16. Yazdanbakhsh M, Wahyuni S (2005) The role of helminth infections in protection from atopic disorders. Curr Opin Allergy Clin Immunol 5: 386–391. 17. Harris N, Gause WC (2010) To B or not to B: B cells and the Th2-type immune response to helminths. Trends Immunol 32: 80–88. 18. Dold S, Heinrich J, Wichmann HE, Wjst M (1998) Ascaris-specific IgE and allergic sensitization in a cohort of school children in the former East Germany. J Allergy Clin Immunol 102: 414–420. 19. Hunninghake GM, Soto-Quiros ME, Avila L, Ly NP, Liang C, et al. (2007) Sensitization to Ascaris lumbricoides and severity of childhood asthma in Costa Rica. J Allergy Clin Immunol 119: 654–661. 20. Palmer LJ, Celedon JC, Weiss ST, Wang B, Fang Z, et al. (2002) Ascaris lumbricoides infection is associated with increased risk of childhood asthma and atopy in rural China. Am J Respir Crit Care Med 165: 1489–1493. 21. Caraballo L, Acevedo N (2011) Allergy in the tropics: the impact of cross- reactivity between mites and ascaris. Front Biosci (Elite Ed) 3: 51–64. 22. Acevedo N, Sanchez J, Erler A, Mercado D, Briza P, et al. (2009) IgE cross- reactivity between Ascaris and domestic mite allergens: the role of tropomyosin and the nematode polyprotein ABA-1. Allergy 64: 1635–1643. 23. Santiago HC, Bennuru S, Boyd A, Eberhard M, Nutman TB (2011) Structural and immunologic cross-reactivity among filarial and mite tropomyosin: Implications for the hygiene hypothesis. J Allergy Clin Immunol 127: 479–486. 24. Santos AB, Rocha GM, Oliver C, Ferriani VP, Lima RC, et al. (2008) Cross- reactive IgE antibody responses to tropomyosins from Ascaris lumbricoides and cockroach. J Allergy Clin Immunol 121: 1040–1046 e1041. 25. Santiago HC, Leevan E, Bennuru S, Ribeiro-Gomes F, Mueller E, et al. (2012) Molecular mimicry between cockroach and helminth glutathione S-transferases promotes cross-reactivity and cross-sensitization. J Allergy Clin Immunol, in press. http://dx.doi.org/10.1016/j.jaci.2012.02.045. 26. Fitzsimmons CM, Dunne DW (2009) Survival of the fittest: allergology or parasitology? Trends Parasitol 25: 447–451. 27. Trompette A, Divanovic S, Visintin A, Blanchard C, Hegde RS, et al. (2009) Allergenicity resulting from functional mimicry of a Toll-like receptor complex protein. Nature 457: 585–588. 28. Karp CL (2010) Guilt by intimate association: what makes an allergen an allergen? J Allergy Clin Immunol 125: 955–960; quiz 961–952. 29. Virtanen T, Zeiler T, Rautiainen J, Mantyjarvi R (1999) Allergy to lipocalins: a consequence of misguided T-cell recognition of self and nonself? Immunol Today 20: 398–400. Tolerance to Self and Allergenicity 30. Emanuelsson C, Spangfort MD (2007) Allergens as eukaryotic proteins lacking bacterial homologues. Mol Immunol 44: 3256–3260. 31. Dreborg S, Bousquet J, Lowenstein H, Frew AJ (1994) Response to What is a ‘major’ allergen? by L. Berrens. Clin Exp Allergy 24: 610–611. 32. D’Urbano LE, Pellegrino K, Artesani MC, Donnanno S, Luciano R, et al. (2010) Performance of a component-based allergen-microarray in the diagnosis of cow’s milk and hen’s egg allergy. Clinical and experimental allergy : journal of the British Society for Allergy and Clinical Immunology 40: 1561–1570. 33. Hoffman DR (1983) Immunochemical identification of the allergens in egg white. The Journal of allergy and clinical immunology 71: 481–486. 34. Rona RJ, Keil T, Summers C, Gislason D, Zuidmeer L, et al. (2007) The prevalence of food allergy: a meta-analysis. The Journal of allergy and clinical immunology 120: 638–646. 35. Scala E, Alessandri C, Bernardi ML, Ferrara R, Palazzo P, et al. (2010) Cross- sectional survey on immunoglobulin E reactivity in 23,077 subjects using an allergenic molecule-based microarray detection system. Clinical and experi- mental allergy : journal of the British Society for Allergy and Clinical Immunology 40: 911–921. 36. Zhu J, Paul WE (2008) CD4 T cells: fates, functions, and faults. Blood 112: 1557–1569. 37. Aalberse RC, Akkerdaas J, van Ree R (2001) Cross-reactivity of IgE antibodies to allergens. Allergy 56: 478–490. 38. Reese G, Ayuso R, Lehrer SB (1999) Tropomyosin: an invertebrate pan- allergen. Int Arch Allergy Immunol 119: 247–258. 39. Hotez PJ, Bethony JM, Diemert DJ, Pearson M, Loukas A (2010) Developing vaccines to combat hookworm infection and intestinal schistosomiasis. Nat Rev Microbiol 8: 814–826. 40. Arbes Jr SJ, Gergen PJ, Elliott L, Zeldin DC (2005) Prevalences of positive skin test responses to 10 common allergens in the US population: Results from the Third National Health and Nutrition Examination Survey. Journal of Allergy and Clinical Immunology 116: 377–383. 41. Capron A, Capron M, Riveau G (2002) Vaccine development against schistosomiasis from concepts to clinical trials. Br Med Bull 62: 139–148. 42. Altschul SF, Madden TL, Schaffer AA, Zhang J, Zhang Z, et al. (1997) Gapped BLAST and PSI-BLAST: a new generation of protein database search programs. Nucleic Acids Res 25: 3389–3402. 43. Ribeiro JM, Topalis P, Louis C (2004) AnoXcel: an Anopheles gambiae protein database. Insect Mol Biol 13: 449–457. PLoS ONE | www.plosone.org 8 July 2012 | Volume 7 | Issue 7 | e40552