Identification of Cortaderia selloana allergens and cross reactivity with Lolium perenne (Poaceae)

GÁLVEZ, M.; BIANCHIMANO, A.; MARTÍNEZ, A.; MURRAY, M. G.; ÁVILA, B.; PRAT, M. I.

Mar del Plata

Otro; Reunión Conjunta de la Sociedad Argentina de Investigación Clínica (SAIC), la Sociedad Argentina de Inmunología (SAI) y la Sociedad Argentina de Fisiología (SAFIS).; 2018

Sociedad Argentina de Investigación Clínica (SAIC), la Sociedad Argentina de Inmunología (SAI) y la Sociedad Argentina de Fisiología (SAFIS).

The pollen of grasses is the fourth in quantitative importance in Bahía Blanca and is a significant cause of pollinosis. Cortaderia selloana is a widely distributed plant often used as an ornamental. Unlike Lolium perenne, little is known about its allergenicity. The aim of this work is to identify the main allergens of C. selloana and establish relationship with L. perenne. The serum of 16 patients with allergic symptomatology, positive skin tests for grasses and specific IgE for C. selloana and/or L. perenne (ELISA) were analyzed. The allergen profiles were revealed for each patient by western blot. The mean inhibitory concentration (IC50) of each extract was established by ELISA preadsorbing the sera with pollen proteins. C. selloana presented a profile of 15 allergens (13-100 kDa). The major one, with 33 kDa, was detected in 91% of patients. Those of 42, 48, 51, 62, 68 and 71 kDa were observed in 82% of patients. L. perenne showed 15 allergens (20-100 kDa). The 57 kDa allergen was present in all patients and those of 34, 48, 71 and 76 kDa in 87% of them. For C. selloana pooled positive sera, the IC50 was 0.28 μg/ml using C. selloana extract and 1.02 μg/mL using L. perenne extract. For L. perenne pooled positive sera, the IC50 was 0.45 μg/mL using L. perenne extract. At a maximum concentration of 200 μg/mL of C. selloana extract only IC14 was reached. C. selloana allergens mentionated would be included in groups 1 and 4 of grass pollen allergens. The cross reactivity observed is broad. Qualitative and quantitative differences detected may be due to the existence of multiple isoforms. This work comprises a first attempt in the molecular characterization of C. selloana allergens and its implication in the design of vaccines and the effectiveness of the grass immunotherapy.