Abstract
BACKGROUND: Pollen grains constitute a significant portion of the aerobiological flora. The plant Coccos nucifera (commonly known as coconut) is found in huge quantities in the tropical coastal areas of the world and is very common in Kolkata, India. A 2 years aerobiological survey was carried out using Burkard Volumetric Sampler to know the seasonal variation of Cocos nucifera pollen. The plant flower through out the year but maximum concentration was found in the month of August. Allergenicity of Cocos nucifera pollen has been reported from the Skin Prick Test, Lung function test, ELISA from a 400 susceptible patients in and around West Bengal in India. An immunobiological study was conducted to identify major allergens from Coccos nucifera pollen causing hay fever, skin allergy and allergic asthma in Kolkata population. METHODS: Proteins from pollen grains were obtained by initially defatting and then extracted with sodium phosphate buffer with 10 mM PMSF. Total protein was divided into 4 fractions by ammonium sulfate at 25%, 50 %, 75% and 100% respectively. SDS PAGE was done with the 25% fraction (result obtained from dot blotting) and subsequently western blotting was performed. Two dimensional gel electrophoresis and immunoblotting was also done from the crude protein. RESULTS: The total protein was separated on a SDS PAGE gel showed 21 prominent bands by Coomassie Blue staining. Dot -blotting the different fractions from ammonium sulfate cut, showed a positive result in the 25% fraction. Western blot with patient specific sera gave 3 bands out of which a major band was obtained at 60Kd. This result was obtained in more than 65% of the patients from whom Sera was isolated. 2D gel electrophoresis of the crude protein sample was performed which showed 120 protein spots in the PI range of 3 to 10 and molecular weight 14Kd to 97Kd. Immunoblotting the 2D gel with pooled patient specific sera showed 20 spots thus implying IgE reactivity. CONCLUSIONS: It can thus be inferred that Coccos nucifera pollen grains are very common in the air and are important to cause allergy to susceptible persons. More over the 60 Kd protein is responsible for allergenicity.