Antibody activity

Cocaine vaccine Passive monoclonal antibodies, active vaccinations Further studies are required for this novel approach. 

Immunoglobulins are associated with the y-globulin fraction of plasma proteins but, as stated earlier, not all immunoglobulins exhibit antibody activity. 

Figure 20.9 Polysaccharide groups on antibody molecules may be oxidized with periodate to create aldehydes. Modification with biotin-hydrazide results in hydrazone linkages. The sites of modification using this technique often are away from the antibody-antigen binding regions, thus preserving antibody activity.

Freedman, M.H., Grossberg, A.L., and Pressman, D. (1968) The effects of complete modification of amino groups on the antibody activity of antihapten antibodies. Reversible inactivation with maleic anhydride. Biochemistry 7, 1941-1950. 

No antibody activity was found after oral immunization in any of the individual rabbits immunized with liposphere R32NS 1-vaccine formulation. However, rabbit immunization by all parenteral routes tested resulted in enhanced immunogenicity, with increased antibody IgG levels over the entire postimmunization period. The individual rabbit immune response shows that immunization by subcutaneous injection was the most effective vaccination route among all parenteral routes of administration tested. 

The feasibility of polymeric biodegradable lipospheres as carriers for the controlled release of a recombinant malaria antigen was also demonstrated. Polymeric lipospheres containing R32NS1 malaria antigen were able to induce very high levels of antibody activity after a single injection, in the absence of immunomodulators. 

Defining the biochemical mechanisms that couple stimulation at the cell surface to secretion by exocytosis is a major focus in biological research. In the mast cell, the steps by which immunologic secretagogues (for example, specific antigen, anti-IgE antibodies) activate a secretory response have been extensively studied and there are several reviews covering this area [ 12-14, 16, 121, 177],... 

Antibodies are members of a group of proteins known collectively as immunoglobulins. The name is derived from the observation that during electrophoresis of blood plasma the proteins associated with antibody activity migrate with the gamma globulin fraction. 

Binding of nitroso-procainamide to histone proteins may perturb chromatin structure or catabolism, resulting in immunogenic forms of DNA-free histones. In fact, all sera of patients (n = 24) with procainamide-induced Lupus showed IgG and IgM antibody activity against various histone components of chromatin (chromosome subunits)122. The nature of the procainamide adduct to histone proteins still awaits elucidation. 

The topologically defined region(s) on an enzyme responsible for the binding of substrate(s), coenzymes, metal ions, and protons that directly participate in the chemical transformation catalyzed by an enzyme, ribo-zyme, or catalytic antibody. Active sites need not be part of the same protein subunit, and covalently bound intermediates may interact with several regions on different subunits of a multisubunit enzyme complex. See Lambda (A) Isomers of Metal Ion-Nucleotide Complexes Lock and Key Model of Enzyme Action Low-Barrier Hydrogen Bonds Role in Catalysis Yaga-Ozav /a Plot Yonetani-Theorell Plot Induced-Fit Model Allosteric Interaction... 

Immunoglobulin. Immunoprotein glycoprotein of animal origin with known antibody activity, or protein related by chemical structure, which may or may not have antibody activity. Divided into five classes IgM, IgG, IgA, IgD, and IgE on the basis of structure and biological activity. Immunostimulant. Stimulating various functions or activities of the immune system. Immunosuppressant. An agent capable of suppressing immune responses. 

A major breakthrough in the treatment of lymphoid malignancies was the discovery of monoclonal antibody activity, especially that of rituximab. Rituximab was the first monoclonal antibody approved by the U.S., FDA for the treatment of relapsed follicular lymphoma (1), and it has now been extensively used for the treatment of various lymphoid neoplasm which express CD20 antigen. Its efficacy has been also demonstrated against diffuse large B-cell lymphoma when administered as a combination regimen such as rituximab plus CHOP (R-CHOP) chemotherapy (2). 

An understanding of Fey receptor gene polymorphism explains why some patients do not respond to monoclonal antibody, and it may broaden our understanding of monoclonal antibody activity and improve treatment outcomes in the future. Specific strategies include modulation of Fey receptor affinity or introduction of Fey receptor-reengineered monoclonal antibody designed to enhance binding to the Fey receptor. 

In summary, the mechanism of monoclonal antibody activity for CLL might be different from that for lymphoma. Besides ADCC, other pathways such as caspase-dependent apoptosis or CDC are more likely to contribute to rituximab or alemtuzumab-induced clearance of CLL cells in vivo. 

It has been demonstrated that monoclonal antibodies may be chemically modified by reaction with metal chelates without loss of antibody activity or specificity. A radionuclide generator has been made to provide a source for Bi-212 to be used for attachment of bismuth chelates to antibody. Such antibody-metal-chelate conjugates appear to be stable in vivo and may provide a new method for radiotherapy. 

Myeloma proteins occur in animal tumors of various types. The synthesis of these proteins can be induced in some experimental animals by injection of mineral oil, or the implantation of plastic discs.161 Myeloma proteins were shown to possess antibody activity, with specificity for different types of substances.161 Some of these proteins were found to combine with such carbohydrates as bacterial, cell-wall polysaccharides, lipopolysaccharides, dextrans, levans, and galactans.162 Myeloma proteins that combine with galactans or dextrans possess anti-galactan activity,163,164 or anti-dextran activity,165-167 and have been studied most extensively. 

There are five classes of immunoglobulins that can be distinguished by antigenic determinants on the heavy chains (see later), namely, IgM, IgG, IgA, IgD, and IgE. Antibody activity has been demonstrated in each of the classes. The molecular organization of immunoglobulins is based on a four-chain, unitary structure con-... 

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