Suppression of IgE antibody production after exposure to ozone in mice

The effect of ozone exposure on IgE antibody production with aerosolized ovalbumin (OA) administration was investigated in Balb/c mice. Mice were continuously exposed to 0.8 ppm ozone for 1, 2, or 4 weeks, respectively, and subsequently aerosolized OA was administered through the respiratory tract for 6 min with a nebulizer. The mice were then immunized intraperitoneally 1 week later with OA. IgE antibody production was suppressed in ozone-exposed mice. However, no significant difference in the primary IgE antibody production by intraperitoneal immunization alone with OA was observed between ozone-exposed mice and nonexposed mice. In order to elucidate the suppressive mechanism of IgE antibody production, hapten-carrier antigenic system was used. It is shown that the induction of helper T cell function was suppressed if the aerosolized carrier protein was administered before intraperitoneal immunization in the mice exposed to ozone. These results suggest that ozone exposure has the effect on the stage of administration of inhaled antigen and the quite insignificant effect on the IgE antibody production after intraperitoneal immunization with OA.     

Induction of IgE antibody production to aerosolized ovalbumin in mice treated intratracheally with aluminum silicate

Induction of IgE antibody production was studied in mice with aerosolized antigen exposure and intratracheal instillation of adjuvants. BALB/c mice were immunized intratracheally with 10 micrograms ovalbumin (OA) adsorbed with or without aluminum silicate as an adjuvant. A primary IgE antibody production was observed in mice immunized with OA plus adjuvant, but not with OA alone. In mice immunized with OA plus adjuvant, a secondary IgE antibody production was observed after a booster of OA aerosol exposure on day 28. Mice were instilled intratracheally with aluminum silicate or aluminum hydroxide (alum) and subsequently exposed to aerosolized OA for 30 min. Primary and secondary anti-OA IgE antibody productions were obtained in the groups instilled with the adjuvants. After the intratracheal instillation of alum, aluminum remained in the mice for a long period. These results suggest that the intratracheal instillation of adjuvants is effective in the induction of IgE antibody production by aerosolized antigen exposure.     

New immunomodulator lobenzarit disodium (CCA): activation of IgE class-specific suppressor T lymphocytes and regulation of IgE antibody response enhanced by sublethal X-irradiation in SJL/J mice

The effect of the new immunomodulator lobenzarit disodium (CCA, disodium-2,2'-iminodibenzoate) on IgE antibody response was studied in X-irradiated SJL/J mice. IgE antibody response to dinitrophenyl-keyhole limpet hemocyanin (DNP-KLH) was enhanced by sublethal X-irradiation (400 R), and this enhanced IgE production was suppressed by unprimed normal spleen cell transfer. Oral administration of CCA, every day from 1 day after immunization with DNP-KLH to 1 day before bleeding out, reduced IgE antibody response in sublethally X-irradiated SJL/J mice. The suppressive effect of CCA in the mice was exerted at an early stage of the IgE antibody response. Moreover, CCA showed IgE class-specific suppression and did not suppress IgG class antibody production. CCA-induced reduction of IgE antibody response in SJL/J mice seems to be mediated by suppressor T cells, since depletion of T cells by treatment with antithymocyte serum and complement abolished the CCA-induced reduction and splenic T cells from CCA-treated mice were able to transfer the suppressive effect.     

Tolerance induction via antigen inhalation: isotype specificity, stability, and involvement of suppressor T cells

Mice were exposed to aerosolized ovalbumin (OA) once weekly for 5 min on 6 occasions, prior to systemic challenge with soluble or alum-adsorbed (AH-OA) antigen. Mice challenged with AH-OA manifested profound IgE isotype-specific tolerance; those challenged with soluble OA initially manifested anamnestic IgE/IgG responses, but secondary intraperitoneal immunization 13 days later with soluble OA revealed IgE isotype-specific tolerance. The tolerized mice contained splenic suppressor T cells which inhibited IgE but not IgG responses in an adoptive transfer assay. Tolerance was still demonstrable in mice 6 months after the cessation of aerosol exposures. Exposure of low IgE responder rat strains to aerosolized OA tolerized for both IgE and IgG responses.     

Suppression of IgE antibody response by the fatty acid-modified antigen

Ovalbumin (OA) of hens was chemically coupled with fatty acids (lauric acid, myristic acid, palmitic acid and stearic acid). These hydrophobically modified antigens were unable to react with mouse antiserum against native OA and were incapable of eliciting primary and secondary anti-OA antibody responses in BALB/c mice. Preadministration of these modified antigens, especially of palmitoyl OA (OA-pal), suppressed both primary and secondary anti-OA IgE antibody responses without affecting IgG antibody production. Administration of OA-pal after the primary immunization resulted in a rapid decrease of the ongoing anti-OA IgE antibody production and inhibited the anamnestic anti-OA IgE antibody response upon subsequent immunization with OA. The passive transfer of spleen cells from OA-pal-treated animals with OA-primed spleen cells suppressed the adoptive secondary anti-OA IgE antibody response in irradiated recipients. The suppressive effect was abrogated by treatment with an anti-T-cell antiserum indicating that suppressor T cells were primed by administration of hydrophobically modified antigens.     

Regulation of the IgE antibody response in mice. II. Radioresistance of established IgE antibody production.

The protracted IgE anti-ovalbumin (OA) response given by BDF1 mice was studied using an adoptive transfer model. Spleen cells taken from immunized BDF1 mice can produce IgE antibody in irradiated recipients without further overt antigenic challenge. Depletion of macrophages in active spleen cell suspensions did not diminish the capacity of the remaining cells to give an adoptive response. Evidently the cells subserving the adoptive response are not fully developed in donor mice until 4 weeks after immunization, since spleen cells removed at shorter intervals after immunization gave either no or weak adoptive responses. The production of IgE antibody in irradiated recipient mice is prevented if transferred B or T lymphocytes are treated in vitro with either gamma irradiation or mitomycin C, suggesting proliferation of both B and T lymphocytes is essential for the adoptive response to develop. However, the requirement for proliferation is only transient, since one IgE antibody production reached a steady state in the adoptive recipients, it manifested extreme resistance to high dose irradiation. Whole body irradiation of 800 and 1000 rad was without effect on sustained IgE production. This latter observation was valid for both intact mice which were irradiated 8 weeks after immunization and also for irradiated adoptively immunized mice. It is suggested that the IgE anti-OA antibody measured in serum of BDF1 mice several months after immunization with 1 microgram OA and 1 mg Al(OH)3 is the product of long-lived antibody secreting cells.     

Antigenic competition in IgE antibody production. III. Suppressive effect on Th and B cells

An adoptive cell transfer system was utilized to evaluate the site of action of the suppressive mechanism involved in antigenic competition in IgE antibody production. Carrier-primed (OA) and hapten-primed (DNP-KLH) spleen cells were transferred to syngeneic irradiated recipients that were challenged with a heterologous conjugate (DNP-OA). To study the effect of antigenic competition on T and B cells, donor mice of one or the other cell type received in addition the competitor antigen (Asc) at immunization. The adoptive secondary IgE anti-DNP antibody response was suppressed in both situations. This effect could not be attributed to transfer of Asc-primed cells. Irradiation of donor mice before immunization with the two antigens abrogated the suppressive effect. These results indicate that both Th and B cells primed to the test antigen were affected by antigenic competition.     

The effect of hapten-specific suppression of IgE on antigen-induced histamine release from mouse peritoneal mast cells.

Subcutaneous injections of a mixture of dinitrophenylated ovalbumin (DNP3-OA) and dextran sulfate into Swiss-Webster mice elicited short-lived primary and long-lasting secondary IgE antibody responses to both DNP and OA. Histamine was released on in vitro challenge with antigen (OA or DNP22-BSA) of washed peritoneal mast cells (PMC) obtained from mice during a primary or a secondary IgE response. Administration of an intravenous injection of a tolerogenic conjugate of DNP8-mouse gamma-globulin, either prior to immunizationor during an ongoing IgE response, resulted in almost complete disappearance of circulating anti-DNP IgE antibody and in a very marked decrease in histamine release from PMC on challenge with DNP22-BSA. However, the IgE response to OA of these mice and the histamine release from their PMC on challenge with OA were not affected. Moreover, the PMC of mice, which had been tolerized to DNP, could be passively sensitized with serum containing DNP-specific IgE antibody for the release of histamine on DNP22-BSA challenge. The most significant finding of this study is the observation that the time course for the loss of reactivity of PMC to DNP22-BSA, after administration of the tolerogen during an ongoing secondary response, paralleled the decrease in circulating anti-GNP IgE antibody.     

IgE-isotype-specific suppressor cells in the mouse: characterization using tetraparental chimera mice of high (DBA/2) and low (SJL) IgE responder embryos

Tetraparental chimera mice were developed by aggregation of IgE high responder (DBA/2) and IgE low responder (SJL) embryos. Anti-dinitrophenyl (DNP) IgE antibody response in such mice (SJL----DBA/2) upon challenge with DNP-keyhole-limpet hemocyanin (KLH) in alum was clearly suppressed, while anti-DNP IgG antibody response was not. High-titer anti-DNP IgE and IgG antibody response developed in F1 hybrid mice of SJL and DBA/2 (SDF1) mice. The experimental results suggest that high IgE antibody production is the dominant trait, and the IgE-specific suppressor gene in SJL mice is autosomal recessive. IgE-specific suppressor T cells in SJL mice actively suppressed IgE antibody formation by DBA/2 immuno-competent cells across the histocompatibility barrier. Hapten-specific B cells and carrier-specific T cells were prepared in SJL----DBA/2 and SDF1 mice by immunization with DNP-KLH or ovalbumin (OA) in alum and transferred to irradiated SDF1 mice followed by challenge with DNP-OA. Hapten-specific B cells and carrier-specific helper T cells clearly developed in SDF1 mice. Recipient mice transferred with DNP-KLH-primed SDF1 spleen cells and OA-primed SDF1 spleen cells showed high-titer anti-DNP IgE and IgG antibody responses. OA-primed SJL----DBA/2 spleen cells cotransferred with DNP-KLH-primed SDF1 spleen cells and OA-primed SDF1 spleen cells completely abolished secondary anti-DNP IgE antibody response. The data suggest that carrier-specific helper T cells for IgE and IgG antibody responses are distinct. The regulatory role of IgE-isotype-specific suppressor cells were considered to be the interference of cooperative cellular interaction between IgE B cells and carrier-specific, IgE-specific helper T cells.     

Inhibition of specific IgE responses in mice by pre-exposure to inhaled antigen.

Exposure of mice to aerosolized ovalbumin (OA) once weekly for 5 min, or once weekly to 10 microgram OA in PBS intranasally, elicited transient IgE responses which declined by the seventh week. When these animals were challenged intraperitoneally (i.p.) with soluble or alum-precipitated OA, their subsequent IgE responses were markedly suppressed relative to controls. In contrast, i.p. challenge provoked hemaagglutinating antibody (HA) responses to OA in the same animals which were considerably more vigorous than in controls. Adoptive transfer experiments employing splenocytes from mice repeatedly exposed to OA via the respiratory tract revealed the presence of suppressor cells active against OA-specific IgE but not HA responses. Radiotracer studies employing 125I-OA, administered intranasally and by aerosol, indicated that much of the antigen rapidly became associated with the gut.     

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.     

The effect of disodium 4-chloro-2-iminodibenzoate (CCA) on IgE levels and anaphylactic shock

The effect of disodium 4-chloro-2,2-iminodibenzoate (CCA) on IgE antibody response was examined in C₃H/A and (BALB/c×C57BL/6J) F1 hybrid mice immunized with low doses of ovalbumin (OA) adsorbed on aluminium hydroxide gel. CCA administered orally at the doses of 5 and 50 mg/kg/day reduced IgE antibody production in these mice as determined by PCA test. High doses of CCA (100 mg/kg/day) given from day 7 before immunization of C57BL mice and during 1 week after immunization of mice with OA and Bordetella Pertussis Vaccine reduced the mortality of these mice subjected to anaphylactic shock on day 7 of immunization. CCA treatment was ineffective in anaphylactic shock of C57BL mice immunized with very high dose of OA, known to elicit little or no IgE antibody production but high IgG antibody response.The treatment of OA-immunized Guinea pigs with one oral dose of CCA (100 mg/kg) did not reduce mortality in protracted anaphylactic shock. Our results demonstrate that CCA inhibits IgE production as well as IgE mediated hypersensitivity reactions in mice.     

Adjuvant activity of the histamine-sensitizing factor of Bordetella pertussis in different strains of mice.

The effect of an extract of histamine-sensitizing factor (HSF) of Bordetella pertussis on the immune response of different strains of mice to ovalbumin (OA) was investigated with regard to optimal dose of antigen and adjuvant. It was observed that all strains of mice treated with HSF during immunization with OA demonstrated enhanced production of hemagglutinating antibodies, as compared to animals treated with antigen alone. This enhancement was generally not as great as that demonstrated when Al(OH)3 was the adjuvant. HSF also stimulated a reaginic antibody response (IgE) to OA, but not in all strains of mice. In reagin responders optimal responses were observed with high doses of both antigen and adjuvant, whereas low doses of both produced little or no response. Maximal reagin production occurred usually 14-28 days after immunization and persisted for long periods of time. An anamnestic reagin response was elicited upon secondary immunization with antigen alone, not only in mice immunized with OA and HSF but also in animals treated with OA alone. These studies demonstrate the profound effect that a microbial substance such as HSF can have on reaginic antibody production and suggest that the stimulation of IgE antibody production is the net result of a number of factors including genetic capabilities of the host, environmental influence such as adjuvants, and prior exposure to an antigen.     

Immune responses to polyethylene glycol modified L-asparaginase in mice

Suppression of anti-L-asparaginase (anti-A-ase) IgG and IgE antibody responses was achieved in Balb/c mice with polyethylene glycol (PEG, MW, 5,000) conjugated Escherichia coli A-ase. Following the administration of the mixture of A-ase and PEG-A-ase, antibody production to A-ase was reduced. PEG-A-ase administration prior to A-ase suppressed the primary and secondary responses to A-ase antibody. The suppression could be transferred to normal mice with spleen cells from A-ase tolerant mice. The cell transfer experiment showed that the suppression was caused by suppressor T cells. Since PEG-A-ase administration failed to suppress antibody response to ovalbumin, the suppression seemed to be A-ase specific. PEG-A-ase administration also suppressed the delayed type hypersensitivity reaction. IgG and IgE antibodies to PEG or PEG-A-ase were not detected in mice immunized with PEG or PEG-A-ase in the presence of Freund's complete adjuvant or A1(OH)3, respectively.     

Oral tolerance induction in dermatophagoides pteronyssinus-sensitized mice induces inhibition of IgE response and upregulation of TGF-beta secretion.

Oral antigen administration induces peripheral tolerance in naive animals. Studies of oral tolerance induction in sensitized mice have clinical relevance as a strategy to modulate allergy. In this study, the A/Sn mice sensitized with extract of Dermatophagoides pteronyssinus (Dp) and submitted to oral Dp administration showed a marked decrease in IgE anti-Dp antibody production compared with sensitized phosphate-buffered saline (PBS)-fed mice. T cells from Dp-fed mice cocultured with spleen cells from PBS-fed mice were able to inhibit IgE anti-Dp antibody production and did not interfere in IgG1 antibody levels. The analysis of cytokine profile after Dp feeding showed a significant decrease in interleukin-4 (IL-4), IL-5, and IL-13 antigen-induced secretion levels by spleen cells, without shifting to IL-2 and interferon-gamma (IFN-gamma) production. Both transforming growth factor-beta (TGF-beta) baseline and TGF-beta antigen-stimulated levels were increased in Dp-fed mice. The effects of regulatory cytokines on anti-Dp IgE antibody production were investigated in vitro. The addition of recombinant TGF-beta (rTGF-beta) to spleen cell cultures stimulated by Dp inhibited IgE antibody secretion in both mouse groups. Neutralizing antibodies to IL-4, but not anti-TGF-beta, induced a marked inhibition of IgE production. Therefore, a negative modulatory effect on IgE response by inhibition of the axis Th2 was observed in sensitized Dp-fed mice, possibly mediated by induction of regulatory cytokines.     

Effects of cyclophosphamide treatment and gamma irradiation of SJL mice on the IgE antibody response and the nature of IgE-binding factors

Immunization with alum-absorbed ovalbumin (OA) failed to induce IgE antibody responses in SJL mice, while mice pretreated with either cyclophosphamide (CY) or gamma-irradiation prior to immunization transiently formed IgE antibodies. Spleen cells of OA-primed SJL mice formed IgE-suppressive factors upon incubation with OA. In contrast, spleen cells of the CY-treated or irradiated mice formed IgE-potentiating factors. It was found that CY treatment diminished the formation of glycosylation inhibiting factor (GIF) and enhanced the formation of glycosylation enhancing factor (GEF). The results suggest that the enhancement of the IgE antibody response by CY treatment is due not only to elimination of suppressor T cells but also to the activation of GEF-forming lymphocytes.     

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.     

Selective inhibition of systemic anti-OVA IgE production in response to oral pre-treatment with OVA-liposome conjugates

BACKGROUND: We have previously reported that intraperitoneal injection with OVA-liposome conjugates induces OVA-specific and IgE-selective unresponsiveness in mice. METHODS: In the present study, the effects of oral pre-treatment with OVA-liposome conjugates or with plain OVA solution on anti-OVA IgG antibody production were investigated in mice after subsequent immunization with alum-adsorbed OVA. Control mice received only the immunization. RESULTS: The levels of serum anti-OVA IgG antibody in mice receiving oral administration of OVA-liposome were comparable to those in the control mice. However, in mice receiving oral administration of the same dose of plain OVA, levels of serum anti-OVA IgG antibody were significantly lower than those in control mice. Surprisingly, anti-OVA IgE antibody production was completely inhibited in mice receiving oral administration of OVA-liposome conjugates. Splenic CD4(+) T cells of mice receiving oral administration of OVA-liposome and those of control mice produced comparable levels of cytokines, while those of mice receiving oral administration of plain OVA solution produced significantly lower levels of cytokines than those in the other two groups. CONCLUSION: Orally administered OVA-liposome did not affect anti-OVA IgG production but did inhibit anti-OVA IgE antibody production, while orally administered OVA solution inhibited production of both IgG and IgE antibodies. These results suggest that antigen-liposome conjugates can possibly be orally administered in order to control antigen-specific IgE antibody production, without affecting IgG antibody production.     

IgE enhances specific antibody and T-cell responses in mice overexpressing CD23

Abstract IgE administered with its specific antigen in vivo induces enhanced proliferation of specific T cells as well as enhanced production of specific antibodies. Both effects are dependent on the low-affinity receptor for IgE (CD23) and the underlying mechanism is thought to be increased antigen presentation following uptake of IgE/antigen complexes via CD23⁺ B cells. By contrast, CD23 negatively regulates antibody responses to antigens administered with alum, i.e. without IgE. This effect has been observed as low IgG1 and IgE responses in transgenic mice overexpressing CD23 (CD23Tg). The present study was designed to test whether IgE could enhance antibody and T-cell responses in CD23Tg animals or whether CD23's downregulatory effect precludes IgE-mediated enhancement. IgE-anti-TNP administered with OVA-TNP enhances the OVA-specific antibody responses in wild-type (wt) and CD23Tg mice equally well. Interestingly, the total magnitude of antibody responses to IgE + OVA-TNP and to uncomplexed OVA-TNP, as well as to sheep erythrocytes and keyhole limpet haemocyanine, were lower in the CD23Tg mice. IgE induced proliferation of OVA-specific CD4⁺ T cells to the same degree in wt and CD23Tg mice. The effect on T cells was dependent on CD23⁺ B cells as demonstrated in in vitro proliferation assays. In conclusion, CD23 does indeed have dual immunoregulatory effects in the same animal. The receptor mediates enhancement of antibody and T-cell responses to IgE-complexed antigen, most likely via increased presentation of complexed antigen, while it negatively regulates the total antibody response to a variety of antigens.     

The effect of anti-IL-4 monoclonal antibody, rapamycin and interferon-γ on airway hyperreactivity to acetylcholine in mice

Background The role of IgE in airway hyperreaetivity is obscure. Objective In order to clarify the role of IgE in airway hyperreactivity, we investigated the effect of anti-IL-4 monoclonal antibody, rapamycin and interferon-γ on the antigen-induced IgE response, airway eosinophilia and hyperreactivity in mice. Methods Mice were immunized with an antigen (ovalbumin; OA) at intervals of 12 days. OA was inhaled 10 days after the secondary immunization. Twenty-four hours after the last inhalation, airway reactivity to acetylcholine was measured and bronchoalveolar lavage fluid (BALF) was obtained. Results Three inhalations of antigen caused an increase in the number of eosinophils in bronchoalveolar lavage fluid (BALF) and in airway hyperreactivity to acetylcholine with a significant elevation of serum IgE level. Anti-IL-4 at a dose of 1000 μg/animal and rapamycin at doses between 0.1 and 1 mg/kg inhibited the IgE production, but did not affect the airway eosinophilia or hyperreactivity to acetylcholine. In contrast, IFN-γ clearly inhibited the antigen-induced airway eosinophilia and hyperreactivity, but did not affect the IgE antibody production. Conclusion These results suggest that the inhibition of IgE production does not suppress the onset of airway hyperreactivity and eosinophilia in mice, and that IFN-γ inhibits the antigen-induced airway hyperreactivity, probably due to the inhibition of airway eosinophilia.