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Therapeutic Effect of Flt3-Ligand in Cockroach Antigen Induced Allergic Airway Inflammation and Airway Hyper-Responsiveness
S150 Abstracts
Therapeutic Effect of Flt3-Ligand in Cockroach Antigen Induced Allergic Airway Inflammation and Airway HyperResponsiveness J. H. Edwan1, D. K. Agrawal1,2; 1Biomedical Sciences Department, Creighton University School of Medicine, Omaha, NE, 2Medical Microbiology and Immunology Department, Creighton University School of Medicine, Omaha, NE. RATIONALE: Asthmatic patients are hypersensitive to many allergens and develop asthma symptoms upon exposure to these allergens. Cockroach is one of the most common allergens involved in increased incidence of asthma especially in inner-city areas. In the present study, we investigated the effect of Flt3-L in a murine model of asthma induced by cockroach antigen. METHODS: Balb/c mice were sensitized and challenged with cockroach antigen (10g) and airway hyper-responsiveness (AHR) to methacholine was established. These mice were then administered intraperitoneally with Flt3-L (3g) daily for ten days. Following this response to Flt3-L therapy was assessed by measuring AHR to methacholine. Serum was collected, cytokines and immunoglobulins were measured, cytospin slides were prepared from bronchoalveolar lavage fluid (BALF) to count total and differential cells. RESULTS: Flt3-L treatment completely reversed established AHR to methacholine (p<0.01). Flt3-L significantly decreased both BALF IL-5 levels and eosinophilia (p<0.05). There was no significant effect of Flt3-L on total and antigen-specific serum IgE, IgG2a and IgG1. CONCLUSIONS: Flt3-L treatment reverses established AHR to methacholine in cockroach induced asthma model. We have previously reported the therapeutic effect of Flt3-L in ovalbumin induced asthma model. These data suggest that Flt3-L could be a novel approach in the treatment of asthma induced by different antigens. Funding: NIH RO1-HL070885
583
SUNDAY
Persistent Aeroallergen Sensitization at Ages One and Two in the Cincinnati Childhood Allergy and Air Pollution Study P. H. Ryan1, G. K. LeMasters1, J. E. Lockey1, G. K. Hershey2, M. Villareal1, D. I. Bernstein1; 1University of Cincinnati, Cincinnati, OH, 2Cincinnati Children’s Hospital Medical Center, Cincinnati, OH. RATIONALE: Few studies have evaluated the annual reproducibility of skin prick testing in infants and young children. METHODS: Children (n = 601) born to at least 1 atopic parent were skin prick tested (SPT) at ages 1 and 2 with the following categories of allergens: 1) pollen (fescue, timothy, white oak, maple, American elm, red cedar, or short ragweed), 2) mold (Alternaria, Aspergillus fumigatus, Penicillium mix, or Cladosporium), 3) dust mite or German cockroach, and 4) epidermals (cat or dog). RESULTS: The prevalence of children sensitized to aeroallergens increased from age 1 (18%) to 2 (38%). Although 66% of those SPT+ at age 1 remained positive to an aeroallergen at age 2, the rate of persistent sensitization to pollen, mold, dust, and epidermals was 53%, 29%, 24%, and 32%, respectively. A positive SPT to pollen or epidermal antigens was significantly associated with persistent sensitization at age 2 to the same category of allergen (p<0.05). Sensitization to pollen at age 1 was significantly associated with mold sensitization at age 2 (p<0.05). Sensitivity to mold or dust allergens was not associated with the same allergen category at age 2 (p>0.05). CONCLUSIONS: Sensitization at age 1 to pollen and animals is associated with persistent sensitization at age 2, but sensitization at age 1 to other allergen groups was not reproducible at age 2. The developing immune system could influence patterns of early aeroallergen sensitization in the first years of life. This ongoing study will determine the predictive value of skin testing in identifying infants at risk for allergic diseases. Funding: National Institute of Environmental Health Sciences
584
J ALLERGY CLIN IMMUNOL FEBRUARY 2006
IL-13 Receptor Alpha 2 Lung-transgenic Mice Displayed Reduced Airway Hyperresponsiveness and Inflammation in a House Dust Mite Challenged Model W. Chen, C. M. Cunningham, M. O. Daines, M. R. Warrier, A. M. Gibson, G. K. Khurana Hershey; Cincinnati Children’s Hospital Medical Center, Cincinnati, OH. RATIONALE: IL-13 receptor alpha 2 (IL-13R2) has high affinity to IL-13 but its expression is insufficient to render cells responsive to IL-13, suggesting that IL-13R2 acts as a decoy receptor. IL-13R2-deficient mice displayed enhanced IL-13 effects. We examined the effect of overexpresson of IL-13R2 in mouse lung on the allergen-induced airway hyperresponsiveness and inflammation. METHODS: The pBluescript II KS+/rCC10/mIL-13R2/hGH transgenic construct was generated from murine IL-13R2 cDNA and human growth hormone (hGH) intronic and polyadenylation sequences using the rat Clara cell 10-kDa (rCC10) promoter for lung-specific expression. The generated IL-13R2 transgenic mice were genotyped by Southern blot analysis and PCR. The expression of IL-13R2 was determined by Northern blot analysis and RT-PCR. The transgenic and nontransgenic mice were sensitized and challenged with house dust mite. The airway hyperresponsiveness was measured by whole body barometric plethysmography. The airway inflammation was determined by analysis of bronchoalveolar lavage samples and lung histology. RESULTS: The lungs of IL-13R2 transgenic mice were grossly normal without any histological changes. The overexpression of IL-13R2 transgene is lung-specific since the transgene mRNA was not detected from other tissues. The lung IL-13R2 expression in transgenic mice was 700fold higher than that in nontransgenic mice as quantified by real-time PCR. The transgenic mice challenged with house dust mite had reduced airway hyperresonsiveness in response to methacholine and reduced number of total cells and eosinophils in bronchoalveolar lavage samples comparing to the nontransgenic mice. CONCLUSIONS: IL-13R2 inhibits the airway hyperresponsiveness and inflammation in allergen-challenged mice when it is overexpressed in lung. Funding: NIH
585
The Antioxidants, Glutathione-S-Transferase-Omega1-1 (GST1-1) and Glutathione Peroxidase2 (GPX2), Are Increased in Allergic Airway Inflammation D. Quarcoo, A. M. Dittrich, M. Krokowski, A. Awagjan, B. Ahrens, E. H. Hamelmann; Pediatric Pneumology and Immunology, Charité University Medicine, Berlin, GERMANY. RATIONALE: Allergen-induced bronchial asthma is a chronic airway disease that involves the interplay of various genes with environmental factors triggering a multitude of inflammatory pathways. We attempted to delineate novel molecules that are yet not recognized as mediators and who operate independently of atopic susceptibility as common mediators of allergic pulmonary inflammation. METHODS: In a mouse model of allergen-induced sensitization and airway inflammation, RNA expression in whole lung tissues was compared between a high-IgE responder mouse strain (BALB/c) and mice with lower allergic susceptibility (C57/Bl6) by using microarray based RNA expression analysis. Results were confirmed by using western blot analysis of protein expression in murine lung tissues. Additionally, the location of target proteins was determined by immune histochemistry of murine and human airways. Finally, the functional relevance of the targets was assessed by using genetically deficient knock-out mice. RESULTS: The expression of two antioxidant enzymes involved in the glutathione pathway, GPX2 and GST1-1, was increased in both strains after induction of airway inflammation on the RNA level. Using western blot analysis a significant increase in protein expression was also found. GPX2 and GST1-1 were both located in the airway epithelium of murine and human lung tissues. Allergen sensitization and airway challenges of GPX2 knock-out mice resulted in hightened inflammatory airway responses, suggesting a protective role for this molecule.
586
Therapeutic Effect of Flt3-Ligand in Cockroach Antigen Induced Allergic Airway Inflammation and Airway HyperResponsiveness J. H. Edwan1, D. K. Agrawal1,2; 1Biomedical Sciences Department, Creighton University School of Medicine, Omaha, NE, 2Medical Microbiology and Immunology Department, Creighton University School of Medicine, Omaha, NE. RATIONALE: Asthmatic patients are hypersensitive to many allergens and develop asthma symptoms upon exposure to these allergens. Cockroach is one of the most common allergens involved in increased incidence of asthma especially in inner-city areas. In the present study, we investigated the effect of Flt3-L in a murine model of asthma induced by cockroach antigen. METHODS: Balb/c mice were sensitized and challenged with cockroach antigen (10g) and airway hyper-responsiveness (AHR) to methacholine was established. These mice were then administered intraperitoneally with Flt3-L (3g) daily for ten days. Following this response to Flt3-L therapy was assessed by measuring AHR to methacholine. Serum was collected, cytokines and immunoglobulins were measured, cytospin slides were prepared from bronchoalveolar lavage fluid (BALF) to count total and differential cells. RESULTS: Flt3-L treatment completely reversed established AHR to methacholine (p<0.01). Flt3-L significantly decreased both BALF IL-5 levels and eosinophilia (p<0.05). There was no significant effect of Flt3-L on total and antigen-specific serum IgE, IgG2a and IgG1. CONCLUSIONS: Flt3-L treatment reverses established AHR to methacholine in cockroach induced asthma model. We have previously reported the therapeutic effect of Flt3-L in ovalbumin induced asthma model. These data suggest that Flt3-L could be a novel approach in the treatment of asthma induced by different antigens. Funding: NIH RO1-HL070885
583
SUNDAY
Persistent Aeroallergen Sensitization at Ages One and Two in the Cincinnati Childhood Allergy and Air Pollution Study P. H. Ryan1, G. K. LeMasters1, J. E. Lockey1, G. K. Hershey2, M. Villareal1, D. I. Bernstein1; 1University of Cincinnati, Cincinnati, OH, 2Cincinnati Children’s Hospital Medical Center, Cincinnati, OH. RATIONALE: Few studies have evaluated the annual reproducibility of skin prick testing in infants and young children. METHODS: Children (n = 601) born to at least 1 atopic parent were skin prick tested (SPT) at ages 1 and 2 with the following categories of allergens: 1) pollen (fescue, timothy, white oak, maple, American elm, red cedar, or short ragweed), 2) mold (Alternaria, Aspergillus fumigatus, Penicillium mix, or Cladosporium), 3) dust mite or German cockroach, and 4) epidermals (cat or dog). RESULTS: The prevalence of children sensitized to aeroallergens increased from age 1 (18%) to 2 (38%). Although 66% of those SPT+ at age 1 remained positive to an aeroallergen at age 2, the rate of persistent sensitization to pollen, mold, dust, and epidermals was 53%, 29%, 24%, and 32%, respectively. A positive SPT to pollen or epidermal antigens was significantly associated with persistent sensitization at age 2 to the same category of allergen (p<0.05). Sensitization to pollen at age 1 was significantly associated with mold sensitization at age 2 (p<0.05). Sensitivity to mold or dust allergens was not associated with the same allergen category at age 2 (p>0.05). CONCLUSIONS: Sensitization at age 1 to pollen and animals is associated with persistent sensitization at age 2, but sensitization at age 1 to other allergen groups was not reproducible at age 2. The developing immune system could influence patterns of early aeroallergen sensitization in the first years of life. This ongoing study will determine the predictive value of skin testing in identifying infants at risk for allergic diseases. Funding: National Institute of Environmental Health Sciences
584
J ALLERGY CLIN IMMUNOL FEBRUARY 2006
IL-13 Receptor Alpha 2 Lung-transgenic Mice Displayed Reduced Airway Hyperresponsiveness and Inflammation in a House Dust Mite Challenged Model W. Chen, C. M. Cunningham, M. O. Daines, M. R. Warrier, A. M. Gibson, G. K. Khurana Hershey; Cincinnati Children’s Hospital Medical Center, Cincinnati, OH. RATIONALE: IL-13 receptor alpha 2 (IL-13R2) has high affinity to IL-13 but its expression is insufficient to render cells responsive to IL-13, suggesting that IL-13R2 acts as a decoy receptor. IL-13R2-deficient mice displayed enhanced IL-13 effects. We examined the effect of overexpresson of IL-13R2 in mouse lung on the allergen-induced airway hyperresponsiveness and inflammation. METHODS: The pBluescript II KS+/rCC10/mIL-13R2/hGH transgenic construct was generated from murine IL-13R2 cDNA and human growth hormone (hGH) intronic and polyadenylation sequences using the rat Clara cell 10-kDa (rCC10) promoter for lung-specific expression. The generated IL-13R2 transgenic mice were genotyped by Southern blot analysis and PCR. The expression of IL-13R2 was determined by Northern blot analysis and RT-PCR. The transgenic and nontransgenic mice were sensitized and challenged with house dust mite. The airway hyperresponsiveness was measured by whole body barometric plethysmography. The airway inflammation was determined by analysis of bronchoalveolar lavage samples and lung histology. RESULTS: The lungs of IL-13R2 transgenic mice were grossly normal without any histological changes. The overexpression of IL-13R2 transgene is lung-specific since the transgene mRNA was not detected from other tissues. The lung IL-13R2 expression in transgenic mice was 700fold higher than that in nontransgenic mice as quantified by real-time PCR. The transgenic mice challenged with house dust mite had reduced airway hyperresonsiveness in response to methacholine and reduced number of total cells and eosinophils in bronchoalveolar lavage samples comparing to the nontransgenic mice. CONCLUSIONS: IL-13R2 inhibits the airway hyperresponsiveness and inflammation in allergen-challenged mice when it is overexpressed in lung. Funding: NIH
585
The Antioxidants, Glutathione-S-Transferase-Omega1-1 (GST1-1) and Glutathione Peroxidase2 (GPX2), Are Increased in Allergic Airway Inflammation D. Quarcoo, A. M. Dittrich, M. Krokowski, A. Awagjan, B. Ahrens, E. H. Hamelmann; Pediatric Pneumology and Immunology, Charité University Medicine, Berlin, GERMANY. RATIONALE: Allergen-induced bronchial asthma is a chronic airway disease that involves the interplay of various genes with environmental factors triggering a multitude of inflammatory pathways. We attempted to delineate novel molecules that are yet not recognized as mediators and who operate independently of atopic susceptibility as common mediators of allergic pulmonary inflammation. METHODS: In a mouse model of allergen-induced sensitization and airway inflammation, RNA expression in whole lung tissues was compared between a high-IgE responder mouse strain (BALB/c) and mice with lower allergic susceptibility (C57/Bl6) by using microarray based RNA expression analysis. Results were confirmed by using western blot analysis of protein expression in murine lung tissues. Additionally, the location of target proteins was determined by immune histochemistry of murine and human airways. Finally, the functional relevance of the targets was assessed by using genetically deficient knock-out mice. RESULTS: The expression of two antioxidant enzymes involved in the glutathione pathway, GPX2 and GST1-1, was increased in both strains after induction of airway inflammation on the RNA level. Using western blot analysis a significant increase in protein expression was also found. GPX2 and GST1-1 were both located in the airway epithelium of murine and human lung tissues. Allergen sensitization and airway challenges of GPX2 knock-out mice resulted in hightened inflammatory airway responses, suggesting a protective role for this molecule.
586