Allergenicity assessment of pollen grain and identification of allergens by immunoproteomic approach.

Background: Plantation of road-side avenue trees has become a major part of urbanization programme for megacity beautification and environmental management. Due to evergreen habit and vibrant flower colour, (Gulmohor/Flamboyant) is frequently selected as ornamental tree for plantation programme. However, pollen is related to IgE mediated allergic reactions and no allergen has been reported so far.

Objective: Measuring the prevalence of pollen sensitivity among the local atopic individuals and identifying the allergens using immunoproteomic tools.

Methods: Aerobiological study was conducted for a period of two years to record the pollen concentration in the outdoor ambient air. Clinico-immunological tests were performed on atopic individuals to check the prevalence of sensitivity against pollen. Allergens were detected in the pollen proteome, fractionated in 1D and 2D gel by IgE serology and finally identified by mass spectrometry.

Result: In the study area pollen grains were present in ample amount in the air during May to July. About 38% of atopic individuals displayed positive Skin Prick Test (SPT) against pollen along with elevated level of specific IgE and histamine in the sera. Immunoproteomic analyses revealed the presence of 14 IgE reactive proteins in the 2D pollen proteome, of which 8 IgE reactive proteins were identified by MALDI TOF/TOF using homology driven proteomic approach.

Conclusion: This study demonstrated pollen related allergy symptoms by and gave significant message regarding the plantation programme to avoid the unnecessary load of allergic pollen. Also, a panel of 8 allergens were identified for the first time from pollen. Detailed study of these allergens would help to design immunotherapeutic strategies for pollinosis management.