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). 

Fitzgerald42 found that the antibody response of rabbits toward 1.5% aqueous dextran solutions (both types) varied with the nitrogen (t. e., bacterial) content of the dextran. Injections were administered both interperitoneally and intravenously, and no antibody production resulted when the nitrogen content of the dextrans was below 0.2%. 

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. 

IgG or IgM antibodies direct the immune response toward the antigen located on a cell (e.g., a red blood cell or thrombocyte). Macrophages, NK cells, and neutrophils are recruited by the antibodies to the site of the antigen on the cell surface and destroy the cell by phagocytosis or lysis. Additionally, complement activation will damage the cell (Fig. 6.32). The result, for example, where red cells are the targets is hemolytic anemia. 

Figure 273 Cationized BSA even can increase the specific antibody response to large proteins coupled to it. This graph shows a comparison of the relative antibody response in mice to injections of ovalbumin, either in an unconjugated form or conjugated to native or cationized BSA. The quantity injected was standardized according to the amount of ovalbumin present. The highly basic cBSA molecule modulates the immune response to enhance the production of antibodies toward even proteins conjugated with it.

Monoclonal antibody therapy (MAT) makes use of all the major features of the immune response. It involves vaccination/ immunization, albeit in experimental animals, to induce the desired specific immune response. It exploits the high specificity, selectivity, and affinity of the antibody CDR toward the target antigen to be recognized, highlighted, inactivated, or eliminated, using the characteristics of the Fc portion of an immunoglobulin to facilitate the means for such inactivation or elimination and for selection of appropriate effector mechanisms. Finally, MAT represents a modern form of serotherapy, in which parenteral administration of whole serum or Ig preparations has been replaced by recombinant antibody molecules of a defined specificity. 

Because protein microarrays (antibody microarrays) have been successfully used for a variety of applications, such as antibody response profiling, identification and detection of bacterial and protein analytes, as well as disease proteomics with a clear focus toward oncoproteomics, it can be assumed that they will also prove to be a useful tool in studies on allergens (Wingren and Borrebaeck, 2007). 

Cleomiscosins A (9), B (10), and C (7), isolated from the seeds of Cleome viscosa, were shown to have immunomodulatory activity in vivo by Bawankule et al. (84). These coumarinolignans, at a dose of 10 mg kg body weight, enhanced the body immune function by significantly increasing the white blood cell count and hemagglutination antibody titer responses, by reducing the delayed-type hypersensitivity response towards rabbit red blood cells. The same group, led by Chattopadhyay, filed a patent on an immunomodulatory pharmaceutical composition, comprised of cleomiscosins isolated from the seeds of C. viscosa (85). 

A -THC, like morphine, has been shown to suppress in vitro antibody formation by mouse spleen cells (Kaminski et al., 1992 Kaminski et al., 1994). Interestingly, A -THC is reported to increase IgGl responses to Legionella pneumophila in drug-treated animals, presumably by polarizing the immune response towards a Th2 phenotype (see below under T cell responses) (Newton et al., 1994). 

Thl/Tli2 subclasses of T helper cells that are distinguished by their cytokine profiles. Thl cells are characterized by production of IFN-g. Thl cells are characterized by production of IL-4. Th2 cells polarize the immune response towards cellular immunity and Th2 cells polarize towards antibody formation. 

The pattern of proinflammatory cytokines produced has implications for the character of the adaptive immune response, which will occur if the host is exposed to a foreign antigen. A T-helper type 1 (Thl) cytokine profde polarizes the immune response towards a cellular immune response, whereas a T-helper type 2 (Th2) profde favors antibody responses (Mos-mann and Coffman, 1987). IFN-y is a marker of a Thl response, and lL-4 is indicative of a Th2 response. There is evidence that morphine given in vivo biases the immune response toward a Th2 response (Roy et al., 2004). The consequences of this apparent shift toward Th2-type immunity are not clear, since other studies show that antibody production is suppressed in animals treated simUarly with morphine (Bus-siere et al., 1993). These results wUl be discussed in greater detaU below. 

Despite this initial clinical setback, Ap-directed active vaccination continues to warrant further assessment via careful step-wise refinement and testing of novel immunotherapeu-tic approaches. It is clearly important to evaluate the antibody isotypes that are induced by candidate vaccine constructs, as well as determining the types of CD4 and CDS T cell immunity that are elicited. This information will undoubtedly facilitate the design of safer active vaccination strategies to direct the resultant immune response towards more desired effector functions. 

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