Identification of a 17 kDa protein that is a potentially novel antigen of lettuce‐associated respiratory allergy in farmers

Abstract

AbstractBackgroundWe have identified and reported a novel antigen, nonprotein‐specific secreted EP1‐like glycoprotein (51 kDa), for lettuce‐related respiratory allergy.ObjectiveWe aimed to identify a novel antigen for lettuce‐related respiratory allergy that is different from epidermis‐specific secreted EP1‐like glycoprotein.MethodsImmunoblotting was performed using an immunoglobulin E‐specific antibody. The antigen‐antibody reaction was confirmed by means of enzyme‐linked immunosorbent assaying. LC‒MS/MS analysis was carried out to detect a novel protein found in sera from 3 of 13 patients with lettuce‐related respiratory allergy. Finally, we purified a novel protein from Escherichia coli.ResultsImmunoblotting assays showed common bands of 17 kDa in the sera of 3 of 13 patients. An enzyme‐linked immunosorbent assay confirmed that the patient sera reacted with lettuce latex juice. A 17 kDa protein band that showed antigenic reactivity in 3 of 13 patient sera was identified as a kirola‐like protein by LC‒MS/MS. In addition, although we purified this protein, we failed to show the inhibitory effect.ConclusionA 17 kDa protein that is a potentially novel antigen of lettuce‐associated respiratory allergy was identified. In further studies, we will focus on purifying this novel protein to diagnose lettuce allergy.