ABSTRACT
For those with allergy, vaccination with a specific allergen has often been used as a major therapeutic measure. However, the universal application of this technique in clinics have been restricted due to its low success rates and the risk of active systemic anaphylactic shock (ASAS). In this regard, we constructed a fusion protein (OVA-DT), ovalbumin (OVA) fused with diphtheria toxin protein (DT), which may exert a specific cytotoxicity to cells bearing OVA-specific IgE. Its therapeutic effect was evaluated in mice (BALB/c) sensitized with OVA (Os-mice). OVA challenges to the OVA-sensitized mice (Os-mice) caused ASAS to death within 30 min, but OVA-DT treatment afforded mice complete protection. When OVA-DT was treated to the Os-mice, none showed the signs of ASAS when re-challenged 48 h after the treatment. OVA-DT itself was not found to be toxic or allergenic in normal mice. The effect of OVA-DT on the biological functions of mast cells was also studied. Binding of OVA-DT to OVA-specific IgE bearing mast cells and the inhibition of histamine release from these cells were observed. In addition, OVA-DT treatment inhibited the proliferation of OVA-specific B cells in mice. In Os-mice treated with OVA-DT, levels of anti-OVA IgG2a in serum and the production of IFN-gamma by splenic lymphocytes were found to increase, but the production of IL-4 by these cells decreased. Re-direction of cytokine profiles from OVA-specific Th2 to OVA-specific Thl is suggested. These results indicate that OVA-DT can protect Os-mice from ASAS due to OVA challenge, because it inactivates OVA-specific IgE-expressing cells, including mast cells and B cells.
Subject(s)
Female , Mice , Anaphylaxis , Animals , B-Lymphocytes/immunology , Histamine Release/drug effects , Immunoglobulin E/metabolism , Interferon-gamma/biosynthesis , Interleukin-4/biosynthesis , Lymphocyte Activation/drug effects , Mast Cells/metabolism , Mice, Inbred BALB C , Ovalbumin/immunology , Recombinant Fusion Proteins/therapeutic useABSTRACT
We have used BALB/c mice as an animal model for the study of anaphylactic hypersensitivity to the house dust mite. For the sensitization, BALB/c mice were injected with a single dose of extracts of Oermatophagoides farinae (D. pa) or Dermatophagoides pteronyssinus (D. pt) mixed with adjuvants (aluminum hydroxide and Bordetella pertussis) intraperitonealy. On days of 15, 30, and 60 after the sensitization, the mice received a challenge dose of the same allergen intravenously to induce anaphylactic shock. The hypersensitivity reactions were scored by anaphylactic shock. And various immunological parameters, including cytokines and immunoglobulin isotypes, were studied in relation with the shock. A high level of anaphylactic shock was produced in the mice by both of the allergens, D, fa and D, pt, at 15 and 30 days after sensitization. In vitro Ag specific proliferative reponses of spleen cells from D. pt treated mice (D. pt mice) was six times higher than those from O. fa treated mice (O. fa mice). Regardless the differences in antigens, the production of IFN-r by spleen cells from D. pt mice or O. fa mice was equally high at 15 days after sensitization. However, the ability to produce IFN-r by the spleen cells from D, pt mice was three times higher compared to that from D. fa mice. The production of IL-4 by the spleen cells was enhanced slightly but not significant in both groups. In studies of the allergen-specific immunoglobulin isotypes in the sera of the mice, the level of IgE in both groups was enhanced slightly but not significant. In contrast, the level of IgG subtypes were increased in both groups. When the levels of IgG were compared by subtypes, the level of IgG1 increased significantly on day 15 when the anaphylactic shock score was maximized in both groups. Increase in IgG2a level at the day was not significant, instead, asignificant increase in IgG2 levels was observed on day 60 after sensitization when the anaphylaxis was almost discontinued. Although a higher level of IgG3 was examined on day 15 and 30 in D. pt mice and on day 60 in D, fa mice, anaphylaxis was not appeared to be associated with the levels of IgG3 in this study. The IgG1, rather than IgE, was assumed to the major factor involved in the anaphylactic response observed in this experiment. In conclusion, BALB/c mice would be an animal model for the study of anaphylactic hypersensitivity to D. fa or D, pt., which might be an essential tool for the future development of immuno-therapeutic agents.
Subject(s)
Mice , AnimalsABSTRACT
OBJECTIVES: From asymptomatic asthmatic patients unable to produce sputum spontaneously, we performed a non-invasive method obtaining sputum via inhalation of ultrsonically nebulised hyperosmolar saline(3%) which provides a way to investigate airway inflammation, And we also evaluated the effectiveness of the ultrasonic nebulizer in these patients. METHODS: 50 asymptomatic patients unable to produce sputum spontaneously inhaled a hyperosmolar saline via an Ultrasonic nebulizer to induce sputum. We examined the quality of the sputum, total cell counts and differential cell counts of eosinophil after sputum processing. RESULTS: 1) The quality of the sputum was uninterpretable (12%); poor(16%); fair(34%); good(38%), repectively. The mean induction time of expectoration was about 10 minutes. 2) The most common complaint was of a salty taste(45 cases). The mean fa11 in peak expiratory flow rate during inhalation of saline was 4.0% and the fall more than 20% was observed in 5 cases. 3) The mean eosinophil percent in induced sputum was 38.5%, The mean value of the total IgE and total peripheral eosinophil count was 818.2 IU/ml, 401.2/mm3 respectively, 4) There were no relationships between the sputum eosinophil count(%) and both the total IgE and the PC20(r=0.13, r=0.18). There was also an insignificant correlation between the sputum eosinophil count(%) and the total peripheral eosinophil count(r=D.22). CONCLUSION: We find that there are many eosinophils within induced sputum via inhalation of ultrsonically nebu1ised hyperosmolar saline from asymptomatic asthmatic patients unable to produce sputum spontaneously, Therefore we suggest that an induced sputum study via inhalation of hyperosmolar saline is useful to determine a patient`s status of airway inflammation.