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DETERMINING COMMON PHYSICAL CHEMICAL PROPERTIES OF IGE EPITOPES WITH A DATABASE OF FOOD ALLERGENS. - F1
ABSTRACTS PRESENTED AT FOOD ALLERGY SYMPOSIUM November 6, 2003 Hilton New Orleans Riverside Hotel F1 DETERMINING COMMON PHYSICAL CHEMICAL PROPERTIES OF IGE EPITOPES WITH A DATABASE OF FOOD ALLERGENS. Schein,C.H., Ivanciuc, O., Braun,W., Galveston, TX. Introduction. Patients allergic to one food may react to others that contain similar proteins. Comparison of allergen sequence and structure can determine what other proteins the patient is likely to react to. We show here that matching the physical chemical properties (PCP) of known epitopes can identify IgE binding peptides in other allergens in the database. Methods. A cross referenced database of food allergens has been established as a separate area of our structural database of allergenic proteins (SDAP; www.scsb.utmb.edu). Allergens containing sequences similar to a query epitope can be found using our PD search tool, which identifies areas of proteins that are closely related according to their PCP. Data. Starting from the list of known peanut allergen epitopes available in SDAP-food, we used the automatic PD tool to find sequences with similar PCP, and analyzed the results. We found that many of the sequences returned by the tool were known epitopes in related or unrelated allergens. Also, the epitopes of the major allergens have PCP homologues within their own sequences. Sequences matching the PCP matrix of the epitopes were found frequently in other nut proteins. For example the epitope 303 DEDEYEYDEEDRRRG 317 of Ara h 3 finds similar areas in three other nut allergens, including a known epitope of Ara h 1, 123 REREEDWRQP 132. This epitope in turn maps to five other areas of its own sequence, including two known linear epitopes. The 134 EDWRRPSHQQ 143 epitope of Ara h 1 matched to two other known epitopes in its own sequence, 127 EDWRQPREDW 136 and 102 DDRRQPRREE 111. Similarly, a major epitope of Ara h 2, 27 DRRCQSQLER 36, mapped to two other regions of its sequence that were also known epitopes, 119 GRQQEQQFKR 128 and 142 PQRCDLDVES 151. The epitope regions are very flexible loops, according to our model. Conclusions. This study suggests that there are indeed common properties, at the physical chemical level, in the diverse sequences identified as IgE binding sites of allergens. As more information about the specific IgE binding sites of allergens becomes available, we should be able to define these common properties in a computational fashion. This can aid in predicting the allergenic potential of novel proteins and even in directing design of hypoallergenic foods.
F2 FOOD ANTIGEN STIMULATED TH1/TH2 MONONUCLEAR CELL(MNC) CYTOKINES IN ATOPIC DERMATITIS (AD) WITH LGG PROBIOTIC. J. Kaplan,1* Y. Huang,1 M. Zitt,2 R. Young,1 P. Delapia,3 D. Bouboulis,3 M. Frieri,1 1. East Meadow, NY; 2. North Babylon, NY; 3. Stamford, CT. Introduction: LGG modulates antigen transport, intestinal inflammation and benefits infants with AD and cow milk allergy (CMA), Majamaa H, et al (J Allergy Clin Immunol 99: 179-85, 1997). IL-4 levels and dust mite (DM) sensitivity correlate with dietary and skin changes in AD patients (Frieri M. Ped Asthma Allergy Immunol 7: 27-35, 1993). Methods: We clinically and immunologically evaluated 6 children (4F, 2M) with moderate to severe AD, ages 22-months to 16 years with DM and either CMA or egg allergy. None were on systemic steroids. Three of six AD children had positive skin tests to CMA or egg allergy and 3 were AD skin test negative controls. A dietary assessment was also performed. MNC at 0.6 million cells/ml after Ficoll separation in cRPMI with 50 ug of CMA and egg antigen, 10 ug/ml ConA were incubated in 5% CO2 at 37°C for 72 hrs in the presence and absence of antigen and 10 million colonies of LGG were added for an additional 17hrs of incubation. IL-4/IFNγ were assayed with a sensitive monoclonal ELISA. Results: DM sensitivity from 4+ or class V was present in 4 of 6 children. Three AD children with either CMA or egg allergy had increased antigen-stimulated IL-4 levels, mostly to CMA(0.2pg/ml)(x=0.1pg/ml) which
decreased with LGG (x=.08pg/ml). No mean difference was observed in three AD controls (x=0.1pg/ml). IFNγ levels in three AD food sensitive children were negative with food antigens. ConA responses were elevated @ 985 pg/ml, which decreased with LGG to 936 pg/ml (%Δ5%) vs. 850-713 pg/ml (%Δ16%) in three AD controls. Conclusion: One author (MF) demonstrated in 4 of 12 CMA children with AD high IgE levels which could be triggered by IL-4 and elevated CD45 RA/62L (L-selectin) levels. Those with low total IgE,L-selectin expression was lost with casein and mitogen stimulation (Bennuri B, Frieri M, et al. Ann Allergy Asthma Immunol 88: 59a, 2002). Measurment of TNFα in this study may also provide further insight as demonstrated by Majamaa et al. Probiotic bacteria such as LGG can promote endogenous barrier mechanisms in children with AD and food allergy by modifying the Th1/Th2 cytokine profile and decreasing intestinal inflammation.
F3 ORAL ALLERGY SYNDROME TO TOMATO, BANANA AND APPLE IN MOUNTAIN CEDAR (MC) POLLINOSIS. G.S. Sharma,1* T. Midoro-Horiuti,1 J.H. Van Bavel,2 R.M. Goldblum,1 1. Galveston, TX; 2. Austin, TX. Mountain cedar (Juniperus ashei, MC, Cupressaceae) pollen is a major cause of seasonal hypersensitivity in the central US. Some patients with hypersensitivity to other pollen allergens have oral allergy syndrome (OAS), an IgE-mediated reaction of the lips, mouth and pharynx after eating native fruits and vegetables. OAS is thought to be due to IgE anti-pollen antibodies that cross-react with the food allergens. OAS has not been reported in MC pollinosis, but OAS to tomatoes has been described in a few patients with Japanese cedar pollinosis. We performed a mail-out / telephone survey of 800 mountain cedar-sensitive patients in the Austin, TX area. After telephone screening, 28 patients were interviewed, skin tested and had serum collected for serological testing. Of the 28 cedar sensitive patients with suspected food allergies, 15 had clinical manifestations of oral allergy syndrome. Eleven of the 28 subjects had positive skin tests to tomato and 6 of these patients were also positive to banana. Subjects with oral allergy syndrome to tomatoes and bananas tended to have stronger cutaneous and in vitro reactivity to cedar pollen. The intensities of the tomato and banana reactivities were correlated with the intensity of cedar reactivity. Sera from the 11 cedar-sensitive patients with positive skin tests to tomato were tested for IgE antibodies to these fruits by ImmunoCAP. ImmunoCAP inhibition assays with cedar and tomato extracts were performed on the 7 sera with adequate IgE antibodies to one or more of the fruits. The results of the inhibition experiments demonstrated a strong cross-reactivity between IgE antibodies to cedar pollen and the three fruits. The primary sensitization was to mountain cedar, since absorption with cedar pollen extract strongly inhibited reactivity to each of the fruits, but absorption with tomato extract did not significantly inhibit IgE binding to cedar extract. This is the first report of an OAS in mountain cedar pollinosis patients. Sensitivity to tomato, banana and apple should be considered in cedar-sensitive patients and confirmed if symptoms develop.
F4 ALLERGY TO NATURAL AND SUPPLEMENTAL FOLIC ACID AS A CAUSE OF CHRONIC, INTERMITTENT URTICARIA AND ANGIOEDEMA. G.M. Sanders,1* S.B. Fritz,2 1. Ann Arbor, MI; 2. Billings, MT. Introduction: While rare, anaphylactic reactions have been documented after administration of oral or parenteral folic acid, but not with naturally occurring folates. However, there are no reports of chronic urticaria and angioedema with either natural or synthetic folic acid consumption. Case Report: A 61 y.o. woman
ACAAI International Food Allergy Symposium
VOLUME 93, NOVEMBER, 2004
S51
F2 FOOD ANTIGEN STIMULATED TH1/TH2 MONONUCLEAR CELL(MNC) CYTOKINES IN ATOPIC DERMATITIS (AD) WITH LGG PROBIOTIC. J. Kaplan,1* Y. Huang,1 M. Zitt,2 R. Young,1 P. Delapia,3 D. Bouboulis,3 M. Frieri,1 1. East Meadow, NY; 2. North Babylon, NY; 3. Stamford, CT. Introduction: LGG modulates antigen transport, intestinal inflammation and benefits infants with AD and cow milk allergy (CMA), Majamaa H, et al (J Allergy Clin Immunol 99: 179-85, 1997). IL-4 levels and dust mite (DM) sensitivity correlate with dietary and skin changes in AD patients (Frieri M. Ped Asthma Allergy Immunol 7: 27-35, 1993). Methods: We clinically and immunologically evaluated 6 children (4F, 2M) with moderate to severe AD, ages 22-months to 16 years with DM and either CMA or egg allergy. None were on systemic steroids. Three of six AD children had positive skin tests to CMA or egg allergy and 3 were AD skin test negative controls. A dietary assessment was also performed. MNC at 0.6 million cells/ml after Ficoll separation in cRPMI with 50 ug of CMA and egg antigen, 10 ug/ml ConA were incubated in 5% CO2 at 37°C for 72 hrs in the presence and absence of antigen and 10 million colonies of LGG were added for an additional 17hrs of incubation. IL-4/IFNγ were assayed with a sensitive monoclonal ELISA. Results: DM sensitivity from 4+ or class V was present in 4 of 6 children. Three AD children with either CMA or egg allergy had increased antigen-stimulated IL-4 levels, mostly to CMA(0.2pg/ml)(x=0.1pg/ml) which
decreased with LGG (x=.08pg/ml). No mean difference was observed in three AD controls (x=0.1pg/ml). IFNγ levels in three AD food sensitive children were negative with food antigens. ConA responses were elevated @ 985 pg/ml, which decreased with LGG to 936 pg/ml (%Δ5%) vs. 850-713 pg/ml (%Δ16%) in three AD controls. Conclusion: One author (MF) demonstrated in 4 of 12 CMA children with AD high IgE levels which could be triggered by IL-4 and elevated CD45 RA/62L (L-selectin) levels. Those with low total IgE,L-selectin expression was lost with casein and mitogen stimulation (Bennuri B, Frieri M, et al. Ann Allergy Asthma Immunol 88: 59a, 2002). Measurment of TNFα in this study may also provide further insight as demonstrated by Majamaa et al. Probiotic bacteria such as LGG can promote endogenous barrier mechanisms in children with AD and food allergy by modifying the Th1/Th2 cytokine profile and decreasing intestinal inflammation.
F3 ORAL ALLERGY SYNDROME TO TOMATO, BANANA AND APPLE IN MOUNTAIN CEDAR (MC) POLLINOSIS. G.S. Sharma,1* T. Midoro-Horiuti,1 J.H. Van Bavel,2 R.M. Goldblum,1 1. Galveston, TX; 2. Austin, TX. Mountain cedar (Juniperus ashei, MC, Cupressaceae) pollen is a major cause of seasonal hypersensitivity in the central US. Some patients with hypersensitivity to other pollen allergens have oral allergy syndrome (OAS), an IgE-mediated reaction of the lips, mouth and pharynx after eating native fruits and vegetables. OAS is thought to be due to IgE anti-pollen antibodies that cross-react with the food allergens. OAS has not been reported in MC pollinosis, but OAS to tomatoes has been described in a few patients with Japanese cedar pollinosis. We performed a mail-out / telephone survey of 800 mountain cedar-sensitive patients in the Austin, TX area. After telephone screening, 28 patients were interviewed, skin tested and had serum collected for serological testing. Of the 28 cedar sensitive patients with suspected food allergies, 15 had clinical manifestations of oral allergy syndrome. Eleven of the 28 subjects had positive skin tests to tomato and 6 of these patients were also positive to banana. Subjects with oral allergy syndrome to tomatoes and bananas tended to have stronger cutaneous and in vitro reactivity to cedar pollen. The intensities of the tomato and banana reactivities were correlated with the intensity of cedar reactivity. Sera from the 11 cedar-sensitive patients with positive skin tests to tomato were tested for IgE antibodies to these fruits by ImmunoCAP. ImmunoCAP inhibition assays with cedar and tomato extracts were performed on the 7 sera with adequate IgE antibodies to one or more of the fruits. The results of the inhibition experiments demonstrated a strong cross-reactivity between IgE antibodies to cedar pollen and the three fruits. The primary sensitization was to mountain cedar, since absorption with cedar pollen extract strongly inhibited reactivity to each of the fruits, but absorption with tomato extract did not significantly inhibit IgE binding to cedar extract. This is the first report of an OAS in mountain cedar pollinosis patients. Sensitivity to tomato, banana and apple should be considered in cedar-sensitive patients and confirmed if symptoms develop.
F4 ALLERGY TO NATURAL AND SUPPLEMENTAL FOLIC ACID AS A CAUSE OF CHRONIC, INTERMITTENT URTICARIA AND ANGIOEDEMA. G.M. Sanders,1* S.B. Fritz,2 1. Ann Arbor, MI; 2. Billings, MT. Introduction: While rare, anaphylactic reactions have been documented after administration of oral or parenteral folic acid, but not with naturally occurring folates. However, there are no reports of chronic urticaria and angioedema with either natural or synthetic folic acid consumption. Case Report: A 61 y.o. woman
ACAAI International Food Allergy Symposium
VOLUME 93, NOVEMBER, 2004
S51