Anaphylactic Mice Research Articles

Antigen-specific secretory IgA antibodies in the gut are decreased in a mouse model of food allergy

Background A large body of evidence implicates IgA antibodies in the immune response to pathogens present in the gut. Whether IgA antibodies play a similar role in food allergy remains to be determined. Objective We sought to characterize β-lactoglobulin (BLG)–specific serum and secretory IgA antibody production in the gut and to define the role of antigen-induced cytokines in IgA production in a murine model of food allergy. Methods BLG-specific IgA antibodies were measured in the sera and feces of mice anaphylactic or tolerant to BLG. The number of antibody-secreting cells in the spleen and Peyer's patches was determined by means of ELISPOT. Mesenteric lymph node cells and Peyer's patch T cells were transferred to naive mice, and antibody production in the sera and feces in recipient mice, as well as antibody-secreting cell numbers, were measured. Results Serum IgA antibody titers were strongly increased in anaphylactic mice. In contrast, BLG-specific IgA antibody titers were increased in feces but not in sera from tolerant mice. These results were correlated with an increased number of BLG-specific IgA-secreting cells in Peyer's patches from tolerant mice. The adoptive transfer of Peyer's patch CD3 + cells from tolerant mice induced an increased number of IgA-secreting cells preferentially in the Peyer's patches of naive recipient mice. Furthermore, an increase of BLG-induced IL-10 and TGF-β levels was found at IgA production sites. Conclusions These results suggest a role for secretory IgA in tolerance mechanisms to foods. Peyer's patch CD3 + cells are primarily involved by favoring IgA production through the release of IL-10 and TGF-β.

Lymphocytes in Peyer patches regulate clinical tolerance in a murine model of food allergy

Background Food allergy can lead to severe, potentially life-threatening anaphylactic reactions. To generate efficient strategies aimed at an active cure, a better understanding of the pathogenic mechanisms is strongly needed. Objective To investigate T-cell–related mechanisms of food allergy and tolerance to β-lactoglobulin (BLG) in gut-associated lymphoid structures. Methods β-Lactoglobulin–specific IgG1, IgG2a, and IgE in serum from mice anaphylactic to BLG were analyzed by ELISA and compared with those obtained in mice actively tolerized to BLG. The number of Ab-secreting cells in the spleen and in Peyer patches was determined by ELISPOT. The numbers of cytokine-producing cells after antigen-specific activation were measured by the same method. Furthermore, mesenteric lymph node cells and Peyer patches cells were transferred to naive mice, and Ab production as well as Ab-secreting cells were measured. Results Serum IgG1 and IgE Ab titers as well as IL-4–producing cell numbers were strongly increased in anaphylactic mice. IL-10 was found in Peyer patch cells from tolerant mice after BLG activation but not in anaphylactic mice. Peyer patch cells, in contrast to mesenteric lymph node cells, proliferated weakly in anaphylactic mice after antigen activation, and activation of Peyer patches was partially inhibited by tolerization. Conclusions Our data suggest a specific role for lymphocytes in Peyer patches in tolerance to BLG. Low IL-10 production in Peyer patches may favor symptoms of food allergy.

Lymphocytes in Peyer's patches regulate clinical tolerance in a murine model of food allergy

Rationale Food allergy can elicit severe, potentially life-threatening anaphylactic reactions. In order to generate efficient strategies for an active cure of the disease, a better understanding of the pathogenic mechanisms of the disease is strongly needed. We investigated mechanisms of food allergy and tolerance to β-lactoglobulin (BLG) in gut-associated lymphoid structures. Methods β-lactoglobulin-specific IgG1, IgG2a, and IgE in serum from mice anaphylactic to BLG were analyzed by ELISA, and compared to those obtained in mice actively tolerized to BLG. The number of antibody secreting cells in the spleen and in Peyer's patches was determined by ELISPOT. Cell cytokine production after antigen-specific activation was measured by the same method. Further, mesenteric lymph node cells and Peyer's patch cells were transferred to naive mice and antibody production as well as antibody producing cell numbers were measured. Results We found that food-induced anaphylaxis or tolerance to BLG correlated with a specific antibody and cytokine pattern. IgG1 and IgE antibody titers, as well as IL-4 producing cell numbers were strongly increased in anaphylactic mice. IL-10 was found specifically in Peyer's patches cells from tolerant mice. Peyer's patch cells did weakly proliferate in anaphylactic mice after antigen activation, and activation was partially inhibited by tolerization. Furthermore, no Ab production was seen after adoptive transfer of Peyer's patches cells in naïve mice. Conclusions Our data show a specific role for lymphocytes in Peyer's patches for modulation of tolerance to BLG. A low IL-10 production in Peyer's patches might favor symptoms of food allergy.

Oral carrageenan induces antigen-dependent oral tolerance: prevention of anaphylaxis and induction of lymphocyte anergy in a murine model of food allergy.

Immunosuppressive effects of carrageenan, a high-molecular-weight polysaccharide, on antibody and T cell responses have been previously demonstrated. However, its effect on anaphylaxis is unknown. Our objectives were to test carrageenan-mediated oral tolerance induction in young mice subsequently sensitized to a common cow's milk antigen. C3H/HeJ mice were fed or not lambda-carrageenan (0.5 g/L) and/or 0.01 mg/mL beta-lactoglobulin (BLG) for 5 d before oral sensitization with BLG and cholera toxin. Subsequently, the mice were challenged with BLG and symptom scores of anaphylaxis were recorded. Mesenteric lymph node cells, spleen cells, Peyer's patches cells, intraepithelial lymphocytes, and lamina propria lymphocytes were isolated and stimulated in vitro with BLG, IL-2, or left unstimulated. BLG-specific IgG, IgG(1), and IgG(2a) antibodies were measured. Pretreatment with carrageenan and BLG, but not pretreatment with either carrageenan or BLG alone or omission of pretreatment, diminished significantly the number of anaphylactic mice after BLG challenge (6.3 % versus 53 % in mice without pretreatment, p = 0.006). Mesenteric lymph nodes and spleen cells from pretreated mice proliferated less in presence of BLG or IL-2 than cells from sensitized control mice. Antigen-specific antibody production and passive cutaneous anaphylaxis was not suppressed by carrageenan and BLG pretreatment. In conclusion, carrageenan administered to young mice in conjunction with low doses of allergen before sensitization efficiently prevents anaphylaxis.

Chronic oral antigen exposure induces lymphocyte migration in anaphylactic mouse intestine.

Persistent diarrhea, vomiting, and dehydration are symptoms often seen in patients suffering from food allergy after chronic antigen exposure; however, the precise mechanisms involved have not been well defined. In an effort to clarify the mechanisms of the chronic intestinal changes attributable to genuine IgE-mediated anaphylactic reactions induced by orally administered antigen, a mouse model was established by s.c. implantation of a murine hybridoma capable of producing monoclonal anti-trinitrophenyl IgE antibody, and the morphologic and immunologic changes occurring in the intestine upon chronic antigen exposure were investigated. In the early stage after ingestion of the antigen, diarrhea and noticeable infiltration of mast cells as well as eosinophils into the lamina propria were observed. A substantial increase in serum histamine levels as well as an increase in leukotriene C4 synthesis in the jejunal mucosa were observed 1 h after antigen challenge. Also, the synthesis of leukotriene B4 was significantly elevated for up to 9 h after antigen challenge. The expression of both intercellular adhesion molecule-1 (ICAM-1) on mucosal vascular endothelial cells and IAd on epithelial cells was markedly enhanced, and noticeable infiltration of eosinophils and lymphocytes was also confirmed in the mouse model after chronic antigen exposure. These findings suggest that oral antigen exposure induces anaphylactic reactions in the intestine mediated by mast cells and eosinophils in response to the IgE-antigen complex in the early phase, and also induces lymphocyte migration after chronic antigen exposure.

Involvement of leukotrienes in allergic imflammation in mice

The involvement of leukotrienes in the anaphylactic paw edema was investigated in sensitized boosted or unboosted mice. No difference was noted in the intensity of the antigen-induced paw edema between boosted and unboosted animals. Since the non-steroidal anti-inflammatory agents, indomethacin and aspirin, were inactive, cyclooxygenase products are not involved in the anaphylactic reaction in boosted or unboosted mice. In contrast, the mixed lipoxygenase/cyclooxygenase inhibitor, BW 755C (3-amino-1- m-(trifluoroethylphenyl-2-pyrazoline)4, and the LTD 4, (leukotriene D 4) receptor antagonist, LY 171883 (1-(2-hydroxy-3-propyl-4-(4-(1 H-tetrazol-5-yl)butoxy)phenyl)ethanone, reduced the edema in boosted but not unboosted mice, suggesting the involvement of lipoxygenase metabolites in the allergic edema in boosted mice. Dexamethasone was only effective in inhibiting allergic edema in boosted mice when administered 12 h before provacation, but failed to reduce the edema in unboosted mice. Our results suggest that the booster injection during immunization shifts the anaphylactic mouse paw edema from a leukotriene-independent to a leukotriene-dependent reaction.

Differential inhibition by the PAF receptor antagonist, WEB 2170, of allergic inflammation in single sensitized and boosted mice

Interference of the PAF antagonist, WEB 2170, with the paw edema induced by antigen in boosted or unboosted sensitized mice was investigated. Edema was triggered by the intraplantar injection of ovalbumin to animals activel sentized 21 days before and that received (boosted), or did not receive (unboosted), a second immunization after 14 days. There was no difference in the intensity of the response to antigen or to PAF (platelet-activating factor) in boosted or in unboosted animals. Intraperitoneal treatment with WEB 2170 1 h before challenge reduced dose dependently the edema in boosted mice but did not modify the reaction in unboosted mice. It is noteworthy that WEB 2170 was more effective against PAF-induced paw edema in unboosted than in boosted mice, the maximum inhibition of 84% being reached at 16 mg/kg. In addition, topical and selective desensitization to PAF inhibited the edema caused by antigen only in boosted animals. Our findings indicate that the booster injection during the immunization process shifts the anaphylactic mouse paw edema from a PAF-independent to a PAF-dependent reaction.

Effect of PAF-acether antagonists on active anaphylactic mouse paw edema.

A new model of active anaphylactic reaction in mice was developed. The edematogenic reaction appeared 5 min after the intraplantar injection of ovalbumin, peaked at 30 min after the antigenic challenge, and decreased thereafter. Using the non-steroidal, anti-inflammatory agents indomethacin and aspirin, we found that cyclooxygenase products do not participate in the reaction. In contrast, vasoactive amines appear to be involved, because meclizine and methysergide reduced the edema. Dexamethasone, BW755C, LY 171883 and WEB 2170 effectively interfered with the edematogenic reaction, which suggests that lipid mediators such as leukotrienes and PAF play a role in the active anaphylactic response.

Participation of PAF-acether in the anaphylactic mice paw edema

Participation of PAF-acether in the anaphylactic mice paw edema

Inhibition of adjuvant arthritis in the rat and pinnal inflammation in the mouse by an extract of Hymenocardia acida

AbstractHymenocardia acida TUL, a shrub belonging to the family Euphorbiaceae, has been investigated for anti‐inflammatory activity in the rat and mouse. Various parts of the plant are claimed by practitioners of herbal medicine in some West African countries to be effective remedies for inflammation of tissues. Two experimental models of inflammation were used in the study. In rat adjuvant arthritis, the orally administered aqueous extract of the stem bark of H. acida (10–20 mg/kg) inhibited both the acute and chronic phases of the reaction in a dose‐related manner, producing inhibition of the magnitude of 37.4–70.2%. Similarly, in the anaphylactic mouse pinnal inflammation model, the orally administered extract (10–40 mg/kg) inhibited the reaction to a magnitude of 6.5–68.2%. In both models, indomethacin, a cyclo‐oxygenase inhibitor, also exhibited inhibitory effects and in the mouse pinnal model the glucocortico‐steroid, hydrocortisone, also produced inhibition. The extract of H. acida used in this study was coloured brown and, on that basis, could contain plant phenolics. H. acida may belong to a class of plant drugs which produce inhibition of phospholipid–arachidonic acid metabolism due to their phenolic constituents.

Sensitization of mice with human IgA.

IT is well known that an increased vascular permeability produced by various agents can be visualized by the leakage of intravenously administered dye through the affected vessels. The vascularity and high histamine and serotonin content of mouse ears1 suggested that these organs might be useful in the visualization of in vivo antigen–antibody reactions. While investigating the ability of intravenously administered pollen extracts to induce blueing of the ears of mice2, Kind et al. also found that mice sensitized with bovine serum albumin (BSA) developed blueing of the ears when later challenged intravenously with BSA and Evans blue dye. When blueing of the ears was produced in normal mice by the intravenous injection of BSA, rabbit anti-BSA and dye, no latent period was found to be necessary for the ‘fixation’ of antigen or antibody3. Indeed, in mice, maximal incidence of anaphylaxis with rabbit antibody can be obtained by injecting antibody and antigen intravenously in rapid succession4. The apparent absence of a requirement for tissue fixation in mice suggested that blueing of the ears in anaphylactic mice might be useful for detecting such proteins as normal human IgA or myeloma IgA, which will not sensitize guinea-pig skin for reverse passive cutaneous anaphylaxis probably because of the lack of fixation sites on such molecules5.

Quantification of anaphylaxis in mice.

SummaryResults indicate that hematocrit rise in anaphylactic mice is a sigmoidal function of the log dose bovine albumin in the challenge antigen preparation. Over a given range, the relationship tends to be linear. Indications are that hematocrit change is a continuous function, and not a ratio of “all or none” responses. This method is recommended for drawing quantitative comparisons in studies of mouse anaphylaxis.

Hematocrit change as indication of anaphylactic shock in the mouse.

SummaryAn increase in hematocrit regularly accompanies anaphylaxis in mice. The incidence of hematocrit increase is higher than the incidence of death in groups of anaphylactic mice. It is suggested that hematocrit change is a useful index of anaphylaxis in mice.