Molecular insight into IgE-mediated reactions to sesame (Sesamum indicum L.) seed proteins

Background Food allergy is becoming a major public health concern in recent times. Several sesame seed allergenic proteins have been identified. However, sensitization toward these proteins does not follow a common and unique pattern of clinical reactivity, as shown by the differential geographic recognition of single proteins. Objective To evaluate the sensitization profiles of 18 Italian individuals who experienced clinical symptoms after sesame seed consumption, including 4 anaphylactic reactions. Methods Using an in vitro approach, we adopted a 2-dimensional electrophoretic technique combined with immunoblotting analyses by using sera from 18 Italian sesame-allergic patients. Results We showed the prevalent and almost exclusive reactivity of the sesame 11S globulin. We shed light on the active role of the basic subunit of this globulin family. The limited accessibility of this polypeptide chain, unless the interchain disulphide bonds are cleaved, may be one of the reasons for its structural/functional stability and, thus, great potential for induction of IgE reactivity. Conclusions These results confirmed previous findings on the reactivity of the basic subunit of 11S globulin in various legume species. Moreover, this experimental approach proved to be useful for the noninvasive screening of specific reactivities in sensitized patients.