Comparison of Sublingual Immunotherapy (SLIT) versus Oral Immunotherapy (OIT) in the Treatment of Peanut Allergy

Comparison of Sublingual Immunotherapy (SLIT) versus Oral Immunotherapy (OIT) in the Treatment of Peanut Allergy

AB140 Abstracts J ALLERGY CLIN IMMUNOL FEBRUARY 2012 SUNDAY 530 Der p 2 Stimulate Inflammatory Responses from Lung Epithelial cells and Macrophage...

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AB140 Abstracts

J ALLERGY CLIN IMMUNOL FEBRUARY 2012

SUNDAY

530

Der p 2 Stimulate Inflammatory Responses from Lung Epithelial cells and Macrophages through the TLR2 and MAPK pathway S. Tanyaratsrisakul1, O. Jirapongsananuruk2, W. R. Thomas3, S. Piboonpocanun4, D. R. Voelker1; 1Department of Medicine, Program in Cell Biology, National Jewish Health, Denver, CO, 2Department of Pediatrics, Siriraj Hospital, Mahidol University, Bangkok, THAILAND, 3Center for Child Health Research, University of Western Australia, Perth, AUSTRALIA, 4Institute of Molecular Biosciences, Mahidol University, Nakorn Pathom, THAILAND. RATIONALE: Der p 2 is the major inhaled allergen from house dust mite. A Der p 2-LPS complex has been shown to activate proinflammatory responses via TLR4 in mouse peritoneal macrophages and human kidney (HEK293) cells, and also induced airway inflammation in mice. However, the mechanism of activation of innate immunity by Der p 2 has not been fully elucidated. This study is focused upon the mechanism of activation of human bronchial epithelial cells (BEAS 2B) and mouse alveolar macrophages (RAW 264.7) in response to Der p 2. METHODS: Recombinant Der p 2 (rDer p 2) was produced in Pichia pastoris. Secondary structure and conformation of rDer p 2 were confirmed by Circular Dichroism (CD) and fluorescence compared to natural Der p 2. Serum IgE inhibition confirmed native-like IgE binding reactivity of rDer p 2. Proinflammatory responses and the underlying mechanisms were determined using BEAS2B and RAW 264.7 incubated with rDer p 2 in the presence, or absence of anti-TLR2, or anti-TLR4 antibodies. RESULTS: rDer p 2 stimulated IL-8 and TNFa secretion from BEAS2B and RAW 264.7 cells in dose dependent manner. These responses were inhibited by anti-TLR2 IgG antibody, but not anti-TLR4 IgG antibody, or polymyxin B. Increased phosphorylation of p-38 MAPK was observed with activation by Der p 2. CONCLUSIONS: The effects of Der p 2 in bronchial epithelial and alveolar macrophage cells were TLR2-dependent, but not TLR4-, or LPSdependent. The Der p 2-TLR2 activated proinflammatory responses occurred via the p38 MAPK signaling pathway.

Comparison of Sublingual Immunotherapy (SLIT) versus Oral Immunotherapy (OIT) in the Treatment of Peanut Allergy S. J. Chin1, E. H. Kim1, M. D. Kulis1, P. Varshney1, P. Steele1, J. Kamilaris1, A. Hiegel2, S. K. Carlisle2, A. M. Scurlock2, P. B. Smith1, B. P. Vickery1, S. M. Jones2, A. W. Burks1; 1Duke University Medical Center, Durham, NC, 2University of Arkansas for Medical Sciences, Little Rock, AR. RATIONALE: Both SLIT and OIT have been used to induce clinical desensitization in peanut-allergic subjects. To our knowledge, there has been no direct comparison of the two modes of treatment for peanut allergy. METHODS: Subjects were enrolled in double-blind, placebo-controlled studies using either peanut SLIT or peanut OIT with maintenance doses of 2mg and 4000mg respectively. Immunologic parameters were measured longitudinally. Double-blind, placebo-controlled food challenges (DBPCFC) were performed after 12 months of treatment. RESULTS: 26 subjects on SLIT and 23 subjects on OIT (median age 8.8 and 8.6 years respectively) were evaluated after 2 years of treatment. Baseline and 24 month peanut-IgE levels were similar between the two groups but were higher at 12 months in the OIT group (median 204kU/L vs 57kU/L, p50.03). Compared to SLIT, OIT resulted in higher peanut-IgG4 levels at 12 and 24 months (median 20mg/L vs 3.5mg/L, p<0.001, and 20mg/L vs 9.7mg/L, p50.001). The absolute decrease in SPT was greater following 12 and 24 months of OIT versus SLIT (median -7.5mm vs -3.8mm, p50.02, and -8.5mm vs -3.5mm, p50.02). After 12 months of treatment, 16/18 subjects on OIT and 7/26 subjects on SLIT passed a DBPCFC (p<0.0001; RR50.3, 95% CI50.13 to 0.52). The 23 subjects who passed the DBPCFC had greater absolute change in peanut-IgG4 (median 9.9mg/L vs 3.07mg/L, p50.05). CONCLUSIONS: During this limited observation period at the doses used, OIT induced more extensive immunologic changes associated with desensitization. These findings are reflected in the more variable degree of desensitization demonstrated by SLIT versus OIT subjects during DBPCFCs.

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Transient Receptor Potential Melastatin 8 Mediates Airway Inflammation Of Toluene-diisocyanate Induced Asthma J. Kim1, E. Yang2, H. Jin2, Y. Nam2, E. Hwang2, G. Choi3, Y. Ye2, H. Park2; 1Hallym University College of Medicine, Anyang, REPUBLIC OF KOREA, 2Ajou University School of Medicine, Suwon, REPUBLIC OF KOREA, 3Kosin University Gaspel Hospital, Pusan, REPUBLIC OF KOREA. RATIONALE: Neurogenic inflammation is one of the pathogenic mechanisms of toluene diisocyanate induced asthma (TDI-OA) where transient receptor potential melastatin family member 8 (TRPM8) receptor is a wellestablished cold- and menthol-sensing caution channel. Our previous GWAS study suggested this gene as a potential candidate in the pathogenic mechanism of TDI-OA. This study was aimed to investigate the functional effect of TRPM8 receptor in the pathogenesis of TDI-OA. METHODS: Human airway epithelial cell line, BEAS-2B, was treated with TDI-HSA conjugate. The mRNA and protein expressions of TRPM8 receptor were determined by real time PCR and western blotting. The change of surface expression of TRPM8 receptor was examined by flow cytometry. IL-8 was measured by ELISA method. RESULTS: TRPM8 receptor was expressed primarily in human airway epithelial cells, which increased significantly with IL8 production after TDI exposure in dose- and time- dependent manners. Flow cytometry identified a significant increased surface expression of TRPM8 receptor after TDI exposure. CONCLUSIONS: TDI exposure could activate TRPM8 receptor expression and production from airway epithelial cells, leading to airway inflammation in patients with TDI-OA.

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Infants Who Develop Eczema at 12 Months Have a Deficient T Regulatory Cell Response to Microbial Stimuli at the Time of Birth I. Ismail; Murdoch Childrens Research Institute, Melbourne, AUSTRALIA. RATIONALE: T Regulatory (Treg) cells and may play an essential role in regulating early immune development and shaping the immune response toward a proallergic or tolerant status. Proinflammatory cytokines may be associated with tolerance induction. METHODS: Cord blood mononuclear cells of 72 neonates at high risk allergy whose mothers participated in a prenatal probiotic eczema prevention study (PEPS) were cultured with TLR2 ligands- lipoteichoic acid (LTA) and heat-killed LGG (HKL), a TLR4 ligand - lipopolysaccharide (LPS), ovalbumin (OVA), anti-CD3 or media for 48 hours. Numbers of Treg and production of Treg and inflammatory cytokines were compared between children who developed eczema at any time during the first year of life (n 5 24) and those who did not (n 5 48). RESULTS: Infants who developed eczema had lower percentages of FoxP3hiCD25hi CD4+ Treg cells after LTA (p50.009) and HKL (p50.04) stimulations, and lower IL-6 production following HKL induction (p50.03) than those without eczema. No differences in the percentages of Foxp3hiCD25hi Treg following stimulation with OVA, LPS, or antiCD3. There was a negative correlation between the SCORAD score and the percentage of Treg cells induced by LTA (r 5 -0.48, p50.0002). CONCLUSIONS: Children who develop allergic disease in the first year of life have deficient Treg and inflammatory responses to microbial stimuli from the time of birth. A reduced ability to generate Treg cells and IL-6 in response to microbial stimuli could be a contributing factor to the failure of normal tolerance development in infancy, and this warrants further investigation.