Influenza A virus enhances Staphylococcus aureus-induced basophil histamine release in normal individuals and patients with intrinsic asthma

Influenza A virus was found to enhance Staphylococcus aureus-induced histamine release in human leukocyte suspensions, but did not per se release histamine. This potentiating effect was found to be similar in cells from normal individuals and from patients with intrinsic asthma. The enhancement of mediator release could be due to viral neuraminidase on the surface of the virus, since a similar potentiating effect was caused by a purified neuraminidase preparation obtained from Vibrio cholerae, and the effect of virus as well as of the purified neuraminidase was completely abolished by a potent neuraminidase inhibitor. The potentiating effect of virus on bacteria-induced mediator release might be of importance for the conversion from latent to manifest asthma in upper respiratory tract infections.     

Influenza A virus potentiates basophil histamine release caused by endotoxin-induced complement activation

Histamine release from human basophil leukocytes was triggered by complement activation by means of endotoxins isolated from E. coli and Salmonella bacteria. Influenza A virus was found to enhance the mediator release, and the effect was caused by synergism, since virus itself did not release histamine. The potentiating effect was similar in cells from normal individuals and from patients with intrinsic asthma. The involvement of viral neuraminidase was examined by a potent neuraminidase inhibitor and this inhibitor completely abolished the potentiating effect by virus. A purified neuraminidase preparation obtained from Vibrio cholerae caused a similar potentiating effect in mediator release and the effect was abolished by the neuraminidase inhibitor. These findings indicate that viral neuraminidase is responsible for the potentiating effect of virus on the histamine release. This effect might play a role in septic conditions and possibly contribute to asthmatic attacks by infections.     

Influenza A virus enhances IgE-mediated histamine release from human basophil leukocytes. Examination of the effect of viral neuraminidase and haemagglutinin

Histamine release caused by anti-IgE was examined in leukocyte suspensions from 10 healthy individuals. Influenza A virus was found to enhance the histamine release but did not release histamineper se. When monoclonal antibodies directed against the viral neuraminidase were included in the samples, the potentiating effect of the virus was completely abolished. The same occurred using a neuraminidase inhibitor. However, monoclonal antibodies directed against the viral haemagglutinin also abolished the potentiation. A binding of virus to the basophil cell surface by haemagglutinin therefore seems to be necessary for the viral neuraminidase to cause potentiation of mediator release.     

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.     

Virus enhances histamine release from human basophils

Histamine release from human basophil leukocytes was triggered byStaph. aureus or by complement activation caused by endotoxins isolated fromE. coli or Salmonella bacteria. Influenza A virus was found to enhance the mediator release and the effects was caused by synergism, since the virus itself did not release histamine. The potentiating effect of the virus was abolished by a potent neuraminidase inhibitor. Furthermore, a purified neuraminidase preparation obtained fromVibrio cholerae caused a similar potentiating effect, which was also abolished by the neuraminidase inhibitor. These findings indicate that the neuraminidase on the surface of influenza A virus is responsible for the potentiating effect of the virus on basophil histamine release.     

Influence of Neuraminidase and N-Acetylneuraminic Acid on Basophil Histamine Release in Vitro

Since N-acetylneuraminic acid (NANA) in cell membrane glucocalyx mediates or modulates a variety of actions, such as mediator release, we examined a possible modulating role of this amino sugar in histamine release from human basophil leukocytes. Removal of NANA from the cell membrane by the enzyme neuraminidase caused a dose-dependent histamine release. Removal of smaller amounts of NANA enhanced histamine release induced by anti-IgE, Concanavalin A and the calcium ionophore A23187, and reduced the interval between addition of antigen and initiation of histamine release. Pretreatment with free NANA had the opposite effects, i.e. a diminished and delayed maximal histamine release. The hypothesis that NANA in the cell membrane modulates the cellular response to stimulation was further substantiated by demonstrating that the altered response was reflected by a change in the sensitivity of the cell to extracellular calcium. NANA in the cell membrane glucocalyx thus seems to modulate the basophil response to stimulation by modulating transmembraneous calcium transport.     

Influence of Bacterial Endotoxins on Basophil Histamine Release Potentiation of Antigen- and Bacteria-Induced Histamine Release

The histamine-releasing capability of lipopolysaccharides (LPS) was examined in human leukocyte suspensions. LPS alone did not release histamine, but was found to enhance the histamine release caused by anti-IgE. Also the IgE-mediated histamine release caused by specific antigens (allergens or bacteria) in sensitized individuals was enhanced by LPS. The potentiating effect of LPS was observed in grass pollen and dog dander allergic patients as well as in patients sensitized to E. coli or Staph. aureus bacteria. No potentiation was obtained by exposure to unspecific allergens or bacteria to which the persons were not sensitized. Bacteria can release histamine by immunological or nonimmunological mechanisms, and only the immunological histamine release was found to be potentiated by LPS. It is speculated that endotoxins reinforce release of histamine caused by allergens in allergic patients or by bacteria in persons sensitized to these microorganisms.     

Endotoxin from Haemophilus influenzae enhances IgE-mediated and non-immunological histamine release

Haemophilus influenza and its extracellular products (EP) did not release histamine from basophil leukocytes in cell suspensions from normal individuals, patients with chronic bronchitis or patients allergic to either house dust mite, grass pollen, cat dander or to their own bacteria. However, the EP was found to enhance their basophil histamine release. IgE-mediated histamine release was examined by stimulation of the cells with anti-IgE or the specific allergens, and non-immunological histamine release by stimulating the cells with the calcium ionophore A23187 or Staphylococcus aureus. In all the experiments EP caused a significant increase in the histamine release. When H. influenzae endotoxins were removed from the EP, the potentiating effect of EP was completely abolished, whereas heating (80 degrees C, 30 min) or treatment of EP with proteinase did not influence the potentiating effect. These results indicate that H. influenzae endotoxin potentiates histamine release caused by IgE-mediated reactions or by non-immunological mechanisms.     

Bacteria and their products peptidoglycan and teichoic acid potentiate antigen-induced histamine release in allergic patients

Histamine release was examined in leukocyte suspensions from patients allergic to grass pollen, mite or cat dander or to bacteria (antigen). When the cells were challenged with specific antigen plus bacteria to which the person was not sensitized, these bacteria were found to potentiate the allergic histamine release. The potentiating effect by bacteria might be due to the bacterial cell wall components, peptidoglycan and teichoic acid, which mimic the effect of bacteria.     

Dynamics of viral growth, viral enzymatic activity, and antigenicity in murine lungs during the course of influenza pneumonia

Mice were infected by aerosol inhalation with influenza A/PR8/34 virus, and the kinetics of infection were monitored by the measurement of infectious virus, viral neuraminidase activity, and viral antigen as detected by enzyme immunoassay. Pulmonary levels of neuraminidase activity closely paralleled the infectious titers quantitated by standard egg inoculation techniques. Both viral neuraminidase activity and viral antigen increased in a dose-dependent manner during the early stages of the viral infection. After day 5, however, viral neuraminidase activity precipitously declined, whereas viral antigen levels remained elevated at high concentration for up to 60 days. Immunosuppressive treatment with cyclophosphamide resulted in the prolonged maintenance of peak virus titers without any additional increases in viral antigen. Previously infected mice were resistant to reinfection with homologous virus as evidenced by the lack of detectable viral neuraminidase activity and the lack of generation of additional viral antigen. These data define the temporal relationship between levels of infectious virus, neuraminidase activity, and viral antigen in an experimental model of influenza virus infection.     

Influenza A virus potentiates bacteria-induced histamine release

Influenza A virus was found to enhance basophil histamine release induced by Escherichia coli, Salmonella enteritidis, Staphylococcus aureus, Streptococcus pneumoniae and Streptococcus sanguis, but did not per se release histamine. This potentiating effect of the virus was seen both when the bacteria-induced mediator release was IgE-dependent (i.e. patient allergic to bacterium) and when the bacterium caused histamine release by a non-immunological mechanism independent of IgE (putative sugar-lectin mediated). Also histamine release induced by other immunological and non-immunological stimuli, such as anti-IgE, calcium ionophore or agarose beads was enhanced in the presence of the virus. The potentiating effect of the virus on bacteria-induced mediator release might be of importance for the conversion from latent to manifest asthma in upper respiratory tract infections.     

Bacteria-induced histamine release. Examination of the bacterial cell wall components peptidoglycan,teichoic acid and protein A

The histamine-releasing capability of whole bacteria was examined in leukocyte suspensions from normal individuals. Both gram-positive and gram-negative bacteria caused basophil histamine release. It is probably the bacterial cell wall which interacts with the basophil cell surface leading to release of histamine, since cell walls showed higher histamine releasing capability than the whole bacteria. The releasing effect of the bacterial cell wall components peptidoglycan, teichoic acid and protein A was examined. The peptidoglycan preparations were found to be more potent than the corresponding whole bacteria and cell walls. Since peptidoglycan is found in the cell wall of both gram-positive and gram-negative bacteria, it might be a common factor responsible for histamine release by different bacteria. No release was obtained by teichoic acid, whereas protein A caused histamine release in leukocytes from allergic patients, but only a poor release in normal individuals. The initial step in protein A-induced histamine release might be a binding of protein A to IgE on the cell surface, since removal of cell-bound IgE reduced the release and a high correlation was found between protein A- and anti-IgE-induced histamine release.     

Reduction of biological activity of cholera vibrio culture filtrates by neuraminidase inhibitors

With edema of the albino mouse paw as experimental model the action of neuraminidase inhibitors on the cholerogenic effect of cholera vibrio culture filtrates (CVCF) was studied. Addition of inhibitors to CVCF was found to depress their biological activity. Since purified neuraminidase preparations from cholera vibrios had no cholerogenic action it was postulated that the region of the cholerogen responsible for fixation on cell membranes is chemically similar to the active center of neuraminidase.Plague Research Institute, Volgograd. (Presented by Academician of the Academy of Medical Sciences of the USSR P. A. Vershilova.) Translated from Byulleten' Éksperimental'noi Biologii i Meditsiny, Vol. 81, No. 4, pp. 452–454, April, 1976.     

Isolation and characterization of influenza C virus inhibitor in rat serum

Two hemagglutination inhibitors for influenza C virus were isolated from pooled sera of normal rats by sequential chromatography on Blue Sepharose CL 6B, Ultrogel AcA 22, and DEAE-cellulose. The two inhibitors were identified as alpha 1-macroglobulin and murinoglobulin by comparison with the authentic samples. These inhibitors abolished the hemagglutination by influenza C virus strains but did not affect the hemagglutination by influenza A and B virus strains. Hemagglutination inhibition activity of both inhibitors was completely destroyed by incubation with influenza C virus at 37 degrees C but not with the other types of influenza virus, indicating that the inhibitors are specific for influenza C virus. The inhibitory activity was also destroyed by incubation with neuraminidase from Arthrobacter ureafaciens. By contrast, no activity was lost after treatment with neuraminidase from Vibrio cholerae. These results suggest that the sialic acid residue(s) which is cleavable by the former neuraminidase but not by the latter is essential for the hemagglutination inhibition. The two inhibitors were inactivated by treating with sodium hydroxide and methylamine but not with sodium metaperiodate.     

Bacteria and endotoxin enhance basophil histamine release and potentiation is abolished by carbohydrates

Histamine release caused by anti-IgE, specific antigens and calcium ionophore A23187 was examined in leukocyte suspensions from healthy individuals and patients allergic to house dust mite and birch pollen. Staphylococcus aureus and LPS from Salmonella typhimurium were found to cause a synergistic enhancement of the release. The potentiation of mediator release by the bacteria and the endotoxin depends on a binding to the basophilocyte, followed by a non-transient event, since the potentiating effect persists after preincubation of the cells with the LPS followed by washout and leaving the cells for 30 min at 37 degrees C before stimulation with anti-IgE. The potentiation was abolished or reduced by galactose (10(-7) and 10(-6) M) and N-acetylglucosamine (10(-6) and 10(-5) M), acting by a binding to the basophil cell membrane, demonstrated by the persistence of effect after preincubation and washout of unbound sugar.     

Granulocyte-macrophage colony-stimulating factor and interleukin-3 cause basophil histamine release by a common pathway: downregulation by sodium

Granulocyte-macrophage colony-stimulating factor (GM-CSF) and interleukin-3 (IL-3) are recognized as enhancers, but not as inducers, of histamine release from normal human basophils. However, when extracellular Na+ is removed IL-3 acquires the capacity to induce histamine release. The aim of this study was to evaluate whether GM-CSF can induce basophil histamine release using the same pathway of IL-3. Leucocyte suspensions from normal human subjects were stimulated with GM-CSF, IL-3 and anti-IgE, and histamine release was evaluated by an automated fluorometric method. In a physiological medium, GM-CSF (10 ng/ml) and IL-3 (10 ng/ml) did not provoke histamine release, in spite of an efficient response to anti-IgE (10 micrograms/ml). However, when extracellular Na+ was substituted iso-osmotically with N-methyl-d-glucamine+ or with choline+, GM-CSF and IL-3 were able to trigger histamine release from either mixed leucocyte suspensions or purified human basophils. The effect of GM-CSF on basophil histamine release was dose dependent, with optimal release at a dose of 1 ng/ml after incubation at 37 degrees for 60-120 min. The kinetics of IL-3-induced histamine release were similar, whereas anti-IgE-induced histamine release was more rapid, being almost maximal after incubation for 30 min. A good correlation was found between GM-CSF-induced and IL-3-induced histamine release; furthermore, the combined effects of the two cytokines were less than additive, suggesting that they share the same pathways leading to histamine release. When extracellular Na+ concentration was increased from 0 to 140 mm, histamine release induced by GM-CSF, IL-3 and anti-IgE was reduced progressively. In contrast, histamine release induced by these stimuli was upregulated when the concentration of extracellular Ca2+ was increased. These results provide indirect evidence that GM-CSF and IL-3 can induce basophil histamine release by a common pathway that is downregulated by Na+.     

Different patterns of antigen-induced histamine release during immunotherapy in insect venom and pollen allergy

Antigen-induced histamine release from whole blood was shown to be a suitable parameter for the diagnosis of hypersensitivity in both patients allergic to bee or wasp venom as well as in patients suffering from seasonal tree pollen allergy. Although both groups were treated successfully by specific immunotherapy, only in patients with insect allergy venom induced histamine release decreased significantly during therapy, whereas, in the patient with pollinosis, pollen induced histamine release did not change significantly during or after treatment. This discrepancy in the antigen-induced histamine release could either be due to different routes of immunization with the allergen and/or is caused by the atopic status which is prevalent in patients with pollinosis but not in insect allergic subjects.     

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.     

Naturally occurring aliphatic polyamines-induced histamine release from rat peritoneal mast cells

Rat peritoneal mast cells were incubated with different concentrations of naturally occurring aliphatic polyamines, spermine and spermidine, at 0.1-10 mM and the amount of histamine release into the supernatant solutions was measured. The addition of each polyamine to the suspensions of the mast cells caused a histamine release in a dose-dependent manner. The effect of 10 mM spermine and spermidine was as much as that of 0.5 microgram/ml compound 48/80. The histamine release from the cells incubated with each polyamine was rapid and the amount of histamine release into the supernatant solutions reached a maximum at 1 min with the incubations. 0.1 mM spermine, which in itself could not cause a significant histamine release, showed a tendency to enhance anti-IgE-induced histamine release from the mast cells.     

Budesonide and Nasal Mucosal Histamine Content and Anti-IgE Induced Histamine Release

The possible mode of action of the recently demonstrated steroid effect on the immediate type allergic reaction has been studied. The influence of a topical steroid, budesonide, on the nasal mucosal histamine content and anti-IgE induced histamine release was studied in an open study. A 1-week treatment with budesonide, used locally in the nose, was administered to 22 hay fever patients who were studied out of the pollen season. There was a decrease of histamine content after steroid treatment and also a blockade of the anti-IgE mediated histamine release, as shown in an in vitro release procedure. This steroid effect may partly explain the effect of steroids on the immediate reaction, as it has been demonstrated in allergen challenge studies.