Allergy to carminic acid: in vitro evidence of involvement of protein-binding hapten

We previously described a rare case of anaphylaxis presumably induced by carminic acid in cochineal dye used as a food additive. In this study, highly pure carminic acid was added to an albumin-containing buffer at various concentrations, followed by serial dilution. Varying the mixing ratio of carminic acid and albumin affected the extent of histamine release from passively sensitized basophils. Similar basophil histamine release occurred with carminic acid-globulin solutions. These results provide experimental evidence indicating that basophil activation is dependent on hapten (carminic acid) and carrier (protein) interaction.

Synthesis of huperzine A-bovine serum albumin conjugate and its immunogenicity in mice / 第三军医大学学报

Objective To prepare huperzine A-carrier protein conjugate and determine its immunogenicity for later production of monoclonal antibody against HupA and establishing an enzyme-linked immunosorbent assay ( ELISA) -based detection method for HupA. Methods HupA was conjugated with bovine serum albumin ( BSA) using glutaraldehyde ( GA) method to obtain the HupA-GA-BSA conjugate,and the hapten number in the conjugate was determined by matrix-assisted laser absorption ionization time-of-flight mass spectrometry ( MALDI-TOF-MS) . BALB /c mice were immunized with HupA-GA-BSA to prepare the antiserum against HupA. The serum titer and specificity of the HupA antibodies were detected by indirect ELISA and competitive ELISA,respectively. Results The conjugation ratio of HupA and the carrier protein BSA was 8∶ 1. The antiserum against HupA with a titer of 1∶ 62 500 was obtained after immunizing the mice with the conjugate,and the antiserum reacted specifically to HupA. Conclusion The synthesized HupA-GA-BSA conjugate possesses good immunogenicity in mice,suggesting the feasibility of preparing the monoclonal antibody against HupA using this conjugate.

Regulation of IgE antibody production in mice Ⅲ.IgE antibody response to hapten-carrier conjugate / 中国免疫学杂志

The anti-DNP and anti-OA IgE antibody responses of six strains of mice immunizedwith DNP-OA conjugate in presence of A1(OH)_3 adjuvant was investigated.Signifi-cant differences of the magnitude of serum IgE were found in anti-hapten and anti-carrier responses among strains.The primary and secondary anti-DNP and anti-OAIgE antibodies were elicited in NIH,BALB/c and DBA/2 mice after immunizationwith 1?g of DNP-OA.Among them NIH mice was the highest responder,whereasLACA,C3H and B6D2F1 mice were poor or nonresponders.In comparison the IgEresponse in BALB/c mice immunized with 1?g and 10?g of DNP-OA,the former de-monstrated a latency of primary response,but two groups had a very similar PCAtiters after 4 weeks of immunization.On the other hand,LACA mice gave a dose de-pendent IgE response.Profound primary and secondary IgE antibody responses can beonly seen in mice injected with 10?g of DNP-OA and PCA titer of anti-DNP washigher than that of anti-OA IgE antibody.However,no difference of IgE antibodylevels in NIH mice can be found between groups immunized with different doses.DNP_(4.7)-OA primed mice gave higher IgE response than that of mice immunized withDNP_3-OA.A prevailing anti-hapten IgE response was observed when higher dose ofDNP-OA conjugates was injected.