused mainly by the disturbed regulation of both cytokines.     

A high-affinity monoclonal anti-IgE antibody for depletion of IgE and IgE-bearing cells

Background:  We have identified a monoclonal anti-human immunoglobulin E (IgE) antibody, which recognizes FcepsilonRI-bound IgE and prevents binding of IgE to FcepsilonRI. In this study, we assessed the binding kinetics and affinity of monoclonal antibody 12 (mAb12) for IgE and investigated whether mAb12 can be used for depletion of IgE and isolation of IgE-bearing cells from peripheral blood.
Methods:  Binding kinetics and affinity for IgE were studied using Biacore surface plasmon resonance technique experiments. IgE antibodies were depleted from serum using sepharose-coupled mAb12 and IgE-bearing cells were enriched from heparinized blood samples with mAb12. The extent and biological relevance of IgE depletion were studied by quantitative IgE measurements and basophil histamine release experiments. Specific binding of mAb12 to IgE-bearing cells (basophils, mast cells, IgE-secreting plasma cells) was demonstrated by FACS.
Results:  Monoclonal antibody 12 shows rapid association (k_a = 5.46e5/Ms) with IgE, almost no dissociation (k_d = 8.8e−5/s) and an affinity for IgE (K_D = 1.61e−10 M), which is as high as that of FcepsilonRI. Immobilized mAb12 could be used to deplete IgE antibodies and isolate IgE-bearing cells from peripheral blood in a single-step procedure.
Conclusions:  Monoclonal antibody 12 is a high affinity anti-human IgE antibody, which efficiently removes IgE and IgE-bearing cells from peripheral blood and may thus be used for extracorporeal depletion of IgE and IgE-bearing cells.     

Characterization of the murine interleukin 5 receptor by using a monoclonal antibody

Murine interleukin 5 (IL-5), a lymphokine produced by helper T cells, is involved in the regulation of growth and differentiation of B cells and other hematopoietic cells. The receptor for IL-5 has been identified as two cross-linked complexes on T88-M cells (a murine IL-5-dependent early B cell line). In this study the IL-5 receptor was directly characterized by utilizing an immobilized IL-5 column and a rat monoclonal antibody, designated H7, directed against the IL-5 receptor. H7 completely inhibited specific binding of 35S-labeled IL-5 to T88-M cells, and bound to IL-5-responsive cells, e.g. T88-M, BCL1-B20 (a chronic B-cell leukemia), and MOPC104E (a myeloma), whereas H7 did not bind to IL-5-non-responsive cells, e.g. X5563 (a myeloma), FDC-P1 (an IL-3-dependent line), and MTH (an IL-2-dependent CTLL). H7 could barely bind to T88-M cells in the presence of IL-5, and immunoprecipitated a major band with an Mr of approximately 60 kd from the extract of surface-radioiodinated T88-M cells. The precipitation of this 60 kd molecule was inhibited by the addition of IL-5. Analysis with immobilized IL-5 also revealed that a 60 kd molecule bound specifically to IL-5-coupled beads compared with control beads. Furthermore, no additional molecule with a higher Mr that was recognized by H7 appeared under non-reducing, compared with reducing, conditions. The 60 kd molecule recognized by H7 could be digested with N-glycanase to yield a protein band of approximately 55 kd.(ABSTRACT TRUNCATED AT 250 WORDS)     

Linked in vivo expression of soluble interleukin-4 receptor and interleukin-4 in murine schistosomiasis

Soluble interleukin-4 receptors (sIL-4R) are truncated IL-4R molecules that are secreted into biological fluids. To gain an insight into the mechanisms that control sIL-4R synthesis in vivo and their role in the regulation of immune responses, the expression and secretion of sIL-4R in mice infected with Schistosoma mansoni was studied. Splenocytes from infected animals responded to schistosomal antigen preparations with increased production of both IL-4 and sIL-4R. The synthesis of sIL-4R by spleen cells peaked at 8 weeks following infection and coincided with maximum levels of sIL-4R in serum and sIL-4R-specific mRNA in the liver of infected mice. The expression of IL-4-specific mRNA in the liver was different from that of IL-4R, reaching its peak approximately 2 weeks earlier. A relationship between sIL-4R production and the development and activation of Th2 cells was suggested by the findings that: (a) in vivo administration of anti-IL-4 antibodies (11B11) impaired the ability of splenic cells to secrete either IL-4 or sIL-4R; and (b) splenic cells from mice vaccinated with irradiated cercariae, which tend to develop much weaker Th2 responses than mice injected with live cercariae, expressed reduced levels of sIL-4R when challenged with schistosomal antigens. Moreover, a direct role for IL-4 in regulating the expression of sIL-4R was suggested by the ability of anti-IL-4 antibodies to inhibit sIL-4R synthesis in vitro. These data provide the first evidence demonstrating that the production of sIL-4R in vivo is up-regulated during immune responses, especially during those characterized by the development and activation of Th2 cells and IL-4 secretion. The association between sIL-4R and IL-4 syntheses is consistent with a potential role for sIL-4R in the regulation of IL-4 activity in vivo.