Background and aims.The present study investigates immunological cross-reactivity between Par o 1, the major pollen allergen of Parietaria, a weed causing in Europe a highly prevalent allergy and the VP4 protein of rotavirus, a microorganism which is world-wide the main etiological agent of gastro-enteritis in children. It was prompted by the results of protein sequences databases similarity searches, showing that the peptide p96 (EFGTSSCRI), containing a Par o 1 epitope, and the C-terminal amino-acid sequence of VP4 share partial identity. Methods. Cross-reactivity was assessed by ELISA and DARIA, using recombinant VP4 from rhesus infectious rotavirus (RR) and antibodies affinity purified from pooled and individual human sera. Results. Par o 1 and RRVP4 cross-reacted in ELISA. In inhibition essays RVP4 extensively inhibited Par o 1 binding of IgG (ELISA) and IgE (DARIA) antibodies. Cross-reactive binding was inhibited by p96 and by synthetic peptides derived from the C-terminal sequences of the VP4 proteins from human and rhesus infectious rotavirus. The analysis of 35 individual sera and 14 pools showed that Par o 1-specific antibodies with binding affinity for RRVP4 could be affinity purified from the large majority of sera. The binding affinity for RRVP4 tended to be comparatively increased in antibodies obtained from donors without atopy to Parietaria (p<0.002). Par o 1-specific antibodies with binding affinity for RRVP4 were affinity purifed also from 12 sera obtained from donors living in Maryland (U.S.A.), were Parietaria is not known to grow. Conclusions. This study reports the first evidence of cross-reactivity between an allergen and a viral antigen. Cross-reactivity may represent one mechanism by which certain common infections influence the outcome of the immune response to specific environmental allergens.
Cross-reactivity between the major Parietaria allergen and rotavirus VP4 protein
2003
Abstract
Background and aims.The present study investigates immunological cross-reactivity between Par o 1, the major pollen allergen of Parietaria, a weed causing in Europe a highly prevalent allergy and the VP4 protein of rotavirus, a microorganism which is world-wide the main etiological agent of gastro-enteritis in children. It was prompted by the results of protein sequences databases similarity searches, showing that the peptide p96 (EFGTSSCRI), containing a Par o 1 epitope, and the C-terminal amino-acid sequence of VP4 share partial identity. Methods. Cross-reactivity was assessed by ELISA and DARIA, using recombinant VP4 from rhesus infectious rotavirus (RR) and antibodies affinity purified from pooled and individual human sera. Results. Par o 1 and RRVP4 cross-reacted in ELISA. In inhibition essays RVP4 extensively inhibited Par o 1 binding of IgG (ELISA) and IgE (DARIA) antibodies. Cross-reactive binding was inhibited by p96 and by synthetic peptides derived from the C-terminal sequences of the VP4 proteins from human and rhesus infectious rotavirus. The analysis of 35 individual sera and 14 pools showed that Par o 1-specific antibodies with binding affinity for RRVP4 could be affinity purified from the large majority of sera. The binding affinity for RRVP4 tended to be comparatively increased in antibodies obtained from donors without atopy to Parietaria (p<0.002). Par o 1-specific antibodies with binding affinity for RRVP4 were affinity purifed also from 12 sera obtained from donors living in Maryland (U.S.A.), were Parietaria is not known to grow. Conclusions. This study reports the first evidence of cross-reactivity between an allergen and a viral antigen. Cross-reactivity may represent one mechanism by which certain common infections influence the outcome of the immune response to specific environmental allergens.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
