Tehran University of Medical Sciences Iranian Journal of Allergy, Asthma and Immunology 1735-1502 12 2 2013 06 15 99 106 EN Maryam Sharif Shoushtari Immunology, Asthma and Allergy Research Institute, Tehran University of Medical Sciences, Tehran, Iran AND Department of Biology, Faculty of Biology Science, Islamic Azad University, North Tehran Branch, Iran Ahmad Majd Department of Biology, Faculty of Biology Science, Islamic Azad University, North Tehran Branch, Iran Zahra Pourpak Immunology, Asthma and Allergy Research Institute, Tehran University of Medical Sciences, Tehran, Iran AND Department of Immunology and Allergy, Children Medical Center, Tehran University of Medical Sciences, Tehran, Iran Youcef Shahali Laboratoire “Sciences Analytiques, Bioanalytiques et Miniaturisation”, ESPCI ParisTech, UMR 7195 CNRS, 75231 Paris cedex 05, France Mostafa Moin Immunology, Asthma and Allergy Research Institute, Tehran University of Medical Sciences, Tehran, Iran AND Department of Immunology and Allergy, Children Medical Center, Tehran University of Medical Sciences, Tehran, Iran Mohammad Bagger Eslami Department of Pathobiology, Immunology Division, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran 2015 10 16 Weed pollen grains belonging to  the  Asteraceae  family contain  a variety of  allergens inducing type I  and IV allergies in susceptible people. The  aim of this research was to compare  the  allergenic properties  of  immature  and  mature  Shasta  daisy pollen  grains (Chrysanthemum maximum Ramond) to define the potential role of the maturation process on the allergenicity of Asteraceae pollen grains. The  immature (IP) and mature  pollen (MP) grains were first studied by optical and scanning electron microscopand their protein contents were quantitatively and qualitatively analyzed. Pollen extracts were finally used to sensitize guinea pigs in order to obtain IP and MP specific antibodies. Nasal provocation tests using IP and MP crude extracts were also performed on pre-sensitized guinea pigs. The  MP  extract  induced  IgE  and  eosinophilia in  blood  and  positive skin  tests  in sensitized guinea pigs. Moreover, high number of eosinophils was found in the nasal mucosa of MP sensitized guinea pigs. SDS-PAGE analysis of the IP and MP protein content showed seven and five apparent bands ranging from 7 to 66kDa respectively. According to immunoblot analysis, MP extract contained a single allergen of 66kDa. The overall results showed developmental processes of Shasta daisy pollen grains towards both morphological and molecular changes increasing their allergenic potency. https://ijaai.tums.ac.ir/index.php/ijaai/article/view/526 https://ijaai.tums.ac.ir/index.php/ijaai/article/download/526/479