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IgE enhances mouse mast cell Fc(epsilon)RI expression in vitro and in vivo: evidence for a novel amplification mechanism in IgE-dependent reactions.

Yamaguchi M, Lantz CS, Oettgen HC, Katona IM, Fleming T, Miyajima I, Kinet JP, Galli SJ - J. Exp. Med. (1997)

Bottom Line: This IgE- and antigen-specific mast cell activation and mediator production is thought to be critical to the pathogenesis of allergic disorders, such as anaphylaxis and asthma, and also contributes to host defense against parasites.Moreover, baseline levels of Fc(epsilon)RI expression on peritoneal mast cells from genetically IgE-deficient (IgE -/-) mice are dramatically reduced (by approximately 83%) compared with those on cells from the corresponding normal mice.In turn, IgE-dependent upregulation of Fc(epsilon)RI expression significantly enhances the ability of mouse mast cells to release serotonin, interleukin-6 (IL-6), and IL-4 in response to challenge with IgE and specific antigen.

View Article: PubMed Central - PubMed

Affiliation: Department of Pathology, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, Massachusetts 02215, USA.

ABSTRACT
The binding of immunoglobulin E (IgE) to high affinity IgE receptors (Fc(epsilon)RI) expressed on the surface of mast cells primes these cells to secrete, upon subsequent exposure to specific antigen, a panel of proinflammatory mediators, which includes cytokines that can also have immunoregulatory activities. This IgE- and antigen-specific mast cell activation and mediator production is thought to be critical to the pathogenesis of allergic disorders, such as anaphylaxis and asthma, and also contributes to host defense against parasites. We now report that exposure to IgE results in a striking (up to 32-fold) upregulation of surface expression of Fc(epsilon)RI on mouse mast cells in vitro or in vivo. Moreover, baseline levels of Fc(epsilon)RI expression on peritoneal mast cells from genetically IgE-deficient (IgE -/-) mice are dramatically reduced (by approximately 83%) compared with those on cells from the corresponding normal mice. In vitro studies indicate that the IgE-dependent upregulation of mouse mast cell Fc(epsilon)RI expression has two components: an early cycloheximide-insensitive phase, followed by a later and more sustained component that is highly sensitive to inhibition by cycloheximide. In turn, IgE-dependent upregulation of Fc(epsilon)RI expression significantly enhances the ability of mouse mast cells to release serotonin, interleukin-6 (IL-6), and IL-4 in response to challenge with IgE and specific antigen. The demonstration that IgE-dependent enhancement of mast cell Fc(epsilon)RI expression permits mast cells to respond to antigen challenge with increased production of proinflammatory and immunoregulatory mediators provides new insights into both the pathogenesis of allergic diseases and the regulation of protective host responses to parasites.

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Effects of various mouse IgE or IgG2a mAb preparations on  surface expression of (A–C) FcεRI or (D) FcγRII/III in BMCMCs.  BALB/c BMCMCs were cultured with or without various concentrations of mouse IgE or IgG2a mAb, either as diluted ascites preparations  (Ascites IgE or IgG2a) or as affinity-purified mAb preparations (Purified  IgE or IgG2a), for 4 d. Negative control in (A–C), cells cultured for 4 d  without IgE or IgG2a and then incubated with FITC–anti-IgE without  prior sensitization with IgE. (A) Incubation with either purified or ascites  IgE mAb (at 5.0 μg IgE/ml) resulted in an equivalent increase in the  FcεRI expression of the cells, whereas cells incubated with either purified  IgG2a (at 5.0 μg/ml) or no antibody (none) exhibited similar low levels  of staining. (B and C) Incubation with high concentrations of purified (B)  or ascites (C) IgG2a resulted in little or no increase in BMCMC FcεRI  expression, in comparison with positive control BMCMCs that had been  incubated with IgE at 5.0 μg/ml. (D) Incubation for 4 d with IgE or  IgG2a had little or no effect on the expression of FcγRII/III by BMCMCs.  Negative control in (D), cells cultured for 4 d without IgE or IgG2a and  then incubated with a rat IgG2b mAb of irrelevant specificity, instead of  the rat 2.4G2 anti–mouse FcγRII/III mAb, before staining with the PE– anti-rat IgG antibody. The same results were obtained with ascites IgE  (shown) or purified IgE (not shown).
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Figure 3: Effects of various mouse IgE or IgG2a mAb preparations on surface expression of (A–C) FcεRI or (D) FcγRII/III in BMCMCs. BALB/c BMCMCs were cultured with or without various concentrations of mouse IgE or IgG2a mAb, either as diluted ascites preparations (Ascites IgE or IgG2a) or as affinity-purified mAb preparations (Purified IgE or IgG2a), for 4 d. Negative control in (A–C), cells cultured for 4 d without IgE or IgG2a and then incubated with FITC–anti-IgE without prior sensitization with IgE. (A) Incubation with either purified or ascites IgE mAb (at 5.0 μg IgE/ml) resulted in an equivalent increase in the FcεRI expression of the cells, whereas cells incubated with either purified IgG2a (at 5.0 μg/ml) or no antibody (none) exhibited similar low levels of staining. (B and C) Incubation with high concentrations of purified (B) or ascites (C) IgG2a resulted in little or no increase in BMCMC FcεRI expression, in comparison with positive control BMCMCs that had been incubated with IgE at 5.0 μg/ml. (D) Incubation for 4 d with IgE or IgG2a had little or no effect on the expression of FcγRII/III by BMCMCs. Negative control in (D), cells cultured for 4 d without IgE or IgG2a and then incubated with a rat IgG2b mAb of irrelevant specificity, instead of the rat 2.4G2 anti–mouse FcγRII/III mAb, before staining with the PE– anti-rat IgG antibody. The same results were obtained with ascites IgE (shown) or purified IgE (not shown).

Mentions: The mast cells that were incubated with the highest concentration of ascites IgE that was used routinely in our experiments (i.e., 5 μg IgE/ml) were exposed to an ∼100-fold dilution of the stock preparation of ascites. However, this ascites-derived IgE preparation also significantly enhanced mast cell FcεRI expression even when tested at dilutions of 10,000- to 100,000-fold (to yield IgE concentrations of 0.05 or 0.005 μg/ml, respectively, e.g., see Fig. 1 C). Nevertheless, to rule out the possibility that some constituent of the ascites preparation other than IgE might have significantly influenced our results, we incubated aliquots of the same population of BALB/c BMCMCs for 4 d with either ascites or affinity-purified IgE at 5 μg IgE/ml. We found that either preparation of IgE markedly increased the FcεRI expression of the cells, and to essentially equivalent levels (Fig. 3 A). Similar results were obtained in two additional experiments. By contrast, incubation of such BMCMCs for 4 d with a mouse IgG2a mAb at 5 μg/ml had no detectable effect on the cells' surface expression of FcεRI (Fig. 3 A). A separate experiment gave the same result.


IgE enhances mouse mast cell Fc(epsilon)RI expression in vitro and in vivo: evidence for a novel amplification mechanism in IgE-dependent reactions.

Yamaguchi M, Lantz CS, Oettgen HC, Katona IM, Fleming T, Miyajima I, Kinet JP, Galli SJ - J. Exp. Med. (1997)

Effects of various mouse IgE or IgG2a mAb preparations on  surface expression of (A–C) FcεRI or (D) FcγRII/III in BMCMCs.  BALB/c BMCMCs were cultured with or without various concentrations of mouse IgE or IgG2a mAb, either as diluted ascites preparations  (Ascites IgE or IgG2a) or as affinity-purified mAb preparations (Purified  IgE or IgG2a), for 4 d. Negative control in (A–C), cells cultured for 4 d  without IgE or IgG2a and then incubated with FITC–anti-IgE without  prior sensitization with IgE. (A) Incubation with either purified or ascites  IgE mAb (at 5.0 μg IgE/ml) resulted in an equivalent increase in the  FcεRI expression of the cells, whereas cells incubated with either purified  IgG2a (at 5.0 μg/ml) or no antibody (none) exhibited similar low levels  of staining. (B and C) Incubation with high concentrations of purified (B)  or ascites (C) IgG2a resulted in little or no increase in BMCMC FcεRI  expression, in comparison with positive control BMCMCs that had been  incubated with IgE at 5.0 μg/ml. (D) Incubation for 4 d with IgE or  IgG2a had little or no effect on the expression of FcγRII/III by BMCMCs.  Negative control in (D), cells cultured for 4 d without IgE or IgG2a and  then incubated with a rat IgG2b mAb of irrelevant specificity, instead of  the rat 2.4G2 anti–mouse FcγRII/III mAb, before staining with the PE– anti-rat IgG antibody. The same results were obtained with ascites IgE  (shown) or purified IgE (not shown).
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Figure 3: Effects of various mouse IgE or IgG2a mAb preparations on surface expression of (A–C) FcεRI or (D) FcγRII/III in BMCMCs. BALB/c BMCMCs were cultured with or without various concentrations of mouse IgE or IgG2a mAb, either as diluted ascites preparations (Ascites IgE or IgG2a) or as affinity-purified mAb preparations (Purified IgE or IgG2a), for 4 d. Negative control in (A–C), cells cultured for 4 d without IgE or IgG2a and then incubated with FITC–anti-IgE without prior sensitization with IgE. (A) Incubation with either purified or ascites IgE mAb (at 5.0 μg IgE/ml) resulted in an equivalent increase in the FcεRI expression of the cells, whereas cells incubated with either purified IgG2a (at 5.0 μg/ml) or no antibody (none) exhibited similar low levels of staining. (B and C) Incubation with high concentrations of purified (B) or ascites (C) IgG2a resulted in little or no increase in BMCMC FcεRI expression, in comparison with positive control BMCMCs that had been incubated with IgE at 5.0 μg/ml. (D) Incubation for 4 d with IgE or IgG2a had little or no effect on the expression of FcγRII/III by BMCMCs. Negative control in (D), cells cultured for 4 d without IgE or IgG2a and then incubated with a rat IgG2b mAb of irrelevant specificity, instead of the rat 2.4G2 anti–mouse FcγRII/III mAb, before staining with the PE– anti-rat IgG antibody. The same results were obtained with ascites IgE (shown) or purified IgE (not shown).
Mentions: The mast cells that were incubated with the highest concentration of ascites IgE that was used routinely in our experiments (i.e., 5 μg IgE/ml) were exposed to an ∼100-fold dilution of the stock preparation of ascites. However, this ascites-derived IgE preparation also significantly enhanced mast cell FcεRI expression even when tested at dilutions of 10,000- to 100,000-fold (to yield IgE concentrations of 0.05 or 0.005 μg/ml, respectively, e.g., see Fig. 1 C). Nevertheless, to rule out the possibility that some constituent of the ascites preparation other than IgE might have significantly influenced our results, we incubated aliquots of the same population of BALB/c BMCMCs for 4 d with either ascites or affinity-purified IgE at 5 μg IgE/ml. We found that either preparation of IgE markedly increased the FcεRI expression of the cells, and to essentially equivalent levels (Fig. 3 A). Similar results were obtained in two additional experiments. By contrast, incubation of such BMCMCs for 4 d with a mouse IgG2a mAb at 5 μg/ml had no detectable effect on the cells' surface expression of FcεRI (Fig. 3 A). A separate experiment gave the same result.

Bottom Line: This IgE- and antigen-specific mast cell activation and mediator production is thought to be critical to the pathogenesis of allergic disorders, such as anaphylaxis and asthma, and also contributes to host defense against parasites.Moreover, baseline levels of Fc(epsilon)RI expression on peritoneal mast cells from genetically IgE-deficient (IgE -/-) mice are dramatically reduced (by approximately 83%) compared with those on cells from the corresponding normal mice.In turn, IgE-dependent upregulation of Fc(epsilon)RI expression significantly enhances the ability of mouse mast cells to release serotonin, interleukin-6 (IL-6), and IL-4 in response to challenge with IgE and specific antigen.

View Article: PubMed Central - PubMed

Affiliation: Department of Pathology, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, Massachusetts 02215, USA.

ABSTRACT
The binding of immunoglobulin E (IgE) to high affinity IgE receptors (Fc(epsilon)RI) expressed on the surface of mast cells primes these cells to secrete, upon subsequent exposure to specific antigen, a panel of proinflammatory mediators, which includes cytokines that can also have immunoregulatory activities. This IgE- and antigen-specific mast cell activation and mediator production is thought to be critical to the pathogenesis of allergic disorders, such as anaphylaxis and asthma, and also contributes to host defense against parasites. We now report that exposure to IgE results in a striking (up to 32-fold) upregulation of surface expression of Fc(epsilon)RI on mouse mast cells in vitro or in vivo. Moreover, baseline levels of Fc(epsilon)RI expression on peritoneal mast cells from genetically IgE-deficient (IgE -/-) mice are dramatically reduced (by approximately 83%) compared with those on cells from the corresponding normal mice. In vitro studies indicate that the IgE-dependent upregulation of mouse mast cell Fc(epsilon)RI expression has two components: an early cycloheximide-insensitive phase, followed by a later and more sustained component that is highly sensitive to inhibition by cycloheximide. In turn, IgE-dependent upregulation of Fc(epsilon)RI expression significantly enhances the ability of mouse mast cells to release serotonin, interleukin-6 (IL-6), and IL-4 in response to challenge with IgE and specific antigen. The demonstration that IgE-dependent enhancement of mast cell Fc(epsilon)RI expression permits mast cells to respond to antigen challenge with increased production of proinflammatory and immunoregulatory mediators provides new insights into both the pathogenesis of allergic diseases and the regulation of protective host responses to parasites.

Show MeSH
Related in: MedlinePlus