Cellular events in the IgE antibody response

Vaccine allergy

Overdiagnosis of vaccine allergy is considered a major public health problem. This article discusses the different types of allergic reactions after immunization based on the timing (immediate vs nonimmediate) and the extent of the reaction (local vs systemic). The vaccine components potentially responsible for an allergic reaction are discussed, as well as the management of patients with a history of reaction to a specific vaccine and those with a history of allergy to one of the vaccine components.

Smoking and circulating IgE in bronchial carcinoma

The serum concentrations of total IgE were significantly raised in smokers compared to those who had never smoked (p less than 0.005) among male patients with bronchial carcinoma, while no differences were found between smoking and non-smoking female bronchial carcinoma patients. The total IgE levels in male and female patients with non-malignant pulmonary diseases were not correlated to smoking habits. No significant differences in the IgE levels were observed between smoking males subgrouped according to the WHO histological types of bronchial carcinoma. Males with carcinoma who had stopped smoking more than 10 years ago had significantly reduced IgE levels compared to male cancer patients continuously smoking (p less than 0.01). These data, indicating that smoking is associated with elevated IgE levels in males with bronchial carcinoma, might suggest that smoking in certain, preferably male, individuals induces an impaired cellular immunity which is reflected by an enhanced IgE synthesis and a depressed resistance to carcinogens of tobacco smoke.

Special regulatory T-cell review: T-cell dependent suppression revisited

The concept of T-cell dependent regulation of immune responses has been a central tenet of immunological thinking since the delineation of the two cell system in the 1960s. Indeed T-cell dependent suppression was discovered before MHC restriction. When reviewing the data from the original wave of suppression, it is intriguing to reflect not just on the decline and fall of suppressor T cells in the 1980s, but on their equally dramatic return to respectability over the past decade. Hopefully their resurgence will be supported by solid mechanistic data that will underpin their central place in our current and future understanding of the immune system. Cannon to right of them, Cannon to left of them, Cannon in front of them Volley'd and thunder'd Storm'd at with shot and shell, Boldly they rode and well, Into the jaws of Death, Into the mouth of Hell, Rode the six hundred (suppressionists). (Adapted from The Charge of the Light Brigade, Alfred, Lord Tennyson)

Immunopathological study on the development of swine serum-induced bile duct lesions in BALB/c and DBA/2 mice

To compare the difference in the development of swine serum (SS)-induced bile duct lesion (BDL) between high responder BALB/c and low responder DBA/2 mice, the mice of both strains injected with SS twice a week for up to 4 weeks were killed and examined immunopathologically after the 2nd, 4th, 6th and 8th SS-injection, respectively. In BALB/c mice, BDL developed rapidly following the SS-injections, and a slight enlargement of common bile ducts accompanied with infiltration of T helper cells and eosinophils was detected after the 2nd SS-injection. From the 4th injection on, BDL was characterized by proliferation of mucous glands, hyperplasia and hypertrophy of biliary and glandular epithelial cells, periductal fibrosis, infiltration of eosinophils, plasma cells and T helper cells, and increase of mast cells, resulting in more apparent enlargement of common bile ducts. Several hypertrophied biliary and glandular epithelial cells were positive for mouse immunoglobulins and SS. BDL subsided after cessation of the SS-treatment. On the other hand, in DBA/2 mice, immune response and inflammatory reaction were very weak, and only slight BDL were detected.

A possible role of immunoglobulin E in patients with hyperthyroid Graves' disease

To investigate the possible participation of immunoglobulin E (IgE) in the autoimmune process of Graves' disease, incidence of elevation of serum IgE level, TSH receptor antibody (TRAb), and thyroid status were studied in 66 patients with hyperthyroid Graves' disease, 54 patients with Hashimoto's thyroiditis, 19 patients with bronchial asthma, and 15 patients with pollen allergy. In hyperthyroid Graves' patients, elevation of serum IgE levels (> or = 170 U/mL) was found in 19 of 66 patients (29%), 11 of whom had hereditary and/or allergic conditions. Elevations of serum IgE levels were found in 63% of patients with bronchial asthma and in 40% of patients with pollen allergy. Mean values of serum IgE were the same in patients with hyperthyroid Graves' disease and with bronchial asthma. During methimazole treatment TRAb decreased without fluctuation of IgE levels in both groups. The decrease in TRAb was significantly greater in patients with normal IgE than in patients with IgE elevation. After prednisone administration, reduction in TRAb was greater in patients with normal IgE than that in patients with IgE elevation. High incidence of IgE elevation in hyperthyroid Graves' disease and slower reduction in TRAb in association with IgE elevation suggest a difference in the autoimmune processes in Graves' disease with and without elevation of IgE.

The role of alpha4 (CD49d) and beta2 (CD18) integrins in eosinophil and neutrophil migration to allergic lung inflammation in the Brown Norway rat

We investigated the role of beta2 (CD18) and alpha4 (CD49d) integrins in eosinophil and neutrophil recruitment to lung parenchyma and bronchoalveolar lavage fluid (BALF) of allergen-challenged Brown Norway (BN) rats. Challenge of sensitized BN rats with ovalbumin induced an eosinophil- and neutrophil-rich infiltrate in BALF at 24 h, accompanied by an increase in BALF protein content. Treatment with either the TA-2 monoclonal antibody (mAb) against alpha4 (as an F[ab']2 fragment) or the WT.3 mAb against beta2 integrin significantly reduced eosinophil and neutrophil accumulation in BALF by 54 to 66% and eosinophil accumulation in the parenchyma by 48%. A significant difference in effect was observed between mAb TA-2 in intact immunoglobulin G or F(ab)2 form. Combined treatment with mAbs WT.3 plus TA-2 (F[ab]2) virtually abolished eosinophil accumulation in BALF and in the parenchyma, and reduced neutrophil accumulation in BALF by 91%. In contrast, neutrophil accumulation in the lung was not inhibited by these mAb treatments. The increase in BALF protein concentration was significantly inhibited by TA-2 (by 40%) and by WT.3 plus TA-2 in combination (71% inhibition). We conclude that eosinophil and neutrophil migration into the air space in allergic lung inflammation is partially CD18 (beta2)- and CD49d (alpha4)- dependent and that alpha4 integrins mediate essentially all of the CD18-independent migration. Similarly, eosinophil accumulation in the parenchyma is completely alpha4 and CD18 (beta2) integrin-dependent. In marked contrast, neutrophil accumulation in the lung in this allergen model can occur independently of both alpha4 and beta2 integrins.

Staphylococcal toxins augment specific IgE responses by atopic patients exposed to allergen

Microbial agents are known to play a significant role in aggravating allergic diseases. Recently described viral and bacterial superantigens represent one important strategy by which infectious agents can stimulate the immune response. In previous work, we reported that the staphylococcal toxin toxic shock toxin-1 (TSST-1), a prototypic superantigen, induces in vitro total IgE synthesis after cross-linking T and B cells. This study was carried out to establish a potential link between superantigens and the enhanced IgE response to specific allergens in allergic patients. Peripheral blood mononuclear cells from atopic patients were isolated during and outside the pollen allergen season and stimulated with TSST-1, a prototypic superantigen. Total IgE and interferon-gamma production were measured in supernatants of these cultures. Outside the pollen season, TSST-1 significantly increased total IgE production only in the presence of exogenous interleukin-4, whereas during the pollen season IgE production was significantly enhanced without the need of exogenous interleukin-4. This increase in the absence of exogenous interleukin-4 was associated with significantly lower interferon-gamma production by peripheral blood mononuclear cells stimulated by TSST-1 during the pollen season. Moreover, TSST-1 stimulation of peripheral blood mononuclear cells from inhalant allergic patients was followed by an increased production of allergen-specific IgE that was restricted to the allergen to which the patient was allergic and recently exposed. In addition, TSST-1 induced on B cells the expression of B7.2, a molecule that has recently been demonstrated to enhance T helper 2 responses and to be involved in IgE regulation. This study, by demonstrating that superantigens can augment allergen-specific IgE synthesis and B7.2 expression, provides a mechanism by which microbial superantigens may modulate allergic responses.

Cell interactions that regulate the T-cell dose-response profile to concanavalin A

We have tested the ability of structures on macrophage (M phi) membranes (M phi-MEM) and on several other types of cells with Fc receptors to affect the DNA synthetic response of concanavalin-A-stimulated T cells. Of the cells tested, only M phi-MEM have the capacity to relieve the suppression produced by supra-optimal doses of the mitogen. The M phi-MEM do not increase Con A responses by altering the stimulatory capacity of the Con A. These observations, analysed together with previous results, which have indicated that live intact M phi are required for the transfer of information between lymphocyte sets and that M phi-MEM preparations can act as competitive antagonists for this function, are interpreted as follows: some supraoptimal doses of Con A activate suppressor cells, which are responsible for limiting the DNA synthetic response to the mitogen; the M phi-MEM abrogate this suppression by absorbing the signal that activates the suppressor cell. Kinetic studies suggest that the M phi-MEM do not affect the activity of already activated suppressor cells. We also found that Con A usually activates two separately responding T-cell populations with different sensitivities to dose and to time of contact with mitogen and that the suppression of both populations can be relieved by M phi-MEM. These results support the notion that the overall immunological circuit is composed of multiple independently regulated mini-circuits, with M phi acting as transmission posts for intra- and perhaps also inter-circuit communication.

Kinetics and quantitation of eosinophil and neutrophil recruitment to allergic lung inflammation in a brown Norway rat model

We quantitated neutrophil and eosinophil migration into lung parenchyma using specific peroxidase enzyme assays, and into the bronchoalveolar compartment by bronchoalveolar lavage (BALF), in sensitized brown Norway (BN), Fischer, and Lewis rats and also assessed the lungs by histopathology. Fourteen days after sensitization with ovalbumin (OA in alum [given subcutaneously] and OA with Bordetella pertussis [given intraperitoneally]), rats were challenged with an OA aerosol for 1 h. In BN rats, there was marked perivascular and peribronchial edema, focal hemorrhages, and increase in lung wet weight and BALF protein content, accompanied by neutrophilic infiltration at 3-14 h postchallenge. Few eosinophils were seen at 14 h in lung tissue or in BALF. Neutrophils peaked at 24 h in parenchyma ([94 +/- 7] x 10[6]) and in BALF ([2.7 +/- 0.4] x 10[6]) and declined rapidly thereafter. Marked eosinophil infiltration into parenchyma was apparent by 24 h. Eosinophil accumulation peaked at 48 h in parenchyma ([127 +/- 18] x 10[6]) and at 72 h in BALF ([10 +/- 2.4] x 10[6]), comprising up to 85% of lavage cells at this time. Lung eosinophilia persisted for at least 6 d with only a slow decline or clearance, not approximating baseline until day 13 after challenge. Histopathology showed peribronchial and interstitial eosinophilic pneumonia, most severe on day 3. In contrast to the BN rats, essentially no pulmonary inflammation was observed in Lewis and Fischer rats. This model in the BN rat, and the specific peroxidase assays for quantitating tissue eosinophils and neutrophils, should be useful for investigating the regulation of allergen-induced eosinophil and neutrophil migration into and clearance from the lung.

Immunoglobulin E and G responses to pertussis toxin in children immunised with adsorbed and non-adsorbed whole cell pertussis vaccines

The IgE and IgG responses to pertussis toxin were measured in blood samples from 70 children (age 1.5-2.9 years) after primary immunisation with either a non-aluminium adsorbed, whole cell vaccine (n = 34) or an aluminium adsorbed whole cell vaccine (n = 36). Two years later, they received a booster immunisation with either the non-adsorbed (n = 24) or the aluminium adsorbed vaccine (n = 14). Neutralising antibodies to pertussis toxin were higher (P < 0.05) after the three priming doses of the adsorbed vaccine than of the non-adsorbed vaccine, although both groups showed > 90% seropositives after the third dose. IgE antibodies to PT (PT-IgE) were detected in samples from 11/52 children after completed primary immunisation and the levels were low (median < or = 0.1 PRU ml-1) in both groups. No significant differences between the groups were found. PT-IgE levels did not increase after the booster injection. Thus, the aluminium content of the whole cell vaccines influenced the IgG response but not the IgE responses to pertussis toxin. The high rates of PT-IgE responses noted after a booster dose of acellular or whole cell pertussis vaccine to children primed with acellular vaccine in previous studies can therefore be mainly ascribed to the nature of the priming vaccine rather than the aluminium adjuvant.

Modeling immunotherapy for allergy

Type I hypersensitivity, which functions to protect the organism from parasites, is caused by binding of antigen to IgE antibodies pre-attached to the cell surface of tissue mast cells and their circulating counterparts, the basophils. In "allergy," type I hypersensitivity is inappropriately induced by protein-based foreign substances (such as pollen) or protein components of insect stings, which in the normal course of events would be cleared from the organism without causing any damage. Paradoxically, a successful clinical treatment of allergy involves repeated immunization of allergic persons with low doses of the allergen--immunotherapy. Investigation of the available experimental evidence leads to the conclusion that the phenomena of immunotherapy are best addressed in terms of the interplay among the mechanism(s) of immune memory--Th1/Th2 cross-regulation--and the physical compartmentalization of the immune system. These conclusions are illustrated with a numerical simulation.

Neuropeptide-mediated regulation of hapten-specific IgE responses in mice. II. Mechanisms of substance P-mediated isotype-specific suppression of BPO-specific IgE antibody-forming cell responses induced in vitro

Previous studies in our laboratory have shown that substance P (SP), injected into benzylpenicilloyl-keyhole limpet hemocyanin (BPO-KLH) sensitized mice at the peak of the benzylpenicilloyl (BPO)-specific IgE response, suppressed these responses in isotype-specific fashion within 48 h. These studies also showed that SP, but not neurotensin (NT), serotonin (5-HT), somatostatin (SOM) or gastrin, suppressed BPO-specific memory IgE antibody-forming cell (AFC) responses induced in vitro, also in isotype-specific fashion. To investigate the mechanisms by which SP suppressed BPO-specific IgE AFC responses were induced in vitro, these responses were induced by culturing spleen cells from BPO-KLH sensitized mice for 5 days with BPO-KLH with or without whole SP, amino terminal SP (SP 1-4: Arg-Lys-Pro-Lys), or carboxy terminal SP (SP 8-11: Phe-Gly-Leu-Met). In some experiments, the SP receptor antagonist (D-Pro2, D-Phe7, D-Trp9)-SP (D-SP) was included in culture. In other experiments anti-interferon monoclonal antibody (anti-IFN gamma mAb) was in culture. Whole SP and SP 8-11, but not SP 1-4, suppressed BPO-specific IgE AFC responses induced in vitro. The suppression obtained was IgE isotype-specific and dose-dependent. Inclusion of SP receptor antagonist (D-Pro2, D-Phe7, D-Trp9)-SP inhibited suppression of BPO-specific memory IgE AFC responses by SP or SP 8-11. The SP-mediated suppression of BPO-specific memory IgE responses appeared to involve interferon gamma (IFN gamma).

Lol p I-induced IL-4 and IFN-gamma production by peripheral blood mononuclear cells of atopic and nonatopic subjects during and out of the pollen season

The reciprocal effects of IL-4 and IFN-gamma on IgE synthesis have been well established. It has also been shown that these two lymphokines are secreted by different subsets of CD4+ T cells (TH1 and TH2), and that TH2 helper T lymphocytes could be involved in the pathophysiology of allergic diseases. But little is known about the effects of an allergen on the profile of lymphokine synthesis by human peripheral blood mononuclear cells (PBMCs) of allergic and nonallergic subjects. We studied the production of IL-4 and IFN-gamma by PBMCs of atopic and nonatopic donors after in vitro stimulation by the group 1 allergen from Lolium perenne pollen (Lol p I), during and out of the grass pollen season. On natural exposure to pollen, Lol p I-induced IL-4 production was observed only with atopic donors (6 of 8), whereas the synthesis of IFN-gamma was observed for all nonatopic donors (7 of 7) and most allergic patients (5 of 7). At the time of the study, higher amounts of IFN-gamma were produced by PBMCs of nonatopic donors than by PBMCs of atopic patients. Out of the pollen season the production of IL-4 was not observed either by atopic (n = 11) or by nonatopic subjects (n = 5). On the other hand, IFN-gamma was produced by PBMCs of most subjects (atopic, 10 of 11; nonatopic, 5 of 5), but at the time of the study no difference was observed between the two groups. These results show that Lol p I induces different profiles of IL-4 and IFN-gamma production by PBMCs of atopic and nonatopic subjects. In atopic subjects this profile of lymphokine synthesis is influenced by the natural exposure to pollen, which is in keeping with the seasonal rise of IgE antibodies.

Comparison of different inhalation schedules to control childhood asthma

In a double-blind, placebo-controlled study control of asthma was assessed by diary symptom cards, peak-flow measurements and lung function within 3 treatment groups over a 6 months period. 36 children (25 boys, 11 girls 5.5 to 13.2 years of age) with exogen allergic, perennial asthma inhaled either beclomethasone dipropionate (BDP) with salbutamol (S) or disodium cromoglycate (DNCG) with S or a placebo preparation with S from metered dose inhalers (MDI) through a large-spaced auxiliary device (Volumatic). At entry, after 2 and 4 months lung function tests were performed evaluating changes in the degree of pulmonary hyperinflation, bronchial obstruction, and bronchial hyperreactivity (BHR). Daily PF measurements showing wide variations (up to 10-12%) were insensitive to indicate any significant changes. In contrast evaluation of symptom diaries presented dramatic improvement during the first 3 months of the study. In addition, the DNCG group showed significant improvement of BHR (p = 0.02). Moreover, the majority of patients on regular therapy with salbutamol and placebo showed an increase of airway resistance. It is concluded that even in mild childhood asthma, for optimal control a combination of a beta 2-stimulant as bronchodilator and DNCG or BDP as protector should be applied.

Regulation of IgE synthesis by T cells and cytokines

Human IgE synthesis is tightly regulated by cytokines. IgE production by normal B cells is specifically induced by IL-4, but requires additional, yet to be defined, signals that are provided by CD4+ T cells. Single surface IgM+ B cells can be induced to proliferate and switch to IgG4 and IgE producing cells, indicating that the induction of IgE synthesis by IL-4 and CD4+ T cells reflects direct isotype switching. Although IL-4 is the sole inducing cytokine of IgE synthesis known thus far, multiple cytokines modulate IL-4 induced IgE synthesis in vitro. IFN-alpha, IFN-gamma TGF-beta and IL-10 are inhibitory, whereas IL-5, IL-6 and TNF-alpha act synergistically with IL-4. Results obtained with animal models, as well as from clinical studies in the human have indicated that IL-4, IFN-alpha and IFN-gamma are operational in vitro. Cocultivation of B cells with allergen-specific CD4+ T cell clones producing high levels of IL-4 and IL-5, but normal to undetectable levels of IL-2 and IFN-gamma, following activation resulted in the synthesis of IgE, in the absence of exogenously added IL-4. These results indicate that aberrant ratio's of IL-4 and IFN-gamma production are sufficient for induction of IgE synthesis in vitro.(ABSTRACT TRUNCATED AT 250 WORDS)

Role of sodium in antigen-induced contraction of tracheal smooth muscle in dogs

We examined the role of Na+ influx in the airway response to antigen (ragweed pollen extract) in sensitized dogs, using amiloride analogs to block Na(+)-dependent processes. In in vivo studies, respiratory resistance was measured in amiloride treated and untreated groups. The resistance increased by 9.3 cmH2O.L-1.sec in response to ragweed aerosol in the untreated group, but increased only by 5.2 cmH2O.L-1.sec in the treated group. In in vitro studies, isometric tension was measured in ragweed pollen sensitized tracheal strips. Tissues were treated with amiloride or its derivatives (50 microM) for specifically blocking Na+ channels (phenamil), Na(+)-H+ exchanger [5-(N-methyl-N-guanidinocarbonyl methyl)-amiloride] or Na(+)-Ca2+ exchanger [5-(4-chlorobenzyl)-2',4'-dimethylbenzamil]. In untreated strips, tension increased in response to ragweed by 1.9 +/- 0.5 mN/mg. The increase was reduced by phenamil (95.2 +/- 2.5%; P < 0.01) and amiloride (41.7 +/- 13.1%; P < 0.01), but not by the other two agents. Furthermore, phenamil also inhibited histamine-induced tension response and histamine-induced 22Na+ uptake of the muscle. We conclude that antigen-induced airway response is attenuated by blocking Na+ influx in smooth muscle.

Changes in cell-mediated immune responses after experimentally-induced anaphylaxis in dogs

Experimentally-induced type 1 hypersensitivities were induced in normal dogs to either ovalbumin or Ascaris antigen. In vitro and in vivo cell-mediated immune responses were measured before sensitization and again at 1 and 6 days after induction of anaphylaxis by intravenous challenge with antigen. Histamine-modulated lymphocyte functions, such as histamine-induced suppression, histamine co-mitogen induced blastogenesis and the in vivo cutaneous responses to intradermally injected mitogens decreased post anaphylaxis. Spontaneous suppression of the autologous mixed-lymphocyte reaction increased post anaphylaxis. Lymphocyte blastogenic response to Concanavalin A (Con A) decreased at 6 (but not at 1) days post anaphylaxis probably due to a mediator other than histamine. Blastogenesis of 24 h preincubated cells by suboptimal concentration of Con A, declined post anaphylaxis, but Con A-induced suppression was not significantly altered. Dogs with atopic dermatitis have some altered cell-mediated immune responses. Altered histamine-induced and spontaneous suppression, histamine suppression of mitogenesis and decreased contact sensitivity observed in this experimental type 1 hypersensitivity mimicked that of atopic dogs. Increased cutaneous response to mitogens observed in atopic dogs was not reproduced in the type 1 hypersensitive dogs. These findings suggest some of the altered cell-mediated immune functions observed in dogs with atopic dermatitis result from type 1 hypersensitivity. The other abnormalities may be intrinsic to the atopic state.

Neopterin quantification in acute severe asthma

To investigate the pathogenic role of cell-mediated immunity (CMI) in acute severe asthma, 10 patients with acute asthma requiring admission to hospital had measurements of serum and urine absolute neopterin and neopterin/creatinine ratios. Serum was collected upon entry to hospital, 24 hr later and at 2 weeks; and urine at 24 hr and at 2 weeks after admission. Comparisons were made with 12 stable asthmatic patients, healthy control subjects, and six renal transplant patients undergoing transplant rejection. In contrast to the renal transplant patients who demonstrated T-lymphocyte-macrophage activation, neopterin concentrations and neopterin/creatinine ratios in both acute and stable asthmatic patients were not elevated. We have not found functional evidence that CMI participates in the pathogenesis of acute severe asthma.

Influence of indomethacin and L-cysteine on histamine and peptidoleukotriene release from superfused tracheas taken from guinea pigs passively sensitized with IgG1 and IgE antibodies

We have previously reported differences in mediator release during equivalent levels of antigen (Ag)-induced smooth muscle contraction of guinea pig pulmonary tissues after passive sensitization with IgG1 versus IgE antibodies (Abs). In the present study, we have examined the influence of indomethacin (5 x 10(-6) mol/L) and L-cysteine (3 or 10 mmol/L) on mediator release from superfused trachea taken from guinea pigs passively sensitized with IgG1 or IgE Ab 1 day before in vitro studies. Tissues were challenged with Ag (oxazolone-human serum albumin conjugate), and contractions and superfusate histamine and peptidoleukotrienes were monitored at discrete time intervals thereafter. Superfusate mediator contents were determined by spectrophotofluorimetry (histamine) and RAST (peptidoleukotrienes). The profiles of peptidoleukotrienes were examined with high-pressure liquid chromatography. At equivalent levels of contraction, significantly less histamine and peptidoleukotrienes were found in superfusate samples after sensitization with IgE Abs. None of the drug pretreatments significantly altered Ag-induced histamine release after IgG1 or IgE sensitization. Indomethacin resulted in an increase in total measurable peptidoleukotrienes found only after IgG1 receptor activation, but it did prolong tracheal contractions with both Abs. L-cysteine, 10 mmol/L, resulted in an increase in total measurable superfusate peptidoleukotriene content under all experimental conditions. The percentage increase in peptidoleukotriene content from that found without drug pretreatment was larger in the case of IgE compared to IgG1 sensitization. During early time periods, after Ag challenge, measurable peptidoleukotriene levels in superfusate samples were similar for both Abs in the presence of L-cysteine, 10 mmol/L. These data suggest that there is a differential pattern of peptidoleukotriene metabolism after activation of IgG1 versus IgE receptors in guinea pig trachea.

Patient education in asthmatic children

The major goal of all diagnostic and therapeutic efforts in childhood asthma is to prevent progression of lung disease into adulthood. To improve the uncomfortable situation of underdiagnosis and undertreatment and to lower the risk of acquiring irreversible lung damage, an optimal co-working relationship between family doctor and parents, and a patient education program toward that end, is essential.

Regulation of immunoglobulin E production in mice immunized with an extract of Toxoplasma gondii

Repeated infection with Toxoplasma gondii could not induce immunoglobulin E (IgE) antibody production. When mice were injected intraperitoneally twice over a 3-week interval with an extract of tachyzoites of T. gondii and Al(OH)3 as adjuvant, antitoxoplasma IgE antibody was produced. Antitoxoplasma IgE antibody titers were low and diminished after a short time in B10.S, BALB/c, C3H, and C57BL/6 mice. This tendency was more evident in IgE low-responder SJL mice. IgE-inducing activity of Toxoplasma antigen was weaker than those of keyhole limpet hemocyanin, ovalbumin, and an extract from Nippostrongylus brasiliensis. The antitoxoplasma IgE antibody production was enhanced by and persisted after whole-body irradiation (150 R) following secondary immunization. The enhanced antitoxoplasma IgE antibody production was suppressed by transferring spleen cells from Toxoplasma antigen-immunized mice. The suppressive effect of the spleen cells was Toxoplasma antigen specific and was removed by treatment with anti-Thy-1.2 and complement. These results indicate that the low IgE production induced by Toxoplasma antigen is the result of irradiation-sensitive and antigen-specific suppressor T cells. These findings might explain the lack of IgE antibody response in mice with Toxoplasma infection.

Clonal and molecular characteristics of the human IgE-committed B cell subset

We have followed the pathway of the IgE-committed B lymphocyte from fresh, unstimulated peripheral blood, through EBV activation, transformation, and eventual cloning. Using cell sorting in conjunction with limiting dilution culture systems, we found that: (a) cells that are selected in the cell sorter and secrete IgE in culture are sIgM+/sIgD+. They secrete all three isotypes after EBV activation and continue to do so stably in culture; (b) individual IgE+ cells in culture coproduce IgM, IgD, and IgE and cytoplasmic Ig of each isotype can be detected in single cells; (c) no rearrangement was observed of VDJ to epsilon in any of six lines tested. DNA between the rearranged VDJ-mu and -epsilon appears to be overall intact, including a region 10.5 kb upstream and 18 kb downstream of the 2-kb epsilon coding region and; (d) mRNA of mu and epsilon species is of normal and comparable size. In contrast to IgG- and IgA-producing clones, multiple isotype expression appears to be both frequent and stable in cells committed to IgE production. We propose that IgE-committed cells represent a unique B cell sublineage whose differentiation pathway may be more strictly regulated than that of other isotypes with regard to the signals required for classical, deletional switch recombination that has been observed in rare IgE-producing myeloma cell lines.

Different immunological sensitizing regimens and airway responsiveness in vitro to contractile agonists in guinea-pigs

Groups of guinea-pigs were sensitized to ovalbumin, using different regimens to induce either IgG-like antibodies or IgE-like and IgG-like antibodies and the responsiveness to histamine and carbachol in vitro of tracheal and lung parenchymal strips was determined. EC50 values for histamine and carbachol in both tracheal and lung parenchymal strips were not significantly different for either group of sensitized guinea-pigs or their respective controls. The maximal tension developed in parenchymal strips was not significantly different for either sensitized or control groups. For tracheal strips, maximal tension was not significantly different in each group except in animals with IgG-like antibodies, which developed less maximal tension with histamine than controls. The absence of any increase in maximal tension or any change in EC50 to histamine or to carbachol in tracheal or parenchymal strips from immunized guinea-pigs indicates that immunological sensitization does not increase the responsiveness of smooth muscle to these contractile agonists.

Frequency analysis of functional Ig C epsilon gene expression in the presence and absence of interleukin 4 in lipopolysaccharide-reactive murine B cells from high and low IgE responder strains

Nonresponder SJL mice produce low levels of antigen-specific IgE after immunization, compared to responder strains. Young athymic BALB/c nude mice are unable to produce antigen-specific or total IgE in their serum. These mice also have very numbers of background IgE-secreting cells in their lymphoid organs. High-responder BALB/c mice do have substantial numbers of background IgE-secreting cells while low-responder AKR mice show intermediate numbers. Similar differences were found when analyzing lipopolysaccharide (LPS)-reactive B cells in cell suspensions of spleen and bone marrow in limiting dilution cultures. Limiting dilution analysis of T cell-depleted splenic B cell cultures revealed that the defective IgE production in SJL mice is not due to an intrinsic B cell defect. This defect can be substantially overcome by addition of exogenous interleukin 4 (IL4) to these cultures. Furthermore, it was shown in limiting dilution cultures that SJL thymocyte feeder cells were able to suppress IgE production by LPS-activated high-responder BALB/c B cells. The addition of IL4 or neutralizing antibodies against IL4 or interferon-gamma to these cultures helped to overcome this suppressive effect to a large extent. We conclude that different IgE responder types are caused, at least in part, by a defective IL4 production or by a defect in the TH2 system that is functionally detectable at the level of thymocytes.

Induction of human in vitro IgE synthesis via stimulation by anti-CD3 antibody

Mitogens such as pokeweed mitogen, Staphylococcus aureus Cowan I, concanavalin A and phytohemagglutinin and monoclonal anti-CD antibodies were examined for their capacity to induce IgE synthesis by peripheral blood leukocytes obtained from both atopic and nonatopic individuals. While lectins failed to induce IgE synthesis, monoclonal anti-CD3 antibodies were very potent stimuli for the induction of human in vitro IgE synthesis, possibly due to the activation of T cells. Activation via CD4 or CD8 molecules by OKT4 or OKT8 antibodies did not lead to a T cell-dependent modulation of IgE synthesis. PWM acted in synergy with the enhancing effect of anti-CD3 antibodies for IgE synthesis. In vitro IgG production was less affected. These results indicate that activation of T cell via CD3 molecules may be important in the regulation of IgE immune responses in man. Furthermore, the successful induction of IgE synthesis by anti-CD3 antibody in unfractionated peripheral blood leukocytes culture provides a simple model for investigation of human IgE regulatory mechanism in vitro.

Induction of IgG2a secretion from mIgG2a+ B-lymphoid tumor cells by BCDF present in several antigen-specific T-helper clones

In order to study the soluble factor(s) that play an important role for the differentiation of IgG2-secreting B cells, we examined whether membrane IgG2a (mIgG2a)-bearing BALB/c B-lymphoid tumor cells, A20, could be induced to secrete IgG2a after treatment with soluble factors. We detected a potent B-cell differentiation activity inducing the Ig secretion of A20 tumor cells (BCDF-A20) in supernatants of several soluble antigens as well as alloantigen-specific T-cell clones of various genetic backgrounds. Thus, this BCDF-A20 activity was working in an antigen-nonspecific and MHC-nonspecific manner and abundant in many T-cell clones. It was shown that neither interleukin 1, interleukin 2, interferon, T-cell replacing factor, B-cell maturation factor, nor B-cell stimulatory factor-1 alone had any significant effect on the induction of Ig secretion of A20 tumor cells. Using isotype-specific rabbit anti-mouse Ig developers, we showed that mIgG2a+ A20 tumor cells secreted IgG2a after the treatment with soluble factors. The peak of the response of A20 tumor cells to BCDF-A20 was obtained 3 days after the treatment with culture supernatants of T-cell clones. In this study, we have clearly shown that mIgG2a+ A20 tumor cells were able to secrete IgG2a after treatment with T-cell soluble factors.

Influence of Plasmodium chabaudi adami on the isotypic distribution of the antibody response of mice to sheep erythrocytes

The influence of an infection with P. chabaudi adami on the isotypic distribution of the in vivo antibody response to SRBC was investigated. Previous experiments suggested that the IgG1 isotype was poorly represented in the antibody response to plasmodial antigens and in the non-specific B cell response which accompanies an infection with P. chabaudi. The experiments described here indicated that although the magnitude of the total primary or secondary in vivo PFC response to SRBC was relatively unaffected by infection, the SRBC-specific IgG1 PFC response was depressed. Maximum depression of the IgG1 component of the response was observed when the priming dose of SRBC was administered at the same time as or after infection with P. chabaudi organisms. Coincident with the depression in the IgG1 response in infected mice was a corresponding increase in the SRBC-specific IgM response. The IgG1 depression was not a consequence of different kinetics of the generation of an IgG1 response, since at all times measured, the IgG1-PFC response was lower. In addition, the depressed IgG1 responses occurred only during a viable infection and could not be induced by inoculation of large amounts of irradiated erythrocytic stages of the parasite. These data suggest therefore, that there is a selective depression of IgG1 antibodies (but not those of other isotypes) regardless of antigenic specificity as a result of infection of C57BL/6 mice with P. chabaudi adami.

The IgE antibody response to the phosphorylcholine hapten

The immune response to the phosphorylcholine (PC) hapten elicited by PC-keyhole limpet hemocyanin (KLH) is composed of 2 groups of antibodies with specificity to either PC or phenylphosphorylcholine which were designated as group I and II anti-PC antibodies, respectively. We demonstrate that anti-PC IgE antibody expression is restricted to group II antibodies and does not display the T15 idiotype. Accordingly anti-PC IgE antibodies recognize the same epitope (PC-phenyl) as IgG1, IgG2a and IgG2b antibodies which is different from that (PC) recognized by IgM and IgG3 antibodies. A monoclonal anti-PC IgE antibody, representing group II characteristics was established. From amino acid sequences of light chains of purified group I and II antibodies from serum as well as of monoclonal representatives thereof it appears that both populations are relatively homogenous and represent independent clonal expressions. Nevertheless the formation of anti-PC IgE antibodies in mice can be suppressed by isologous anti-T15 anti-idiotypic antiserum. This antiserum, however, crossreacts with different anti-PC antibodies including monoclonal group II anti-PC IgE antibodies and is composed of a large number of anti-idiotopes. An analyses performed with monoclonal anti-T15 idiotopes demonstrates that some but not all antibodies suppress the formation of anti-PC IgE. We conclude that syngeneically induced anti-idiotypic interactions may display regulation of a wide range of specificities affecting responses to various antigenic determinants.

IgE class-specific regulatory factor(s) and Fc epsilon receptors on lymphocytes

The IgE isotype-specific regulatory factor(s) of rodents as well as humans was shown to have an affinity to IgE molecules, suggesting that the factor(s) are Fc epsilon receptors (Fc epsilon R) on lymphocytes or include a fragment of Fc epsilon R. In order to test this possibility, the monoclonal anti-Fc epsilon R antibodies with different epitope specificities were prepared. FACS analysis showed that approximately 50 percent of B cells from normal individuals expressed Fc epsilon R and the augmentation of the expression was observed by the incubation with T cell factors and IgE. However, the Fc epsilon R expression on T cells was not detected even after induction. The result suggests that T cells may secrete Fc epsilon R but not express it on the surface or the IgE-binding factor(s) from T cells may not be antigenically cross-reactive with Fc epsilon R on B cells.

Suppression of the anti-hapten IgE antibody response with hapten-modified spleen cells

Spleen cells of BALB/c mice were chemically modified with phosphorylcholine or benzylpenicilloyl hapten. The i.v. administration of such cells into syngeneic animals suppressed the formation of specific IgE antibodies against the respective hapten. The IgE antibody response against ovalbumin, which was used as an immunogenic carrier for the haptens, was not affected and the anti-hapten IgG or IgG1 response remained at the levels of the controls. The suppression could be transferred into X-irradiated mice by T cells from tolerized animals. Moreover, it was demonstrated that not only the induction of IgE, but also an established anti-hapten IgE antibody response is accessible to suppression by treatment with hapten-modified spleen cells from syngeneic animals. The results indicate that the i.v. administration of antigen coupled to syngeneic spleen cells induces T cells which suppress the formation of specific IgE antibodies in the primary and the secondary response without significantly affecting the formation of IgG antibodies.

Suppression of in vivo polyclonal IgE responses by monoclonal antibody to the lymphokine B-cell stimulatory factor 1

The lymphokine B-cell stimulatory factor 1 (BSF-1) has been shown to greatly enhance the differentiation of lipopolysaccharide-activated B cells into IgG1- and IgE-secreting cells in vitro. To determine whether in vivo IgG1 and IgE antibody responses are BSF-1 dependent, the ability of a monoclonal rat IgG1 anti-BSF-1 antibody, 11B11, to affect polyclonal IgG1 and IgE production in mice infected with the nematode parasite Nippostrongylus brasiliensis or injected with a purified goat antibody to mouse IgD was studied. 11B11-containing ascites fluid or purified 11B11 strongly inhibited IgE production in both systems but did not affect IgG1 production, while control ascites or normal rat IgG1 had no IgE-inhibitory activity. These results indicate an important physiologic role for BSF-1 in the generation of IgE antibody responses and suggest means for limiting the production of antibodies responsible for allergic reactions without inhibiting protective antibody responses.

Lesions and saliva-specific antibody responses in rabbits with immediate and delayed hypersensitivity reactions to the bites of Glossina morsitans centralis

Rabbits exposed to feeding tsetse flies developed cutaneous hypersensitivity responses to fly bites. These responses had characteristics of immediate and delayed type hypersensitivity. Saliva components from the tsetse fly Glossina morsitans centralis were electrophoretically separated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Major salivary proteins of 160, 92, 66, 64, 55, 42, 33, 28, and 15 kilodaltons were identified. Separated salivary components were transferred to nitrocellulose filters and probed with lectins and with whole sera and purified IgG from rabbits which had been exposed, via fly feeding, to tsetse antigens for variable periods. Many of the salivary proteins were identified as glycoproteins. Several major salivary proteins were recognized by antibodies from sensitized rabbits.

Degranulation and histamine release from murine mast cells sensitized with dengue virus-immune sera

Mice were immunized with dengue type 2 virus (DEN 2) under a schedule favoring the production of IgE antibody. The antibody obtained could sensitize peritoneal resident mast cells both in vitro and in vivo so that the sensitized cells were degranulated and released histamine on challenge with the DEN 2 antigen. It was also demonstrated that the antibody was cytophilic and heat-labile. The above observations suggest that the present experimental system can be used to detect anti-DEN 2 IgE antibody in mice.

Leakage of macromolecules from guinea-pig tracheobronchial microcirculation. Effects of allergen, leukotrienes, tachykinins, and anti-asthma drugs

The tracheobronchial mucosa of anaesthetized guinea-pigs (normal or sensitized with ovalbumin to produce IgE and IgG antibodies) was superfused (0.02 ml min-1, 5 min) with saline, mediators, and (in sensitized animals) ovalbumin via a catheter atraumatically introduced orally. The intravascular blood pool and amount of macromolecules in excised trachea and adjoining main bronchi were quantified by measuring erythrocytes, that had been labelled in vivo with 99Tcm, and analysing for FITC-dextran, MW = 70,000, that had been given i.v. Extravasation of macromolecules was determined as the analysed total content minus the calculated intravascular content of FITC-dextran. Capsaicin 0.1 nmol extravasated 223 micrograms of FITC-dextran per g wet weight of airway tissue (P less than 0.001). Substance P 0.1 nmol, 41 micrograms g-1 (P greater than 0.05); substance P 0.3 nmol, 142 micrograms g-1 (P less than 0.001); eledoisine 0.1 nmol, 101 micrograms g-1 (P less than 0.01); ovalbumin 0.1 microgram, 179 micrograms g-1 (P less than 0.001); LTC4 0.2 pmol, 180 micrograms g-1 (P less than 0.001); LTD4 0.2 pmol 223 micrograms ml-1 (P less than 0.001). Bronchi and trachea were similarly affected by these agents. Prior superfusion (0.02 ml min-1, 30 min) with terbutaline 0.06 nmol, enprofylline 12 nmol, or lidocaine 6 nmol significantly reduced the effect of capsaicin. Enprofylline also reduced significantly the effect of LTC4. The degree of extravasation in this study was smaller than could be detected by changes in tissue wet to dry weight ratios. The present data support the view that tracheobronchial vascular permeability to macromolecules is subject to physiological and pharmacological control.

Proliferative response in solid culture of T cells from patients with extrinsic bronchial asthma

T cells proliferative response in both liquid and solid culture conditions (the later prevents direct cell to cell contact) was investigated in nineteen Extrinsic Bronchial Asthma patients (EBA). Tetradecanoyl-phorbol-13-acetate (TPA), a T cell mitogen was used as mitogenic stimulus in both liquid and solid conditions. While the response to phytohemaglutinin (used in liquid culture as reference) was intact, the EBA group showed a significant reduction in the proliferative response to TPA in both culture conditions. Furthermore, when adherent cells were removed prior to TPA stimulation, while the control group showed a significant decrease in proliferation, the already depressed low proliferation of the EBA group remained unchanged. These results suggest the prevalence of suppressor signals in EBA and may indicate heterogeneity of the suppressor cells pool since high levels of total serum IgE were also present in the same patients.

Anaphylaxis: clinical presentation, immunologic mechanisms, and treatment

Anaphylaxis is a devastating allergic catastrophe. It is described as a systemic, immediate-type hypersensitivity reaction induced by exposure to a specific antigen and is immunologically based. The clinical manifestations may be mild but are often rapidly progressive, leading to respiratory distress and cardiovascular collapse. In addition to avoiding exposure to the antigen, treatment includes general supportive measures and specific therapeutic modalities. The purpose of this article is to review the current concepts of anaphylaxis and discuss the etiologic agents, immunologic mechanisms, clinical presentation, and treatment of this true allergic emergency.

Activation by bradykinin and vasoactive intestinal peptide of adenylate cyclase from immunologically sensitized lung membranes

Bradykinin receptors on normal lung membranes seem to be coupled to adenylate cyclase. Stimulation of the enzyme from sensitized lung membranes by adrenaline and vasoactive intestinal peptide was markedly reduced, whereas the ability of bradykinin and histamine to activate the sensitized adenylate cyclase was unaffected. Additional experiments are necessary in order to delineate the precise molecular events associated with activation of each of the two presently known bradykinin receptor types.

Eosinophil activation by lymphokines and T cell clone products in the rat

T cell lines and T cell clones derived from inbred Fischer rats and specific for Schistosoma mansoni antigens were established. Cell-free supernatants from the T cell lines demonstrated a marked capacity to enhance IgE- and IgG2a-dependent eosinophil-mediated killing of S. mansoni larvae in vitro. In addition, supernatants from cloned T cells stimulated with concanavalin A or specific antigen, or unstimulated, enhanced IgE-dependent eosinophil-mediated helminthotoxicity. The enhancing activity in both cases was very heat-stable (100 degrees C, 10 min). We also found that clone-derived supernatants enhance eosinophil peroxidase release upon stimulation with homologous IgE and anti-IgE as well as inducing a more delayed spontaneous release of peroxidase. In view of the established thymus dependency for the development of immunity to schistosomiasis in the rat, the availability of these S. mansoni-specific cloned T cells has enabled the relationship between eosinophils, lymphocytes and anaphylactic antibodies to be examined more closely.

Abnormal regulation of in vitro IgE synthesis by T cells obtained from patients with atopic dermatitis

The regulatory influence of atopic eczema and non-atopic T cells on spontaneous IgE synthesis by eczema B cells was examined. Eczema B cells were cocultured with either autologous or allogeneic T cells in RPMI 1640 with 10% fetal calf serum at 0.75 X 10(6) cells/ml (B/T = 0.5) and supernatant IgE was measured by a modified PRIST assay. Net IgE synthesis was obtained by subtracting preformed IgE (+ cycloheximide at Day 0) from total IgE in 7-day supernatants. T cells were either untreated, heat-killed, exposed to 2000 rad, or depleted of helper/suppressor T cells by "panning" with monoclonal antibodies (Leu 3a and Leu 2a). Atopic eczema B cells spontaneously synthesized IgE when cultured alone. No significant suppression of net IgE synthesis occurred when atopic eczema T cells were cocultured with autologous B cells. In allogeneic recombinations, non-atopic T cells significantly suppressed net IgE synthesis by atopic eczema B cells (mean suppression = 59%; P less than 0.05). This suppression was abrogated if allogeneic control T cells were heat-killed, irradiated, or depleted of Leu 2a+ suppressor cells. In order to exclude an "allogeneic effect" as the sole mechanism to explain the suppression of IgE synthesis observed by coculturing non-atopic T cells with eczema B cells, the latter were recombined with either T cells from HLA-DR and mixed lymphocyte culture-matched sibling or autologous T cells. Greater suppression of net IgE synthesis was seen in the presence of histoidentical non-atopic T cells than in the presence of autologous eczema T cells, indicating that the latter have a partial defect in their suppressor function. This apparent "defect" in immunoregulatory function may be overcome by in vitro activation of atopic eczema T cells by concanavalin A.

Induction of antigen-specific suppressor cells in patients with hay fever receiving immunotherapy

In order to evaluate the effect of immunotherapy on subpopulations of lymphocytes, peripheral blood mononuclear cells were fractionated into T and non-T cells by incubating in anti-immunoglobulin-coated plates. T cells were further fractionated into rye grass antigen-adherent and nonadherent fractions and human serum albumin (HSA)-adherent and nonadherent fractions by incubating in rye grass antigen-coated and HSA-coated plates, respectively. The mean rye antigen-stimulated proliferative response of rye antigen-adherent fraction was significantly lower than that of rye antigen-nonadherent fraction in patients with rye grass hay fever receiving immunotherapy. There was no difference in the rye antigen-stimulated proliferative response between the HSA-adherent and nonadherent fractions. Both the rye antigen-adherent and nonadherent fractions proliferated similarly when they were stimulated by an unrelated antigen, Candida albicans. The rye antigen-stimulated proliferative response of rye antigen-nonadherent cells could be suppressed by coculturing with rye antigen-adherent cells from patients receiving immunotherapy. Furthermore, the treatment of cocultures with monoclonal antibody against suppressor-cytotoxic T cell (OKT8) subpopulation and guinea pig serum complement reversed the suppression. In patients receiving no immunotherapy, there was no difference in the rye grass antigen-stimulated proliferative response between the rye antigen-adherent and nonadherent fractions. These results suggest that immunotherapy induces a subpopulation of T cells that are adherent to antigen-coated plates and are capable of suppressing T cell proliferation stimulated by the specific antigen.

Histamine sensitivity influences reactivity to allergens

The ability to mount an IgE response to allergens is a prerequisite for the development of positive allergen skin tests, and this is reflected to some extent by the observation that allergen-responsive subjects tend to have higher total serum IgE concentrations. To determine whether histamine sensitivity also contributes to allergen responsiveness, 893 subjects in a rural community were prick tested with 14 allergens and tenfold dilutions of histamine phosphate beginning at 1 mg/ml-1. IgE was measured in a subset of 400 subjects. Three-way contingency table analysis confirmed previous reports of an association between allergen responsiveness and IgE (p less than 0.001) and also demonstrated that allergen responsiveness is associated with sensitivity to histamine (p less than 0.001). This association is independent of IgE so that the additive effect of IgE and histamine sensitivity allows more nearly accurate prediction of allergen responsiveness than either measurement alone.

Experimental autoimmune uveoretinitis in athymic rats: specific IgE response to retinal S-antigen and disease

Experimental autoimmune uveoretinitis (EAU) is an ocular autoimmune disease induced in rats by immunization with retinal S-antigen. Athymic nude rats (rnu/rnu) have been previously shown to be refractory to EAU induction and antibody production to S-antigen, while heterozygous (rnu/+) are good responders. Increasing the antigen dose and adding pertussis adjuvant produced ocular disease in some nude rats, and antibody response in most of them. Specific IgE antibodies were demonstrated by ELI-SA only in the serum of nude rats presenting the disease. However, most immunized nude rats had evidence of mast cell sensitization to S-antigen (direct degranulation test) and of circulating specific IgE detected by passive sensitization of normal mast cells (indirect degranulation test). This positive response could be explained by an incomplete depletion of the different T lymphocyte subsets.