Epitopes nature

A second type of occultation concerns the relations that exist between biomolecules. In the same way that the antibody nature of an immunoglobulin molecule becomes evident only when its complementary antigen has been recognized, the epitope nature of a set of amino acids in a protein can... 

To evaluate the influence of structural parameters governed by the cyclophosphazene core concerning the valency and the spatial orientation of epitopes, as well as the nature of linkers directly related to the ligation technique used for the mannoside incorporation, the authors performed preliminary kinetic turbidimetric assays with Con A. Insoluble cross-linked complexes formed rapidly for all compounds, without marked difference for the hexavalent analogues. On the other hand, the incorporation of additional mannosyl units led merely to statistical binding-affinity enhancements, notably for the less-dense decamer 194, which presents favorable extended intersugar distances. 

The design of such low-molecular weight compounds that inhibit or mimic the action of a naturally occurring protein epitope or peptide ligand is a con-... 

The problem of the immunogenic nature of many human recombinant DNA proteins, and the potential to generate antibodies to a normal human protein, is of special interest to the immunotoxicologist. For example, 3 of 16 patients administered the rDNA-derived interferon-a (clone A) developed antibodies of the IgG class that were undetectable prior to or during therapy (Gutterman et al., 1982). These antibodies were capable of in vitro neutralization of interferon activity, although in vivo neutralization of interferon has not been documented. Since there are several different subtypes of interferon-a s, some contain epitopes not present on their own interferon subtype. Similarly, two patients treated with interferon-/ for many months developed high-titered antibody, which in one case was correlated with an inability of the patient s fibroblasts to produce interferon (Vallbracht et al., 1982). 

Variable Fragment (Fv) The tips of the two Y arms vary greatly from one antibody to another. They are the regions that bind to epitopes of antigens and bring them to the natural killer cells and macrophages for destruction. 

Volume 32 ot-Gal and Anti-Gal al3-Galactosyltransferase, a-Gal Epitopes, and the Natural Anti-Gal Antibody... 

Clearly, further studies will be necessary to sort out the multiple factors involved in the in vivo immune response to C. neoformans carbohydrate-mimetic peptides. Several conclusions may be drawn from the results to date. Peptides that mimic the cryptococcal capsular polysaccharide show specificity, in that each peptide binds with differing affinity to closely related mAbs [140,149]. The pattern of binding to protective and nonprotective mAbs differs between the mimetic peptides and the polysaccharide [140]. Protective efficacy is related to the location of carbohydrate epitopes recognized by these mAbs, within the polysaccharide capsule, but hkely also depends on interactions between mAbs and cellular responses [149]. Peptides have been shown to be functional, immunogenic mimics, but their protective efficacy depends on multiple factors, including the type of Abs elicited and interactions with the cellular immune system. Protective efficacy does not correlate with binding affinity to representative mAbs, but rather depends on the nature of these interactions. 

The method described here assumes certain things about the nature of the antigen and the antibody reagents to be used. First, the epitope reactive with the antibody must be accessible on the exterior of the cell. Some transmembrane molecules have multiple epitopes that are present on the intracellular domains of the molecule, and these would not be applicable using the method described. Second, the antibody must react with this epitope when the molecule... 

Several antigenic peptides that are naturally processed and presented by A2.1 and corresponding to human wild-type (wt) p53, hdm2, and CD19 sequences have been identified in the laboratory. Tg mice-derived CTL lines specific for the identified wt p53 and hdm2 peptide epitopes were of sufficiently high... 

U. Knckelkorn, E.A. Ferreira, 1. Drung, U. Eiewer, P.M. Kloetzel, and M. Theobald, The effect of the interferon-y indncible processing machinery on the generation of a naturally tumor-associated human cytotoxic T lymphocyte epitope within a wild type and mntant p53 sequence context, Eur. J. Immunol., 1368-1375 (2002). 

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