Antigens Conformational

Nevertheless, the inactivated vaccine approach suffers from several shortcomings. The process could inactivate not only the organism but also destroy the antigen conformation required to elicit protective immunity. Incomplete inactivation (e.g., virion aggregation resulting in poor exposure to the inactivating agent) could result in disease transmission or severe complica-... 

Epitopes do not act as templates for the formation of antibodies. Instead, antibodies are synthesized against all antigenic conformations the immune system could possibly encounter, before the actual contact with the immunogen. The precursor of each antibody-forming lymphocyte (derived from B cells) makes Ig of only one specificity which is inserted in the cell membrane as a surface receptor to... 

Wilson, I.A., 5tanfield, R.L. Antibody-antigen interactions new structures and new conformational changes. 

Madden, D.R., Garboczi, D.N., Wiley, D.C. The antigenic identity of peptide-MHC complexes a comparison of the conformation of five viral peptides persented by HLA-A2. Cell 75 693-708, 1993. 

The NHR contains also the conserved Calcineurin docking site, PxlxIT, required for the physical interaction of NEAT and Calcineurin. Dephosphorylation of at least 13 serines residues in the NHR induces a conformational change that exposes the nuclear localization sequences (NLS), allowing the nuclear translocation of NEAT. Rephosphorylation of these residues unmasks the nuclear export sequences that direct transport back to the cytoplasm. Engagement of receptors such as the antigen receptors in T and B cells is coupled to phospholipase C activation and subsequent production of inositol triphosphate. Increased levels of inositol triphosphate lead to the initial release of intracellular stores of calcium. This early increase of calcium induces opening of the plasma membrane calcium-released-activated-calcium (CRAC) channels,... 

Baribaud F, Edwards TG, Sharron M, et al. Antigenically distinct conformations of CXCR4. J Virol 2001 75(19) 8957-8967. 

Under this proposal, device manufacturers could choose to use horizontal standards for class II devices when an SCGD exists or when the FDA has recognized an individual special control such as relevant vertical standards (e.g., prostate-specific antigen). In addition to the required elements of a 510(k) (21 CFR 807.87), these applications could include summary information that describes how special controls have been used to address the risks associated with the device type and a declaration of conformity with any relevant recognized standard(s), as applicable. As expected, a declaration of conformity with a standard would provide a summary of a manufacturer s efforts to conform with the recognized standard and would outline any deviations specifying ... 

In the rare case when a peptide showing some promise has been identified, further immunization trials are necessary to establish its value as a practical synthetic vaccine. Since peptides are usually poor immunogens and do not mimic well the conformation of the corresponding antigenic site in the... 

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