We have investigated whether oral administration of ovalbumin (OVA) could prevent active systemic anaphylaxis to the antigen. Oral tolerance was induced by a single feecfing with 40 mg OVA before, but not after, sensitization characterized by diminished OVA-specific IgE and IgG responses. Feeding 15 mg OVA suppressed anaphylaxis and antibody responses to a lesser extent. Spleen cells from tolerant donors were incapable of transferring the tolerance to naive recipients. Pretreatment of cyclophosphamide (100 mg/kg) 2 days before OVA feeding did not restore the tolerance. Furthermore, in vitro cell mixing studies showed that the proliferation of spleen cells from OVA- sensitized donors was not inhibited by the addition of spleen cells from tolerant donors, arguing against the role of suppressor cells. Anergy was demonstrated by the ability to reverse the tolerant state after culturing tolerant cells in the presence of IL-2. These findings indicate that only a high-dose (40 mg) feeding OVA was found to be effective in inducing tolerance in this experimental system, and demonstrate anergy as the mechanism underlying oral tolerance to systemic anaphylaxis.
Administration, Oral ; Anaphylaxis* ; Antibody Formation ; Cyclophosphamide ; Humans ; Immunoglobulin E ; Immunoglobulin G ; Interleukin-2 ; Ovalbumin ; Ovum ; Spleen ; Tissue Donors

No abstract available.
Anaphylaxis* ; Immunoglobulin G*

No abstract available.
Cryptococcosis* ; Hybridomas* ; Immunity, Cellular* ; T-Lymphocytes*

No abstract available.
Cryptococcosis* ; Hybridomas* ; Immunity, Cellular* ; T-Lymphocytes*

BACKGROUND: Although glucocorticoids (GCs) are effective in controlling asthma in the majority of patients, a subset of asthmatics fails to demonstrate a satisfactory response, even to systemic GC therapy. This population is referred to as being "steroid-resistant". The actual mechanism underlying steroid resistance in asthma remains to be elucidated. METHODS: We have investigated how dexamethasone (DEX) regulates asthmatic phenotypes in a murine model of asthma, in which mice received i.p. immunization twice, followed by two bronchoprovocations with aerosolized OVA with a one-week interval, which we have recently described. RESULTS: Pretreatment with DEX resulted in an inhibition of NF-kappaB activation in asthmatic lungs, and also inhibited bronchoalveolar lavage (BAL) levels of NF-kappaB-dependent cytokines such as TNF-alpha and CC chemokines [eotaxin and monocyte chemotactic protein (MCP)-1]. DEX was effective in suppressing airway hyperresponsiveness (AHR) at 10 h, Th2-dependent asthmatic phenotypes such as airway eosinophilia, BAL levels of Th2 cytokines (IL-5 and IL-13), and mucin production. However, DEX failed to suppress BAL levels of CXC chemokines [macrophage inflammatory protein-2 (MIP-2) and keratinocyte-derived chemokine (KC)] and airway neutrophilia. CONCLUSION: Airway neutrophilia is among the phenomena observed in patients with severe GC-resistant asthma. This study will provide insight into the molecular basis for airway neutrophila seen in steroid-resistant asthma. Further studies are required to delineate the underlying mechanism of CXC chemokine expression in asthma.
Animals ; Asthma* ; Bronchoalveolar Lavage ; Chemokines, CC ; Chemokines, CXC ; Cytokines ; Dexamethasone* ; Eosinophilia ; Glucocorticoids ; Humans ; Immunization ; Lung ; Mice ; Monocytes ; Mucins ; NF-kappa B ; Ovum ; Phenotype ; Tumor Necrosis Factor-alpha

BACKGROUND: Anti-IgE mAb which binds circulating but not receptor-bound IgE has been shown to be effective in treatment for asthma and other allergic diseases. However, the mechanisms by which anti-IgE mAb influences the pathophysiological responses are remained to be illustrated. This study was undertaken to examine the therapeutic efficacy of non-anaphylactogenic anti-mouse IgE mAb using murine models of IgE-induced systemic fatal anaphylaxis. METHODS: Active systemic anaphylaxis was induced by either penicillin V (Pen V) or OVA and passive systemic anaphylaxis was induced by either anaphylactogenic anti-mouse IgE or a mixture of anti-chicken gamma globulin (CGG) IgG1 mAb and CGG. The binding of the Fc portion of anti-IgE to CHO-stable cell line expressing mouse FcgammaRIIb was examined using flow cytometry. Fc fragments of anti-IgE mAb were prepared using papain digestion. The expression of phosphatases in lungs were assessed by Western blotting and immunohistochemistry. RESULTS: Anti-IgE mAb prevented IgE- and IgG-induced active and passive systemic fatal reactions. In both types of anaphylaxis, anti-IgE mAb suppressed antigen-specific IgE responses, but not those of IgG. Anti-IgE mAb neither prevented anaphylaxis nor suppressed the IgE response in FcgammaRIIb-deficient mice. The Fc portion of anti-IgE mAb was bound to murine FcgammaRIIb gene-transfected CHO cells and inhibited systemic anaphylaxis. Anti-IgE mAb blocked the anaphylaxis-induced downregulation of FcgammaRIIb-associated phosphatases such as src homology 2 domain-containing inositol 5-phosphatase (SHIP) and phosphatase and tensin homologue deleted on chromosome ten (PTEN). CONCLUSION: Anti-IgE mAb prevented anaphylaxis by delivering nonspecific inhibitory signals through the inhibitory IgG receptor, FcgammaRIIb, rather than targeting IgE.
Anaphylaxis* ; Animals ; Asthma ; Blotting, Western ; Cell Line ; CHO Cells ; Cricetinae ; Digestion ; Down-Regulation ; Flow Cytometry ; gamma-Globulins ; Immunoglobulin E ; Immunoglobulin Fc Fragments ; Immunoglobulin G* ; Immunohistochemistry ; Inositol ; Lung ; Mice* ; Ovum ; Papain ; Penicillin V ; Phosphoric Monoester Hydrolases

No abstract available.
Anaphylaxis* ; Animals ; Antibodies, Monoclonal* ; Hypersensitivity* ; Immunoglobulin G* ; Interferons* ; Mice*

Besides their role as building blocks of protein, there are growing evidences that some amino acids have roles in regulating key metabolic pathways that are necessary for maintenance, growth, reproduction, and immunity. Here, we evaluated the modulatory functions of several amino acids in protective immunity against mucosal infection of herpes simplex virus type 1 (HSV-1). We found that glutamine (Gln) and leucine (Leu) showed enhanced protective immunity to HSV-1 mucosal infection when two administration of Gln and single administration of Leu per day, but not when administered in combinations. Ameliorated clinical signs of HSV-1 challenged mice by the intraperitoneal administration of Gln and Leu were closely associated with viral burden and IFN-gamma production in the vaginal tract at 2 and 4 days post-infection. In addition, the enhanced production of vaginal IFN-gamma appeared to be caused by NK and HSV-1 antigen-specific Th1-type CD4+ T cells recruited into vaginal tract of mice treated with Gln and Leu, which indicates that IFN-gamma, produced by NK and Th1-type CD4+ T cells, may be critical to control the outcome of diseases caused by HSV-1 mucosal infection. Collectively, our results indicate that intraperitoneal administration of Gln and Leu following HSV-1 mucosal infection could provide beneficial effects for the modulation of protective immunity, but dosage and frequency of administration should be carefully considered, because higher frequency and overdose of Gln and Leu, or their combined treatment, showed detrimental effects to protective immunity.
Amino Acids ; Animals ; Glutamine ; Herpes Simplex ; Herpesvirus 1, Human ; Leucine ; Metabolic Networks and Pathways ; Methylmethacrylates ; Mice ; Polystyrenes ; Reproduction ; Simplexvirus ; T-Lymphocytes ; Viral Load

It is well known that tumor necrosis factor (TNF-a), interleukin-1, platelet-activating factor (PAF) and arachidonic acid metabolites, such as thromboxane and leukotriens, are major mediators involved in the pathogenesis of endotoxic shock. In this study, we have investigated the effect of pentoxifylline (inhibitor of TNF-a release), BN50739 (PAF antagonist), indomethacin (cyclooxygenase inhibitor) and diethylcarbamazine (lipoxygenase inhibitor) on LPS- induced lethality as well as the relationship between major mediators in endotoxic shock. All inhibitors described above except diethylcarbamazine significantly protected mice against LPS- induced lethality. BN50739 and indomethacin were also effective in protection of TNF-a-induced lethality. The elevation of circulating TNF-a by LPS was significantly blocked by BN50739, but not affected by indomethacin. Convulsion appeared shortly after LPS injection was prevented by BN50739 but not by indomethacin, whereas diarrhea and limited movement was prevented by indomethacin but not by BN50739. These results indicate that i) TNF-a, PAF and cyclooxygenase products are important mediators involved in the pathogenesis of septic shock and ii) TNF-a directly influenced the release or production of PAF as well as cyclooxygenase products, and strongly suggest that i) TNF-a and PAF stimulate the release of each other via positive feedback network but TNF-a and cyclooxygenase products do not form the network and ii) PAF and cyclooxygenase product appear not to affect the release of each other.
Animals ; Arachidonic Acid ; Diarrhea ; Diethylcarbamazine ; Gene Expression* ; Indomethacin ; Interleukin-1 ; Mice ; Pentoxifylline ; Prostaglandin-Endoperoxide Synthases ; Seizures ; Shock, Septic ; Tumor Necrosis Factor-alpha*

Trimellitic anhydride (TMA) is widely used industrially to make epoxy and alkyd resins, plasticizers and surfactants. The purpose of this study was to investigate whether contact hypersensitivity (CHS) is induced by repeated TMA challenge and the role of TNF-a and IgE in the TMA-induced CHS. The repetition of the challenge enlarged the extent of an early and a late phase of CHS in TNF-alpha+/+ (B6129SF2/J) and Balb/c mice. In the late phase of TMA-induced CHS, the peak of ear swelling responses by single challenge showed at 24 h after challenge, but the peak was observed at 8 h after repeated challenge. In the TNF-a knockout TNF-alpha-/- (B6;129S-Tnf(tm1Gk1) mice, the repetition of the TMA challenges enlarged the extent of the late phase of CHS, but less than those in TNF-alpha+/+ mice. Injection of anti-TNF-alpha antibody into the peritoneal cavity of Balb/c mice significantly decreased the extent of the late phase of CHS. Subcutaneous injection of anti-IgE antibody into Balb/c mice also decreased the extent of the late phase of CHS in dose-dependent manner. Histologically, infiltration of polymorphonuclear leukocytes and eosinophils was more pronounced in repeatedly TMA-challenged TNF-alpha+/+ and Balb/c mice than in the TNF-alpha-/- mice and anti-TNF-alpha or anti-IgE antibodies treated Balb/c mice. These results indicate that mice sensitized by TMA could possibly offer a useful model to study the mechanism of CHS, and TNF-a and IgE may act as potential modulators in the late phase of TMA-induced CHS. Neutralization of TNF-alpha and IgE by anti-TNF-a or anti-IgE antibodies may provide therapeutic tools for the treatment of TMA-induced CHS.
Animals ; Dermatitis, Contact/genetics/*immunology/*metabolism/pathology ; Ear/pathology ; Immunoglobulin E/*immunology ; Leukocytes ; Male ; Mice ; Mice, Inbred BALB C ; Mice, Knockout ; Phthalic Anhydrides/*toxicity ; Research Support, Non-U.S. Gov't ; Time Factors ; Tumor Necrosis Factor-alpha/deficiency/genetics/*metabolism