The effect of T-cell depletion on enhanced basophil histamine release after in vitro incubation with live influenza A virus.

A number of mechanisms participate in virus-induced asthma. Previously, we described enhanced basophil histamine release (HR) during an experimentally induced rhinovirus infection and after in vitro incubation of peripheral blood mononuclear cells (PBMC) with influenza virus. This study extends our previous observations and examines the effect of influenza A virus on basophil leukotriene C4 (LTC4) release as well as the effect of T-cell depletion on virus-enhanced basophil HR. PBMC were isolated from ragweed-allergic subjects and incubated with live influenza A virus or control medium (allantoic fluid). After incubation with influenza A, ragweed antigen (AgE) stimulated LTC4 and HR were enhanced (P less than 0.05). To further define the role of T cells in virus-enhanced basophil secretion, PBMC were isolated and divided into two aliquots. In one aliquot, T cells were removed by magnetic bead separation of mouse monoclonal anti-CD3-coated lymphocytes. T-cell-depleted and nontreated PBMC suspensions were incubated with influenza A or control medium, collected, and challenged with AgE to release histamine. Basophil HR was enhanced in the virus-treated group of PBMC that had not undergone T-cell depletion. In contrast, virus incubation did not enhance HR in the T-cell-depleted fraction. Finally, preliminary analysis of the supernate from virus-treated leukocytes indicates the presence of interferon-gamma. These findings suggest that T cells, and their cytokine products, play an integral role in the process by which viruses enhance basophil HR.     

Influenza A virus enhances basophil histamine release and the enhancement is abolished by carbohydrates

Basophil histamine release was studied in leukocyte suspensions from normal individuals and from patients allergic to house dust mite or birch pollen. Mediator release caused by IgE-mediated reactions was examined by stimulating the cells with anti-IgE or specific antigens, and the calcium ionophore A23187 was used for a non-immunological histamine release. In all experiments influenza A virus caused a synergic enhancement of the mediator release and the potentiation was abolished by galactose (10(-7) to 10(-6) M) and by 10(-6) to 10(-5) M of N-acetylglucosamine, alpha-methyl-D-glucoside, alpha-methyl-D-mannoside, N-acetylneuraminic acid and lactose, but not by glucose. Wash-out experiments show that the sugars prevent the aggravation of mediator release by a binding of sugar to the basophil cell membrane, thereby causing a blockade of binding sites responsible for the potentiating effect of virus.     

Effect of misoprostol on the secretion of histamine from basophils of whole blood.

BACKGROUND: Misoprostol (MSP), the synthetic prostaglandin E1 (PGE1) analog, possesses multifunctional features, including modulating some inflammatory aspects of immune and allergic disorders. OBJECTIVES: To investigate the effect of MSP on histamine release (HR) from basophils of whole blood using anti-IgE, specific allergens, and calcium ionophore. METHODS: The study was performed using the automated glass fiber-based whole blood leukocyte histamine release test (LHRT). RESULTS: Very low concentrations of MSP produced a marked inhibition of HR induced with anti-IgE. Maximum inhibition was observed at 10-9 M. It was also shown that the levels of HR inhibition with MSP varied at different incubation times. The greatest inhibition of HR was noted at 1 to 2 hours of incubation at MSP concentrations of 10-8 and 10-9 M, respectively. Incubation of blood from allergic patients at the optimal MSP concentration and optimal elapsed time (2 hours) resulted in significant reductions of allergen-specific HR induced by both Timothy pollen grass allergen and D.pteronissinus. Incubation of blood with varying concentrations of MSP and subsequent stimulation with calcium ionophore A23187 also inhibited HR from basophils. In the latter case, the most effective concentrations of MSP ranged from 10-8 to 10-6 M. CONCLUSIONS: This study demonstrated that MSP can inhibit basophil HR indicating a potentially beneficial role of PGE1 analogs as pharmacotherapy for allergic diseases.     

A controlled study of the effectiveness of the Rinkel method of immunotherapy for ragweed pollen hay fever

In a double-blind study, we compared the effects of the Rinkel method of immunotherapy with ragweed pollen extract and placebo on symptoms of ragweed hay fever and immunologic parameters in 24 ragweed-sensitive patients. Each had a skin-test end point by Rinkel serial dilution titration to ragweed pollen extract at 1:312,500 w/v or greater dilution, a 2+ skin test to ragweed AgE at 0.1 μg/ml or greater dilution, and in vitro leukocyte histamine release by ragweed pollen extract. None had had immunotherapy for at least 7 yr. Patients matched on the basis of leukocyte histamine release by ragweed were assigned to two treatment groups (12 patients in each group). One group received ragweed pollen extract, and the other, placebo, both administered by the Rinkel method between June and October, 1978. Treatment doses were derived from skin-test end points. The median maintenance (“optimal dose”) for patients receiving ragweed pollen extract was 0.53 ml of 1:312,500 w/v and the mean cumulative dose of ragweed pollen extract given during the study contained 0.094 μg of ragweed AgE. Symptom-medication scores of all patients rose and fell with ragweed pollen counts. No significant differences were observed in mean daily symptom-medication scores, antiragweed IgG or IgE levels, leukocyte histamine release by ragweed, total IgE levels, or skin-test end-point dilutions with ragweed pollen extract between the group receiving ragweed pollen extract and the group receiving placebo. Despite the absence of specific effect on symptom-medication scores and measured immunologic variates, 10 of the 12 ragweed-treated patients and 10 of the 12 placebo-treated patients were of the opinion that their hay fever symptoms during the ragweed pollen season were less severe in 1978 than in 1977 and that they had been helped by Rinkel method immunotherapy. Under the conditions of the study, Rinkel method immunotherapy with ragweed pollen extract was no more effective than placebo given in an imitation of the Rinkel method.     

In vitro incubation with influenza virus primes human polymorphonuclear leukocyte generation of superoxide.

Viral respiratory illnesses exacerbate asthma, increase airway responsiveness, and enhance the frequency of late asthmatic reactions. A number of mechanisms have been identified to explain how respiratory viral illnesses provoke wheezing, including enhanced inflammatory activity of leukocytes. To further understand how respiratory virus-caused illnesses promote leukocyte-dependent airway injury, the following study evaluated the effect of an in vitro incubation of influenza A virus on human polymorphonuclear leukocyte (PMN) generation of superoxide (O2-). PMNs were isolated from anticoagulated human blood following density gradient centrifugation; purified PMNs were then incubated (37 degrees C x 30 min) with influenza virus (PMN:virus ratio of 5:1 [egg-infective dose 50%] and 10:1) in the presence of 10% autologous serum. After incubation, the viable PMNs (greater than 95% exclusion of trypan blue) were activated, by the chemotactic peptide formyl-methionine-leucine-phenylalanine (fMLP), calcium ionophore A23187, or phorbol myristate acetate (PMA), and O2- generation was then measured. Generation of O2- to fMLP and A23187 was significantly enhanced from PMNs that had been incubated with influenza virus. Although influenza virus itself did not generate O2-, it caused a transient increase in intracellular calcium ([Ca2+]i), when measured with Indo-1-loaded cells. These results suggest that influenza virus primes PMNs to generate increased amounts of O2- and that the priming effect is associated with a transient increase in [Ca2+]. Consequently, we postulate that influenza virus priming produces PMNs of enhanced inflammatory potential to cause greater airway injury, obstruction, and responsiveness during a viral respiratory infection.     

A comparative study of the effectiveness of the Rinkel method and the current standard method of immunotherapy for ragweed pollen hay fever

In a double-blind study, we compared the effects of the Rinkel and the current standard methods of immunotherapy with ragweed pollen extract and those of placebo on symptoms of ragweed hay fever and immunologic parameters in 43 patients highly sensitive to ragweed. Each had a skin-test end point by Rinkel serial titration at 1:312,500 w/v or greater dilution, a 2+ skin test to ragweed AgE 0.01 μg/ml, and in vitro histamine release by ragweed pollen extract. None had had immunotherapy for at least 7 yr. Patients were matched on the basis of leukocyte histamine release to ragweed pollen extract and assigned to treatment groups. Fourteen received ragweed pollen extract by the Rinkel method, 14 received placebo, and 15 received ragweed pollen extract by the current standard method weekly between February and October, 1979. Rinkel method doses were derived from skin-test end points and were advanced to 0.5 ml of the end-point dilution; current standard method doses were advanced to the highest tolerated dose. The median maintenance dose for Rinkel method patients was 0.5 ml of 1:1,562,500 w/v (0.001 μg AgE), and for current standard method patients was 0.3 ml of 1:100 w/v (11 μg AgE). An additional unmatched group of nine similar patients received Rinkel method immunotherapy in both 1978 and 1979. Under the conditions of this study, the current standard method of immunotherapy produced a significant decrease in ragweed hay fever symptom-medication scores, increase in antiragweed IgG levels, and decrease in seasonal rise in antiragweed IgE levels in comparison with the effects of either Rinkel method or placebo. The effect of the Rinkel method on these variates was not significantly different from the effects of placebo.     

Effect of staurosporine on histamine release from rat serosal mast cells

Rat serosal mast cells were challenged with compound 48/80 or calcium ionophore A23187 and the effect of staurosporine, a new inhibitor of protein kinase C, on histamine release from the cells was investigated. Histamine release induced by compound 48/80 or calcium ionophore A23187 was inhibited by staurosporine in a concentration-dependent manner and 0.1 and 1 microM staurosporine inhibited the histamine release significantly. The inhibitory effect of K-252a, another novel protein kinase C-inhibitor, was significantly higher than that of staurosporine on calcium ionophore A23187-induced histamine release. These results suggest that protein kinases will be involved in the process during mediator release from rat serosal mast cells.     

Cytotoxicity of ionophore A23187 for basophils and other human blood cells.

The calcium ionophore A23187(A23) at concentrations exceeding 1 microgram/ml has been shown to be progressively cytotoxic for human blood basophils, neutrophils, lymphocytes, and erythrocytes. Toxicity to basophils was considered to be manifested by the increasing inability of 2-deoxyglucose (2DG) to inhibit histamine release (HR) at increasing concentrations of A23. The toxicity to neutrophils and lymphocytes was demonstrated by decreased lactate production (LP) after incubation with A23 of Ficoll-Hypaque fractions greatly enriched in each respective cell type. Red cells present in dextran-sedimented leukocytes were increasingly susceptible to lysis during washing subsequent to exposure to increasing concentrations of A23. A concentration of 4 microgram A23/ml, which is cytotoxic at 37 degrees C, produced optimal and noncytotoxic HR at 22 degrees C. It was possible to reduce A23 concentrations required for optimal HR by increasing Ca++ from 0.6 to 3 mM.     

Reactivity of ragweed allergens with IgE antibodies. Analyses by leukocyte histamine release and the radioallergosorbent test and determination of cross-reactivity.

Five distinct proteins with allergenic activity have been isolated from short ragweed pollen. We initially tested three of these, AgE, AgK, and Ra3, for reactivity with IgE antibodies by leukocyte histamine release and by the radioallergosorbent test (RAST). We found highly significant correlations between the reactivities of these allergens by leukocyte histamine release and by the RAST, consistent with the view that both procedures detected comparable allergenic activity. We next tested the allergenic cross-reactivity of all five ragweed allergens. AgE, AgK, Ra3, Ra4, and Ra5, by RAST inhibition. With solid-phase AgE the only nonhomologous inhibitor was AgK, which cross-reacted weakly and required a 140-fold mass excess of AgK compared to AgE. With solid-phase AgK both AgK and AgE produced significant inhibition; AgE was slightly more potent than the homologous AgK, Ra3 and Ra5 were allergenically unique, because only the homologous allergen produced 50% inhibition. Ra4 was weakly inhibited by AgE, Ra3, and Ra5 when these allergens were added in 300- to 5---fold mass excesses; this weak inhibition may represent either cross-reaction or cross-contamination. We found that RAST inhibition could be used as an assay for the individual ragweed allergens and we demonstrated the presence of all of the allergens in a whole ragweed extract. The sensitivity of the RAST inhibition assay ranged from 10 ng to 100 ng for 50% inhibition. Finally, the solid-phase ragweed allergens were used to determine the frequency of elevated IgE antibody levels in 65 patients with ragweed hay fever. Virtually all of the patients reacted with AgE (97%), while 88% reacted with AgK, 51% reacted with Ra3, 28% reacted with Ra4, and 17% reacted with Ra5. These results highlight the usefulness of the RAST as a specific and sensitive tool for immunochemical studies of allergens.     

Influenza A virus-induced polymorphonuclear leukocyte dysfunction.

Previous studies have shown that influenza A virus can activate the polymorphonuclear leukocyte (PMN) respiratory burst and that upon subsequent stimulation of the cell there is depressed metabolic function. We examined the mechanism by which influenza virus causes PMN dysfunction by measuring the effect upon the chemiluminescent activity of cells of varying the type of influenza virus used, the period of time that cells were exposed to virus, and the secondary stimulus that was used. The various types of intact influenza virus elicited different amounts of chemiluminescent activity, but when cells were subsequently stimulated with phorbol myristate acetate, each virus caused equivalent depression of the PMN response. Purified glycoproteins incorporated into a liposome structure similarly stimulated the PMN chemiluminescence, yet did not induce PMN dysfunction. Depressed PMN function was noted after as little as 5 min of incubation of cells with virus and occurred to both receptor-dependent (zymosan, N-formylmethionyl-leucyl-phenylalanine, and phorbol myristate acetate) and -independent (calcium ionophore A23187) stimuli.     

Enhancement of basophil histamine release by a human basophil-like cell promoting activity

A basophil-like cell promoting activity (BaPA) is a lymphokine which has the ability to proliferate metachromatically staining cells in human bone marrow. We studied the effect of BaPA on histamine release from human peripheral basophils. BaPA did not directly induce histamine release from basophils. However BaPA ranging from 0.001 to 0.5 U/ml enhanced histamine release from basophils stimulated with anti-IgE, calcium ionophore A23187 or FMLP in a dose-dependent manner. On the basis of recent observations that in addition to their capacity for proliferating progenitor cells, colony-stimulating factors are capable of regulating functions of end-stage cells of the same lineage, this finding that BaPA is able to modulate a basophil function raises the possibility that BaPA also regulates progenitors of basophils.     

Carbohydrates inhibit the potentiating effect of bacteria,endotoxin and virus on basophil histamine release

Histamine release caused by calcium ionophore A23187 and anti-IgE was examined in leukocyte suspensions from 8 healthy individuals.Staphylococcus aureus, lipopolysaccharide (LPS) fromSalmonella typhimurium and influenza A virus were found to enhance the histamine release but did not release histamineper se. The potentiation of mediator release depends on a non-transient signal since the potentiating effect was also obtained by preincubation of the cells with LPS followed by wash-out and stimulation of the cells with anti-IgE. The potentiation was abolished or reduced by galactose, N-acetyl-glucosamine, -methyl-d-glucoside, -methyl-d-mannoside, N-acetylneuraminic acid and lactose, but not by glucose. These findings indicate that the enhancement of mediator release by bacteria, endotoxin, and virus depends on a sugar-mediated reaction.     

Regulation of histamine release from human bronchoalveolar lavage mast cells by stem cell factor in several respiratory diseases

We investigated the effects of stem cell factor (SCF) on histamine release (HR) from human bronchoalveolar lavage (BAL) mast cells. BAL cells were recovered from lavage performed in patients undergoing clinical bronchoscopy. SCF (0.02–20 ng/ml), which is by itself a poor secretagogue (mean ± SEM HR: 3.7 ± 0.9%; n = 27), strongly enhanced HR induced by anti-IgE in a concentration-related manner. Significant potentiation began at 0.2 ng/ml (30 ± 10°0; p <0.05; n = 12) and reached a plateau at 2 ng/ml (40 ± 10%; P <0.01 at 2 ng/ml and 45 ± 10%; P <0.01 at 20 ng/ml; n = 12). In contrast, SCF failed to enhance HR induced by calcium ionophore A23187. Among the BAL cell samples initially unresponsive to anti-IgE (55° of samples), 36% (10/28) were converted to responders if the cells were shortly preincubated with SCF. In 25% of samples (7/27), SCF (20 ng/ml) caused direct HR of 10 ± 2.1 %. The mast cells which released histamine when challenged with SCF also secreted higher levels of histamine in response to anti-IgE and calcium ionophore than those nonresponsive to SCF. While interleukin (IL)-3 and IL-5 (20 ng/ml) were unable to modulate immunologic HR. GM-CSF (20 ng/ml) produced significant potentiation ( P <0.05), which was, however, smaller than that observed with SCF. The rate of responders to anti-IgE in atopic asthma (47 %) was greater than that in control (9%) and intrinsic asthma (10%) but not different from that in some other respiratory diseases such as chronic bronchitis (44%), lung cancer (47%), or interstitial disease (68%,). The potentiation of HR afforded by SCF did not differ significantly among the several disease groups. We conclude that, whatever the underlying respiratory disease, SCF selectively enhances IgE-mediated HR from human BAL mast cells. Furthermore, this cytokine is sometimes necessary to render mast cells able to release histamine in response to anti-IgE.     

Histamine release from cord blood basophils.

The histamine release (HR) after challenge with anti-IgE, concanavalin A, N-formyl-met-leu-phe and the calcium ionophore A23187 from 97 cord blood samples was determined by a microfiber-based assay. Maximum HR with anti-IgE showed great inter-individual variation (median: 20.5; range: 1-104 ng/ml blood), but was not significantly different from the results obtained in identically treated blood samples from 50 adults (median: 23; range: 1-93 ng/ml blood). Both the maximum HR and the sensitivity to anti-IgE were dependent on total plasma IgE content. Blood samples with plasma IgE greater than or equal to 0.5 IU/ml (n = 15) had significantly higher maximum HR than those with plasma IgE less than 0.5 IU/ml (n = 82; median: 32 vs. 18 ng/ml blood; p less than 0.01). Passive sensitization with IgE-rich atopic plasma increased the maximum HR with anti-IgE only in samples with a plasma IgE content of less than 0.5 IU/ml, although sensitivity to anti-IgE was universally increased. Preincubation with pharmacologic agents modulating the IgE-mediated HR produced effects generally similar to previous findings in adult blood. However, the effects of inhibiting the cyclooxygenase pathway in cord blood differed from our observations in adult blood, and may represent a maturational phenomenon. The family history of allergy was obtained by a questionnaire, and clinical observations were gathered from patient records. None of these parameters were found to influence HR with any secretagogue. However, HR stimulated by the calcium ionophore A 23187 was found to be highly dependent on the storage time of the EDTA-anticoagulated blood samples, which should be carefully controlled.     

The mechanism of histamine release induced by the ionophore X537A from isolated rat mast cells. II. The relationship between increase of cell volume and histamine release

The ionophore X537A induced swelling of isolated rat mast cells parallel to histamine release. Both actions were depressed by extracellular calcium and BSA, temperatures below 37°C, NEM, PMSF, and TTX, and were enhanced by high potassium and pretreatment of the cells with ATP. DSCG, theophylline, and DFP enhanced the histamine release noted after 10 min of incubation without influencing the swelling action of X537A. The swelling action could not be separated from histamine release and it is suggested that it right be inherent in the mechanism of secretion induced by X537A. The present results further distinguish histamine release induced by the two ionophores X537A and A23187.     

Virus enhances IgE- and non-IgE-dependent histamine release induced by bacteria and other stimulators

Histamine release from human basophil leukocytes was triggered byStaph. aureus, Salmonella enteriditis, non-haemolytic streptococci, orE. coli. Influenza A virus was found to enhance the mediator release and the effect was caused by synergism, since the virus did not induce release of histamineper se. This potentiating effect of the virus was seen both when the bacteria-induced histamine release was IgE-dependent (i.e. patient sensitized to the bacterium) and when the bacterium caused mediator release by a non-immunological mechanism independent of IgE (putative sugar-lectin mediated). Histamine release induced by anti-IgE and calcium ionophore or agarose-beads was also enhanced in the presence of the virus. These findings indicate that influenza A virus potentiates both IgE-and non-IgE-mediated histamine release induced by bacteria and other stimulators.     

The influence of tetradecanoyl-phorbol-acetate (TPA) on histamine release from isolated rat mast cells

A detailed investigation of the influence of tetradecanoyl-phorbol-acetate (TPA) on isolated rat mast cells was undertaken in order to explore the possible involvement of protein kinase C in histamine release. TPA alone could induce histamine release in a medium without calcium, whereas 1 mM CaCl₂ suppressed the release. TPA in combination with a low concentration of the ionophore A23187 induced a considerable histamine release. Preincubation with TPA followed by incubation with the ionophore induced a similar release at low concentrations of TPA (2.5 nM) whereas the response was reduced at higher concentrations of TPA. The inhibition after preincubation with TPA was almost at a maximum within 2 min and was due to a decreased rate of release. TPA could also increase antigen-induced histamine release. After preincubation the potency of low concentrations of TPA increased, whereas higher concentrations (50 nM) became inhibitory. The effects of preincubation were almost fully expressed after 2 min and were not due to altered kinetics of the release. The interaction of oleoylacetylglycerol (OAG) with the ionophore A23187 and with antigen resembled that of TPA, but OAG was considerably less potent. Preincubation with TPA was inhibitory to the histamine release induced by compound 48/80, particularly in the absence of calcium. The release induced by TPA and the ionophore or antigen was calcium-dependent and energy-requiring, and the effects of TPA persisted after washing the cells before exposure to antigen or the ionophore. Preincubation with the protein kinase C inhibitor isoquinolinesulfonyl-methylpiperazine (H-7) slightly enhanced the histamine release induced by the combination of TPA and the ionophore. The suppression exerted by preincubation with TPA on ionophore- and antigen-induced release was counteracted by H-7. The results indicate that only the inhibitory effects of protein kinase C are affected by H-7. Although not conclusive, the results are compatible with an involvement of protein kinase C in both the enhancing and the inhibitory effects of TPA on mast cell histamine release.Parts of this investigation were presented at the meeting of the European Histamine Research Society in May 1986.     

Inhibitory Effect of Calcium Antagonists on Histamine Release from Human Leukocytes

A study was made of the influence of calcium antagonists on human basophil histamine release induced in vitro by specific antigen, anti-IgE or the calcium ionophore A23187. Both verapamil, nifedipine, and nimodipine were found to inhibit the release, and a similar effect was also observed after peroral administration of verapamil and nifedipine. The inhibitory effect of the drugs on histamine release seems to depend on interaction with calcium at different sites. The anti-allergic effect might explain the improvement found with calcium antagonists in exercise-induced asthma.     

Helicobacter pylori potentiates histamine release from rat serosal mast cells

We have studied the effect ofHelicobacter pylori (H. pylori) and its bacterial products on mast cell histamine release evoked by compound 48/80, calcium ionophore A 23187 and cholic acid. No significant histamine release is obtained when the various bacterial preparations ofH. pylori are incubated alone with mast cells, but the release of histamine is dose-dependently and significantly enhanced when whole washed and formalin killed cells or crude cell walls are incubated with compound 48/80, calcium ionophore A 23187 or cholic acid. Crude cell walls show the highest activity whereas the filtered supernatants from broth cultures are consistently inactive.The present results indicate a link betweenH. pylori and histamine release and suggest a further involvement of gastric mucosal mast cells in the pathogenesis ofH. pylori-associated gastritis. However, these data need to be extended before any clinical implications can be drawn.     

The determination of histamine in challenged human leukocyte preparations by high-performance liquid chromatography

A highly sensitive and rapid method was developed for the determination of histamine in challenged human leukocyte preparations by high-performance liquid chromatography. The assay is based on the Shore's OPT-reaction of the unpurified sample and on a specific separation of the derivate with analytical reversed phase phenyl column combined with spectrofluorometric detection. The detection limit of histamine by this method was 0.07 pmol (signal to noise ratio 21) and the within-day variation for peak height was 3.6% and for retention time 0.8%. A good linear standard curve ranging from 12.5 pg to 500 pg (0.07 pmol–2.7 pmol) was obtained with correlation coefficient of 0.998. The histamine release from human basophils in mixed leukocyte preparation was induced by the calcium ionophore A 23187. A concentration of 0.4 g/ml ionophore was required for 50% histamine release with a Ca²⁺-concentration of 1.8 mmol/l. The measured total histamine content was 1.5 pg/basophil.