Haptens antibody response toward

Raising the pi of macromolecules also can significantly alter the immune response toward them upon in vivo administration. Cationized proteins (those modified with diamines to increase their net charge or pi) are known to generate an increased immune response compared to their native forms (Muckerheide et al., 1987a, b Apple et al., 1988 Domen et al., 1987 Domen and Hermanson, 1992). The use of cationized BSA as a carrier protein for hapten conjugation can result in a dramatically higher antibody response toward a coupled hapten (Chapter 19). 

This chapter describes the design, preparation, and use of hapten-carrier conjugates used to elicit an immune response toward a coupled hapten. The chemical reactions discussed for these conjugations are useful for coupling peptides, proteins, carbohydrates, oligonucleotides, and other small organic molecules to various carrier macromolecules. The resultant conjugates are important in antibody production, immune response research, and in the creation of vaccines. 

Some synthetic carriers actually are designed to have low immunogenicity on their own to minimize the potential for antibody production against them. When a hapten is coupled to these molecules, the immune response is directed principally toward the modification, not at the carrier. This design approach guides most of the immune response toward the desired target and minimizes the production of carrier-specific antibodies. 

Once the hapten has been designed and prepared, it is conjugated with a carrier protein to induce the best immunogenicity as possible to elicit an immune response in the animal (most commonly a mouse) in which it is inoculated. The antibodies produced by the defense mechanism of the adaptive immune system that specifically recognizes the hapten are then isolated, overproduced, and purified for testing their catalytic activity toward the targeted chemical reaction. 

Hapten monolayer electrode sensor assembly was used to detect triazine in a flow injection analysis mode. The interaction of the electrode with different antibody concentrations resulted in the formation of an antibody-antigen (Ab-Ag) complex which insulated the electrode towards the [Fe(CN)6] /Fe(CN)6] " redox probe and diis in turn resulted in no charge transfer. The extent of insulation depends on the antibody concentration and the time of exposure to the antibody solution. The decrease in amperometric response of the antigenic monolayer to corresponding antibody solution for a fixed time produces a quantitative measurement of the antibody concentration. Typical responses obtained for cyanazine-hapten monolayer electrode to different antibody concentrations is shown in Figure 4. The lowest detection limit achieved for cyanazine sensor was 4.0 pg/ml at a response time of few minutes and a less-than 2% cross-reactivity to atrazine, simazine and other metabolites. 

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