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Platelet-activating factor-mediated NF-kappaB dependency of a late anaphylactic reaction.

Choi IW, Kim YS, Kim DK, Choi JH, Seo KH, Im SY, Kwon KS, Lee MS, Ha TY, Lee HK - J. Exp. Med. (2003)

Bottom Line: Using a murine model of penicillin V-induced systemic anaphylaxis, we show an autoregulatory cascade of biphasic anaphylactic reactions.The induction of NF-kappaB activity is accompanied by TNF-alpha production, which, in turn, promotes late phase PAF synthesis.This secondary wave of PAF production leads eventually to the late phase of anaphylactic reactions.

View Article: PubMed Central - PubMed

Affiliation: Department of Immunology, University National Medical School, Chonju, Chonbuk, 561-182, South Korea.

ABSTRACT
Anaphylaxis is a life-threatening systemic allergic reaction with the potential for a recurrent or biphasic pattern. Despite an incidence of biphasic reaction between 5 and 20%, the molecular mechanism for the reaction is unknown. Using a murine model of penicillin V-induced systemic anaphylaxis, we show an autoregulatory cascade of biphasic anaphylactic reactions. Induction of anaphylaxis caused a rapid increase in circulating platelet-activating factor (PAF) levels. In turn, the elevated PAF contributes to the early phase of anaphylaxis as well as the subsequent activation of the nuclear factor (NF)-kappaB, a crucial transcription factor regulating the expression of many proinflammatory cytokines and immunoregulatory molecules. The induction of NF-kappaB activity is accompanied by TNF-alpha production, which, in turn, promotes late phase PAF synthesis. This secondary wave of PAF production leads eventually to the late phase of anaphylactic reactions. Mast cells do not appear to be required for development of the late phase anaphylaxis. Together, this work reveals the first mechanistic basis for biphasic anaphylactic reactions and provides possible therapeutic strategies for human anaphylaxis.

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PAF-induced activation of NF-κB during anaphylaxis and its association with the development of the late phase of anaphylaxis. (a) NF-κB activation during anaphylaxis and its inhibition by the pretreatment with PAF antagonists and NF-κB inhibitors. After the challenge, lungs were removed at the indicated time points and the time course of NF-κB activation was measured by gel shift assay with nuclear extracts (n = 3–5 for each time point). For gel shift assay of CRE mobilization, lungs were removed 1 h after challenge. A representative of four independent experiments is shown. (b and c) Inhibition of the second phase of increase in plasma PAF (b) and hematocrit value (c) by NF-κB inhibitors. Blood was collected 7.5 h after the challenge. Results for all panels are expressed as the mean ± SEM of three to seven separate experiments (n = 4 for each time point). *, P < 0.01 versus control; Mann-Whitney U test.
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fig2: PAF-induced activation of NF-κB during anaphylaxis and its association with the development of the late phase of anaphylaxis. (a) NF-κB activation during anaphylaxis and its inhibition by the pretreatment with PAF antagonists and NF-κB inhibitors. After the challenge, lungs were removed at the indicated time points and the time course of NF-κB activation was measured by gel shift assay with nuclear extracts (n = 3–5 for each time point). For gel shift assay of CRE mobilization, lungs were removed 1 h after challenge. A representative of four independent experiments is shown. (b and c) Inhibition of the second phase of increase in plasma PAF (b) and hematocrit value (c) by NF-κB inhibitors. Blood was collected 7.5 h after the challenge. Results for all panels are expressed as the mean ± SEM of three to seven separate experiments (n = 4 for each time point). *, P < 0.01 versus control; Mann-Whitney U test.

Mentions: PAF is a potent inducer of NF-κB in vitro as well as in vivo (10–14). We measured NF-κB activity during anaphylaxis by a gel mobility shift assay. Induction of systemic anaphylaxis resulted in NF-κB activation in the lung (Fig. 2 a). NF-κB activity appeared within 30 min of the challenge. A similar pattern of NF-κB activation was also observed in the liver and spleen (unpublished data). Pretreatment of animals with PAF antagonists resulted in an almost complete inhibition of NF-κB activation (Fig. 2 a), confirming that PAF is responsible for the activation of NF-κB during anaphylaxis. To block NF-κB activation, we used the antioxidant, NAC and PDTC. NAC and PDTC also significantly inhibited NF-κB activation (Fig. 2 a). Complete blocking of NF-κB mobilization by adding the cold competitor, but not by adding of an irrelevant motif, CRE, indicated the specificity of NF-κB binding. In addition, NAC had no effect on CRE mobilization, further demonstrating the specificity of the inhibitors (Fig. 2 a). Next, we examined the possible association of NF-κB activity with the late anaphylactic reactions. Both NF-κB inhibitors significantly inhibited the second phase of increased plasma PAF levels (Fig. 2 b) and hematocrit (Fig. 2 c). However, the NF-κB inhibitors did not inhibit the first phase of increase in PAF release and hemoconcentration (unpublished data).


Platelet-activating factor-mediated NF-kappaB dependency of a late anaphylactic reaction.

Choi IW, Kim YS, Kim DK, Choi JH, Seo KH, Im SY, Kwon KS, Lee MS, Ha TY, Lee HK - J. Exp. Med. (2003)

PAF-induced activation of NF-κB during anaphylaxis and its association with the development of the late phase of anaphylaxis. (a) NF-κB activation during anaphylaxis and its inhibition by the pretreatment with PAF antagonists and NF-κB inhibitors. After the challenge, lungs were removed at the indicated time points and the time course of NF-κB activation was measured by gel shift assay with nuclear extracts (n = 3–5 for each time point). For gel shift assay of CRE mobilization, lungs were removed 1 h after challenge. A representative of four independent experiments is shown. (b and c) Inhibition of the second phase of increase in plasma PAF (b) and hematocrit value (c) by NF-κB inhibitors. Blood was collected 7.5 h after the challenge. Results for all panels are expressed as the mean ± SEM of three to seven separate experiments (n = 4 for each time point). *, P < 0.01 versus control; Mann-Whitney U test.
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Related In: Results  -  Collection

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getmorefigures.php?uid=PMC2196087&req=5

fig2: PAF-induced activation of NF-κB during anaphylaxis and its association with the development of the late phase of anaphylaxis. (a) NF-κB activation during anaphylaxis and its inhibition by the pretreatment with PAF antagonists and NF-κB inhibitors. After the challenge, lungs were removed at the indicated time points and the time course of NF-κB activation was measured by gel shift assay with nuclear extracts (n = 3–5 for each time point). For gel shift assay of CRE mobilization, lungs were removed 1 h after challenge. A representative of four independent experiments is shown. (b and c) Inhibition of the second phase of increase in plasma PAF (b) and hematocrit value (c) by NF-κB inhibitors. Blood was collected 7.5 h after the challenge. Results for all panels are expressed as the mean ± SEM of three to seven separate experiments (n = 4 for each time point). *, P < 0.01 versus control; Mann-Whitney U test.
Mentions: PAF is a potent inducer of NF-κB in vitro as well as in vivo (10–14). We measured NF-κB activity during anaphylaxis by a gel mobility shift assay. Induction of systemic anaphylaxis resulted in NF-κB activation in the lung (Fig. 2 a). NF-κB activity appeared within 30 min of the challenge. A similar pattern of NF-κB activation was also observed in the liver and spleen (unpublished data). Pretreatment of animals with PAF antagonists resulted in an almost complete inhibition of NF-κB activation (Fig. 2 a), confirming that PAF is responsible for the activation of NF-κB during anaphylaxis. To block NF-κB activation, we used the antioxidant, NAC and PDTC. NAC and PDTC also significantly inhibited NF-κB activation (Fig. 2 a). Complete blocking of NF-κB mobilization by adding the cold competitor, but not by adding of an irrelevant motif, CRE, indicated the specificity of NF-κB binding. In addition, NAC had no effect on CRE mobilization, further demonstrating the specificity of the inhibitors (Fig. 2 a). Next, we examined the possible association of NF-κB activity with the late anaphylactic reactions. Both NF-κB inhibitors significantly inhibited the second phase of increased plasma PAF levels (Fig. 2 b) and hematocrit (Fig. 2 c). However, the NF-κB inhibitors did not inhibit the first phase of increase in PAF release and hemoconcentration (unpublished data).

Bottom Line: Using a murine model of penicillin V-induced systemic anaphylaxis, we show an autoregulatory cascade of biphasic anaphylactic reactions.The induction of NF-kappaB activity is accompanied by TNF-alpha production, which, in turn, promotes late phase PAF synthesis.This secondary wave of PAF production leads eventually to the late phase of anaphylactic reactions.

View Article: PubMed Central - PubMed

Affiliation: Department of Immunology, University National Medical School, Chonju, Chonbuk, 561-182, South Korea.

ABSTRACT
Anaphylaxis is a life-threatening systemic allergic reaction with the potential for a recurrent or biphasic pattern. Despite an incidence of biphasic reaction between 5 and 20%, the molecular mechanism for the reaction is unknown. Using a murine model of penicillin V-induced systemic anaphylaxis, we show an autoregulatory cascade of biphasic anaphylactic reactions. Induction of anaphylaxis caused a rapid increase in circulating platelet-activating factor (PAF) levels. In turn, the elevated PAF contributes to the early phase of anaphylaxis as well as the subsequent activation of the nuclear factor (NF)-kappaB, a crucial transcription factor regulating the expression of many proinflammatory cytokines and immunoregulatory molecules. The induction of NF-kappaB activity is accompanied by TNF-alpha production, which, in turn, promotes late phase PAF synthesis. This secondary wave of PAF production leads eventually to the late phase of anaphylactic reactions. Mast cells do not appear to be required for development of the late phase anaphylaxis. Together, this work reveals the first mechanistic basis for biphasic anaphylactic reactions and provides possible therapeutic strategies for human anaphylaxis.

Show MeSH
Related in: MedlinePlus