Three T-cell determinants of Cry j 1 and Cry j 2, the major Japanese cedar pollen antigens, retain their immunogenicity and tolerogenicity in a linked peptide.

It has been demonstrated in detail that administration of a dominant T-cell determinant to animals induces activation or immunological tolerance of T cells. However, it has not been determined whether multiple T-cell determinants, when integrated into a single peptide, retain their potential to induce T-cell activation and tolerance. We prepared a synthetic peptide comprising three T-cell determinants of Cry j 1 and Cry j 2, the major Japanese cedar pollen antigens, and investigated the immunogenicity and tolerogenicity of each T-cell determinant in the linked peptide by means of lymph node cell proliferation assays using mice. Lymph node cells from mice immunized with each of the three T-cell determinants proliferated against the linked peptide in a dose-dependent manner, similar to that of the immunized peptide. Lymph node cells from mice immunized with the linked peptide proliferated against all of the three T-cell determinants. In addition, the degree of proliferation against the three T-cell determinants occurred according to their original immunogenicity, as observed in the native protein antigens. Oral administration of the linked peptide to mice before they were immunized with Cry j 1 and Cry j 2 inhibited lymph node cell proliferation against the three T-cell determinants, depending on the dose of the linked peptide administered. In conclusion, it was demonstrated that three T-cell determinants retain their original immunogenicity and tolerogenicity in a linked peptide comprising them.

Chronic inflammation of the skin can be induced in IgE transgenic mice by means of a single challenge of multivalent antigen.

BACKGROUND: It is now widely accepted that IgE mediates immediate-type allergic response. However, the pathologic role of IgE is controversial in the chronic allergic inflammation observed in atopic diseases, such as asthma and atopic dermatitis. OBJECTIVE: We investigated the role of IgE in cutaneous allergic reactions by using 2 newly developed lines of antigen-specific IgE transgenic mice. METHODS: IgE transgenic mice were administered subcutaneously with corresponding antigens, and the subsequent ear swelling was measured. RESULTS: A single subcutaneous administration of TNP-conjugated ovalbumin (OVA) into the ears of nonimmunized mice carrying the TNP-specific IgE transgene elicited immediate-phase and late-phase ear swelling as expected, which peaked at 20 minutes and 8 hours later, respectively. Interestingly, however, 2 to 3 days after the antigen challenge, more intense ear swelling appeared. Its magnitude and duration were dependent on the valency of TNP in OVA, as well as the dose of TNP-OVA, and it lasted over 1 month when 100 microg of OVA conjugated with 11 molecules of TNP was given. Interestingly, administration of OVA to OVA-specific IgE transgenic mice elicited immediate-phase and late-phase ear swelling but not third-phase ear swelling. Massive infiltration of inflammatory cells was observed in the third-phase ear swelling of TNP-specific IgE transgenic mice. Cyclosporine A almost completely inhibited the third-phase ear swelling and cellular infiltration, whereas an antihistamine, cyproheptadine, did not show any significant effect on the third-phase reaction. CONCLUSION: These results indicate that IgE can trigger not only immediate-type hypersensitivity but also chronic allergic inflammation. Our findings highlight a novel immunopathologic role of IgE in chronic atopic disorders.