Recombinant IL-3 induces histamine release from human basophils

Human rIL-3 induces histamine release from some human basophils, with cells from atopics responding to a greater extent than non-atopic donors. The dose response curves were highly variable. IL-3 was active on purified basophils and the release process was slower and required more calcium than anti-IgE. Removal of surface IgE from basophils rendered them unresponsive to IL-3. The response could be restored by passive sensitization of basophils with IgE+, IgE known to bind histamine-releasing factors, and not IgE-, IgE unreactive with histamine-releasing factors. Thus, IL-3 uncovers IgE heterogeneity. IL-3 does not, however, directly interact with IgE+. Rather, passive sensitization with IgE+ or stimulation of basophils with low concentrations of several secretagogues renders the cells sensitive to IL-3. IL-3 may well play a pro-inflammatory role by potentiating the effects of IgE+ or various secretagogues.     

Complement-induced histamine release from human basophils. II. Mechanism of the histamine release reaction.

The activation of human serum complement by incubation with zymosan generates C5a which releases histamine from autologous basophils. The characteristics of the C5a-induced histamine release were investigated. It is similar to IgE-mediated reactions in requiring Ca++ and in being inhibited by EDTA. However, it has marked differences from IgE-mediated reactions. C5a, at all concentrations, released histamine completely in less than 2 min. The C5a reaction has a narrow pH optimum that antigen-induced release and occurs well at 17 degrees to 37 degreesC but not at 0 degreesC. The optimal reaction temperature is 25 degrees to 30 degrees C. Unlike the antigen-induced release, no two-stage activation with C5a for the release of histamine could be demonstrated. There was additive release between C5a- IgE-mediated reactions. Leukocytes could be desensitized to the C5a-mediated reaction by 1) incubating the cells at 37 degrees C for 45 min, 2) pretreating the leukocytes with activated serum in the presence of EDTA, and 3) adding the activated serum to the leukocytes at 0 degrees C before transferring to the optimal reaction temperatures. Cells desensitized to the complement-induced release have normal reactions to IgE-mediated histamine release. In parallel experiments, cells from allergic donors desensitized for IgE-mediated reactions by incubation with antigen under sub-optimal conditions release histamine normally upon the addition of C5a. The results indicate that histamine release by C5a involves a mechanism of basophil activation that is different from the pathway involved in the IgE-induced reaction.     

Involvement of Rab27 in antigen-induced histamine release from rat basophilic leukemia 2H3 cells

The Rab family small G proteins regulate discrete steps in vesicular transport pathways. Recent studies indicate that one member of the Rab family, Rab27A, regulates the transport of lysosome-related organelles, such as melanosome distribution in melanocytes, lytic granule release in cytotoxic T cells, and dense granule release in platelets. Here, we have examined the involvement of Rab27A in the exocytic transport of another lysosome-related organelle, the basophilic secretory granule, in basophils. We have found that Rab27A locates on basophilic secretory granules containing histamine in rat basophilic leukemia (RBL) 2H3 cells. In addition, exogenous expression of dominant active Rab27A reduces antigen-induced histamine release from the cells. We have moreover identified Munc13-4 as a Rab27A target using a CytoTrap system and found that exogenous expression of Munc13-4 affects antigen-induced histamine release from RBL-2H3 cells. These results demonstrate that Rab27A plays a crucial role in antigen-induced histamine release from RBL-2H3 cells.     

The diisopropylfluorophosphate inhibitable step in antigen-induced histamine release from human leukocytes.

DFP inhibits early events in antigen-induced histamine release from human leukocytes. If added to cells 5 min or more after antigen it is ineffective. If added with antigen it can be removed at 5 min but release will still be inhibited. In contrast, ethylenediaminetetraacetate (EDTA) and 2 deoxyglucose (2DG) still inhibit the reactions when added 5 min after antigen. During incubation of leukocytes for 90 to 120 min at 0 degrees C they react with specific antigen since they subsequently release significant quantities of histamine after washing and reincubation at 37 degrees C without addition of antigen. Such priming at 0 degrees C is at least equivalent to priming for 2 to 4 min at 37 degrees C. During antigen priming at 0 degrees C the cells are not activated beyond the step in the release sequence which is inhibited by diisopropylfluorophosphate (DFP). This is apparent from the undiminished inhibitory activity of DFP on these cells. Furthermore, cells primed with antigen at 0 degrees C in the presence of DFP release as much histamine after washing and incubation at 37 degrees D as control cells primed in the absence of DFP. Incubation of leukocytes with specific antigen at 37 degrees C for 3 min resulted in significant but not quite complete priming for subsequent histamine release in the absence of antigen. Most of these primed cells were not activated beyond the step inhibitable by DFP. However, some had completed the entire sequence including the release of histamine while others had not released their histamine but were not inhibited by DFP from subsequent release. After 5 min incubation with antigen at 37 degrees C almost all leukocytes had progressed beyond the stage which is inhibited by DFP. Incubation of leukocytes at 37 degrees C with DFP but without antigen for up to 15 min followed by washing did not impair subsequent antigen-induced histamine release by these cells. Thus, DFP was inhibitory under these conditions only after antigen activation of leukocytes.     

Qualitative characteristics of histamine release from human basophils by covalently cross-linked IgE

We have studied the effects of permanent oligomers of human IgE produced using the cross-linking reagent, dimethyl suberimidate, on histamine release from human basophils. IgE dimers were found to be sufficient stimuli for both release and desensitization of these cells; monomeric IgE had no effect. Histamine release was augmented by deuterium oxide (D2O) in the medium, but D2O was not an absolute requirement to observe release. Desensitization by the dimeric IgE was specific in that the response to anti-IgE was not affected by preincubation of the leukocytes with the IgE dimer under suboptimal releasing conditions. IgE trimers and higher oligomers of IgE also caused both release and desensitization. IgE trimers were 3- to 4-fold more effective than IgE dimers with regard to the amount required for 50% histamine release. Dilution studies with monomeric IgE suggested that the difference was due to the presence of more "active" dimers in the trimeric IgE fractions. We conclude that dimeric IgE, by juxtaposing 2 receptors on the basophil membrane, is the "unit signal" for both release and desensitization of these cells.     

Interleukin 1 releases histamine from human basophils and mast cells in vitro

Interleukin (IL 1) preparations from five different sources (human monocyte, LPS-stimulated, purified IL 1 from two different laboratories) and human recombinant IL 1 (HrIL 1) were shown to be capable of directly inducing histamine (HA) release from human basophils (10 to 50% of total cellular HA, depending on the source of IL 1). The release was not due to the medium, pyrogens, or other contaminants. Il 1-induced HA release was dose dependent between 1 to 100 U/ml of IL 1 and 1 to 15 ng/ml of HrIL 1 and was rapid, with a peak release at 15 min. HA release induced by IL 1 was blocked completely by preexposure of cells to IL 1 but was not affected by prechallenge with anti-IgE. Also, preincubation of IL 1 with anti-IL 1 antibody abolished the HA-releasing activity. IL 1-induced HA release was also observed in preparations of human adenoidal mast cells. Our data indicate that it is unlikely that the HA release induced by IL 1 is due to a contamination with HA-releasing factor. This effect of IL 1 provides a mechanism for non-IgE-related local HA release and raises the possibility of a link between cellular immunity and immediate hypersensitivity of potential importance for the pathology of immuno/inflammatory diseases.     

Histamine release from cultured human basophils: lack of histamine resynthesis after antigenic release.

Human peripheral basophils can be maintained in cultured for up to 72 hr. These cells retain their functional integrity as judged by total histamine content and by their ability to release histamine by an IgE-mediated reaction in response to a specific antigen challenge. Cells cultured after suboptimal antigenic challenge could be activated to release histamine upon the addition of antigen. In contrast, cells culture after supra-optimal antigenic challenge did not fully recover their ability to release histamine even after 24 hr. With a variety of culture conditions, it was impossible to demonstrate any net synthesis of histamine in cells. Cells cultured after depletion of their stores by reaction with antigen did not show any net histamine formation. The experiments suggest that the basophil in peripheral blood is functionally an end-stage cell and can participate in the histamine release reaction only once.     

The effect of salbutamol on histamine release from basophils in vivo and in vitro]

In vivo and in vitro basophil histamine release inhibition by salbutamol was investigated in patients with bronchial asthma. The study involved 14 patients in stable period of the disease: FEV1 = 66-84% of the normal values. Histamine release was determined following an incubation of the isolated basophils with concanavalin A (Sigma Co., USA) or specific allergens (dust, grass pollens, mites; Bencard, UK). Histamine was assayed with isotope-enzymatic technique according to Shaff and Beaven with histamine N-methyltransferase. Salbutamol administered intravenously in the dose of 1 mg inhibited allergen-induced histamine release from the basophils isolated from patient's blood within 30 minutes. Salbutamol in the concentration of 8 X 10(-6) M inhibited in vitro histamine release induced by an allergen and concanavalin A.     

Interferon-induced enhancement of IgE-mediated histamine release from human basophils requires RNA synthesis.

Incubation of human leukocytes with certain viruses results in the enhancement of IgE-mediated release of histamine. This enhancement is produced by interferon. The present experiments show that an induction period of 6 to 9 hr and new RNA synthesis are required for interferon to enhance histamine release. This points to the possibility that interferon may exert its antiviral and histamine-release enhancing activities by acting through a common pathway.     

Complement-induced histamine release from human basophils. I. Generation of activity in human serum.

The incubation of zymosan, endotoxin, or immune aggregates with normal human serum activates a factor which induces release of histamine from autologous basophils. The reaction can be divided into two steps: in the first, complement must be activated and in the second, the histamine-releasing factor interacts with basophils. The generation of histamine-releasing activity in serum occurs at 17 to 37 degrees C but not at 0 degrees C, is inhibited by heating the serum at 56 degrees C for 30 min, or by the addition of EDTA to the serum. Once generated, the histamine-liberating activity is stable to heating at 56 degrees C for 30 min. Gel filtration of the activated serum demonstrated that this factor eluted in the same region as a factor with chemotactic activity. Both factors have a molecular weight of about 16,000 daltons and their activities were inhibited by antibody to human C5. This is therefore a pathway for histamine release by C5a where the activation of the basophil is unrelated to the membrane bound IgE.     

Complement-induced histamine release from human basophils. III. Effect of pharmacologic agents.

Human serum activated with zymosan generates a factor (C5a) that releases histamine from autologous basophils. Previously we have presented evidence that this mechanism for C5a-induced release differs from IgE-mediated reactions. The effect of several pharmacologic agents known to alter IgE-mediated release was studied to determine whether they have a similar action on serum-induced release. Deuterium oxide (D2O), which enhances allergic release, inhibited in a concentration-dependent fashion the serum-induced reaction at incubation temperatures of 25 and 32 degrees C. The colchicine-induced inhibition was not reversed by D2O. Cytochalasin B, which gives a variable enhancement of IgE-mediated release, had a marked enhancing effect on the serum-induced reaction in all subjects tested. The following agents known to inhibit the IgE-mediated reaction also inhibited serum-induced release at 25 degrees C: colchicine, dibutyryl cyclic AMP, aminophylline, isoproterenol, cholera toxin, chlorphenesin, diethylcarbamazine, and 2-deoxy-D-glucose. These results suggest that the serum-induced release is modulated by intracellular cyclic AMP, requires energy, and is enhanced by the disruption of microfilaments. The lack of an effect by D2O would suggest that microtubular stabilization is not required. The data can be interpreted to indicate that IgE- and C5a-mediated reactions diverge at a late stage in the histamine release pathway.     

Low molecular weight thymic factor inhibits histamine release from basophils

Low molecular weight thymic factor stimulates the suppressor function of T-lymphocytes, increases cAMP content (but not cGMP) in lymphocytes and inhibits histamine release from sensitized basophils. The mechanisms of LTF action are discussed.     

Adenosine receptor on human basophils: modulation of histamine release.

Adenosine, at physiologic concentrations, inhibits in vitro IgE-mediated human basophil histamine release in a dose-dependent fashion. The inhibition dose-response curve is paralleled by an adenosine-induced increase in cAMP levels of human leukocyte preparations. Further evidence that the adenosine effect is related to changes in cAMP levels is that the nucleoside inhibits only in the first stage of antigen-induced histamine release and fails to inhibit the release caused by ionophore A23187. A poorly metabolized derivative of adenosine, 2-chloroadenosine inhibits as effectively as adenosine; dipyridamole, which blocks adenosine uptake, does not impair the inhibition caused by adenosine. Finally, theophylline, which is a competitive antagonist of adenosine in human lymphocytes also blocks the inhibition of release caused by adenosine. These data suggest that adenosine acts via a specific cell-surface receptor linked to adenylate cyclase. It appears that the human basophil has a specific receptor for adenosine and that this nucleoside may modulate the in vivo release of the mediators of immediate hypersensitivity reactions.     

Recombinant human IL-1 alpha and -1 beta potentiate IgE-mediated histamine release from human basophils

In this study, we have explored the relationship between interleukins and human basophil activation. Previous studies by ourselves and others have found that recombinant human (rh) IL-3 causes histamine release. The ability to release histamine has also been claimed for IL-1 but we cannot confirm this. In experiments with the basophils of 29 donors (excluding one D2O responder), histamine release with 100 ng/ml rhIL-1 alpha was 1.3 +/- 1% (SEM), whereas with rhIL-1 beta, it was 0.8 +/- 1%. Both IL-1 alpha and -1 beta were also used at concentrations of 0.01 to 1000 ng/ml without causing release. Neither increasing the Ca2+ concentration nor adding D2O or cytochalasin B caused IL-1 alpha and -1 beta to become secretagogues. rhIL-1, however, did augment IgE-dependent histamine release. The enhancement was similar with both rhIL-1 alpha and -1 beta, i.e. they were dose-dependent between 0.1 and 3 ng/ml and reached a plateau from 3 to 100 ng/ml. At submaximal histamine release (less than 10%), there was enhancement of three IgE-dependent secretagogues: 125% with goat anti-human IgE (n = 7), 215% with Ag E (n = 10), and 260% with a histamine releasing factor (n = 7). Non-IgE-dependent stimuli (formyl-methionine-leucine-phenylalanine and the ionophore A23187, n = 10) were enhanced less than 5%. rhIL-1-enhancement persisted after cell washing (n = 10). rhIL-1 was active in preparations of 50 to 75% pure basophils in which mononuclear cells were reduced by greater than 95% (n = 4), and mAbH34 to IL-1 beta blocked the enhancement caused by that molecule. We postulate that basophils have an IL-1 receptor which, when occupied, upregulates the response to IgE-related signals. Thus, this work characterizes a second interaction between interleukins and the cells central to the allergic response.     

Usefulness of testing histamine release from isolated human basophils in anti-allergic and anti-asthmatic drug assessment]

Histamine release from isolated human basophils test was used to evaluate an activity of: histamine receptors H1 and H2 blockers, agonists of beta-receptors, calcium channel blocking agents, hydrocortisone, and disodium cromoglycate (Intal). The study involved 84 patients hospitalized for the bronchial asthma. Basophils were isolated with Day's technique modified by Shov and Norn. Histamine was measured with Shov's spectrofluorimetric technique. It was found that histamine release from isolated human basophils may be used in both evaluation of the mechanism of action and efficiency of drugs used in allergic diseases therapy.